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Firmness and Storage Characteristics of Crisp-Textured Blueberries

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Title:
Firmness and Storage Characteristics of Crisp-Textured Blueberries
Copyright Date:
2008

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Subjects / Keywords:
Air ( jstor )
Analytical estimating ( jstor )
Berries ( jstor )
Blueberries ( jstor )
Emeralds ( jstor )
Error rates ( jstor )
Fruits ( jstor )
Linear regression ( jstor )
Storage time ( jstor )
T tests ( jstor )

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University of Florida
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University of Florida
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4/17/2006

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FIRMNESS AND STORAGE CHARACTERISTICS
OF
CRISP-TEXTURED BLUEBERRIES















By

LES PADLEY JR.


A THESIS PRESENTED TO THE GRADUATE SCHOOL
OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT
OF THE REQUIREMENTS FOR THE DEGREE OF
MASTER OF SCIENCE

UNIVERSITY OF FLORIDA


2005

































Copyright 2005

by

Les Padley Jr.

































This document is dedicated to my wife and both of my families who have been there for
me since the beginning, encouraging me and helping me along the way.















ACKNOWLEDGMENTS

I would like to thank Straughn farms Inc. for providing the blueberry plots used in

these studies. I would also like to thank Dr. Paul Lyrene, Dr. Steven Sargent and Dr.

Jeffrey Brecht for giving me the opportunity to obtain this degree. Finally, I would like

to thank Kim Cordasco for helping me with my research along the way.
















TABLE OF CONTENTS

page

A C K N O W L E D G M E N T S ................................................................................................. iv

LIST O F TA BLE S ............................................................ .............. vii

L IST O F FIG U R E S .... ....... ...................... ........................ .... ...... .. ............. xii

A B S T R A C T ......... .................................. ...................................................x iii

CHAPTER

1 IN TR O D U C T IO N ............................................................. .. ......... ...... .....

H history of Blueberries in Florida.................................................... ...... ...............
B lueberry B reeding......................................... ............................. 2
Growth and Fruit Development of Blueberries .......................................................5
Harvest and Postharvest of Blueberries...................................... .. ..................7
Crisp-Textured Blueberries .............................................................. ............. 11

2 QUALITY DETERMINATIONS OF FRESH BLUEBERRY CLONES .................12

Relative Berry Firm ness of 99 Clones .............................. .................... 12
M materials and M ethods .......................................................... ............... 12
R e su lts ......................................................................... 1 4
D iscussion............... .................. .. ......................... .. .... ........ 14
Firmness Changes During Fruit Development..........................................................17
2003 M materials and M ethods ........................................... .......................... 17
2 0 0 3 R esu lts ....................................................................... 18
2004 M materials and M ethods ........................................... .......................... 18
2 004 R esu lts ....................................................................... 19
D iscu ssio n ...................................... .............................. ................ 2 0
S h e ar-C ell T e stin g ................................................................................................. 2 1
M materials and M ethods ............................................... ............................... 22
R e su lts ............................................................................................................ 2 2
D iscu ssio n .................................................................................. 2 5
Consum er Sensory Panel Study........................................................ ............... 26
2003 M materials and M ethods ............................................ ......................... 26
2 0 0 3 R esu lts .......................................................................2 7
2004 M materials and M ethods ............................................ ......................... 29


v









2 0 0 4 R esu lts ................................................................2 9
D iscu ssion .............................................................................................. ....... 32

3 POSTHARVEST STORAGE TEST ........................................ ........................ 34

2003 Study ............. ................................................................34
M materials an d M eth od s ........................................ ...........................................34
R e su lts ............................................................................................................ 3 6
2004 Study ............. ................................................................45
M materials an d M eth od s ........................................ ...........................................4 5
R e su lts ............................................................................................................ 4 7
D iscu ssion ......... ...... ............ .................................... ............................65

4 C O N C L U SIO N S ........................ .... .... .................... .. .. ........ .... ... .......68

L IST O F R E F E R E N C E S ......................................... .......... ................. .......................... 70

B IO G R A PH IC A L SK E TCH ...................................................................... ..................74















LIST OF TABLES


Tablege

2.1 Meanz force (N) required to deform berries by 2mm for 99 blueberry clones
ranked from lowest to highest sampled in 2003........ ............................................... 15

2.2 Meanz deformation force (2mm deformation) of fruit for eight blueberry clones
sampled at 9 stages of maturity in 2003 ..... ......... ........................................ 19

2.3 Meanz deformation force of fruit for nine blueberry clones sampled at three
stages of m aturity in 2004. .............. ............. .......... ................... 20

2.4 ANOVA for mean deformation force of fruit for 9 blueberry clones sampled at
three stages of m aturity in 2004. ............. ............ ......... ............ ........ 20

2.5 Shear-cell means for 10 clones sampled at two different times during the 2004
grow ing season. ........................................................................24

2.6 Questions asked for the 2003 taste panel study ....................................................27

2.7 Overall appearance of panelists of four blueberry clones on a scale from 1
(dislike extremely) to 9 (like extremely) (n=90; 2003 study). ..............................28

2.8 Overall texture/firmness of panelists of four blueberry clones on a scale from 1
(dislike extremely) to 9 (like extremely) (n=90; 2003 study). ..............................28

2.9 Overall sweetness of panelists of four blueberry clones on a scale from 1 (dislike
extremely) to 9 (like extremely) (n=90; 2003 study). ...................... ...............28

2.10 Overall flavor of panelists of four blueberry clones on a scale from 1 (dislike
extremely) to 9 (like extremely) (n=90; 2003 study). ...................... ...............28

2.11 Overall acceptability of panelists of four blueberry clones on a scale from 1
(dislike extremely) to 9 (like extremely) (n=90; 2003 study). ..............................29

2.12 Questions asked for the 2004 taste panel study.......................................................29

2.13 Previous blueberry eating experience of the 95 panelists whom were part of the
evaluation panel in 2004. .............................................. ............................... 30

2.14 Firmness ranking of 4 blueberry clones by 95 panelists from 1 (softest sample)
to 4 crunchiestt sam ple). .......................................... .. .. ...... .......... .... .... 1









2.15 Desirability of the berry firmness of 4 blueberry clones evaluated on a scale
from 1 (dislike extremely) to 9 (like extremely) by 95 panelists...........................31

2.16 Overall desirability of the berry quality of 4 blueberry clones evaluated by 95
panelists. ................................................................ ... ..... ......... 3 1

2.17 Desirability of berry firmness and overall desirability of berries of 4 blueberry
clones as judged by panelists with differing blueberry consumption histories........32

3.1 Mean deformation force at 2mm depth for 8 blueberry clones stored in air for 8
w weeks at 20C in 2003 ......... .. ..... ............. .................... ... 37

3.2 ANOVA for mean deformation force needed at 2mm for 8 blueberry clones
stored for 8 w weeks in 2003 ................ ............................................. ....................37

3.3 Incidence of decay (%) for eight blueberry clones stored for 8 weeks at 20C in
2003 .................................. ......... ........ .............................. . ................. 38

3.4 ANOVA for incidence of decay (%) of eight blueberry clones stored for 8 weeks
in 2 0 0 3 ...................................... ......................................................3 8

3.5 Incidence of leaking (%) for eight blueberry clones stored for 8 weeks at 20C in
2003 .................................. ........ ......... .............................. . ................. 39

3.6 ANOVA for incidence of leaking (%) for eight blueberry clones stored for 8
w weeks in 2003 ............................................................... ... .... ........ 40

3.7 Incidence of weight loss (%) of eight blueberry clones stored for 8 weeks at 20C
in 2003. Values for each week are the cumulative weight loss from week 0 to
the w eek stated. .......................................................................40

3.8 ANOVA for incidence of weight loss (%) of eight blueberry clones stored for 8
w weeks in 2003 ............................................................... ... .... ........ 40

3.9 Incidence of shriveling (%) for eight blueberry clones stored for 8 weeks at 20C
in 2 0 0 3 ...................................... ......................................................4 1

3.10 ANOVA for incidence of shriveling (%) of eight blueberry clones stored for 8
w weeks in 2003 ............................................................... ... .... ........ 4 1

3.11 Incidence of shrivel severity of eight blueberry clones stored for 8 weeks at 20C
in 2 0 0 3 ...................................... ......................................................4 2

3.12 ANOVA for Incidence of shrivel severity of eight blueberry clones stored for 8
w weeks in 2003 ............................................................... ... .... ........ 42

3.13 Meanz pH of eight blueberry clones stored at 20C over 8 weeks in 2003 ..............43









3.14 ANOVA for mean pH of eight blueberry clones stored at 20C over 8 weeks in
2003 .................................... ...... ........................................... 44

3.15 Meanz SSC of eight blueberry clones stored at 20C over 8 weeks in 2003. ............44

3.16 ANOVA for mean SSC of eight blueberry clones stored at 20C over 8 weeks in
2003 ................................. ........... ..... .............................. . . ............... 44

3.17 Meanz TTA of eight blueberry clones stored at 20C over 8 weeks in 2003.............45

3.18 ANOVA for mean TTA of eight blueberry clones stored at 20C over an 8 weeks
in 2003 ................................................................. ........ ........... 45

3.19 Mean deformation force at 2mm depth for 10 blueberry clones stored in air for
8 weeks at 20C in 2004............... .. .... ...................... .. ......49

3.20 ANOVA for mean force needed to deform the berries by 2mm for 10 blueberry
clones stored for 6 weeks in 2004. (air atmosphere)............... ............................49

3.21 Incidence of decay (%) for 10 blueberry clones stored for 6 weeks in air storage
at 20C in 2004 ................................................... ................. 50

3.22 ANOVA for incidence of decay (%) for 10 blueberry clones stored for 6 weeks
in air storage in 2004 ........................ .... ...................... .... ........ ................50

3.23 Incidence of leaking (%) for 10 blueberry clones stored for 6 weeks in air
storage at 2 C in 2004. .................................................... ........ .. ...... ............51

3.24 ANOVA for incidence of leaking (%) for 10 blueberry clones stored for 6 weeks
in 2 0 0 4 ...................................... ................................... ................ 5 1

3.25 Incidence of shriveling (%) for 10 blueberry clones stored for 6 weeks in air
storage at 20C in 2004. ....................................... ............. .... ....... 52

3.26 ANOVA for incidence of shriveling (%) of 10 blueberry clones stored at 20C for
6 w eek s in 2 0 0 4 .................................................... ................ 52

3.27 Incidence of shrivel severity of 10 blueberry clones stored for 6 weeks in air
storage at 2 C in 2004. ............................ ........................ ........ .. ...... ............53

3.28 ANOVA for incidence of shrivel severity of 10 blueberry clones stored for 6
w weeks at 20C in 2004 ............................................... .. .... .. .. ........ .... 53

3.29 Meanz pH of 10 blueberry clones in an air atmosphere over 6 weeks in 2004........54

3.30 ANOVA for mean pH of 10 blueberry clones in an air atmosphere over 6 weeks
in 2 0 0 4 ...................................... ................................... ................ 5 4

3.31 Meanz SSC 10 blueberry clones in an air atmosphere over 6 weeks in 2004..........55









3.32 ANOVA for mean SSC of 10 blueberry clones in an air atmosphere over 6
w eek s in 2 0 04 ......................................................................................... 5 5

3.33 Meanz TTA of 10 blueberry clones in an air atmosphere over 6 weeks in 2004.....56

3.34 ANOVA for mean TTA of 10 blueberry clones in an air atmosphere over 6
w weeks in 2004.................................................... ...................... ..... ........ 56

3.35 Mean deformation force at 2mm depth for 10 blueberry clones stored in C.A.
for 8 w eeks at 20C in 2004. ...... ........................... ....................................... 58

3.36 ANOVA for deformation force at 2mm for 10 blueberry clones stored for 8
w weeks in 2004.................................................... ...................... ..... ........ 58

3.37 Incidence of decay (%) for 10 blueberry clones stored for 8 weeks in C.A.
storage at 2 C in 2004. ............................ ........................ ........ .. ...... ............59

3.38 ANOVA for incidence of decay (%) for 10 blueberry clones stored for 8 weeks
in C .A storage in 2004 ............. ......................................................... .... .... ... .. 59

3.39 Incidence of leaking (%) for 10 blueberry clones stored for 8 weeks in C.A.
storage at 2 C in 2004. ............................ ........................ ........ .. ...... ............60

3.40 ANOVA for incidence of leaking (%) for 10 blueberry clones stored for 8 weeks
in 2 0 0 4 ...................................... ................................... ................ 6 0

3.41 Incidence of shriveling (%) for 10 blueberry clones stored for 6 weeks in air
storage at 20C in 2004. ......................... .......... ............... .... ....... 61

3.42 ANOVA for incidence of shriveling (%) of 10 blueberry clones stored at 20C for
8 w eek s in 2 0 0 4 .................................................... ................ 6 1

3.43 Incidence of shrivel severity of 10 blueberry clones stored for 8 weeks in C.A.
storage at 2 C in 2004. ............................ ........................ ........ .. ...... ............62

3.44 ANOVA for incidence of shrivel severity of 10 blueberry clones stored for 8
w weeks at 20C in 2004 ........................................... .. ..... ................. 62

3.45 Meanz pH of 10 blueberry clones in a controlled atmosphere over 8 weeks in
2 0 04 .................................................................................6 3

3.46 ANOVA for mean pH of 10 blueberry clones in a controlled atmosphere over 8
w weeks in 2004............................................................... .. ... ......... 64

3.47 Meanz SSC of 10 blueberry clones in a controlled atmosphere over 8 weeks in
2 0 04 .................................................................................64

3.48 ANOVA for mean SSC of 10 blueberry clones in a controlled atmosphere over 8
w weeks in 2004............................................................... .. ... ......... 64









3.49 Meanz TTA of 10 blueberry clones in a controlled atmosphere over 8 weeks in
2 0 04 .................................................................................6 5

3.50 ANOVA for mean TTA of 10 blueberry clones in a controlled atmosphere over
8 w eek s in 2 0 0 4 .................................................... ................ 6 5















LIST OF FIGURES


Figure pge

1.1 Blueberries at white, pink and blue stages after the start of final swell (stage 3). .... 7

2.1 Instron m machine w ith 8 m m probe....................................... ......................... 13

2.2 Histogram of mean firmness of 99 test blueberry clones. Class Interval 0.10 N.
The value for each clone was the average of 10 berries individually tested............16

2.3 Instron 8600 with shear-cell attached................................ ......................... 23

2.4 Relationship between shear-cell forces of nine selected blueberry cultivars and
clones harvested at the blue stage in the first and second sampling dates of 2004..25














Abstract of Thesis Presented to the Graduate School
of the University of Florida in Partial Fulfillment of the
Requirements for the Degree of Master of Science

FIRMNESS AND STORAGE CHARACTERISTICS
OF
CRISP-TEXTURED BLUEBERRIES

By

Les Padley Jr.

December 2005

Chair: Paul Lyrene
Major Department: Horticultural Science

During the 1980s and 1990s several cultivars with a firm texture were released

from blueberry breeding programs, exemplified by 'Reveille' from North Carolina and

'Bluecrisp' from Florida. University of Florida blueberry breeders, along with local

growers, considered 'Bluecrisp' to have a unique crisp texture that had not been

encountered up to that date. Since the discovery of 'Bluecrisp', several new clones with

crisp-texture were found in the test plots of the University of Florida's breeding program.

This research was designed to compare the "crisp" clones, 'Bluecrisp', FL 97-136, FL

98-325, FL 00-59, FL 00-180 and FL 00-270, for crisp-texture and storage life to

standard "non-crisp" clones 'Emerald', 'Millennia', 'Star', and 'Windsor'.

Firmness testing was first conducted on 99 blueberry clones, including the "crisp"

clones 'Bluecrisp' FL97-136, and FL 98-325, using an Instron 8600 with a 10N load cell.

The firmness test, deformation to 2 mm, revealed that the "crisp" characteristic could not

be determined using Instron firmness testing. A test studying the firmness changes









during fruit development did not show differences between the "crisp" and "non-crisp"

clones using Instron measurements of berries at the white, pink and blue stages of

maturity. Berries of all varieties became much softer during the transition from white to

blue. However, shear cell testing, simulating chewing, conducted in 2004 on the two

groups of clones showed that 'Bluecrisp', FL 97-136, FL 00-59 and FL 00-180 were

distinctively different from all of the other clones in maximum force required for the

blades to slice the berries. A consumer sensory panel study in 2004 showed that the

"crisp" clones 'Bluecrisp' and FL 00-59 could be distinguished as "crisp" in comparison

with the "non-crisp" clones 'Star' and 'Windsor'. The average consumer, though, did not

have a preference for the crisp-textured blueberries when compared with the standard

"non-crisp" blueberries. Postharvest storage tests in 2004 showed that, when held in air

storage, the clones 'Bluecrisp', FL 00-59, and FL 00-180 had superior storage life

compared with the other "crisp" and "non-crisp" clones. The shear cell test in 2004 also

separated these three "crisp" clones from the other clones tested. A correlation that

separates "crisp" and "non-crisp" clones using shear cell values and postharvest storage

life might exist. When the same "crisp" and "non-crisp" clones were stored in a

controlled atmosphere of 2% 02 plus 15% CO2, the distinction between 'Bluecrisp',

FLOO-59 and FL 00180 and the other clones was lost.














CHAPTER 1
INTRODUCTION

History of Blueberries in Florida

The commercial blueberry industry is profitable and fast growing. In 2002 North

America produced 390 million pounds of blueberries with a total wholesale value of

about $310 million. Cultivated blueberries represented $210 million of the total and wild

blueberries $100 million. Of the 2002 national total, Florida contributed $18.5 million

from approximately 809 hectares of cultivated blueberries (10, 50). Florida has the

potential to greatly increase blueberry acreage and production without flooding the

market (2). Florida, with its early April to early May market window (20), has the

capability of playing a major role in the expansion of this industry.

Cultivated blueberries (Vaccinium section Cyanococcus) are native to eastern North

America and were first commercialized there. At first, production was mainly located in

the northern United States and was based on the northern highbush blueberry (Vaccinium

corymbosum). These highbush blueberry cultivars produced high yields and large fruit

when planted on soils with high organic matter and low pH in areas that provided high

chilling hours (50). Florida began blueberry production in the early 1900s using the

native Florida blueberry species V. ashei, commonly called rabbiteye blueberry. The

plants were transplanted from the wild into cultivated fields. By 1930, over 2000 acres of

commercial blueberries were in production in North Florida (30, 41). This production

did not last long due to poor fruit quality and marketing problems (9, 50). Over the next

several decades the blueberry industry in Florida went into serious decline (30). Northern









highbush blueberries were tried in Florida during this time, but the plants did not fare

well. Lack of chill hours, low soil organic matter and subtropical diseases made it hard

for the northern plants to survive so far south (25).

In 1984, the blueberry market for the United States was expanding rapidly but

there were no blueberries available until late May, when harvest began in eastern North

Carolina (28, 42). Florida Agricultural Experiment Station horticulturalist Ralph Sharpe

believed that Florida could produce blueberries as early as late April (42). What was

needed to create this industry was high yielding, large fruited, early ripening blueberry

varieties. To breed these varieties, Sharpe propagated several Florida evergreen lowbush

wild blueberry bushes (V darrowi) that he found growing around a lake near Winter

Haven, Florida. These bushes produced unusually large berries with a powdery blue

color. He crossed these plants with northern highbush cultivars. This was the first step in

breeding a type of low-chill, heat-tolerant highbush called southern highbush (25, 28).

Southern highbush revitalized Florida's blueberry industry by allowing Florida blueberry

growers to harvest during the early market window of March 20 to May 20 (42). The

new industry took decades to develop, but by 1985 there was 1058 acres of blueberries in

Florida, and by 1989 the blueberry acreage in Florida had nearly doubled to 2106 acres

(8, 9). In 2003, Florida ranked as the 7th largest state in cultivated blueberry acreage for

the U.S. with around 1900 acres (48).

Blueberry Breeding

Blueberry breeding started in the United States around 1910, and at the University

of Florida (U. F.) about 1950 (42). Florida's breeding program mainly concentrated on

the development of low-chill, early ripening, tetraploid, southern highbush cultivars.

These southern highbush cultivars were obtained by hybridization of Florida native









blueberries (mainly Vaccinium darrowi) and highbush cultivars (V. corymbosum) from

Michigan, New Jersey and North Carolina. The original crosses were followed by a

program of recurrent selection.

Ralph Sharpe and Wayne Sherman continued this program of recurrent selection

until Sharpe's retirement in 1976. The program was continued Sherman, who was

joined by Paul Lyrene in 1977. Sherman retirement in 2003, and the program is now

under the direction of Lyrene.

As currently practiced in the U. F. blueberry breeding program, by Dr. Paul Lyrene,

each cycle of selection is begun by crossing 200 plants to obtain 12,000 seedlings.

Pollination is done by emasculating the flowers before anthesis, and pollen is transferred

by thumbnail as described by Edwards, Sherman and Sharpe (13). The seedlings from

these crosses are grown and evaluated for numerous characteristics that are important in a

cultivar. Desired characteristics included a vigorous, upright plant, high yield potential,

resistance to various insects and diseases, adaptation to Florida soils and climates, and

large, sweet, firm berries that are easy to harvest and have a long shelf life (17). From

the original 12,000 plants, 200 are selected and used as parents to begin the next cycle of

selection. As this process continues, each generation of selection brings better seedling

populations. The seedlings are also the source of new varieties, which are propagated

asexually.

In evaluating genotypes for the U. F. breeding program, seedlings are first fruited

in a high density nursery (Stage 1). The plants are examined for fruit size, color, picking

scar size, firmness, flavor, time of ripening and freedom from major visible defects of

bush or berry (27). From the 12,000 seedlings, 500 are selected and the rest are









discarded. The selected plants are grown for 2 more years (Stage 2 test). During the first

of the 2 years, the bushes and berries are evaluated for the same characteristics that were

evaluated in stage 1, and 100 to 150 plants are selected for propagation. In the second

year the plants are reexamined to find plants showing the desirable qualities that did not

appear in the first year, and an additional 20 to 50 plants are selected. For each plant

selected in Stage 2, 40 softwood cuttings are taken. Based on the rooting ability of the

cuttings and growth characteristics of the ramets, 120 to 150 clones per year are planted

into a commercial field in plots of 20 plants per clone (Stage 3). Here they received the

care and maintenance recommended for commercial blueberries in Florida (27). The

plants are left in the field for 2 to 10 years, depending on the performance of each clone.

Each year, the clones are examined for plant vigor and survival, leafing and flowering

characteristics, and berry yield and quality (27). Approximately 12 clones are selected

from each stage 3 test, and ramets are propagated from each clone. The selected clones

are planted in 100-plant plots in a commercial field. These plots are examined for 3 to 6

years, and the best one to two selections become cultivars (27).

The characteristics that make a successful blueberry cultivar have been studied

for decades by people such as Sharpe (13, 42), Sherman (13, 42), Ballinger (4, 5),

Ballington (6), Lyrene (27, 28) and Finn (17). The heritability of certain characteristics

has also been studied. Edwards, Sherman and Sharpe (13) determined that there was a

high heritability estimate for fruit size, a moderate heritability for fruit color, a low

heritability for fruit firmness and picking scar size and an even lower heritability for plant

vigor. They also determined that additive gene action was high for fruit size, color, and

firmness, and plant vigor, and plants should transmit these traits to their progeny. Finn,









and Luby (17) confirmed this additive gene action in blueberries as it pertains to fruit

color. They also concluded that highbush x highbush segregation patterns indicated

predominately additive gene action. These studies, along with others, have helped

blueberry breeders improve their breeding programs.

Growth and Fruit Development of Blueberries

Growing blueberries in Florida is a challenging business. Blueberries are a

deciduous, perennial, long lived woody shrub with a fibrous root system that requires

high organic matter and acidic soils to thrive. Selecting the proper site is a key to

growing commercial blueberries. A site must have well drained soil at least 40 cm deep,

a pH between 3.5 and 5.5 and 2 to 3% organic matter. The area must also have enough

cool weather during the winter to satisfy the chilling requirement of the variety, but the

frequency of late winter and early spring freezes should be low(49). Once a site is

chosen, southern highbush blueberries are planted 1 m apart in rows 3 m apart. Two or

more cultivars are inter-planted for cross-pollination.

Blueberry plants require at least 100 cm of water yearly to be productive (49).

Overhead irrigation is the most common and practical way of applying water to the plants

in Florida. Overhead irrigation is also used to protect flower buds from February, March

and April freezes (28). Fertilizer (12-4-8-2) is applied frequently beginning about mid-

April and ending in August or September. Bushes are pruned during the summer after

final harvest. Pruning of southern highbush plants is needed to keep the desirable size

and shape of the plant, to increase plant vigor and to promote good fruit development in

next year's crop (49).

Blueberries require several hundred hours of chilling (between 0C and 70C) in the

winter to stimulate the sprouting of floral and vegetative buds in the spring. The amount









of chilling required varies from one cultivar to another. Chilling hours begin in the fall

after the plants go dormant. Previous to the chilling season, some axillary (vegetative)

buds are inverted into flower buds. This transformation is complete by January and the

swollen flower buds can be distinguished from the vegetative buds on the bush. Plants

must have a proper balance between vegetative and flower buds to produce maximum

yields and quality (49). In north Florida, flower buds open during February (Lyrene,

personal communication).

Blueberry flowers consist of a corolla tube (white or pink colored), a pistil and

anthers. The corolla tube is the most visible part of the flower and is made up of five

fused petals. The pistil extends to the end of the corolla tube, but the anthers are situated

in such a way that sonication by an insect, primarily bees, is needed to efficiently remove

pollen from the flower. Sonication occurs when a bee places its head into the corolla

tube and moves its wing muscles at high frequencies causing the pollen to fall out of the

flower. Pollen lands on the bee's head, and some of it is taken to other flowers, where it

may be left on the stigfmas. For optimum fruit set and berry size, it cross-pollination

(pollen from one variety being placed on the stigma of another) is desirable (49).

After pollination, the flower takes 45 to 120 days to develop into a ripened

blueberry (Lyrene, personal communication). Blueberry fruit development follows a

double-sigmoid curve that consists of three stages (12). In stage I fruit size increases

through cell division. Stage II is characterized by a rapid increase in embryo and

endosperm growth with little or no increase in berry size. In Stage III cells enlarge

without cell division until maturity (12). In the final days of development the blueberry

undergoes a ripening process in which acid decreases while pH, sugar and berry weight









increase (3). As berry color changes from green to white to pink to blue (Figure 1.1) the

berries increase dramatically in size (final swell) (3, Lyrene, personal communication). It

takes about 5 days for the berries to undergo this ripening process for a climacteric fruit,

physical maturity is reached at mature green stage (i.e., when it can ripen on or off the

plant). to become fully ripened, physiologically mature blueberries (Lyrene, personal

communication).






















Figure 1.1. Blueberries at white, pink and blue stages after the start of final swell (stage
3).

Harvest and Postharvest of Blueberries

Florida blueberries are harvested, packed and shipped to many parts of the world

from March 20 to May 20 (46). Worldwide shipment of fresh berries requires good

cultivars, and a first-rate packing and storage system. The process of producing

blueberries that pack and store well begins in the field before the berries are picked.

Blueberries must be ripe, firm and have a small, dry picking scar to survive the trip to the









market. A picking scar that is small and dry is especially important, because a wet

picking scar, caused by the skin of the berry tearing as it is removed from the stem, is a

primary locus of fungus infection (7, 19, 29, 46). In the field, the berries are picked into

buckets and poured into field lugs, which are kept shaded. Great care must be taken

during the harvesting and handling process to avoid dropping or bruising the berries,

which would lead to decay. In the packing house, the berries are placed on a conveyer

belt, and unripe, overripe or damaged berries are removed, along with leaves and twigs.

Berries must be firm to avoid bruising or juice leakage during this process. The sorted

berries are placed in plastic clamshells, 125 to 400 g per clamshell. These are typically

packed in 12-unit cartons for shipping.

After packing, the berries are placed into a storage unit at 00 to 50C with relative

humidity of 95% (5, 15, 23, 24, 35). Under these conditions, blueberries can be stored for

2 weeks without decay (5, 31, 36, 38, 46). Blueberries have been stored using modified

atmosphere (MA) since 1919. Research on storage conditions has primarily focused on

the quality of the blueberries. Quality parameters have included weight loss, number of

defective berries, firmness, color, and decay (23, 29). As expected, weight loss, number

of defective berries and decay increase over time, whereas firmness decreases and color

becomes darker. Further research has shown that many of the changes that occur on the

outside of the blueberry are due to internal changes in the berry. As fruit develop and

mature, total titratable acidity (TTA) decreases while weight, pH, soluble solids content

(SSC), sugar, and SSC/TTA ratio increase (3, 20, 26). Blueberries with low pHs of 3.5 or

less tend to have slower rates of decay (3, 19, 38). These changes in acid, weight, pH,

TTA, SSC, sugar and SSC/TTA occur naturally as a blueberry matures, ripens and









senesces. Controlled atmospheres (CA) are used in blueberry storage to reduce the rate

of senescence in the berries. CA storage consists of altering the concentrations of CO2,

02 and N in the storage units containing the blueberries.

Using CA for blueberries began in the early 1980s when it was discovered that high

CO2 and low 02 levels helped prevent the decay of the fruit (7, 46). Much research has

been done since then. Optimum levels for these gases have been found to be 2 to 5% 02,

15 to 20% CO2 and nitrogen as a filler gas to make the atmosphere 100% (7, 24, 46 ). At

these levels, blueberries harvested at the blue maturity stage can be stored for over a

month at 10C with little decay or damage to the outside of the berries. At least one study,

though, has shown that high levels of CO2 in the CA may cause internal changes in

blueberries that produce an 'off flavor' (7). The reasons for the development of this

flavor are yet unknown.

Of the variables that have been studied in the postharvest storage of blueberries,

firmness has been found to be a key indicator of berry quality change during storage (25).

Early methods of determining blueberry firmness included squeezing the berry between

the fingers and judging the resistance, or judging firmness by masticating the berry (4,

29, 45). These methods gave variable results from one person to another (45). In 1973,

Ballinger and associates (4) modified an Instron Universal Testing machine (resistance to

compression) to measure the firmness of blueberry fruit. The Instron Universal Testing

machine had been previously used in determining the firmness of other fruit (4, 37).

Instron tests determined that blueberry firmness can vary from one harvest to another and

from one year to another. It was also determined that the greatest decrease in firmness

during berry development came as the berry went from the green to the pink stage (4).









Since the initial tests in 1973 many more studies have confirmed that the Instron is a

reliable indicator of blueberry firmness (14, 15, 16, 23, 32). Variations in berry firmness

among harvests and among years as well as dramatic decreases in firmness from the

green to pink stage of development were also confirmed through other studies (14, 33,

34, 46). Although many studies have used an Instron to determine firmness, a set of

standard guidelines for measuring berry firmness have still not been developed, except

concerning where the berries should be compressed. It has been determined that

compressing the berry along its lateral axis gives smoother, more consistent force

deformation curves than compressing the fruit in the axial direction (4, 14, 15, 16).

Studies have determined that blueberry firmness decreases over time in storage and that

this decrease can be slowed but not stopped by lower temperature (8, 14, 16, 38). A

study done from 1998 to 2000 surveyed berry firmness in 87 highbush culivars and

species-introgressed highbush blueberry cultivars (14). This study determined that 1.34

N/mm deflection force was average for these cultivars, and that values above 1.57 N/mm

were considered superior.

Crisp-texture has been studied in other berries such as the grape (41). The crisp-

texture in grapes can be traced back to the native North American grapes that were added

to the European grape gene pool. The hybrid grapes, call V. labrusca, can be

distinguished as crisp-textured by means of puncture testing. In the puncture testing the

deformation at first breakdown (DFP) and the maximum peak of force (MF) separate the

"crisp" from the soft cultivars. A grape that has a small DFP and a large MF is

considered "crisp", whereas berries with large DFP and small MF are considered soft









(41). No known research has been done on the DFP or the MF of blueberries as it relates

to "crisp" or soft texture.

Crisp-Textured Blueberries

During the 1980s and 1990s, several blueberry cultivars with very firm texture

were released from breeding programs, exemplified by 'Reveille' from North Carolina

and 'Bluecrisp' from Florida. 'Bluecrisp' was considered by U.F.'s blueberry breeder, as

well as local growers, to have a unique crisp-texture. This texture can best be described

as biting into an apple. In recent years, several other clones with crisp-textured berries

have been found in test plots in Florida. What makes this characteristic even more

unique is that there is no common ancestry between any of these crisp-textured clones.

To determine how these new clones compare in crisp-texture and storage life with

various commercial cultivars, several experiments were conducted. In this study, which

describes these experiments, clones 'Bluecrisp', FL 97-136, FL 98-325, FL 00-59, FL 00-

180 and FL 00-270 will be referred to as "crisp" clones, and the commercial clones

'Emerald', 'Millennia', 'Star', and 'Windsor' will be referred to as "non-crisp" clones.

These designations were based on the perception of the breeder at the start of these

experiments, and as will be seen, were not always supported by the objective tests that

were made in the course of these experiments.














CHAPTER 2
QUALITY DETERMINATIONS OF FRESH BLUEBERRY CLONES



Relative Berry Firmness of 99 Clones

In the first set of experiments, various characteristics of blueberry clones that had

been selected for crisp-texture were compared with the same characteristics in standard

commercial varieties.

For this test, 99 blueberry clones were used, of which three clones, 'Bluecrisp', FL

97-136, and FL 98-325, had previously been classified as crisp based on informal

observations in the field. The purpose of this test was to determine if the berries from

these clones were firmer then these of standard commercial cultivars.

Materials and Methods

On May 2, 2003, berries from 99 clones of southern highbush blueberries were

harvested from a variety test planted in a commercial blueberry planting at Straughn

Farms Inc. in Windsor, Florida (Alachua County). The clones were advanced selections

from the U. F. breeding program. During earlier stages of selection, clones had been

eliminated if the berries were small, dark, had wet picking scars, or were soft. The plants

were growing in 15-plant clonal plots and were about two meters tall. Approximately

20 ripe berries were gathered from each clone and placed in paper bags. Two separate

samples were taken for the firm cultivar 'Bluecrisp'. The bags were placed in a cooler

and transported to a 20 C storage unit. Firmness was measured the next day by removing

the berries from 10 clones at a time from the cooler and placing them on a grading table







for 90 minutes to allow the berries to reach room temperature (about 220C). Once at
room temperature, the berries were inspected for leaking, collapse, decay or other
damage. Damaged berries were discarded, after which 10 berries were randomly selected
from each clone for firmness testing. An Instron 8600 with a 10 N load cell was used to
test firmness. Each berry was placed onto a washer with an outer diameter of 2.2 cm and
an inner diameter of 1 cm to keep it stable. The berries were placed on their sides with
the calyx end to the left and the stem end to the right. An 8 mm probe attached to the
Instron was then lowered from above until it pressed onto the equator of the berry, using
an initial contact force not exceeding .03N (Fig. 2.1). Using a crosshead speed of 50
mm/min, each berry was deformed and the 3 mm deformation at 1 mm, 2 mm, and 3 mm
depth were recorded (10 berries/clone).



1...1I.I -_


figure 2. 1. Instron machine witn 5 mm prooe.









Results

When berry firmness was plotted as a histogram (Fig. 2.2) the 99 clones appeared

to give a normal distribution, except that the sample for FL 98-325 was separated from

the others at the high end of the distribution. Firmness of FL 97-136, FL 98-325 and FL

00-270 fell within the top 10% of the array in firmness measured by the Instron (Table

2.1). One 'Bluecrisp' sample also was in the top 10% in firmness, but the other

'Bluecrisp' sample was less firm with a ranking of 71 out of 100 samples. FL 98-325, a

crisp-textured clone, was firmest and appeared to separate out from the rest of the clones

in the histogram on page 31. A Tukey test was preformed on the top 10% of the

histogram to confirm these observations. The test showed all clones to be similar to each

other, except FL 98-325, at the five percent level. The unusual firmness of FL 98-325 in

this test was not confirmed in subsequent tests (Table 2.2 and 2.3). It is not known why

the firmness of FL 98-325 was so high in this test.

Discussion

Firmness is an important quality factor in blueberry. Several studies (4, 13, 16, 33,

34, 45) have been done on blueberry firmness, and methods of measuring firmness have

varied. These studies have confirmed that blueberry firmness changes from harvest to

harvest and from year to year. In our study, berry firmness of 99 southern highbush

blueberry clones showed a bell-shaped distribution. For the 99 clones, the means force

required to deform the berries 2 mm in an Instron instrument was 3.17 N (Table 2.1).

Ehlenfeldt and Martin studied berry firmness in 87 highbush blueberry clones and

hybrids using a FirmTech 1 firmness tester. They found an average firmness of 1.34

N/mm deflection and values above 1.57 N/mm were considered superior (14). Our 99

clone test used an Instron 8600 to determine firmness, and got an average of 1.59 N/mm.











Table 2.1. Meanz force (N) required to deform berries by 2mm for 99 blueberry clones
ranked from lowest to highest sampled in 2003.

Standard Standard Standard
Mean deviation Mean deviation Mean deviation
Cloney (N) (N) Clone (N) (N) Clone (N) (N)


FL 98-352
FL 98-17
FL 98-357
FL 99-54
FL 96-90
FL 99-74
FL 98-337
FL 91-16
FL 98-339
FL 98-338
FL 99-66
FL 98-341
FL 98-351
FL Jewel
FL 98-365
Sapphire
FL 98-437
FL 99-48
FL 99-59
FL 99-56
FL 99-65
FL 98-423
FL 98-401
FL 98-27
FL 97-118
FL 98-414
FL 98-415
FL 98-372
FL 98-421
FL 98-428
FL 98-431
FL 96-43
FL 99-45
Legacy
FL 98-125
FL 95-197
FL 98-416
FL 98-439
FL 93-171
Sebring
Sharpblue
FL 98-383
Windsor


1.79
2.06
2.09
2.15
2.20
2.25
2.34
2.34
2.36
2.38
2.44
2.46
2.47
2.51
2.56
2.59
2.60
2.63
2.66
2.66
2.67
2.67
2.67
2.67
2.68
2.69
2.71
2.72
2.72
2.74
2.78
2.82
2.83
2.84
2.87
2.90
2.90
2.98
3.00
3.00
3.02
3.03
3.03


FL 98-370
FL 98-370
FL 98-385
FL 95-174
Bluecrisp2*
FL 98-384
Misty
FL 97-136*
FL 99-55
FL 98-363
Magnolia
FL 99-37
FL 98-436
FL 98-325*


Overall
Average


0.50
0.43
0.50
0.55
0.42
0.39
0.38
0.48
0.19
0.48
0.58
0.44
1.39
0.62


FL 98-375
FL 98-25
FL 95-209B
FL 96-96
FL 99-60
FL 99-69
FL 99-51
FL 98-369
FL 95-50
Emerald
FL 98-402
FL 95-174
FL 98-438
FL 98-433
FL 98-388
FL 98-411
FL 98-342
FL 98-29
FL 98-303
FL 90-91
FL 96-24
FL 98-427
FL 86-19
FL 92-166-N
FL 98-18
FL 98-371
FL 98-430
Bluecrispl*
FL 00-270
FL 97-63
Southern Bell
FL 98-358
FL 98-381
FL 98-297
Star
FL 99-50
FL 98-356
FL 95-173
Millennia
FL 98-420
FL 93-221
FL 97-79
FL 99-71


z Mean of 10 berries individually sampled.
Y The symbol following the clone name indicates that it had been considered a crisp-textured clone
previous to this experiment.
x Bluecrisp 1 and 2 were from 2 different fields.


0.43
0.31
0.30
0.45
0.34
0.45
0.29
0.65
0.38
0.46
0.52
0.66
0.62
0.17
0.66
0.25
0.27
0.51
0.28
0.34
0.29
0.30
0.27
0.40
0.44
0.57
0.34
0.39
1.07
0.27
0.53
0.65
0.20
0.32
0.27
0.25
0.60
0.40
0.69
0.46
0.31
0.58
0.33


3.17 0.45








16





Number of Clones


DB'I-8 IB

D.'E1 I.D

Di'E' I-1'
DE-" I-E'
O31' I.ET"

DBo.,' PI."
119'EZ 1VB


DIB'E- ,"'


DD'r, B'I. Z



D'E" L, E
D'E" E EE


DB'E '

DBTE IBE




D011" LBE
Do." IL :'










DI'P" L H'
r'9- DB9
D '9 I- '9
DE'3" 1.14 '
ngE;9L!


- -


- -
--- -
-- -
---


---
--- -
---
-- -


--

--


Figure 2.2 Histogram of mean firmness of 99 test blueberry clones. Class Interval 0.10 N.
The value for each clone was the average of 10 berries individually tested.


A direct comparison between the two experiments can not be made because


different testers were used, but the average firmness, measured as N/mm deflection, for









our 99 clone test was larger then the value Ehlenfeldt and Martin of the 87 highbush

blueberry test considered to be superior in their tests. Further southern highbush testing

using an Instron machine is needed to confirm the results from this test.

Firmness Changes During Fruit Development

Blueberry fruit change dramatically during final swell as the color changes from

green to blue. Weight and SSC increase and TTA (26) and firmness decrease. Firmness

decreases most between the white and pink stages and less significantly thereafter. It had

been hypothesized by Dr. Paul Lyrene that the crisp-textured clones soften more slowly

then standard commercial clones. The purpose of this test was to determine if this

hypothesis was right.

For this experiment, normal and crisp textured blueberries were harvested during

several of the final stages of ripening and for several days afterward. Berries from four

crisp-textured clones were used: 'Bluecrisp', FL 97-136, FL 98-325, and FL 00-59, and

four commercial cultivars were used: 'Emerald', 'Millennia', 'Star' and 'Windsor'.

2003 Materials and Methods

Five to eight bushes of the clones 'Bluecrisp', FL 97-136, FL 98-325, FL 00-59,

'Emerald', 'Millennia', 'Star' and 'Windsor' were netted (to exclude birds and berry

harvesters) in a variety test attached to a commercial field. Once the berries had reached

the white stage of development, 20 berries from each clone were harvested, placed into

clamshells and transported in a cooler of ice back to the lab. At the lab the berries were

warmed up to room temperature and their firmness was tested. The white stage was after

final swell had begun and 1 to 2 days before the berries turned pink then purple.

Blueberries were also harvested at the pink and blue stages of development (Fig. 1.1).

The skins of some blueberries were marked with the date they first became blue using a









paint marker (uniPAINT fine line PX21). Twenty berries were harvested from each

clone at each of six sampling times: 3, 5, 7, 9, 12, and 15 days after they first turned blue.

Berry firmness was tested using an Instron 8600 as described previously. All

twenty berries harvested for each clone at each maturity level were tested for firmness.

2003 Results

The firmness testing during fruit development for 2003 was interrupted by pickers

and some data were lost (Table 2.2). From the remaining data shown in Table 2.2 it can

be seen that a dramatic decrease in firmness occurred from the white to pink stages of

berry development. Changes in firmness after the pink stage of berry development were

small. Both "crisp" and "non-crisp" clones softened significantly during the transition

from white to pink. The data failed to show a major difference between the "crisp" and

"non-crisp" clones in the softening that occurred as the berries went from white to blue.

It had been hypothesized earlier that the high firmness of the "crisp" berries when fully

ripe might be the result of less loss of firmness during the final stages of ripening, but this

seems not to have been the case. 'Bluecrisp' and FL 98-325 were less firm at the pink

stage (Table 2.2) than in the fully ripened blue stage Table 2.1. This indicates that one or

more non-genetic factors have a large effect on Instron firmness.

2004 Materials and Methods

In 2004, FL 00-180 and FL 00-270 were added to the test as possible crisp-textured

clones. Five to eight bushes of the clones 'Bluecrisp', FL 98-325, FL 00-59, FL 00-180,

FL 00-270, 'Emerald', 'Millennia', 'Star' and 'Windsor' were netted in a









Table 2.2. Meanz deformation force (2mm deformation) of fruit for eight blueberry clones
sampled at 9 stages of maturity in 2003.
2mm Deformation Force (N) at Maturity Stage


Cloney White Pink Blue Day 3' Day 7 Day 9 Day 12 Day 15
Bluecrisp* 7.77 ab 2.83 a 2.14 2.17 a 2.30
FL 97-136* 10.24 a 2.51 a 2.41 1.70
FL 98-325* 10.57 a 2.56 ab 2.82 2.97
FL 00-59* 9.03 abw 2.85 a 2.71 a
Emerald 5.85 b 1.70
Millennia 8.34 ab 2.67
Star 9.88 a 1.73 b 0.84
Windsor 8.98 ab 1.77 b 2.12 a
P>F 0.013 0.001 0.045
z Mean of 20 berries individually sampled.
Y Clones followed by a had been considered crisp textured
x Days after berry first turned blue
wWithin columns means followed by the same letter are not significantly different (P<0.05) by
ANOVA and Tukey's test.

commercial field and allowed to ripen. Once the berries had reached the white stage of

development, 20 berries from each clone were harvested, and their firmness was tested as

previously described. Blueberries were also harvested at the pink and blue stages of

development. To test the firmness of the berries an Instron 8600 testing machine with a

10 N load cell was used. The procedure was the same as previously described.

2004 Results

All clones softened significantly between the white and pink stages (Table 2.3).

The six "crisp" clones did not differ conspicuously in the pattern of firmness loss from

the four "non-crisp" cultivars. Analysis of variance (Table 2.4) showed that clones,

stages of ripening, and clone x stage interaction all contributed significantly to variances

in the firmness of the samples.










Table 2.3. Meanz deformation force of fruit for nine blueberry clones sampled at three
stages of maturity in 2004.
2mm Deformation force(N) at maturity stage
Cloney White Pink Blue
Bluecrisp* 7.52 ab 3.20 abc 2.81 ab
FL 98-325* 5.51 ab 3.76 a 2.80 ab
FL 00-59* 7.79 ab" 3.69 a 3.30 a
FL 00-180* 7.32 ab 2.64 bc 2.39 bc
FL 00-270* 7.27 ab 3.39 abc 1.87 c
Emerald 4.78 b 2.45 c 1.97 c
Millennia 9.24 a 3.49 ab 1.86 c
Star 9.08 ab 2.84 abc 2.44 bc
Windsor 5.06 ab 2.64 bc 2.14 bc
Stage means 7.06 3.12 2.40
P > F 0.009 0.000 0.000
zMeans of 10 berries individually sampled.
YClones followed by a are crisp textured
"Within columns means followed by the same letter are not
significantly different (P<0.05) by ANOVA and Tukey's
test.

Table 2.4. ANOVA for mean deformation force of fruit for 9 blueberry clones sampled at
three stages of maturity in 2004.
Source DF Mean Square F value Pr > F
Model 26 53.32 15.70 <0.0001
Clones 8 13.41 3.95 0.0002
Stages 2 566.95 166.93 <.0001
Stages x Clones 16 9.08 2.67 0.0007
Error 243 3.40


Discussion

When "crisp" blueberries were originally observed by Dr. Lyrene theorized that the

crisp texture in these new blueberries could be caused by a lack of polygalacturonase

(PG) in the final stages of fruit development (Lyrene, personal communication). PG is an

enzyme that helps breaks down pectin, causing the cell walls to soften (39). Production

of PG in other fruits has been inhibited through genetic engineering, or by breeding

creating such fruit as the non-melting flesh peach and the Flavor-Savor tomato (18, 43).









Several studies (4, 46, 39) have shown that during the final days of ripening

blueberries soften as they change color from white to blue. The greatest decrease in

firmness occurs from the pink to the blue stage and is caused by the synthesis of PG in

the berry (39). The tests done in 2003 and 2004 showed a decrease in firmness of all

clones as they ripened from white to blue, confirming previous studies. The fact that the

"crisp" berries lost firmness rapidly ass they matured from green to blue suggests that PG

levels are not related to the crisp texture in "crisp" blueberries. Further studies

examining changes in PG levels as "crisp" and "non-crisp" clones mature should be

conducted to confirm these results.

Shear-Cell Testing

In an effort to detect a difference between berries of "crisp" and "non-crisp" clones,

berries were tested using a Kramer shear-cell attached to the Instron. The Kramer shear-

cell is a multi-bladed fixture designed to produce shear stress in a specimen that relates to

firmness (22). The specimen is placed into a metal box (82.5 mm x 98 mm) with a lid.

The top and the bottom of the box have slits designed to allow ten, 3-mm blades to pass

through them. The blades penetrate the top of the box and then push through to the

bottom. As the blades are moved through the box, the specimen is first compressed, then

extruded, and finally sheared as the blades penetrate the bottom slots (22). The forces

needed for the blades to move through the box relate to berry texture (22). The purpose

of this experiment was to determine the maximum force needed to shear blueberries and

to determine if this force is different for crisp textured selections and some standard

cultivars.









Materials and Methods

In 2004, three clamshells of ripe berries (approximately 125 g of berries in each)

were collected from April 30 through May 6 for each of the following clones: 'Bluecrisp'

FL 97-136, FL 98-325, FL 00-59, FL 00-180, FL 00-270, 'Emerald', 'Star', 'Windsor'

and 'Millennia'. The clamshells were placed in a cooler and brought to the lab where

each clamshell was inspected to eliminate damaged or leaking berries. Approximately 70

g of sound berries were randomly selected and placed into a shear-cell box to make

approximately two layers of berries. The shear-cell box, the lid and the blades to the box

were set in place on an Instron 8600 (Fig. 2.3). At a crosshead speed of 50 mm/min the

blades were passed through the box of berries until they penetrated through to the other

side of the box. The maximum force needed for the blades to pass through the box of

berries was recorded. This procedure was repeated for the other two clamshells of berries

for a total of three repetitions per clone.

On May 18 and May 19 of the same year the shear-cell procedure was repeated

using the same clones and technique to obtain a second set of data for each clone. The

berries were harvested from the same bushes. The bushes had been harvested

periodically before the samples were taken to insure that only newly ripened berries were

included in the second samples. Means were obtained from these repetitions and

compared to the earlier shear-cell test results.

Results

There was good agreement between the shear-cell tests run April 30 to May 6 and

those run May 18 and 19 (Table 2.5, Fig. 2.4). 'Bluecrisp', FL 97-136 FL 00-59 and FL

00-180 had high shear-cell readings and FL 00-270, 'Millennia', 'Star' and 'Windsor'

had lower readings (Table 2.5). The shear-cell testing was done on six putative crisp-










textured blueberry clones and four standard commercial clones. In the early harvest, the

firmest four clones in descending order were FL 97-136, 'Bluecrisp', FL 00-59 and FL

00-180 (Fig. 2.4). At the 5% level 'Bluecrisp', FL 97-136, and FL 00-59 were different

from all other clones except FL 00-180. FL 00-59 was not significantly



2.14 1...
... .. ... .



























Figure 2.3. Instron 8600 with shear-cell attached.

different from FL 00-180 but was significantly different from the rest of the clones. The

rest of the clones merge together and are not easily distinguished as seen from Tukey

testing in Table 2.5. In the late season harvest there were not enough berries to do shear-

cell testing on FL 97-136, but all other clones were tested. In the late-season shear-cell









tests, 'Bluecrisp', FL 00-180 and FL 00-59 were the top three clones and differed from

the other clones at the 5% level of a Tukey test.

There was a close relationship between the shear-cell force on the 1st and 2nd

sample dates for the 9 clones that were sampled twice (Fig. 2.4). Clones FL 98-325 and

FL 00-270, which had been thought to be crisp, had relatively low shear force, but the

other four "crisp" clones were very high in shear-cell force. Although the second

samples were harvested approximately 2 weeks later in the season, shear-cell force did

not dramatically change between the two sample dates (Table 2.5). Tukey testing done

on the mean sample times confirmed 'Bluecrisp', FL 00-59 and FL 180 as the top three

clones through out shear cell testing (Table 2.5).

Table 2.5. Shear-cell means for 10 clones sampled at two different times during the 2004
growing season.
Max force (N)
Cloney First sample time Second sample time" Mean sample times
Bluecrisp* 458.0 av 433.7 a 445.84 a
FL 00-59* 418.9 ab 393.7 a 406.34 ab
FL 97-136* 477.5 a
FL 98-325* 308.6 cdef 325.8 b 317.20 c
FL 00-180* 360.4 bc 401.6 a 381.01 b
FL 00-270* 270.1 def 293.5 bcd 281.79 cd
Emerald 317.0 cd 313.2 bc 315.09 c
Millennia 246.8 ef 288.0 bcd 267.38 d
Star 219.9 f 252.5 d 236.21 d
Windsor 269.1 def 257.8 cd 263.44 d
P > F" 0.0001 0.0001 0.0001
zMean of 3 shear-cell tests.
Y Clones followed by a had been considered crisp textured.
xTime period was April 30 to May 6.
'Time period was May 18 to May 19.
VMeans followed by the same letter are not significantly different (P<0.05) by
ANOVA and Tukey's test.
"Probability that the clones did not differ in shear force.











Discussion

The Kramer shear cell was built to study the texture of materials through a process

of compression, extrusion and shearing of the material. It has been used to assess the

texture of many fruits and vegetables (1, 21, 22, 47), but extensive work with the shear

cell has not been done with blueberries. A study published in 2005 examined shear stress

in rabbiteye and highbush blueberries and determined that rabbiteye blueberries (482 N)

require more force then highbush berries (290 N) (44). A combination of certain


600




500




400-

z)

a
1-
3 300




200 -




100 -


0 50 100 150 200 250 300
Second date force (N)


350 400 450 500


*Bluecrisp

*FL 00-5'


*FL 00-180

Emerald FL8-3


VVndsor *FL 00-270
Millennia
SStar


Figure 2.4. Relationship between shear-cell forces of nine selected blueberry cultivars
and clones harvested at the blue stage in the first and second sampling dates of
2004.









rabbiteye genes in the southern highbbush may be creating the crisp texture. Further

shear cell testing on southern and northern highbush, rabbiteye and lowbush blueberries

should be conducted to determine if this is true.

Standard deviations (SD) among berries within samples averaged 6% of the means,

for shear-cell testing compared to eleven percent of the means for firmness testing.

Furthermore, shear cell means fluctuated less from harvest to harvest than Instron

firmness means (Table 2.1, 3.1) (4). Shear cell testing may be a more consistent way of

comparing blueberries than firmness testing.

Consumer Sensory Panel Study

The crisp-textured clones had been selected based on the subjective opinions of

growers and the blueberries breeders at the University of Florida. To determine if the

untrained public could distinguish the difference between the crisp-textured berries and

standard commercial blueberries a consumer sensory panel study was conducted.

'Bluecrisp' and FL 00-59 represented crisp textured blueberries, and 'Emerald' and 'Star'

represented standard commercial blueberries.

2003 Materials and Methods

In a commercial field, 500 blueberries were gathered from each of the following

clones: 'Bluecrisp', FL 00-59, 'Emerald' and 'Star'. The berries from each clone were

placed into 4-liter zip lock bags and placed on ice in a cooler for transport to a 20 C

storage chamber where they were kept overnight. The next day, the berries were taken

out of storage and allowed to reach room temperature (220 C). Each berry was inspected

to eliminate immature and overripe berries and berries with cuts and leaks. The

remaining berries were placed in zip lock bags and taken to the sensory panel facility

operated by the University of Florida, Department of Food Science and Human Nutrition.









Each clone was assigned a random four-digit number. The four-digit numbers were

then randomly assigned to either the top left, top right, bottom left or bottom right of a

tray that was presented to the evaluators. For each clone, four berries were randomly

selected and placed into a cup. The four cups were randomly placed on the tray. Saltine

crackers and a glass of water were also placed on the tray to cleanse the panelist's palate

between samples. When a panelist entered the sensory panel chamber, he/she was seated

at a booth that had a computer and a small sliding window. The window was opened and

a worker presented a tray with the cups of berries. The panelist then sampled the berries

and answered the questions (listed in Table 2.6) about each group of berries using the

computer.

Table 2.6. Questions asked for the 2003 taste panel study.
Question Berry attribute Evaluation
number evaluated scale
1 Appearance Ranked 1 (extremely disliked) to 9 (extremely liked) by number
2 Texture/firmness Ranked 1 (extremely disliked) to 9 (extremely liked) by number
3 Sweetness Ranked 1 (extremely disliked) to 9 (extremely liked) by number
4 Flavor Ranked 1 (extremely disliked) to 9 (extremely liked) by number
5 Overall acceptability Ranked 1 (extremely disliked) to 9 (extremely liked) by number

2003 Results

The panelists preferred some clones over others with respect to fruit appearance,

texture/firmness, and sweetness, but showed no clonal preferences regarding flavor

(Tables 2.7-2.11). In 2003, the panelists tended to prefer the texture of the "crisp" clones

over that of 'Emerald' and 'Star' (Table 2.8). The questions presented with the 2003

samples were ambiguous in that they did not reveal whether the panelists could detect

differences among the clones or whether they could detect differences but did not prefer

one texture over another.









Table 2.7. Overall appearance of panelists of four blueberry clones on a scale from 1
(dislike extremely) to 9 (like extremely) (n=90; 2003 study).
Rating Standard Tukey
Clone 1 2 3 4 5 6 7 8 9 Mean Deviation Test
Bluecrisp 1 7 10 18 24 24 6 6.70 1.41 b
FL 00-59 1 3 11 7 22 31 15 7.21 1.43 a
Emerald 2 6 9 14 18 34 7 6.89 1.49 ab
Star 2 8 8 15 12 19 18 8 6.18 1.87 c
z The number of panelist who rated the clone.

Table 2.8. Overall texture/firmness of panelists of four blueberry clones on a scale from 1
(dislike extremely) to 9 (like extremely) (n=90; 2003 study).
Rating Standard Tukey
Clone 1 2 3 4 5 6 7 8 9 Mean Deviation Test
Bluecrisp 1z 3 8 7 17 31 15 8 6.54 1.57 ab
FL 00-59 2 6 8 10 25 24 15 7.00 1.61 a
Emerald 1 3 1 11 6 22 24 16 6 6.29 1.73 bc
Star 2 2 3 9 10 27 22 10 5 6.02 1.72 c
z The number of panelist who rated the clone.

Table 2.9. Overall sweetness of panelists of four blueberry clones on a scale from 1
(dislike extremely) to 9 (like extremely) (n=90; 2003 study).
Rating Standard Tukey
Clone 1 2 3 4 5 6 7 8 9 Mean Deviation Test
Bluecrisp 1z 1 4 12 13 8 26 16 9 6.30 1.84 Ab
FL 00-59 1 1 4 7 7 10 13 29 18 6.92 1.92 A
Emerald 1 3 7 7 10 19 21 18 4 6.08 1.84 B
Star 5 7 11 10 22 15 18 2 5.82 1.83 B
z The number of panelist who rated the clone.

Table 2.10. Overall flavor of panelists of four blueberry clones on a scale from 1 (dislike
extremely) to 9 (like extremely) (n=90; 2003 study).
Rating Standard Tukey
Clone 1 2 3 4 5 6 7 8 9 Mean Deviation Test
Bluecrisp 5z 4 10 11 17 17 18 8 6.16 1.91 A
FL 00-59 1 4 4 7 6 15 19 15 19 6.59 2.06 A
Emerald 3 4 5 3 17 17 18 15 8 6.03 2.02 A
Star 1 3 6 8 14 18 16 16 8 6.08 1.91 A


The number of panelist who rated the clone.









Table 2.11. Overall acceptability of panelists of four blueberry clones on a scale from 1
(dislike extremely) to 9 (like extremely) (n=90; 2003 study).
Rating Standard Tukey
Clone 1 2 3 4 5 6 7 8 9 Mean Deviation Test
Bluecrisp 1z 4 9 13 16 24 16 7 6.33 1.65 Ab
FL 00-59 2 5 4 8 12 24 20 15 6.78 1.79 A
Emerald 1 1 4 6 15 21 19 19 4 6.23 1.65 Ab
Star 1 3 2 10 14 24 23 10 3 5.94 1.62 B
SThe number of panelist who rated the clone.


2004 Materials and Methods

To resolve this ambiguity of the 2003 sensory panel, the 2004 questionnaire was

changed to directly ask each panelist if they could distinguish between the "crisp" and

commercial berries. The 2004 panel was conducted using the crisp-textured clones

'Bluecrisp' and FL 00-59, and the standard clones 'Star' and 'Windsor'. Each clone was

placed through the same harvesting and taste panel procedure that was used in 2003

except the questions were different (Table 2.12).

Table 2.12. Questions asked for the 2004 taste panel study.
Question
number Question topic Evaluation scale
How often do you eat 1 (never), 2 (1-2 times a year),
1 blueberries 3 (3-10 times a year), 4 (> 10 times a year)
Place in order solely based
on firmness each group of 1 (softest) to 4 crunchiestt) by number
2 berries
Rank each group of berries 1 (extremely disliked) to 9 (extremely liked)
3 on texture/firmness. by number
Rank overall quality of 1 (extremely disliked) to 9 (extremely liked)
4 each group of berries by number

2004 Results

Forty four percent of the panelists who participated in the 2004 panel ate

blueberries 1 to 2 times a year, 32% ate blueberries 3 to 10 times a year and the rest either

never ate blueberries or ate them more then ten times a year (Table 2.13). From these









data it could be said that most of these test subjects were not regular blueberry eaters.

The second question asked the panelist to rank the groups from softest to crunchiest.

This question separated 'Bluecrisp' and FL 00-59 as being the crunchiest and 'Emerald'

and 'Star' as being softer (Table 2.14). Based on a sample of four berries per clone about

78% of the panelists chose one of the two "crisp" clones as being crunchiest and only

22% chose one of the other two clones ( Table 2.14). The third question (Table 2.15)

asked panelists to indicate how well they liked the firmness of the groups of berries on a

scale from one (extremely disliked) to nine (extremely disliked). Here the texture of the

two crisp clones received the highest preference ratings (Table 2.15), although the

preference for 'Bluecrisp' texture was not significantly higher than for 'Star'. The forth

and final question (Table 2.16) asked each panelist to rank the overall desirability of each

group of blueberries. This question did not reveal any major difference among

the groups, although FL 00-59 was ranked significantly higher than 'Star'. The

difference between "crisp" and "non-crisp" clones was more consistent in firmness

ranking than for firmness desirability (Table 2.14 versus Table 2.15). This implies that

some panelist who could recognize crisp texture did not prefer it. Table 2.17 showed that

how often a panelist ate blueberries was not correlated with the recognition of "crisp"

berries. Overall, from these results it could be said that "crisp" berries can be

distinguishable from regular commercial berries, and are often but not always considered

more desirable than "non-crisp" berries.

Table 2.13. Previous blueberry eating experience of the 95 panelists whom were part of
the evaluation panel in 2004.
Number of panelist who had eaten blueberries
never 1-2 times/year 3-10 times/year >10 times/year
6 42 31 16










Table 2.14. Firmness ranking of 4 blueberry clones by 95 panelists from 1 (softest
sample) to 4 crunchiestt sample).
Rank Rank Tukey
Clone 1 2 3 4 total test
Bluecrisp 10z 15 33 37 287 ay
FL 00-59 9 16 32 38 289 a
Star 30 39 17 9 195 b
Windsor 46 25 13 11 179 b
ZNumber of people who ranked the clone at that position.
YTotals followed by the same letter are not significantly different (P<0.05) by
ANOVA and Tukey's test.

Table 2.15. Desirability of the berry firmness of 4 blueberry clones evaluated on a scale
from 1 (dislike extremely) to 9 (like extremely) by 95 panelists.

Desirability Standard Tukey
Clone 1 2 3 4 5 6 7 8 9 Mean deviation test
Bluecrisp 2y 3 4 10 9 13 23 21 10 6.34 1.982 abx
FL 00-59 1 1 3 2 9 21 22 21 15 6.82 1.669 a
Star 3 3 12 9 14 9 18 18 9 5.85 2.188 bc
Windsor 2 6 8 16 11 16 15 12 9 5.63 2.124 c
z Scale from 1(dislike extremely) to 9(like extremely)
Y Number of people who ranked the clone at that position.
x Means followed by the same letter are not significantly different (P<0.05) by
ANOVA and Tukey's test.

Table 2.16. Overall desirability of the berry quality of 4 blueberry clones evaluated by 95
panelists.

Desirability Standard Tukey
Clone 1 2 3 4 5 6 7 8 9 Mean deviation test
Bluecrisp 5x 3 2 8 14 17 22 14 10 6.07 2.074 aby
FL 00-59 3 2 6 9 21 18 20 16 6.71 1.768 a
Star 1 1 7 12 9 23 15 17 10 6.17 1.877 ab
Windsor 1 9 2 13 11 17 15 12 15 6.00 2.183 b
z Scale from 1(dislike extremely) to 9(like extremely)
Y Means followed by the same letter are not significantly different (P<0.05)
by ANOVA and Tukey's test.
xNumber of people who ranked the clone at that position.










Table 2.17. Desirability of berry firmness and overall desirability of berries of 4
blueberry clones as judged by panelists with differing blueberry consumption
histories.

Firmness rank Desirability of firmness Overall desirability
Standard Tukey Standard Tukey Standard Tukey
Clone Panelistsz Mean dev. test Mean dev. test Mean dev. test
FL 00-59 Never 2.67 1.37 a 6.00 1.26 a 6.00 2.28 a
FL 00-59 1-2 times 3.00 0.96 a 6.67 1.95 a 6.45 1.84 a
FL 00-59 3-10 times 2.97 0.91 a 7.48 1.23 a 7.39 1.45 a
FL 00-59 > 10 times 3.31 1.08 a 6.25 1.39 a 6.31 1.70 a
Bluecrisp Never 3.00 0.89 a 5.50 2.07 a 4.33 1.51 a
Bluecrisp 1-2 times 3.12 0.99 a 6.10 1.66 a 6.07 1.67 a
Bluecrisp 3-10 times 3.23 0.96 a 6.61 2.12 a 6.16 2.22 a
Bluecrisp > 10 times 2.50 0.89 a 6.75 2.41 a 6.56 2.68 a
Star Never 2.33 1.03 a 4.50 1.87 a 4.00 2.10 b
Star 1-2 times 2.10 0.91 a 5.74 1.98 a 6.07 1.67 a
Star 3-10 times 1.77 0.84 a 6.10 2.27 a 6.58 1.75 a
Star > 10 times 2.38 1.09 a 6.19 2.61 a 6.44 2.13 a
Windsor Never 2.00 1.26 a 4.67 2.66 a 4.17 3.06 a
Windsor 1-2 times 1.79 1.02 a 5.29 2.04 a 5.81 1.95 a
Windsor 3-10 times 2.03 1.08 a 5.90 2.20 a 6.58 2.13 a
Windsor > 10 times 1.81 0.98 a 6.38 1.86 a 6.06 2.26 a
zPrevious blueberry eating experience in a year

Discussion

Very little work has been done on blueberry taste as it pertains to consumer sensory

panels. The Dave Wilson Nursery has done a taste panel study every year since 1992. In

2002 blueberries were added to this panel, and it was determined that new cultivars

'Southmoon', 'Jubilee', 'Misty' and 'Ozark Blue' (scores ranging from 5.5 to 6.3 on their

10 point scale) tasted better than the older standard cultivars 'O'Neal', 'Georgia Gem'

and 'Bluecrop' (scores ranging from 4.8 to 5.4) (11).

In the 2003 sensory panel study the "crisp" clones could not be distinguished from

the "non-crisp" clones in any of the questions. This was probably because panelists did

not prefer the "crisp" clones over the "non-crisp" clones. Panelists were not asked









whether they could distinguish between "crisp" and "non-crisp" clones. The 2004

sensory panel study directly asked the panelists if they could detect a difference between

the "crisp" and "non-crisp" clones, and if they preferred one type over another. We were

able to determine that panelists could tell a difference but did not always prefer the crisp-

textured clones over the standard cultivars.

The blueberries in our study were harvested the day before each consumer sensory

panel was conducted and kept in an ideal storage condition until they were used. Most

fresh blueberries eaten by consumers are shipped across the country, kept on the grocery

shelf for several days and possibly stored in the home refrigerator for several more days

before they are eaten. If the crisp-textured clones retain their "just-picked"

characteristics longer than standard commercial varieties, sensory panel evaluations done

on berries that had been subjected to commercial packing, transport, and sales might have

separated the "crisp" and normal berries better than our test with just-picked berries.

Further research should be conducted to determine if this is the case.














CHAPTER 3
POSTHARVEST STORAGE TEST

It was hypothesized that the "crisp" blueberries might store longer then standard

commercial blueberries. Standard commercial blueberries can be stored at 20C in air for

up to 2 weeks without serious degradation. To determine if "crisp" blueberries store

longer then standard commercial berries, selected quality parameters of four "crisp"

clones and four "non-crisp" clones determined during air and CA cold storage for 8

weeks in 2003 and 2004.

2003 Study

Materials and Methods

Five to eight blueberry plants of the "crisp" clones 'Bluecrisp', FL 00-59, FL 97-

136, FL 98-325 and the "non-crisp" clones 'Emerald', 'Millennia', 'Star' and 'Windsor'

were netted in a commercial field at the beginning of the harvest season in April 2003.

As the berries from each clone matured, they were harvested at the blue stage and placed

in 125 g plastic clamshells donated by Straughn farms Inc. For each harvest a minimum

of three clamshells per clone were taken. A total of 15 clamshells were needed for each

clone. The name of the clone, date of harvest and a storage time of 0, 2, 4, 6 or 8 weeks

was written on each clamshell. The berries were then placed in a cooler with ice for

transport to a 20 C storage unit where they were separated based on storage time. Berries

harvested for 0 week storage were evaluated for initial quality factors. Berries harvested

for evaluations after 2, 4, 6 and 8 weeks storage were placed in the 20 C storage room for

their designated length of time.









At the end of the designated storage periods each blueberry was taken out of the

clamshell and checked for mold, incident of shrivel, severity of shrivel, leaking/collapse,

weight loss and firmness. To check for decay, each blueberry was visually inspected, and

the total number of berries with decay was recorded. For incident of shrivel, each berry

was examined for signs of shrivel starting at the scar end and going around the berry.

The severity of shrivel was rated for each berry using a 9 point scale, from 1 (no signs of

shriveling) to 9 (severely shriveled). To examine leaking/collapse, the blueberries were

checked for fluid leakage and cellular collapse not caused by decay. To check for weight

loss, each clamshell was weighed before being placed into storage. When removed from

storage the clamshells were reweighed and weight loss was obtained. To examine the

firmness, ten blueberries were randomly taken from each clamshell and force

deformation measurements with an Instron 8600 testing machine, as previously

described, were taken. This process was repeated on all 10 berries for each group of

berries that came out of cold storage. Once examined, the berries were poured into zip

lock freezer bags and placed in a freezer at -300 C. The pH, SSC and TTA were later

determined. All percentage data was converted to arcsin for analysis.

To determine pH, SSC and TTA, the blueberries were taken out of -30 C storage,

eight bags at a time. The frozen berries from each bag were placed in a glass jar. The

jars were sealed and placed in a large plastic container with approximately 2 inches of tap

water to thaw the berries. The berries were left in the containers for 1.5 hours to reach

room temperature. Once at room temperature, the berries were blended for 10 s until

reaching a paste-like consistence. Fifty grams was then placed into a tube and









centrifuged at 34.02 gn for 20 minutes. The supernatant was then poured through cheese

cloth into a small vial. From this supernatant, the pH, SSC and TTA were determined.

Results

Firmness of newly harvested blueberries differed among clones (Table 3.1). FL

98-325 was distinctively firmer than all other clones (Table 3.1). Of the four "crisp"

clones, only 'Bluecrisp' had a firmness mean similar to the four "non-crisp" clones.

Firmness declined for all clones during storage (Table 3.1). The mean rate of

softening ranged from 0.11 to 0.21 N per week for the eight clones. The "crisp" clones

appeared to lose firmness as fast as the "non-crisp" clones. Overall there was a

significant week x clone interaction, but, the "crisp" clones did not maintain firmness

better than the "non-crisp". This is shown both by the slopes in Table 3.1 and by the

Tukey test for firmness at week 8.

All clones except 'Star' had some decayed berries after 2 weeks storage at 20 C.

Decay incidence increased in all clones over time during the storage test (Table 3.3). The

rate of increase in decay incidence ranged from 0.08% to 2.86% per week (Table 3.3).

Even though the week x clone interaction was significant the "crisp" clones did not show

any consistent differences in the rate of decay development compared to the "non-crisp"

clones. This is shown in the slopes and Tukey testing in Table 3.3. Clones FL 00-59

("crisp"), 'Emerald' and 'Millennia' ("non-crisp") had less decay over time than the other

clones (Tables 3.3 and 3.4).

The number of leaking berries increased with each clone over time during the

storage test (Table 3.5). The Tukey test on week 8 and the slopes reveled that the "crisp"

clones did not develop leaking berries significantly slower then the "non-crisp" clones









Table 3.1. Mean deformation force at 2mm depth for 8 blueberry clones stored in air for
8 weeks at 20C in 2003.
2mm Deformation Force (N)


Clone


Week 0 Week 2 Week 4 Week 6


Week 8


mY Prob m = 0


Bluecrisp 2.37 dx 2.21 cd 1.95 b 1.36 c 1.17 c -0.16 be" 0.0001
FL 97-136 3.02 bc 2.80 b 2.47 b 1.96 bc 1.79b -0.17 b 0.0001
FL 98-325 4.18 a 4.55 a 4.18 a 3.72 a 2.74 a -0.19 cd 0.0017
FL 00-59 3.07 b 2.55 be 2.35 b 2.11 b 1.74 b -0.15 be 0.0001
Emerald 2.31 d 2.08 d 2.01 b 1.63 be 1.26 be -0.12 a 0.0001
Millennia 2.67 bcd 2.83 b 2.05 b 1.63 be 1.26 be -0.20 d 0.0001
Star 2.59 cd 2.65 b 1.89 b 1.52 be 1.05 c -0.21 d 0.0001
Windsor 2.27 d 2.12 d 2.24 b 1.79 be 1.36 be -0.11 a 0.0014
P > F <.0001 <.0001 <.0001 <.0001 0.0001
ZMean of 30 berries individually sampled, 10 from each of three clamshells.
Ym is the estimated change in force(N) per week based on linear regression analysis.
xWeek means followed by the same letter are not significantly different (P<0.05) by ANOVA
and Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample
t-tests


Table 3.2.


ANOVA for mean deformation force needed at 2mm for 8 blueberry clones
stored for 8 weeks in 2003.


Source DF Mean Square F value Pr > F
Model 39 2.00 37.84 <.0001
Clones 7 6.87 129.76 <.0001
Weeks 4 6.68 126.11 <.0001
Weeks x Clones 28 0.119 2.25 0.0026


Error


0.053


R-Square 0.95


(Table 3.5). The week x clone interaction was not significant (Table 3.5). Overall there

was an increase in leaking berries over time, but not significant interaction with the

clones over time.

All of the clones lost weight over time (Table 3.7). The week x clone interaction

was significant showing that there were differences amongst the clones over time (Table

3.8). From the Tukey test and the slopes, there were no differences in the rate of weight









loss between the "crisp" clones and the "non-crisp" clones (Table 3.7). FL 00-59,

'Emerald' and 'Millennia' showed less weight loss than the other clones.

Table 3.3. Incidence of decay (%) for eight blueberry clones stored for 8 weeks at 20C in
2003.


Clone


Decay (%)
Week 0 Week 2 Week 4 Week 6 Week 8


mz Prob m = 0


Bluecrisp 0.00 0.38 cx 4.08 ab 7.35 a 18.6 ab 2.22 ab" <.0001
FL 97-136 0.00 0.81 c 5.20 ab 6.26 a 12.81 be 1.55 c <.0001
FL 98-325 0.00 0.81 c 7.62 ab 9.46 a 24.31 ab 2.86 a <.0001
FL 00-59 0.00 7.80 ab 3.27 b 4.01 a 2.74 d 0.08 e 0.2928
Emerald 0.00 2.61 ab 7.44 ab 3.11 a 5.96 cd 0.62 de 0.0201
Millennia 0.00 14.24 a 8.56 ab 11.71 a 10.25 bcd 0.90 d 0.0167
Star 0.00 0.00 c 13.42 a 9.49 a 10.64 bcd 1.53 be 0.0006
Windsor 0.00 14.24 a 4.57 ab 11.39 a 29.35 a 2.79 abc 0.0005
P>F <.0001 0.0951 0.1692 0.0004
Zm is the estimated change in the percent of decaying berries per week based on linear regression
analysis.
YMean of 30 berries individually sampled, 10 from each of three clamshells.
xWeek means followed by the same letter are not significantly different (P<0.05) by ANOVA and
Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample
t-tests


Table 3.4.


ANOVA for incidence of decay (%) of eight blueberry clones stored for 8
weeks in 2003.


Source DF Mean Square F value Pr > F
Model 39 252.03 13.84 <.0001
Clones 7 149.10 8.19 <.0001
Weeks 4 1500.86 82.40 <.0001
Weeks x Clones 28 99.36 5.46 <.0001


Error


18.21


R-Square 0.87

The number of shriveled berries increased dramatically over time during the

storage test (Table 3.9). The week x clone interaction was significant showing that there

were differences amongst the clones over time (Table 3.10). However, in examining the

Tukey test results and the slopes, these differences did not distinguish the "crisp" clones









from the "non-crisp" clones (Table 3.9). Overall, the amount of shriveling increased over

time, but the "crisp" clones were not significantly different from the "non-crisp" clones.

The severity of shrivel for each clone increased over time during this storage test

(Table 3.11). At week 2, "crisp" clones 'Bluecrisp', FL 97-136 and FL 98-325 showed

less severity of shriveling then the other clones. This distinction did not continue as

storage time lengthened (Table 3.11). The week x clone interaction for shriveling

severity was significant. The "crisp" clones did not develop less shriveling than the

"non-crisp" clones.

Table 3.5. Incidence of leaking (%) for eight blueberry clones stored for 8 weeks at 20C
in 2003.
Leaking (%)
Clone Week 0 Week 2 Week 4 Week 6 Week 8 mz Prob m = 0
Bluecrisp 0.00y 0.00 ax 1.41 a 3.92 a 8.80 ab 1.08 c" <.0001
FL 97-136 0.00 0.00 a 0.74 a 2.52 a 10.61 ab 1.19bd 0.0002
FL 98-325 0.00 0.00 a 3.86 a 5.54 a 18.26 ab 2.10 a <.0001
FL 00-59 0.00 0.00 a 0.65 a 5.97 a 6.24 b 0.92 d <.0001
Emerald 0.00 0.00 a 2.30 a 3.14 a 10.16 ab 1.17 bd 0.0008
Millennia 0.00 1.32 a 6.29 a 7.86 a 18.28 ab 2.15 a <.0001
Star 0.00 0.00 a 4.00 a 8.08 a 14.14 ab 1.82 ab <.0001
Windsor 0.00 1.32 a 3.94 a 9.58 a 25.65 a 2.98 a <.0001
P > F 0.0196 0.4777 0.3069 0.0337
Zm is the estimated change in the percent of leaking berries per week based on linear regression
analysis.
YMean of 30 berries individually sampled, 10 from each of three clamshells.
xWeek means followed by the same letter are not significantly different (P<0.05) by ANOVA
and Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample
t-tests.









Table 3.6.


ANOVA for incidence of leaking (%) for eight blueberry clones stored for 8
weeks in 2003.


Source DF Mean Square F value Pr > F
Model 39 222.43 10.11 <.0001
Clones 7 108.01 4.91 0.0001
Weeks 4 1841.62 83.72 <.0001
Weeks x Clones 28 19.72 0.90 0.6169


Error


21.99


R-Square 0.83


Table 3.7. Incidence of weight loss (%) of eight blueberry clones stored for 8 weeks at
2C in 2003. Values for each week are the cumulative weight loss from week
0 to the week stated.
Clone Week 0O Week 2z Week 4z Week 6z Week 8z MY Prob m = 0
Bluecrisp 0.0x 2.0 dw 3.4 c 5.2 c 7.5 cd 0.91 cv <0.0001
FL 97-136 0.0 4.3 ab 5.6 a 7.7 a 9.3 bcd 1.09 b <0.0001
FL 98-325 0.0 4.4 ab 5.2 a 6.5abc 9.7 bc 1.08 b <0.0001
FL 00-59 0.0 3.7bc 5.6 a 5.7 bc 7.7 cd 0.87 d <0.0001
Emerald 0.0 3.4 bc 3.9 bc 5.3 bc 6.7 d 0.77 d <0.0001
Star 0.0 2.8 cd 5.9 a 7.7 a 10.5 ab 1.30 a <0.0001
Windsor 0.0 5.4 a 4.9 ab 7.3 a 12.7 a 1.37 a <0.0001
Millennia 0.0 5.4 a 5.2 a 6.6 ab 8.2 bcd 0.88 d <0.0001
P>F <.0001 <.0001 <.0001 0.0001
zLoss from original weight at week 0.
Ym is the estimated change in weight(g) per week based on linear regression analysis.
XMean of 30 berries individually sampled, 10 from each of three clamshells.
"Week means followed by the same letter are not significantly different (P<0.05) by
ANOVA and Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample t-
tests.


Table 3.8.


ANOVA for incidence of weight loss (%) of eight blueberry clones stored for
8 weeks in 2003.


Source DF Mean Square F value Pr > F
Model 39 31.264 104.01 <.0001
Clones 7 10.341 34.40 <.0001
Weeks 4 267.89 891.23 <.0001
Weeks x Clones 28 2.691 8.95 <.0001


Error


0.301


R-Square 0.98










Table 3.9. Incidence of shriveling (%) for eight blueberry clones stored for
8 weeks at 20C in 2003.
Number of berries per 100
Clone Week 0 Week 2 Week 4 Week 6 Week 8 Mz Prob m = 0
Bluecrisp O.OO0 20.25 bx 88.95 bc 93.07 bc 99.58 ab 13.60 abw <.0001
FL 97-136 0.00 11.17 bc 75.30 bcd 84.32 c 96.45 bc 13.30 a <.0001
FL 98-325 0.00 2.08 c 58.57 d 42.91 d 90.07 c 11.05 bc <.0001
FL 00-59 0.00 12.93 bc 77.82 bc 94.00 abc 98.64 ab 13.92 bc <.0001
Emerald 0.00 26.33 b 73.71 cd 87.17 c 98.16 ab 12.86 c <.0001
Millennia 0.00 66.30 a 99.44 a 99.42 a 100.00 a 11.66 ab <.0001
Star 0.00 16.10 bc 90.39 b 98.97 ab 99.44 ab 14.09 ab <.0001
Windsor 0.00 66.30 a 79.23 bc 94.89 abc 100.00 a 11.43 abc <.0001
P>F <.0001 <.0001 <.0001 0.0001
Zm is the estimated change in number of shriveled berries per week based on linear regression
analysis.
YMean of 30 berries individually sampled, 10 from each of three clamshells.
xWeek means followed by the same letter are not significantly different (P<0.05) by ANOVA and
Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample t-tests.

Table 3.10. ANOVA for incidence of shriveling (%) of eight blueberry clones stored for
8 weeks in 2003.
Source DF Mean Square F value Pr > F
Model 39 3345.82 193.57 <.0001
Clones 7 1174.40 67.94 <.0001
Weeks 4 29112.66 1684.31 <.0001
Weeks x Clones 28 207.70 12.02 <.0001


Error


17.29


R-Square 0.99









Table 3.11. Incidence of shrivel severity of eight blueberry clones stored for 8 weeks at
2C in 2003.
Index values
Clone Week 0 Week 2 Week 4 Week 6 Week 8 mY Prob m = 0
Bluecrisp 1.00 1.51 c" 3.05 abc 3.60 bc 5.10 ab 0.62 av 0.0001
FL 97-136 1.00 1.23 c 2.74 bc 3.07 c 4.41 b 0.53 b 0.0001
FL 98-325 1.00 1.04c 2.19 c 2.11 d 4.50 b 0.50 cd 0.0001
FL 00-59 1.00 3.95 a 2.85 bc 3.63 bc 4.34 b 0.42 d 0.0012
Emerald 1.00 3.93 a 2.96 bc 3.48 bc 4.85 ab 0.46 cd 0.0005
Millennia 1.00 4.23 a 4.03 a 4.49 a 5.60 a 0.57 abcd 0.0001
Star 1.00 3.11 b 3.55 ab 4.26 ab 5.13 ab 0.57 abc 0.0001
Windsor 1.00 4.24 a 2.99 bc 4.63 a 5.65 a 0.59 abc 0.0001
P>F <.0001 0.0008 <.0001 0.0011
zEach berry was rated on a scale from 1 (no shriveling) to 9 (extreme shriveling).
Ym is the estimated change in shrivel severity per week based on linear regression analysis.
XMean of 30 berries individually sampled, 10 from each of three clamshells.
"Week 8 means followed by the same letter are not significantly different (P<0.05) by
ANOVA and Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample
t-tests.

Table 3.12. ANOVA for Incidence of shrivel severity of eight blueberry clones stored for
8 weeks in 2003.
Source DF Mean Square F value Pr > F
Model 39 6.781 83.17 <.0001
Clones 7 5.103 62.59 <.0001
Weeks 4 49.080 601.94 <.0001
Weeks x Clones 28 1.157 14.20 <.0001
Error 80 0.0815

R-Square 0.98

The pH, SSC and TTA for each clone at each week were tested. No significant

differences were found between the "crisp" and "non-crisp" clones. For the pH, all

clones increased slightly except 'Windsor', which decreased, but had a high probability

of having a slope of zero (Table 3.13). All clones started with similar pHs and after 8

weeks differences among the clones could be seen, but the "crisp" and "non-crisp" clones

did not stand out from each other (Table 3.13, 3.14).









SSC of the freshly-picked berries ranged from 7.47 to 12.83 among the clones

(Table 3.15). SSC did not separate the "crisp" from the "non-crisp" clones (Table 3.15).

There were no significant interactions among the storage times and clones with respect to

SSC (Table 3.16). All but three of the slopes showed a decrease in SSC with slopes not

significantly different from zero, except for FL 97-136 and FL 98-325, which had a

tendency to increase with time (Table 3.15). The initial TTA values ranged from 0.22 to

1.45 for the clones (Table 3.17). There was no distinction between the "crisp" and "non-

crisp" clones. Only four clones showed significant changes in TTA over time (Table

3.17). The TTA decreased over time for these four. There were differences over storage

time and clones and a significant variance for clones x weeks of storage (Table 3.18).

Table 3.13. Meanz pH of eight blueberry clones stored at 20C over 8 weeks in 2003.
Clone Week 0 Week 2 Week 4 Week 6 Week 8 mY Prob m = 0
Bluecrisp 3.84 ax 3.84 a 4.06 a 3.96 a n/a 0.029 dw 0.0336
FL 97-136 3.45 bc 3.68 ab 3.73 bc 3.72 bc 3.83 b 0.043 cd 0.0047
FL 98-325 3.65 ab 3.85 a 3.92 ab 3.94 ab 4.06 a 0.047 cd 0.0124
FL 00-59 3.37 c 3.44 c 3.45 de 3.50 cd 3.63 cd 0.021 cd 0.0231
Emerald 3.11 d 3.20 d 3.22 e 3.24 e 3.23 e 0.019 b 0.0236
Millennia 3.47 bc 3.14 d 3.42 de 3.50 cd 3.54 cd 0.018 bc 0.4239
Star 3.38 c 3.51 bc 3.64 cd 3.60 cd 3.67 bc 0.039 cd 0.0066
Windsor 3.46 bc 3.68 ab 3.46 de 3.50 de 3.48 d -0.010 a 0.5135
P > F <.0001 <.0001 <.0001 <.0001 <.0001
zMean of 3 clamshells individually sampled.
Ym is the estimated change in pH per week based on linear regression analysis.
xWeek means followed by the same letter are not significantly different (P<0.05) by ANOVA
and Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample t-
tests.









Table 3.14. ANOVA for mean pH of eight blueberry clones stored at 20C over 8 weeks in
2003.
Source DF Mean Square F value Pr > F
Model 39 0.176 31.39 <.0001
Clones 8 0.724 129.13 <.0001
Weeks 4 0.155 27.55 <.0001
Weeks x Clones 27 0.026 4.65 <.0001


Error


0.006


R-Square 0.94


Table 3.15. Meanz SSC of eight blueberry clones stored at 20C over 8 weeks in 2003.


Clone


Week 0 Week 2 Week 4 Week 6 Week 8


mY Prob m = 0


Bluecrisp 12.83 ax 14.27 a 14.37 a 12.67 a n/a -0.020 abc" 0.9531
FL 97-136 9.00 abc 9.40 b 11.00 a 11.77 a 9.80 ab 0.495 bc 0.0092
FL 98-325 8.47 bc 12.77 ab 12.47 a 12.07 a 13.05 a 0.525 c 0.0232
FL 00-59 11.83 ab 11.30 ab 11.30 a 11.20 a 12.30 a -0.095 bd 0.6377
Emerald 7.47 c 8.43 b 9.80 a 8.93 a 7.60 b 0.288 b 0.2774
Millennia 12.13 ab 10.73 ab 11.30 a 10.47 a 9.10 ab -0.222 a 0.0928
Star 8.93 bc 10.70 ab 12.47 a 10.60 a 10.40 ab 0.338 bc 0.1705
Windsor 9.60 abc 11.33 ab 10.67 a 10.65 a 8.77 ab 0.022 ad 0.9254
P>F 0.0012 0.0176 0.1736 0.3142 0.0143
ZMean of 3 clamshells individually sampled.
Ym is the estimated change in SSC per week based on linear regression analysis.
XWeek means followed by the same letter are not significantly different (P<0.05) by ANOVA
and Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample t-
tests.

Table 3.16. ANOVA for mean SSC of eight blueberry clones stored at 20C over 8 weeks
in 2003.
Source DF Mean Square F value Pr > F
Model 39 8.47 3.00 <.0001
Clones 8 25.04 8.87 <.0001
Weeks 4 9.08 3.21 0.0171
Weeks x Clones 27 3.19 1.13 0.3323


Error


2.82


R-Square 0.61









Table 3.17. Meanz TTA of eight blueberry clones stored at 20C over 8 weeks in 2003.
Clone Week 0 Week 2 Week 4 Week 6 Week 8 mY Prob m = 0
Bluecrisp 0.22 dx 0.28 d 0.21 d 0.25 c n/a 0.003 a" 0.6538
FL 97-136 0.52 bcd 0.37 cd 0.47 c 0.45 c 0.46 be -0.005 ab 0.6493
FL 98-325 0.42 cd 0.36 cd 0.31 cd 0.30 c 0.28 c -0.020 de 0.0074
FL 00-59 0.58 bcx 0.51 c 0.48 c 0.43 c 0.47 be -0.025 c 0.0010
Emerald 1.45 a 0.71 b 0.76 ab 0.81 a 0.95 a -0.093 e 0.0288
Millennia 0.61 be 1.16 a 0.85 a 0.76 ab 0.80 ab 0.007 abcd 0.8389
Star 0.75 b 0.50 c 0.47 c 0.51 be 0.48 be -0.038 e 0.0299
Windsor 0.48 bcd 0.41 cd 0.52 be 0.40 c 0.38 c -0.007 bcd 0.4907
P > F <.0001 <.0001 <.0001 <.0001 0.0013
ZMean of 3 clamshells individually sampled.
Ym is the estimated change in TTA per week based on linear regression analysis.
xWeek means followed by the same letter are not significantly different (P<0.05) by ANOVA
and Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample
t-tests.

Table 3.18. ANOVA for mean TTA of eight blueberry clones stored at 20C over an 8
weeks in 2003.
Source DF Mean Square F value Pr > F
Model 39 0.198 17.69 <.0001
Clones 8 0.723 64.72 <.0001
Weeks 4 0.079 7.06 <.0001
Weeks x Clones 27 0.060 5.41 <.0001


Error


0.011


R-Square 0.90


In 2004, to better determine if crisp-textured blueberries are different from

commercial blueberries, two atmospheres were used one being normal air and the other

a low 02 / high C02 CA. Two new clones were also added that were believed to have

crisp texture: FL 00-180 and FL 00-270.

2004 Study

Materials and Methods

Five to eight blueberry plants of each of the clones 'Bluecrisp', FL 97-136, FL 98-

325, FL 00-59, FL 00-180, FL 00-270, 'Emerald', 'Millennia', 'Star' and 'Windsor' were









netted in a commercial field at Windsor, Florida at the beginning of the harvest season.

As the berries from each clone matured they were harvested at the blue stage and placed

in 125 g clamshells. For each harvest a minimum of three clamshells per clone were

taken. A total of 15 clamshells per clone were needed for the CA storage test, and 15

clamshells were needed for the air storage test. The name of the clone, date of harvest,

storage environment and the storage time were written on each clamshell. The clamshells

were placed in a cooler of ice for transport to a 20 C storage unit, where they were

separated based on storage environment and storage time. Storage time for air was 2, 4,

5, and 6 weeks and CA storage was for 2, 4, 6, and 8 weeks. All the berries for a

particular storage environment and storage time were placed into a sealed 5 gallon (79.49

L) bucket, which had one intake and one outlet hose attached to it. The buckets for the

same atmosphere were then hooked together and a minimum flow rate of 81ml/min was

established through the buckets using pressurized gasses and needle value flow meters to

prevent C02 buildup. For the CA, a mixture of 15% C02, 2% 02 and 83% N with a

relative humidity of 90-95% was delivered to the buckets. For the air atmosphere, a pure

flow of air with a relative humidity of 90-95% was delivered to the buckets. The outlet

tubes from the end of the bucket lines were checked each day for flow rate, C02 and 02

concentrations. As each storage time ended, the lids of the buckets were taken off and the

clamshells were removed for post-storage examination. Berries harvested for week 0

storage were examined without storage.

For evaluation, 10 blueberries were randomly taken from each clamshell and

checked for decay, number of berries that were shriveled, severity of shriveling,

leaking/collapse and firmness. To check for decay, each blueberry was visually









inspected. Of the 10 berries examined, the number with mold was recorded. The same

berries were examined for signs of shriveling, starting at the scar end and going around

the berry. Berries were recorded as shriveled or not shriveled. The severity of shriveling

was recorded for each berry using a 9 point scale, from 1 (no signs of shriveling) to 9

(severely shriveled). Ten random berries per clamshell were visually examined for

leaking fluids or cellular collapse not caused by disease. For firmness testing, a set of 10

different blueberries were placed through the same Instron testing procedure that was

done in 2003. The pH, SSC and TTA for berries in each clamshell were determined

using the same procedures as in 2003.

Results

Before storage, FL 00-59 was the firmest clone (Table 3.19). As a group, the

"crisp" clones were not exceptionally firm at the beginning of the storage test. By week

2 "crisp" clones 'Bluecrisp', FL 98-325 and FL 00-59 had a higher firmness then the

other clones. At week 6, Tukey's test showed three ('Bluecrisp', FL 00-59 and FL 00-

180) of the four "crisp" clones sampled at that time to be significantly firmer than the

"non-crisp" clones (Table 3.19). As indicated by the slopes (Table 3.19), some clones

became firmer during storage, others less firm. 'Bluecrisp' gained the most in firmness

and 'Millennia' lost the most.

Decay incidence in the air atmosphere storage increased over time for all clones

except FL 00-59, which still had no decay after 6 weeks (Table 3.21). The week x clone

interaction showed significance, but the week 6 Tukey's test and the slopes showed that

the "crisp" clones did not fare better the "non-crisp" clones (Tables 3.21 and 3.22).

Among the slopes FL 00-59 was the only clone that differed significantly from the others

(Table 3.21).









The percent of leaking berries increased in all clones over time, except for FL 00-

59, which had only one leaking berry in all the samples (Table 3.23). The week x clone

interaction was significant for number of leaking berries, but the week 6 Tukey's test and

the slopes showed no consistent differences between the "crisp" and "non-crisp" clones

(Tables 3.23 and 3.24). Among the slopes the only clone to stand out as being

significantly different from the rest was FL 00-59.

The incidence of shriveling in the air atmosphere increased with storage time in all

clones (Table 3.25). The week x clone interaction was significant, but the week 6

Tukey's test and the slopes showed no consistent differences amongst the "crisp" and

"non-crisp" clones (Tables 3.25 and 3.26). 'Bluecrisp', FLOO-59 and FLOO-180 had the

lowest rates of shriveling when compared to slopes of the other clones (Tables 3.25).

The same trend could be seen in the severity of shrivel over time as was seen in the

frequency of shriveled berries over time (Tables 3.27 and 3.28).

The pH, SSC and TTA for the blueberries stored in the air atmosphere did not

differ significantly for the "crisp" and "non-crisp" clones (Table 3.29). Slopes indicated

that there were only small and inconsistent pH changes during the weeks of storage

(Table 3.29). The 'weeks' component of the ANOVA analysis for pH was nonsignificant

(Table 3.30).

There were significant differences in SSC among the clones at week 0 (Table 3.31),

and these differences were maintained throughout. SSC was not a factor that

distinguished the "crisp" from the standard clones. All slopes for the clones had high

probabilities of being zero and there was not a significant clone x week interaction

(Tables 3.31 and 3.32).









Clones varied widely in TA at the beginning of the storage test (Table 3.33). As a

group, the six crisp clones had lower TA than the four standard clones. Overall there

were only minor changes in TA during storage.

Table 3.19. Mean deformation force at 2mm depth for 10 blueberry clones stored in air
for 8 weeks at 20C in 2004.
2mm Deformation Force (N)
Clone Week 0 Week 2 Week 4 Week 5 Week 6 mY Prob m = 0
Bluecrisp 2.50 bcdx 3.49 a 3.66 a 3.53 a 3.13 a 0.20 a" 0.0022
FL 97-136 2.26 cde 2.58 b 2.04 d 2.39 bcd M* 0.02 b 0.5897
FL 98-325 2.88 b 3.51 a 3.33 ab 2.57 bc M -0.04 d 0.6251
FL 00-59 3.42 a 3.49 a 3.06 bc 2.96 ab 3.51 a -0.11 cd 0.0009
FL 00-180 2.35 cde 2.64 b 2.52 cd 2.46 bc 3.19 a 0.02 b 0.5337
FL 00-270 1.89 f 1.78 c 1.65 e 1.85 de 1.75 b -0.02 d 0.4183
Emerald 2.01 ef 2.18 bc 2.05 de 2.17 cd 1.93 b 0.02 e 0.5131
Millennia 2.09 def 2.40 b 1.82 e 1.36 e 2.07 b -0.15 e 0.0206
Star 2.54 bc 2.66 b 2.52 cd 2.31 cd 2.06 b -0.04 f 0.3348
Windsor 2.19 def 2.66 b 2.05 de 2.55 bc 1.72 b 0.02 bc 0.7014
P>F <.0001 <.0001 <.0001 <.0001 0.0001
ZMean of 30 berries individually sampled, 10 from each of 3 clamshells.
Ym is the estimated change in force(N) per week based on linear regression analysis.
xWeek means followed by the same letter are not significantly different (P<0.05) by ANOVA
and Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample
t-tests
*Data missing

Table 3.20. ANOVA for mean force needed to deform the berries by 2mm for 10
blueberry clones stored for 6 weeks in 2004. (air atmosphere).
Source DF Mean Square F value Pr > F
Model 47 1.051 18.61 <.0001
Clones 9 4.253 75.28 <.0001
Weeks 4 0.538 9.53 <.0001
Weeks x Clones 34 0.259 4.59 <.0001
Error 96 0.056


R-Square .90









Table 3.21. Incidence of decay (%) for 10 blueberry clones stored for 6 weeks in air
storage at 20C in 2004.


Clone
Bluecrisp
FL 97-136
FL 98-325
FL 00-59
FL 00-180
FL 00-270
Emerald
Millennia
Star
Windsor
P>F


Week 0 Week 2 Week 4 Week 5


0.00y
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00


0.00 ax
6.67 a
6.67 a
0.00 a
0.00 a
0.00 a
0.00 a
0.00 a
0.00 a
0.00 a
.0087


13.33 a
13.33 a
10.00 a
0.00 a
0.00 a
13.33 a
13.33 a
23.33 a
6.67 a
0.00 a
0.2514


13.33 cd
60.00 a
40.00 ab
0.00 d
30.00 abc
53.33 ab
23.33 abcd
26.67 abcd
16.67 abcd
3.33 cd
.0002


Week 6
10.00 cde
63.33 ab
83.33 a
0.00 e
3.33 de
36.67 abcd
33.33 bcd
43.33 abc
20.00 bcde
30.00 bcd
<0.0001


mz Prob m = 0


2.39 e"
11.18 ab
11.95 a
0.00 f
2.44 e
8.13 bc
5.69 c
7.30 bc
3.56 de
3.60 d


0.0176
0.0002
0.0003

0.1510
0.0009
0.0012
0.0012
.0217
0.0554


Zm is the estimated change in the percentage of decaying berries per week based on linear regression
analysis.
YMean of 30 berries individually sampled, 10 from each of 3 clamshells.
xWeek 6 means followed by the same letter are not significantly different (P<0.05) by ANOVA and
Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample t-tests

Table 3.22. ANOVA for incidence of decay (%) for 10 blueberry clones stored for 6
weeks in air storage in 2004.
Source DF Mean Square F value Pr > F
Model 49 929.40 10.27 <.0001
Clones 9 1068.95 11.81 <.0001
Weeks 4 5949.10 65.72 <.0001
Weeks x Clones 36 336.77 3.72 <.0001


Error


90.52


R-Square 0.83









Table 3.23. Incidence of leaking (%) for 10 blueberry clones stored for 6 weeks in air
storage at 20C in 2004.


Clone
Bluecrisp
FL 97-136
FL 98-325
FL 00-59
FL 00-180
FL 00-270
Emerald
Millennia
Star
Windsor
P>F


Week 0 Week 2 Week 4 Week 5 Week 6


0.00y
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00


3.33 bcx 6.67 b
30.00 a 16.67 ab
20.00 ab 10.00 b
0.00 c 3.33 b
0.00 c 3.33 b
0.00 c 46.67 a
3.33 bc 13.33 ab
0.00 c 46.67 a
3.33 bc 10.00 ab
0.00 c 10.00 ab
<.0001 0.0016


20.00 abc
53.33 ab
63.33 a
0.00 c
20.00 abc
53.33 ab
30.00 abc
46.67 ab
16.67 abc
10.00 bc
0.0004


16.67 bc
50.00 ab
70.00 a
0.00 c
30.00 c
30.00 abc
20.00 abc
26.67 abc
16.67 abc
56.67 ab
0.0002


mz Prob m = 0


3.22 dw
7.90 bc
11.26 a
0.00 g
1.84 f
8.25 ab
4.45 cde
7.41 bc
3.08 ef
7.30 bc


0.0040
0.0017
0.0004
0.7920
0.1818
0.0039
0.0017
0.0056
0.0297
0.0087


Zm is the estimated change in the percent of leaking berries per week based on
linear regression analysis.
YMean of 30 berries individually sampled, 10 from each of three clamshells.
xWeek 6 means followed by the same letter are not significantly different (P<0.05) by ANOVA
and Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample
t-tests.

Table 3.24. ANOVA for incidence of leaking (%) for 10 blueberry clones stored for 6
weeks in 2004.
Source DF Mean Square F value Pr > F
Model 49 952.39 10.56 <.0001
Clones 9 1322.88 14.67 <.0001
Weeks 4 5397.03 59.84 <.0001
Weeks x Clones 36 365.92 4.06 <.0001


90.19


R-Square 0.84


Error









Table 3.25. Incidence of shriveling (%) for 10 blueberry clones stored for 6 weeks in air
storage at 20C in 2004.
Clone Week 0 Week 2 Week 4 Week 5 Week 6 mz Prob m = 0


Bluecrisp
FL 97-136
FL 98-325
FL 00-59
FL 00-180
FL 00-270
Emerald
Millennia
Star
Windsor
P>F


3.33 abx 16.67 ab 33.33 bc 33.33 cd 6.26 d" 0.0001


0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00


30.00 a
20.00 ab
0.00 b
0.00 b
10.00 ab
3.33 ab
0.00 b
6.77 ab
6.77 ab
.0104


53.33 ab
16.67 ab
3.33 b
6.67 b
63.33 a
26.67 ab
70.00 a
26.67 ab
40.00 ab
.0024


86.67 a
76.67 ab
6.67 c
63.33 ab
86.67 a
46.67 abc
60.00 ab
66.67 ab
50.00 ab
<.0001


83.33 ab
86.67 a
0.00 e
6.67 de
63.33 abc
53.33 abc
63.33 abc
40.00 bcd
76.67 abc
<0.0001


14.89 a
14.22 ab
1.55 e
5.29 d
14.11 ab
9.68 bc
13.05 abc
9.37 c
12.67 b


0.0001
0.0001
0.2875
0.0993
0.0002
0.0001
0.0002
0.0029
0.0001


Zm is the estimated change in the percent of shriveled berries per week based on
linear regression analysis.
YMean of 30 berries individually sampled, 10 from each of three clamshells.
xWeek 6 means followed by the same letter are not significantly different (P<0.05) by ANOVA
and Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample
t-tests.

Table 3.26. ANOVA for incidence of shriveling (%) of 10 blueberry clones stored at 20C
for 6 weeks in 2004.
Source DF Mean Square F value Pr > F
Model 49 1843.39 16.37 <.0001
Clones 9 2132.30 18.94 <.0001
Weeks 4 13789.26 122.47 <.0001
Weeks x Clones 36 443.85 3.94 <.0001


Error


112.59


R-Square 0.89









Table 3.27. Incidence of shrivel severity of 10 blueberry clones stored for 6 weeks in air
storage at 20C in 2004.
Index values
Prob m
Clone Week 0 Week 2 Week 4 Week 5 Week 6 my = 0
Bluecrisp 1.00" 1.13 bcw 1.50 abc 1.73 e 2.03 cd 0.17 dv 0.0021
FL 97-136 1.00 2.13 a 2.57 bc 5.70 a 4.60 ab 0.71 ab 0.0001
FL 98-325 1.00 1.87 ab 1.47 bc 4.43 abc 6.13 a 0.77 a 0.0002
FL 00-59 1.00 1.00 c 1.10 c 1.13 e 1.00 d 0.01 e 0.3732
FL 00-180 1.00 1.00c 1.13 c 3.10cde 1.17d 0.17 d 0.1424
FL 00-270 1.00 1.10 bc 3.17 ab 4.90 ab 4.00 abc 0.66 b 0.0004
Emerald 1.00 1.13 bc 2.23 abc 2.70 cde 2.30 bcd 0.33 c 0.0001
Millennia 1.00 1.00 c 3.77 a 4.03 abcd 3.50 bcd 0.56 b 0.0004
Star 1.00 1.17 bc 1.63 bc 2.53 cde 2.37 bcd 0.27 c 0.0025
Windsor 1.00 1.07 c 2.00 abc 2.07 de 4.30 abc 0.48 b 0.0003
P>F 0.0002 0.0004 <.0001 <.0001
zEach berry was rated on a scale from 1 (no shriveling) to 9 (extreme shriveling).
Ym is the estimated change in shrivel severity per week based on linear regression analysis.
XMean of 30 berries individually sampled, 10 from each of three clamshells.
"Week 8 means followed by the same letter are not significantly different (P<0.05) by
ANOVA and Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample t-
tests.

Table 3.28. ANOVA for incidence of shrivel severity of 10 blueberry clones stored for 6
weeks at 20C in 2004.
Source DF Mean Square F value Pr > F
Model 49 5.90 16.98 <.0001
Clones 9 0.35 23.4 <.0001
Weeks 4 8.14 94.62 <.0001
Weeks x Clones 36 32.90 6.74 <.0001
Error 100 2.34


R-Square 0.89









Table 3.29. Meanz pH of 10 blueberry clones in an air atmosphere over 6 weeks in 2004.


Week 0
4.10 abx
4.41 a
4.16 ab
3.95 bc
3.55 cd
3.65 cd
3.61 cd
3.65 cd
3.46 d
3.49 d
<.0001


Week 2 Week 4 Week 5 Week 6


4.05 b
4.40 a
4.37 a
3.86 bc
3.46 gf
3.68 cde
3.79 cd
3.30g
3.60 def
3.56 ef
<.0001


4.05 ab
4.08 ab
4.26 a
3.79 bc
3.66 cd
3.63 cd
3.67 cd
3.51 cd
3.54 cd
3.42 d
<.0001


3.99 a
n/av
n/a
3.81 ab
3.54 c
3.63 bc
3.60 c
3.62 c
3.61 c
3.27 d
<.0001


4.09 a
n/a
n/a
3.82 b
3.54 c
3.61 bc
3.58 bc
3.51 c
3.68 bc
3.42 c
<.0001


mY Prob m
-0.013 cde" 0.5636
-0.073 a 0.0272
0.019 def 0.6462
-0.041 bc 0.1162
0.029 e 0.2422
-0.004 cde 0.7421
0.015 d 0.4940
-0.036 cde 0.4707
0.020 f 0.2797
-0.016 b 0.4805


zMean of three clamshells individually sampled.
Ym is the estimated change in titratable acid per week based on linear regression analysis.
xWeeks followed by the same letter are not significantly different (P<0.05) by ANOVA and
Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample t-tests
'Berries were too decayed to obtain any data.

Table 3.30. ANOVA for mean pH of 10 blueberry clones in an air atmosphere over 6
weeks in 2004.
Source DF Mean Square F value Pr > F
Model 45 0.248 23.12 <.0001
Clones 9 1.070 99.75 <.0001
Weeks 4 0.014 1.26 0.2931
Weeks x Clones 32 0.028 2.60 0.0002


0.011


R-Square 0.92


Bluecrisp
FL 97-136
Fl 98-325
Fl 00-59
FL 00-180
FL 00-270
Emerald
Millennia
Star
Windsor
P>F


Error









Table 3.31. Meanz SSC 10 blueberry clones in an air atmosphere over 6 weeks in 2004.
Clone Week 0 Week 2 Week 4 Week 5 Week 6 mY Prob m = 0
Bluecrisp 12.70 abx 12.90 a 12.23 a 12.20 ab 11.70 ab -0.117 bc" 0.6620
FL 97-136 14.50 a 12.97 a 12.10 ab n/aV n/a -0.600 de 0.1292
FL 98-325 10.13 be 12.13 a 9.73 abcd n/a n/a -0.100 abcd 0.7843
FL 00-59 12.20 abc 12.00 a 11.50 abc 12.30 a 12.90 a -0.175 a 0.4884
FL 00-180 8.27 c 7.00 b 8.03 d 8.03 c 7.80 d -0.058 ab 0.7967
FL 00-270 9.87 be 8.93 ab 9.13 cd 8.40 ac 8.83 cd -0.183 be 0.4450
Emerald 11.30 abc 11.77 a 9.20 bcd 9.63 abc 9.00 cd -0.525 d 0.0705
Millennia 11.87 abc 11.50 a 10.37 abcd 12.07 ab 10.93 abc -0.375 be 0.0891
Star 10.33 be 11.93 a 10.33 abcd 10.87 abc 10.60 abc 0.000 abc 1.0000
Windsor 10.27 be 10.70 ab 9.43 abcd 9.10 be 9.80 bcd -0.208 ce 0.2189
P>F 0.0015 0.0009 0.0006 0.0012 <.0001
ZMean of three clamshells individually sampled.
Ym is the estimated change in SSC per week based on linear regression analysis.

xWeeks followed by the same letter are not significantly different (P<0.05) by ANOVA and Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample t-tests
'Berries were too decayed to obtain any data.


Table 3.32. ANOVA for mean SSC of 10 blueberry clones in an air atmosphere over 6
weeks in 2004.
Source DF Mean Square F value Pr > F
Model 45 8.24 5.87 <.0001
Clones 9 33.12 23.61 <.0001
Weeks 4 5.30 3.77 0.0070
Weeks x Clones 32 1.38 0.98 0.5054


Error


1.40


R-Square 0.75









Table 3.33. Meanz TTA of 10 blueberry clones in an air atmosphere over 6 weeks in
2004.


Week 0 Week 2 Week 4


0.23 de 0.26 def
0.13 e 0.20 ef
0.13 e 0.14 f
0.31 cde 0.31 cdef
0.55 b 0.35 bcdef
0.4 bcd 0.44 abcd
0.35 cd 0.41 abcde
0.90 a 0.54 ab
0.43 bc 0.49 abc
0.40 bcd 0.56 a
<.0001 <.0001


Week 5 Week 6


0.31 c
n/av
n/a
0.29 c
0.43 bc
0.13 bc
0.48 b
0.51 b
0.42 bc
0.76 a
<.0001


0.26 b
n/a
n/a
0.35 b
0.46 ab
0.47 ab
0.46 ab
0.65 a
0.43 ab
0.36 ab
0.010


zMean of three clamshells individually sampled.
Ym is the estimated change in TTA per week based on linear regression analysis.
xWeeks followed by the same letter are not significantly different (P<0.05) by ANOVA
test.


and Tukey's


"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample t-tests
'Berries were too decayed to obtain any data.


Table 3.34. ANOVA for mean TTA of 10 blueberry clones in an air atmosphere over 6
weeks in 2004.
Source DF Mean Square F value Pr > F
Model 49 0.105 13.69 <.0001
Clones 9 0.423 55.28 <.0001
Weeks 4 0.025 3.24 0.0152
Weeks x Clones 36 0.034 4.46 <.0001


Error


0.008


R-Square 0.87


Clone
Bluecrisp
FL 97-136
FL 98-325
FL 00-59
FL 00-180
FL 00-270
Emerald
Millennia
Star
Windsor
P>F


0.24 bcdx
0.14 d
0.15 d
0.23 cd
0.30 abcd
0.29 abcd
0.44 ab
0.42 abc
0.46 a
0.43 abc
<.0001


0.003 dw
0.015 cd
-0.003 e
0.021 c
0.013 bcde
0.027 b
-0.007 cd
0.03 bcde
0.006 e
0.027 a


Prob m = 0
0.6885
0.0777
0.4974
0.0701
0.6631
0.0008
0.5744
0.5852
0.7353
0.2646









In the C.A., the clones over time tended to decrease (Table 3.35). Examining the

clones at week 0 showed no difference between the "crisp" clones and the "non-crisp"

clones, except FL 00-59 was firmer than all other clones (Table 3.35). By week 8,

however, the five firmest clones were all "crisp", and of the "crisp" clones, only FL 00-

270 was quite soft. Week x clone interaction was significant with respect to firmness in a

C.A. (Table 3.36).

Very few berries developed decay in the C.A. (Table 3.37). The ANOVA showed

significant differences in weeks and clones but no week x clone interaction (Table 3.38).

Under controlled atmosphere storage, the number of leaking berries did not

increase significantly over time except in 'Emerald', 'Millennia' and 'Windsor' (Table

3.39). Clone, week and week x clone interaction were all significant, but no difference

could be seen between the "crisp" and "non-crisp" clones at week 8 or in the slopes

(Tables 3.39 and 3.40). The lack of decay and leaking berries after the C.A. storage

indicates that the high C02 and low 02 concentrations retarded berry degradation and

mold growth (Tables 3.37, 3.38, 3.39 & 3.40).

The number of shriveled berries increased for each clone over time (Table 3.41).

The clone effect and the week x clone interaction was significant, but the "crisp" clones

did not stand out as being better when compared to the "non-crisp" at week 8 or in the

rate of shriveling as indicated by the slopes (Tables 3.41 and 3.42). The severity of

shrivel for each clone (Table 3.44) followed the same trend as the number of shriveled

berries (Table 3.43).









Table 3.35. Mean deformation force at 2mm depth for 10 blueberry clones stored in C.A.
for 8 weeks at 20C in 2004.
2mm Deformation Force (N)
Clone Week 0 Week 2 Week 4 Week 6 Week 8 my Prob m = 0
Bluecrisp 2.50 bcdx 3.15 a 3.15 a 3.22 a 2.99 a 0.05 ab" 0.1585
FL 97-136 2.26 cdef 2.07 bcd 2.07 b 1.75 bc 2.12 bc -0.03 bc 0.4125
FL 98-325 2.88 b 3.11 a 2.73 a 1.93 b 2.22 bc -0.12 cdef 0.0015
FL 00-59 3.42 a 3.16 a n/a 3.16 a 2.70 ab -0.07 cde 0.0124
FL 00-180 2.35 cde 2.31 b M* 1.69 bcd 2.33 abc -0.03 a 0.2765
FL 00-270 1.89 f 1.79 cd M 1.23 de 1.20 de -0.10 cde 0.0001
Emerald 2.01 ef 1.67 d 1.24 c 0.96 e 0.99 e -0.14 cde 0.0001
Millennia 2.09 def 2.30 b M 1.35 cde 1.08 de -0.15 ef 0.0002
Star 2.54 bc 2.45 b M 1.39 cde 0.90 e -0.22 f 0.0001
Windsor 2.19 def 2.22 bc 2.00 b 1.95 b 1.74 cd -0.06 d 0.0021
P > F <.0001 <.0001 <.0001 <.0001 0.0001
ZMean of 30 berries individually sampled, 10 from each of three clamshells.
Ym is the estimated change in force(N) per week based on linear regression analysis.
xWeeks followed by the same letter are not significantly different (P<0.05) by ANOVA and Tukey's
test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample t-tests.
data missing

Table 3.36. ANOVA for deformation force at 2mm for 10 blueberry clones stored for 8
weeks in 2004.
Source DF Mean Square F value Pr > F
Model 44 1.40 22.72 <.0001
Clones 9 4.69 76.41 <.0001
Weeks 4 2.47 40.14 <.0001
Weeks x Clones 31 0.30 4.81 <.0001
Error 90 0.06


R-Square 0.92









Table 3.37. Incidence of decay (%) for 10 blueberry clones stored for 8 weeks in C.A.
storage at 20C in 2004.
Clone Week 0 Week 2 Week 4 Week 6 Week 8 Mz Prob m = 0
Bluecrisp 0.00y 0.00 bx 0.00 a 3.33 a 0.00 a 0.17 b" 0.5000
FL 97-136 0.00 0.00 b 6.67 a 6.67 a 0.00 a 0.33 ab 0.4455
FL 98-325 0.00 6.67 a 10.00 a 10.00 a 0.00 a 0.17b 0.8162
FL 00-59 0.00 0.00 b 0.00 a 0.00 a 0.00 a 0.0 b
FL 00-180 0.00 0.00 b 3.33 a 0.00 a 0.00 a 0.0 b 1.0000
Fl 00-270 0.00 0.00 b 0.00 a 0.00 a 0.00 a 0.0 b
Emerald 0.00 0.00 b 0.00 a 3.33 a 0.03 a 0.50 a 0.1230
Millennia 0.00 0.00 b 3.33 a 0.00 a 0.00 a 0.17b 0.5000
Star 0.00 0.00 b 0.00 a 0.00 a 0.00 a 0.0 b
Windsor 0.00 0.00 b 6.67 a 0.00 a 0.00 a 0.0 b 1.0000
P>F 0.0047 0.1444 0.1165 0.4711
Zm is the estimated change in the fraction of molding berries per week based on linear
regression analysis.
YMean of 30 berries individually sampled, 10 from each of three clamshells.
xWeeks followed by the same letter are not significantly different (P<0.05) by ANOVA and
Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample
t-tests.

Table 3.38. ANOVA for incidence of decay (%) for 10 blueberry clones stored for 8
weeks in C.A. storage in 2004.
Source DF Mean Square F value Pr > F
Model 49 61.30 2.21 0.0004
Clones 9 106.68 3.84 0.0003
Weeks 4 152.27 5.48 0.0005
Weeks x Clones 36 39.84 1.43 0.0834
Error 100 27.79


R-Square 0.52









Table 3.39. Incidence of leaking (%) for 10 blueberry clones stored for 8 weeks in C.A.
storage at 20C in 2004.


Clone
Bluecrisp
FL 97-136
FL 98-325
FL 00-59
FL 00-180
FL 00-270
Emerald
Millennia
Star
Windsor
P>F


Week 0 Week 2 Week 4
0.00y 3.33 ax 6.67 a
0.00 13.33 a 13.33 a
0.00 16.67 a 13.33 a
0.00 0.00 a 0.00 a
0.00 0.00 a 10.00 a
0.00 16.67 a 16.67 a
0.00 6.67 a 6.67 a
0.00 3.33 a 10.00 a
0.00 10.00 a 10.00 a
0.00 3.33 a 6.67 a
0.0611 0.5941


Week 6
6.67 ab
23.33 ab
20.00 ab
3.33 ab
6.67 ab
10.00 ab
23.33 ab
36.67 a
3.33 ab
0.00 b
0.0105


Week 8
6.67 a
16.67 a
3.33 a
0.00 a
10.00 a
0.00 a
13.33 a
16.67 a
20.00 a
20.00 a
0.233


mZ
0.83 c"
2.17 bc
0.50 ce
0.17 de
1.33 bcd
-0.33 e
2.17b
3.33 a
1.67 bcd
1.83 bc


Prob m
0.2323
0.1023
0.6265
0.5000
0.1130
0.7442
0.0111
0.0108
0.1280
0.0207


Zm is the estimated change in the fraction of leaking berries per week based on linear
regression analysis.
YMean of 30 berries individually sampled, 10 from each of three clamshells.
xWeeks followed by the same letter are not significantly different (P<0.05) by ANOVA and
Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample
t-tests

Table 3.40. ANOVA for incidence of leaking (%) for 10 blueberry clones stored for 8
weeks in 2004.
Source DF Mean Square F value Pr > F
Model 49 302.82 2.91 <.0001
Clones 9 365.21 3.51 0.0008
Weeks 4 1269.06 12.21 <.0001
Weeks x Clones 36 179.87 1.73 0.0175


Error


103.93


R-Square 0.59









Table 3.41. Incidence of shriveling (%) for 10 blueberry clones stored for 6 weeks in air
storage at 20C in 2004.


Week 0 Week 2


0.00y
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00


3.33 bcx
23.33 ab
6.67 abc
0.00 c
0.00 c
26.67 a
13.33 abc
3.33 bc
10.00 abc
6.67 abc
0.0007


Week 4 Week 6 Week 8


13.33 ab
33.33 a
16.67 ab
0.00 b
13.33 ab
33.33 ab
20.00 ab
10.00 ab
10.00 ab
13.33 ab
0.0239


10.00 c
70.00 a
26.67 abc
6.67 c
13.33 bc
53.33 ab
36.67 abc
36.67 abc
16.67 bc
30.00 abc
0.0002


20.00 cd
63.33 a
30.00 bcd
13.33 d
20.00 cd
43.33 abc
50.000 ab
20.00 cd
33.33 abcd
50.00 ab
<0.0001


mz Prob m = 0


2.33 fg"
8.67 a
3.50 eg
1.67 g
2.67 d
5.67 bcde
6.17 bc
3.67 cdef
3.67 def
6.17b


0.0135
0.0001
0.0040
0.0008
0.0002
0.0006
0.0001
0.0059
0.0001
0.0001


Zm is the estimated change in the fraction of shriveled per week based on linear regression analysis.
YMean of 30 berries individually sampled, 10 from each of 3 clamshells.
xWeeks followed by the same letter are not significantly different (P<0.05) by ANOVA and Tukey's
test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample
t-tests.

Table 3.42. ANOVA for incidence of shriveling (%) of 10 blueberry clones stored at 20C
for 8 weeks in 2004.
Source DF Mean Square F value Pr > F
Model 49 784.49 12.77 <.0001
Clones 9 1089.61 17.73 <.0001
Weeks 4 5929.63 96.49 <.0001
Weeks x Clones 36 136.53 2.22 0.0010


Error


61.46


R-Square 0.86


Clone
Bluecrisp
FL 97-136
FL 98-325
FL 00-59
FL 00-180
FL 00-270
Emerald
Millennia
Star
Windsor
P>F









Table 3.43. Incidence of shrivel severity of 10 blueberry clones stored for 8 weeks in
C.A. storage at 20C in 2004.
Index values
Clone Week 0 Week 2 Week 4 Week 6 Week 8 mY Prob m = 0
Bluecrisp 1.00" 1.07 aw 1.13 a 1.33 b 1.40 ab 0.05 ev 0.0326
FL 97-136 1.00 1.63 a 1.87 a 3.37 a 2.13 a 0.20 a 0.0096
FL 98-325 1.00 1.70 a 1.83 a 1.93 ab 1.47 ab 0.06 cdf 0.2302
FL 00-59 1.00 1.00 a 1.00 a 1.10b 1.13b 0.02 g 0.0024
FL 00-180 1.00 1.00 a 1.43 a 1.30 b 1.53 ab 0.07 cef 0.0220
FL 00-270 1.00 1.73 a 1.77 a 2.33 ab 1.77 ab 0.11 bef 0.0499
Emerald 1.00 1.27 a 1.50 a 1.10 b 1.90 ab 0.11 bd 0.0001
Millennia 1.00 1.07 a 1.20 a 2.10 ab 1.63 ab 0.12 bc 0.0005
Star 1.00 1.20 a 1.20 a 1.23 b 1.53 ab 0.06 e 0.0041
Windsor 1.00 1.27 a 1.40 a 1.50 b 2.27 a 0.14 b 0.0001
P>F 0.0069 0.0316 0.0009 0.0060
zEach berry was related on a scale from 1 (no shriveling) to 9 (extreme shriveling).
Ym is the estimated change in the shrivel index value per week based on linear regression
analysis.
XMean of 30 berries individually sampled, 10 from each of 3 clamshells.
"Weeks followed by the same letter are not significantly different (P<0.05) by ANOVA and
Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample
t-tests.

Table 3.44. ANOVA for incidence of shrivel severity of 10 blueberry clones stored for 8
weeks at 20C in 2004.
Source DF Mean Square F value Pr > F
Model 49 0.66 6.25 <.0001
Clones 9 1.19 11.23 <.0001
Weeks 4 2.93 27.67 <.0001
Weeks x Clones 36 0.28 2.63 <.0001
Error 100 0.11

R-Square 0.75

No differences in the pH, SSC and TTA concentration were found that consistently

separated the "crisp" from the "non-crisp" clones. The pH did separate the three "crisp"

clones 'Bluecrisp', FL 97-136 and FL 98-325 from the other seven clones at week 0

(Table 3.45). By the end of the 6 weeks in C.A. storage, the differences between these









three clones and the others were no longer significant (Table 3.45). Changes in pH with

time in storage were inconsistent from one clone to another (Table 3.45).

There were differences in the SSC of the various clones (Table 3.47), but these did

not consistently separate the "crisp" clones from the "non-crisp" clones. Although SSC

did not change greatly during the storage period, there was a highly significant week

effect (Table 3.47) and the tendency was for SSC to decline slowly over time.

Acid concentrations did not separate the "crisp" from the "non-crisp" clones at

week 0, but in Table 3.49 (C.A.) as in Table 3.33 (air storage experiment) the "crisp"

clones 'Bluecrisp', FL 97-136, FL 98-325 and FL 00-59 and were much lower in TTA

then 'Emerald', 'Millennia', 'Star' and 'Windsor'. The 'weeks' effect was highly

significant (Table 3.50), and most clones tended to increase in TTA over time, but this

was not consistent among clones.

Table 3.45. Meanz pH of 10 blueberry clones in a controlled atmosphere over 8 weeks in
2004.
Clone Week 0 Week 2 Week 4 Week 6 Week 8 mY Prob m = 0
Bluecrisp 4.10 abx 3.91 b 3.78 bcd 3.82 bc 3.95 bc -0.016 d" 0.3126
FL 97-136 4.41 a 4.35 a 3.93 b 4.10 b 4.22 b -0.033 ef 0.4213
FL 98-325 4.16 ab 4.36 a 4.47 a 4.57 a 4.61 a 0.053 a 0.0062
FL 00-59 3.95 bc 3.69 bc 3.65 bcde 3.67 c 3.62 de -0.036 f 0.0088
FL 00-180 3.55 cd 3.35 de 3.44 e M* 3.42 e -0.010 cde 0.3669
FL 00-270 3.65 cd 3.49 cde 3.42 e M 3.52 de -0.012 de 0.1983
Emerald 3.61 cd 3.68 bc 3.83 bc 3.68 c 3.79 cd 0.024 b 0.0467
Millennia 3.65 cd 3.24 e 3.57 de 3.64 c 3.59 de 0.008 bc 0.7053
Star 3.46 d 3.50 cde 3.45 de M 3.34 e -0.018 de 0.0271
Windsor 3.49 d 3.54 cd 3.33 e 3.27 d 3.40 e -0.015 ef 0.2195
P>F <.0001 <.0001 <.0001 <.0001 <.0001
zMean of three clamshells individually sampled.
Ym is the estimated change in titratable acid per week based on linear regression analysis.
xWeeks followed by the same letter are not significantly different (P<0.05) by ANOVA and
Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample
t-tests.
Missing data









Table 3.46. ANOVA for mean pH of 10 blueberry clones in a controlled atmosphere over
8 weeks in 2004.
Source DF Mean Square F value Pr > F
Model 46 0.390 27.87 <.0001
Clones 9 1.757 125.54 <.0001
Weeks 4 0.060 4.32 0.0030
Weeks x Clones 33 0.054 3.83 <.0001


Error


0.014


R-Square 0.93


Table 3.47. Meanz SSC of 10 blueberry clones in a controlled atmosphere over 8 weeks
in 2004.


Week 0 Week 2 Week 4


12.70 abx
14.50 a
10.13 bc
12.20 abc
8.27 c
9.87 bc
11.30 abc
11.87 abc
10.33 bc
10.27 bc
0.0015


13.63 ab
13.83 a
10.47 cd
11.87 abc
8.40 d
9.93 cd
10.20 cd
12.07 abc
10.73 cd
11.23 bc
<.0001


12.37 a
12.20 ab
11.00 abc
12.60 a
7.77 d
9.20 cd
9.50 cd
11.17 abc
10.93 abc
9.33 cd
<.0001


Week 6 Week 8


11.80 at
12.97 a
10.47 at
12.43 at
M*
M
10.03 b<
12.10 at
M
8.80 c
0.0008


12.73 a
12.40 ab
10.43 abcd
12.23 ab
8.10d
8.97 cd
8.73 cd
10.07 bcd
9.63 cd
10.93 abc
<.0001


mY Prob m = 0


-0.040 bcw
-0.274 d
-0.100 ab
0.024 a
-0.034 bc
-0.128 c
-0.309 d
-0.250 cd
-0.099 abc
0.031 bc


0.7219
0.0215
0.4132
0.7538
0.7010
0.1667
0.0072
0.0343
0.5232
0.7512


ZMean of three clamshells individually sampled.
Ym is the estimated change in SSC per week based on linear regression analysis.
xWeeks followed by the same letter are not significantly different (P<0.05) by ANOVA and Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample t-tests.
* Missing data

Table 3.48. ANOVA for mean SSC of 10 blueberry clones in a controlled atmosphere
over 8 weeks in 2004.
Source DF Mean Square F value Pr > F
Model 46 7.76 7.55 <.0001
Clones 9 33.19 32.30 <.0001
Weeks 4 3.88 3.78 0.0068
Weeks x Clones 33 1.26 1.22 0.2251


Error


1.03


R-Square 0.79


Clone
Bluecrisp
FL 97-136
FL 98-325
FL 00-59
FL 00-180
FL 00-270
Emerald
Millennia
Star
Windsor
P>F









Table 3.49. Meanz TTA of 10 blueberry clones in a controlled atmosphere over 8 weeks
in 2004.


Clone
Bluecrisp
Fl 97-136
Fl 98-325
Fl 00-59
FL 00-180
FL 00-270
Emerald
Millennia
Star
Windsor
P>F


week 0
0.24 bcdx
0.14 d
0.15 d
0.23 cd
0.30 abcd
0.29 abcd
0.44 ab
0.42 abc
0.46 a
0.43 abc
<.0001


week 2 week 4 week 6 week 8


0.26 cd 0.34 bc
0.15 d 0.31 bc
0.13 d 0.12 c
0.32 bc 0.31 bc
0.45 b 0.40 ab
0.44 b 0.45 ab
0.37 bc 0.36 bc
0.88 a 0.55 ab
0.44 b 0.52 ab
0.39 bc 0.65 a
<.0001 <.0001


0.30 cd
0.24 de
0.12 e
0.34 cd
M*
M
0.46 bc
0.51 ab
M
0.63 a
<.0001


0.28 ef
0.19 f
0.12 f
0.44 cde
0.51 bcd
0.41 cde
0.38 de
0.55 bc
0.77 a
0.61 ab
<.0001


mY Prob m = 0


0.004 dw
0.008 cdfg
0.004 e
0.025 b
0.022 bc
0.011 cdg
-0.005 ef
0.001 eg
0.042 a
0.021 b


0.4769
0.2948
0.0586
0.0001
0.0364
0.2002
0.4194
0.9773
0.0024
0.0873


zMean of three clamshells individually sampled.
Ym is the estimated change in TTA per week based on linear regression analysis.
xWeeks followed by the same letter are not significantly different (P<0.05) by ANOVA and
Tukey's test.
"Slopes followed by the same letter are not significantly different (P<0.05) by two-sample
t-tests
*Missing data

Table 3.50. ANOVA for mean TTA of 10 blueberry clones in a controlled atmosphere
over 8 weeks in 2004.
Source DF Mean Square F value Pr > F
Model 46 0.087 17.93 <.0001
Clones 9 0.329 67.90 <.0001
Weeks 4 0.058 12.04 <.0001
Weeks x Clones 33 0.025 5.06 <.0001


Error


0.005


R-Square 0.90

Discussion

Postharvest storage of blueberries has been studied extensively over the past

several decades (3, 5, 7, 30, 31, 35, 38, 46). From these studies it has been determined

that low temperatures and CA storage can delay senescence in blueberries by several

weeks. Our 2004 CA storage study confirms these results with the lack of decay (Table

3.37) and reduced severity of shrivel (Table 3.43) on blueberries during the 8 weeks they









were stored. The 2004 air storage experiment (Table 2.31) confirms past research (4, 25,

29, 30, 32, 37) showing that blueberries kept at 1 to 50C in an air atmosphere can store

for 2 weeks without decay.

Air storage tests were done in 2003 and 2004. With respect to decay rates, the

2003 air experiment more closely resembles previous studies (5, 7, 23, 31) than the 2004

study. The constant air flow through the buckets in 2004 may be the reason for the lack

of decay. Weight loss increased over time in the 2003 air storage test. The same was

found by Miller and Mcdonald (30), and Smittle and Miller in 1988 (46). Firmness

decreased over time in the 2003 air storage test and in the 2004 CA storage, as had been

previously seen by Ferraz (15).

Comparing the air and CA storage tests done in 2004 shows that the blueberries

stored in air decayed faster (Tables 3.21 and 3.37) and shriveled more than berries stored

in CA. These results agree with Ceponis and Cappellini's study done in 1985 (7) and the

Smittle and Miller study done in 1988(46). Comparing the different parameters in each

storage treatment to each other did not reveal any connection between them. Clone FL

00-59 was the only blueberry that did not show any signs of decay (Tables 3.21 and 3.37)

in the air and CA storage test. The clone also had the lowest levels of leaking and

shriveling in both the air and CA storage tests. Reasons for its exceptional storage life

are yet unknown.

A few studies (30, 31) have shown that differences in the storage life of blueberry

clones can best be seen if the berries are kept at room temperature for a few days before

examination. Tests should be conducted to determine if the "crisp" clones could be

distinguished more easily from the "non-crisp" clones if this procedure was followed.






67


The properties that cause the crisp texture in blueberries is yet unknown. When the

skin of one of the "crisp" clones is pealed away, the pulp has a consistency very similar

to that of "non-crisp" clones. Examination of the "crisp" and "non-crisp" blueberries at

the cellular level could help uncover the properties responsible for the crisp texture in

blueberry.














CHAPTER 4
CONCLUSIONS

One of the major goals of these experiments was to find some objective test that

could distinguish the six clones that had been subjectively identified as being "crisp"

from other blueberry cultivars that had been identified as not "crisp". The consumer

sensory panel study in 2004 confirmed that most untrained subjects could recognize

"crispness" in blueberries, although they did not necessarily prefer it. This indicates that

there is some objective reality to the "crisp" phenotype.

Shear-cell testing appeared to be the most promising objective test for the "crisp"

phenotype clones. These tests had good repeatability over two sample dates and gave

good separation between the "crisp" clones 'Bluecrisp', FL 00-59 and FL 00-180 and

other clones in the test. However, putatively crisp clones FL 98-325 and FL 00-270 were

not separated from conventional cultivars by shear-cell testing.

Another goal of the experiments was to see if "crisp" clones, when compared with

"non-crisp" clones, showed a unique softening pattern as they went from white to blue on

the plant. Firmness decreased from white to pink stages among all clones, with a similar

pattern for all the clones. This decrease in firmness matches that of previous studies done

on blueberry ripening. In this study it was hypothesized that "crisp" berries would soften

less as they ripened when compared with "non-crisp" clones, but this was not the case.

The next objective of this study was to see if the "crisp" texture could be

distinguished by firmness testing. The resistance to deformation of 99 clones was tested

along with four of the six "crisp" clones. The only clone that was statistically different









from the other clones by this measure was the "crisp" clone FL 98-325. From this it can

be seen that the crisp characteristic is not closely associated with the resistance to

deformation of the blueberry.

The final objective of this study was to determine if the "crisp" characteristics

contributed to longer postharvest life. In 2003, the "crisp" clones did not store longer in

air than the "non-crisp" clones. In 2004, the "crisp" clone FL 00-59 had a longer

postharvest life than any of the other clones in air storage. Also, the same "crisp" clones

that distinguished themselves in the shear-cell tests, 'Bluecrisp', FL 00-59 and FL 00-

180, also showed great resistance to shriveling in air storage. A correlation between high

shear-cell values and low shriveling during storage is possible. Comparing the air storage

and C.A. storage tests of 2004 showed that if the "crisp" characteristic contributes to a

longer postharvest life, it is only in an air atmosphere. When the "crisp" blueberries were

placed into C.A. storage, their advantage over regular clones was lost.
















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BIOGRAPHICAL SKETCH

Les Padley Jr. was born in Largo, Florida, on January 9, 1980, to Les and Pam

Padley. He graduated high school from the Center for Advanced Technologies in 1998,

and received his Bachelor of Science degree from Florida Southern College in

environmental horticultural and business. Moving to Gainesville in 2002, he began

studies for his Master of Science degree in plant breeding at the University of Florida.

On November 20, 2004, Les Padley Jr. was married to Michelle Cook in

Gainesville, Florida. He plans on continuing his education with a PhD in the field of

Horticulture studying plant breeding in cucurbits.




Full Text

PAGE 1

FIRMNESS AND STORAGE CHARACTERISTICS OF CRISP-TEXTURED BLUEBERRIES By LES PADLEY JR. A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLOR IDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2005

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Copyright 2005 by Les Padley Jr.

PAGE 3

This document is dedicated to my wife and both of my families who have been there for me since the beginning, encouraging me and helping me along the way.

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iv ACKNOWLEDGMENTS I would like to thank Straughn farms Inc. fo r providing the blueberry plots used in these studies. I would also like to thank Dr Paul Lyrene, Dr. Steven Sargent and Dr. Jeffrey Brecht for giving me the opportunity to obtain this degree. Finally, I would like to thank Kim Cordasco for helping me with my research along the way.

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v TABLE OF CONTENTS page ACKNOWLEDGMENTS.................................................................................................iv LIST OF TABLES............................................................................................................vii LIST OF FIGURES..........................................................................................................xii ABSTRACT.....................................................................................................................xi ii CHAPTER 1 INTRODUCTION........................................................................................................1 History of Blueberries in Florida..................................................................................1 Blueberry Breeding.......................................................................................................2 Growth and Fruit Development of Blueberries............................................................5 Harvest and Postharvest of Blueberries........................................................................7 Crisp-Textured Blueberries........................................................................................11 2 QUALITY DETERMINATIONS OF FRESH BLUEBERRY CLONES.................12 Relative Berry Firmness of 99 Clones........................................................................12 Materials and Methods........................................................................................12 Results.................................................................................................................14 Discussion............................................................................................................14 Firmness Changes During Fruit Development...........................................................17 2003 Materials and Methods...............................................................................17 2003 Results........................................................................................................18 2004 Materials and Methods...............................................................................18 2004 Results........................................................................................................19 Discussion............................................................................................................20 Shear-Cell Testing......................................................................................................21 Materials and Methods........................................................................................22 Results.................................................................................................................22 Discussion............................................................................................................25 Consumer Sensory Panel Study..................................................................................26 2003 Materials and Methods...............................................................................26 2003 Results........................................................................................................27 2004 Materials and Methods...............................................................................29

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vi 2004 Results........................................................................................................29 Discussion............................................................................................................32 3 POSTHARVEST STORAGE TEST..........................................................................34 2003 Study..................................................................................................................34 Materials and Methods........................................................................................34 Results.................................................................................................................36 2004 Study..................................................................................................................45 Materials and Methods........................................................................................45 Results.................................................................................................................47 Discussion...................................................................................................................65 4 CONCLUSIONS........................................................................................................68 LIST OF REFERENCES...................................................................................................70 BIOGRAPHICAL SKETCH.............................................................................................74

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vii LIST OF TABLES Table page 2.1 Meanz force (N) required to deform berri es by 2mm for 99 blueberry clones ranked from lowest to highest sampled in 2003.......................................................15 2.2 Meanz deformation force (2mm deformation) of fruit for eight blueberry clones sampled at 9 stages of maturity in 2003...................................................................19 2.3 Meanz deformation force of fruit for nine blueberry clones sampled at three stages of maturity in 2004........................................................................................20 2.4 ANOVA for mean deformation force of fr uit for 9 blueberry clones sampled at three stages of maturity in 2004...............................................................................20 2.5 Shear-cell meansz for 10 clones sampled at two different times during the 2004 growing season.........................................................................................................24 2.6 Questions asked for the 2003 taste panel study........................................................27 2.7 Overall appearance of panelists of four blueberry clone s on a scale from 1 (dislike extremely) to 9 (lik e extremely) (n=90; 2003 study)..................................28 2.8 Overall texture/firmness of panelists of four blueberry clones on a scale from 1 (dislike extremely) to 9 (lik e extremely) (n=90; 2003 study)..................................28 2.9 Overall sweetness of panelists of four blueberry clones on a scale from 1 (dislike extremely) to 9 (like extremely) (n=90; 2003 study)...............................................28 2.10 Overall flavor of panelists of four bl ueberry clones on a scale from 1 (dislike extremely) to 9 (like extremely) (n=90; 2003 study)...............................................28 2.11 Overall acceptability of pa nelists of four blueberry clones on a scale from 1 (dislike extremely) to 9 (lik e extremely) (n=90; 2003 study)..................................29 2.12 Questions asked for the 2004 taste panel study........................................................29 2.13 Previous blueberry eating e xperience of the 95 panelists whom were part of the evaluation panel in 2004..........................................................................................30 2.14 Firmness ranking of 4 blueberry clones by 95 panelists from 1 (softest sample) to 4 (crunchiest sample)...........................................................................................31

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viii 2.15 Desirability of the berry firmness of 4 blueberry clones evaluated on a scale from 1 (dislike extremely) to 9 (like extremely) by 95 panelists.............................31 2.16 Overall desirability of the berry qual ity of 4 blueberry clones evaluated by 95 panelists....................................................................................................................31 2.17 Desirability of berry firmness and overall desirability of be rries of 4 blueberry clones as judged by panelists with diffe ring blueberry consumption histories........32 3.1 Mean deformation forcez at 2mm depth for 8 blueberry clones stored in air for 8 weeks at 2C in 2003................................................................................................37 3.2 ANOVA for mean deformation force need ed at 2mm for 8 blueberry clones stored for 8 weeks in 2003.......................................................................................37 3.3 Incidence of decay (%) for eight bluebe rry clones stored for 8 weeks at 2C in 2003..........................................................................................................................3 8 3.4 ANOVA for incidence of decay (%) of eight blueberry clones stored for 8 weeks in 2003......................................................................................................................38 3.5 Incidence of leaking (%) for eight bluebe rry clones stored for 8 weeks at 2C in 2003..........................................................................................................................3 9 3.6 ANOVA for incidence of leaking (%) for eight blueberry clones stored for 8 weeks in 2003...........................................................................................................40 3.7 Incidence of weight loss (%) of eight bl ueberry clones stored for 8 weeks at 2C in 2003. Values for each week are the cumulative weight loss from week 0 to the week stated.........................................................................................................40 3.8 ANOVA for incidence of weight loss (%) of eight blueberry clones stored for 8 weeks in 2003...........................................................................................................40 3.9 Incidence of shriveling ( %) for eight blueberry clones stored for 8 weeks at 2C in 2003......................................................................................................................41 3.10 ANOVA for incidence of shriveling (%) of eight blueberry clones stored for 8 weeks in 2003...........................................................................................................41 3.11 Incidence of shrivel severityz of eight blueberry clones stored for 8 weeks at 2C in 2003......................................................................................................................42 3.12 ANOVA for Incidence of shrivel severity of eight blueberry clones stored for 8 weeks in 2003...........................................................................................................42 3.13 Meanz pH of eight blueberry clones stored at 2C over 8 weeks in 2003................43

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ix 3.14 ANOVA for mean pH of ei ght blueberry clones stored at 2C over 8 weeks in 2003..........................................................................................................................4 4 3.15 Meanz SSC of eight blueberry clones stored at 2C over 8 weeks in 2003.............44 3.16 ANOVA for mean SSC of eight blueberry clones stored at 2C over 8 weeks in 2003..........................................................................................................................4 4 3.17 Meanz TTA of eight blueberry clones stored at 2C over 8 weeks in 2003.............45 3.18 ANOVA for mean TTA of eight blueberry clones stored at 2C over an 8 weeks in 2003......................................................................................................................45 3.19 Mean deformation forcez at 2mm depth for 10 blueberry clones stored in air for 8 weeks at 2C in 2004.............................................................................................49 3.20 ANOVA for mean force needed to defo rm the berries by 2mm for 10 blueberry clones stored for 6 weeks in 2004. (air atmosphere)................................................49 3.21 Incidence of decay (%) for 10 blueberry cl ones stored for 6 weeks in air storage at 2C in 2004...........................................................................................................50 3.22 ANOVA for incidence of decay (%) for 10 blueberry clones stored for 6 weeks in air storage in 2004................................................................................................50 3.23 Incidence of leaking (%) for 10 bluebe rry clones stored for 6 weeks in air storage at 2C in 2004..............................................................................................51 3.24 ANOVA for incidence of leaking (%) for 10 blueberry clones stored for 6 weeks in 2004......................................................................................................................51 3.25 Incidence of shriveling ( %) for 10 blueberry clones st ored for 6 weeks in air storage at 2C in 2004..............................................................................................52 3.26 ANOVA for incidence of shriveling (%) of 10 blueberry clones stored at 2C for 6 weeks in 2004........................................................................................................52 3.27 Incidence of shrivel severityz of 10 blueberry clones st ored for 6 weeks in air storage at 2C in 2004..............................................................................................53 3.28 ANOVA for incidence of shrivel severity of 10 blueberry clones stored for 6 weeks at 2C in 2004................................................................................................53 3.29 Meanz pH of 10 blueberry clones in an ai r atmosphere over 6 weeks in 2004........54 3.30 ANOVA for mean pH of 10 blueberry clone s in an air atmosphere over 6 weeks in 2004......................................................................................................................54 3.31 Meanz SSC 10 blueberry clones in an air atmosphere over 6 weeks in 2004..........55

PAGE 10

x 3.32 ANOVA for mean SSC of 10 blueberry cl ones in an air atmosphere over 6 weeks in 2004...........................................................................................................55 3.33 Meanz TTA of 10 blueberry clones in an air atmosphere over 6 weeks in 2004.....56 3.34 ANOVA for mean TTA of 10 blueberry cl ones in an air atmosphere over 6 weeks in 2004...........................................................................................................56 3.35 Mean deformation forcez at 2mm depth for 10 blueberry clones stored in C.A. for 8 weeks at 2C in 2004.......................................................................................58 3.36 ANOVA for deformation for ce at 2mm for 10 blueberry clones stored for 8 weeks in 2004...........................................................................................................58 3.37 Incidence of decay (%) for 10 blueberry clones stored for 8 weeks in C.A. storage at 2C in 2004..............................................................................................59 3.38 ANOVA for incidence of decay (%) for 10 blueberry clones stored for 8 weeks in C.A. storage in 2004.............................................................................................59 3.39 Incidence of leaking (%) for 10 bluebe rry clones stored for 8 weeks in C.A. storage at 2C in 2004..............................................................................................60 3.40 ANOVA for incidence of leaking (%) for 10 blueberry clones stored for 8 weeks in 2004......................................................................................................................60 3.41 Incidence of shriveling ( %) for 10 blueberry clones st ored for 6 weeks in air storage at 2C in 2004..............................................................................................61 3.42 ANOVA for incidence of shriveling (%) of 10 blueberry clones stored at 2C for 8 weeks in 2004........................................................................................................61 3.43 Incidence of shrivel severityz of 10 blueberry clones st ored for 8 weeks in C.A. storage at 2C in 2004..............................................................................................62 3.44 ANOVA for incidence of shrivel severity of 10 blueberry clones stored for 8 weeks at 2C in 2004................................................................................................62 3.45 Meanz pH of 10 blueberry clones in a c ontrolled atmosphere over 8 weeks in 2004..........................................................................................................................6 3 3.46 ANOVA for mean pH of 10 blueberry cl ones in a controlled atmosphere over 8 weeks in 2004...........................................................................................................64 3.47 Meanz SSC of 10 blueberry clones in a c ontrolled atmosphere over 8 weeks in 2004..........................................................................................................................6 4 3.48 ANOVA for mean SSC of 10 blueberry clon es in a controlled atmosphere over 8 weeks in 2004...........................................................................................................64

PAGE 11

xi 3.49 Meanz TTA of 10 blueberry clones in a c ontrolled atmosphere over 8 weeks in 2004..........................................................................................................................6 5 3.50 ANOVA for mean TTA of 10 blueberry cl ones in a controlled atmosphere over 8 weeks in 2004........................................................................................................65

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xii LIST OF FIGURES Figure page 1.1 Blueberries at white, pink and blue stages after the start of fina l swell (stage 3)......7 2.1 Instron machine with 8 mm probe............................................................................13 2.2 Histogram of mean firmness of 99 test bl ueberry clones. Class Interval 0.10 N. The value for each clone was the average of 10 berries individually tested............16 2.3 Instron 8600 with sh ear-cell attached.......................................................................23 2.4 Relationship between shear-cell forces of nine selected blueberry cultivars and clones harvested at the blue stage in th e first and second sampling dates of 2004..25

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xiii Abstract of Thesis Presen ted to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science FIRMNESS AND STORAGE CHARACTERISTICS OF CRISP-TEXTURED BLUEBERRIES By Les Padley Jr. December 2005 Chair: Paul Lyrene Major Department: Horticultural Science During the 1980s and 1990s several cultivar s with a firm texture were released from blueberry breeding programs, exemplif ied by Reveille from North Carolina and Bluecrisp from Florida. University of Florida blueberry breeders, along with local growers, considered Bluecrisp to have a unique crisp texture that had not been encountered up to that date. Since the discove ry of Bluecrisp, several new clones with crisp-texture were found in the te st plots of the University of Floridas breeding program. This research was designed to compare th e crisp clones, Bluecrisp, FL 97-136, FL 98-325, FL 00-59, FL 00-180 and FL 00-270, for crisp-texture and storage life to standard non-crisp clones Emerald, Millennia, Star, and Windsor. Firmness testing was first conducted on 99 bl ueberry clones, including the crisp clones Bluecrisp FL97-136, and FL 98-325, using an Instron 8600 with a 10N load cell. The firmness test, deformation to 2 mm, reveal ed that the crisp characteristic could not be determined using Instron firmness test ing. A test studying the firmness changes

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xiv during fruit development did not show differences between the crisp and non-crisp clones using Instron measurements of berries at the white, pink and blue stages of maturity. Berries of all vari eties became much softer duri ng the transition from white to blue. However, shear cell testing, simu lating chewing, conducted in 2004 on the two groups of clones showed that Bluecrisp , FL 97-136, FL 00-59 and FL 00-180 were distinctively different from all of the ot her clones in maximum force required for the blades to slice the berries. A consumer sensory panel study in 2004 showed that the crisp clones Bluecrisp and FL 00-59 could be distinguished as crisp in comparison with the non-crisp clones Star and Wi ndsor. The average consumer, though, did not have a preference for the crisp-textured blue berries when compared with the standard non-crisp blueberries. Postharvest storage tests in 2004 showed that, when held in air storage, the clones Bluecrisp, FL 00-59, and FL 00-180 had superior storage life compared with the other crisp and non-crisp clones. Th e shear cell test in 2004 also separated these three crisp clones from th e other clones tested. A correlation that separates crisp and non-crisp clones usi ng shear cell values and postharvest storage life might exist. When the same crisp and non-crisp clones were stored in a controlled atmosphere of 2% O2 plus 15% CO2, the distinction between Bluecrisp, FL00-59 and FL 00180 and the other clones was lost.

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1 CHAPTER 1 INTRODUCTION History of Blueberries in Florida The commercial blueberry industry is prof itable and fast growing. In 2002 North America produced 390 million pounds of bluebe rries with a total wholesale value of about $310 million. Cultivated blueberries repr esented $210 million of the total and wild blueberries $100 million. Of the 2002 nationa l total, Florida contributed $18.5 million from approximately 809 hectares of cultivat ed blueberries (10, 50). Florida has the potential to greatly increa se blueberry acreage and produc tion without flooding the market (2). Florida, with its early Ap ril to early May market window (20), has the capability of playing a major role in the expansion of this industry. Cultivated blueberries ( Vaccinium section Cyanococcus) are native to eastern North America and were first commercialized there. At first, production was mainly located in the northern United States and was base d on the northern highbush blueberry ( Vaccinium corymbosum) These highbush blueberry cultivars produced high yields and large fruit when planted on soils with high organic matte r and low pH in areas that provided high chilling hours (50). Florida began bluebe rry production in the early 1900s using the native Florida blueberry species V. ashei commonly called rabbiteye blueberry. The plants were transplanted from the wild in to cultivated fields. By 1930, over 2000 acres of commercial blueberries were in production in North Florida (30, 41). This production did not last long due to poor fruit quality a nd marketing problems (9, 50). Over the next several decades the blueberry indu stry in Florida went into se rious decline (30). Northern

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2 highbush blueberries were tried in Florida during this time, but the plants did not fare well. Lack of chill hours, low soil organic matter and subtropical diseases made it hard for the northern plants to survive so far south (25). In 1984, the blueberry market for the United States was expanding rapidly but there were no blueberries available until late May, when harvest began in eastern North Carolina (28, 42). Florida Agricultural Experi ment Station horticulturalist Ralph Sharpe believed that Florida could produce blueberries as early as late April (42). What was needed to create this industry was high yiel ding, large fruited, ear ly ripening blueberry varieties. To breed these va rieties, Sharpe propagated se veral Florida evergreen lowbush wild blueberry bushes ( V. darrowi) that he found growing around a lake near Winter Haven, Florida. These bushes produced unusually large berries with a powdery blue color. He crossed these plants with northern hi ghbush cultivars. This was the first step in breeding a type of low-chill, heat-toleran t highbush called southern highbush (25, 28). Southern highbush revitalized FloridaÂ’s bluebe rry industry by allowing Florida blueberry growers to harvest during the early market window of March 20 to May 20 (42). The new industry took decades to develop, but by 1985 there was 1058 acres of blueberries in Florida, and by 1989 the blueberry acreage in Florida had nearly doubled to 2106 acres (8, 9). In 2003, Florida ranked as the 7th largest state in cultivated blueberry acreage for the U.S. with around 1900 acres (48). Blueberry Breeding Blueberry breeding started in the United States around 1910, and at the University of Florida (U. F.) about 1950 (42). FloridaÂ’ s breeding program mainly concentrated on the development of low-chill, early ripening, tetraploid, southern highbush cultivars. These southern highbush cultivars were obt ained by hybridization of Florida native

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3 blueberries (mainly Vaccinium darrowi ) and highbush cultivars ( V. corymbosum ) from Michigan, New Jersey and North Carolina. The original crosses were followed by a program of recurrent selection. Ralph Sharpe and Wayne Sherman continue d this program of recurrent selection untill SharpeÂ’s retirement in 1976. The program was continued Sherman, who was joined by Paul Lyrene in 1977. Sherman retirement in 2003, and the program is now under the direction of Lyrene. As currently practiced in the U. F. blue berry breeding program, by Dr. Paul Lyrene, each cycle of selection is begun by cro ssing 200 plants to obtain 12,000 seedlings. Pollination is done by emasculating the flowers before anthesis, and pollen is transferred by thumbnail as described by Edwards, Sherma n and Sharpe (13). The seedlings from these crosses are grown and eval uated for numerous characterist ics that are important in a cultivar. Desired characteristics included a vigorous, upright plant, high yield potential, resistance to various insects and diseases, adaptation to Florida soils and climates, and large, sweet, firm berries that are easy to harvest and have a long shelf life (17). From the original 12,000 plants, 200 are selected and us ed as parents to begin the next cycle of selection. As this process continues, each generation of selection brings better seedling populations. The seedlings are also the sour ce of new varieties, which are propagated asexually. In evaluating genotypes for the U. F. breed ing program, seedlings are first fruited in a high density nursery (Stage 1). The plants are examined for fruit size, color, picking scar size, firmness, flavor, time of ripening and freedom from majo r visible defects of bush or berry (27). From the 12,000 seedli ngs, 500 are selected and the rest are

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4 discarded. The selected plants are grown for 2 more years (Stage 2 test). During the first of the 2 years, the bushes and berries are eval uated for the same characteristics that were evaluated in stage 1, and 100 to 150 plants ar e selected for propagation. In the second year the plants are reexamined to find plan ts showing the desirable qualities that did not appear in the first year, and an additional 20 to 50 plants are selected. For each plant selected in Stage 2, 40 softwood cuttings are taken. Based on the rooting ability of the cuttings and growth characteristics of the ramets, 120 to 150 clones per year are planted into a commercial field in plots of 20 plants pe r clone (Stage 3). Here they received the care and maintenance recommended for commer cial blueberries in Florida (27). The plants are left in the field for 2 to 10 year s, depending on the performance of each clone. Each year, the clones are examined for plan t vigor and survival, leafing and flowering characteristics, and berry yield and quality (27). Approximately 12 clones are selected from each stage 3 test, and ramets are propaga ted from each clone. The selected clones are planted in 100-plant plots in a commercial field. These pl ots are examined for 3 to 6 years, and the best one to two selections become cultivars (27). The characteristics that make a successf ul blueberry cultivar have been studied for decades by people such as Sharpe ( 13, 42), Sherman (13, 42), Ballinger (4, 5), Ballington (6), Lyrene (27, 28) and Finn (17). The heritability of ce rtain characteristics has also been studied. Edwards, Sherman a nd Sharpe (13) determined that there was a high heritability estimate for fruit size, a m oderate heritability for fruit color, a low heritability for fruit firmness and picking scar si ze and an even lower heritability for plant vigor. They also determined that additive gene action was high for fruit size, color, and firmness, and plant vigor, and plants should transmit these tr aits to their progeny. Finn,

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5 and Luby (17) confirmed this additive gene acti on in blueberries as it pertains to fruit color. They also concluded that highbus h x highbush segregati on patterns indicated predominately additive gene action. These studies, along with others, have helped blueberry breeders improve their breeding programs. Growth and Fruit Development of Blueberries Growing blueberries in Florida is a ch allenging business. Blueberries are a deciduous, perennial, long lived woody shrub wi th a fibrous root system that requires high organic matter and acidic so ils to thrive. Selecting the proper site is a key to growing commercial blueberries. A site must have well drained soil at least 40 cm deep, a pH between 3.5 and 5.5 and 2 to 3% organic matter. The area must also have enough cool weather during the winter to satisfy the chilling requir ement of the variety, but the frequency of late winter a nd early spring freezes should be low(49). Once a site is chosen, southern highbush blueberries are plan ted 1 m apart in rows 3 m apart. Two or more cultivars are inter-pla nted for cross-pollination. Blueberry plants require at least 100 cm of water yearly to be productive (49). Overhead irrigation is the most common and practical way of applying water to the plants in Florida. Overhead irrigati on is also used to protect fl ower buds from February, March and April freezes (28). Fertilizer (12-4-8-2) is applied frequently beginning about midApril and ending in August or September. Bushes are pruned during the summer after final harvest. Pruning of southern highbush plan ts is needed to keep the desirable size and shape of the plant, to increase plant vigor and to promote good fruit development in next yearÂ’s crop (49). Blueberries require several hundred hours of chilling (between 0C and 7C) in the winter to stimulate the sprou ting of floral and vegetative buds in the spring. The amount

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6 of chilling required varies from one cultivar to another. Chilling hours begin in the fall after the plants go dormant. Previous to th e chilling season, some axillary (vegetative) buds are inverted into flower buds. This tr ansformation is complete by January and the swollen flower buds can be distinguished fr om the vegetative buds on the bush. Plants must have a proper balance between vege tative and flower buds to produce maximum yields and quality (49) In north Florida, flower b uds open during February (Lyrene, personal communication). Blueberry flowers consist of a corolla tube (white or pink colored), a pistil and anthers. The corolla tube is the most visibl e part of the flower and is made up of five fused petals. The pistil extends to the end of the corolla tube, but th e anthers are situated in such a way that sonication by an insect, primarily bees, is needed to efficiently remove pollen from the flower. Sonication occurs wh en a bee places its he ad into the corolla tube and moves its wing muscles at high fre quencies causing the polle n to fall out of the flower. Pollen lands on the beeÂ’s head, and so me of it is taken to other flowers, where it may be left on the stigfmas. For optimum fruit set and berry size, it cross-pollination (pollen from one variety being placed on th e stigma of another) is desirable (49). After pollination, the flower takes 45 to 120 days to develop into a ripened blueberry (Lyrene, personal communication) Blueberry fruit development follows a double-sigmoid curve that consists of three stages (12). In stage I fruit size increases through cell division. Stage II is character ized by a rapid increase in embryo and endosperm growth with little or no increase in berry size. In St age III cells enlarge without cell division until matur ity (12). In the final days of development the blueberry undergoes a ripening process in which acid de creases while pH, sugar and berry weight

PAGE 21

7 increase (3). As berry color changes from gr een to white to pink to blue (Figure 1.1) the berries increase dramatically in size (final swell) (3, Lyrene, pers onal communication). It takes about 5 days for the berr ies to undergo this ripening pro cess for a climacteric fruit, physical maturity is reached at mature green stage (i.e., when it can ripen on or off the plant). to become fully ripened, physiologi cally mature blueberries (Lyrene, personal communication). Figure 1.1. Blueberries at white, pink and blue stages after th e start of fina l swell (stage 3). Harvest and Postharvest of Blueberries Florida blueberries are harvested, packed and shipped to many parts of the world from March 20 to May 20 (46). Worldwid e shipment of fresh berries requires good cultivars, and a first-rate packing and storage system. The process of producing blueberries that pack and store well begins in the field before th e berries are picked. Blueberries must be ripe, firm and have a small, dry picking scar to su rvive the trip to the

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8 market. A picking scar that is small and dry is especially important, because a wet picking scar, caused by the skin of the berry te aring as it is removed from the stem, is a primary locus of fungus infection (7, 19, 29, 46). In the field, the berries are picked into buckets and poured into field lugs, which are kept shaded. Great care must be taken during the harvesting and handling process to avoid dropping or bruising the berries, which would lead to decay. In the packi ng house, the berries are placed on a conveyer belt, and unripe, overripe or damaged berries are removed, along with leaves and twigs. Berries must be firm to avoid bruising or ju ice leakage during this process. The sorted berries are placed in plastic clamshells, 125 to 400 g per clamshell. These are typically packed in 12-unit cart ons for shipping. After packing, the berries are placed into a storage unit at 0 to 5C with relative humidity of 95% (5, 15, 23, 24, 35). Under these conditions, blueberries can be stored for 2 weeks without decay (5, 31, 36, 38, 46). Bluebe rries have been stored using modified atmosphere (MA) since 1919. Research on st orage conditions has primarily focused on the quality of the blueberries. Quality para meters have included weight loss, number of defective berries, firmness, color, and decay (23, 29). As expected, weight loss, number of defective berries and decay increase over time, whereas firmness decreases and color becomes darker. Further research has shown that many of the cha nges that occur on the outside of the blueberry are due to internal changes in the berry. As fruit develop and mature, total titratable acidity (TTA) decrea ses while weight, pH, soluble solids content (SSC), sugar, and SSC/TTA ratio increase (3, 20, 26). Blueberries with low pHs of 3.5 or less tend to have slower rate s of decay (3, 19, 38). These changes in acid, weight, pH, TTA, SSC, sugar and SSC/TTA occur naturall y as a blueberry matures, ripens and

PAGE 23

9 senesces. Controlled atmospheres (CA) are us ed in blueberry storage to reduce the rate of senescence in the berries. CA storage consists of altering the concentrations of CO2, O2 and N in the storage units containing the blueberries. Using CA for blueberries began in the ear ly 1980s when it was discovered that high CO2 and low O2 levels helped prevent th e decay of the fruit (7, 46). Much research has been done since then. Optimum levels for th ese gases have been found to be 2 to 5% O2, 15 to 20% CO2 and nitrogen as a filler gas to make the atmosphere 100% (7, 24, 46 ). At these levels, blueberries harves ted at the blue maturity st age can be stored for over a month at 1C with little decay or damage to th e outside of the berries. At least one study, though, has shown that high levels of CO2 in the CA may cause internal changes in blueberries that produce an ‘off flavor’ (7). The reasons for the development of this flavor are yet unknown. Of the variables that have been studied in the postharvest storage of blueberries, firmness has been found to be a key indicator of berry quality change during storage (25). Early methods of determining blueberry fi rmness included squeezing the berry between the fingers and judging the resistance, or j udging firmness by masticating the berry (4, 29, 45). These methods gave variable results from one person to another (45). In 1973, Ballinger and associates (4) modified an Inst ron Universal Testing machine (resistance to compression) to measure the firmness of bluebe rry fruit. The Inst ron Universal Testing machine had been previously used in determ ining the firmness of other fruit (4, 37). Instron tests determined that blueberry firmne ss can vary from one harvest to another and from one year to another. It was also dete rmined that the greatest decrease in firmness during berry development came as the berry went from the green to the pink stage (4).

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10 Since the initial tests in 1 973 many more studies have conf irmed that the Instron is a reliable indicator of blueberry firmness (14, 15, 16, 23, 32). Variations in berry firmness among harvests and among years as well as dramatic decreases in firmness from the green to pink stage of development were also confirmed through other studies (14, 33, 34, 46). Although many studies have used an Instron to determine firmness, a set of standard guidelines for measuring berry fi rmness have still not been developed, except concerning where the berries should be comp ressed. It has been determined that compressing the berry along its lateral axis gives smoother, more consistent force deformation curves than compressing the fr uit in the axial dire ction (4, 14, 15, 16). Studies have determined that blueberry firm ness decreases over time in storage and that this decrease can be slowed but not st opped by lower temperature (8, 14, 16, 38). A study done from 1998 to 2000 surveyed berry firmness in 87 highbush culivars and species-introgressed highbush bl ueberry cultivars (14). This study determined that 1.34 N/mm deflection force was average for thes e cultivars, and that values above 1.57 N/mm were considered superior. Crisp-texture has been studied in other be rries such as the grape (41). The crisptexture in grapes can be traced back to the native North American grapes that were added to the European grape gene pool The hybrid grapes, call V. labrusca can be distinguished as crisp-textured by means of puncture testing. In th e puncture testing the deformation at first breakdown (DFP) and the maximum peak of force (MF) separate the “crisp” from the soft cultivars. A grape that has a small DFP and a large MF is considered “crisp”, whereas berries with la rge DFP and small MF are considered soft

PAGE 25

11 (41). No known research has been done on the DFP or the MF of blueberries as it relates to “crisp” or soft texture. Crisp-Textured Blueberries During the 1980s and 1990s, several bluebe rry cultivars with very firm texture were released from breeding programs, exem plified by ‘Reveille’ from North Carolina and ‘Bluecrisp’ from Florida. ‘Bluecrisp’ wa s considered by U.F.’s blueberry breeder, as well as local growers, to have a unique crisp-texture. This texture can best be described as biting into an apple. In recent years, several other clones with crisp-textured berries have been found in test plots in Florida. What makes this characteristic even more unique is that there is no co mmon ancestry between any of th ese crisp-textured clones. To determine how these new clones compare in crisp-texture and storage life with various commercial cultivars, several experi ments were conducted. In this study, which describes these experiments, clones ‘Blu ecrisp’, FL 97-136, FL 98-325, FL 00-59, FL 00180 and FL 00-270 will be referred to as “cr isp” clones, and the commercial clones ‘Emerald’, ‘Millennia’, ‘Star’, and ‘Windsor’ will be referred to as “non-crisp” clones. These designations were based on the percep tion of the breeder at the start of these experiments, and as will be seen, were not always supported by the objective tests that were made in the course of these experiments.

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12 CHAPTER 2 QUALITY DETERMINATIONS OF FRESH BLUEBERRY CLONES Relative Berry Firmness of 99 Clones In the first set of experiments, various ch aracteristics of blueberry clones that had been selected for crisp-texture were compared with the same characteristics in standard commercial varieties. For this test, 99 blueberry clones were use d, of which three clones, ‘Bluecrisp’, FL 97-136, and FL 98-325, had previously been cl assified as crisp based on informal observations in the field. The purpose of this test was to determine if the berries from these clones were firmer then these of standard commercial cultivars. Materials and Methods On May 2, 2003, berries from 99 clones of southern highbush blueberries were harvested from a variety test planted in a commercial blueberry planting at Straughn Farms Inc. in Windsor, Florida (Alachua C ounty). The clones were advanced selections from the U. F. breeding program. During earl ier stages of selection, clones had been eliminated if the berries were small, dark, had wet picking scars, or were soft. The plants were growing in 15-plant clonal plots and were about two meters tall. Approximately 20 ripe berries were gathered from each clone and placed in paper bags. Two separate samples were taken for the firm cultivar ‘Bluecrisp’. The bags were placed in a cooler and transported to a 2 C storage unit. Fi rmness was measured the next day by removing the berries from 10 clones at a time from th e cooler and placing them on a grading table

PAGE 27

13 for 90 minutes to allow the berries to reach room temperature (about 22C). Once at room temperature, the berries were inspect ed for leaking, collapse, decay or other damage. Damaged berries were discarded, af ter which 10 berries were randomly selected from each clone for firmness testing. An In stron 8600 with a 10 N load cell was used to test firmness. Each berry was placed onto a washer with an outer diameter of 2.2 cm and an inner diameter of 1 cm to keep it stable The berries were placed on their sides with the calyx end to the left and the stem end to the right. An 8 mm probe attached to the Instron was then lowered from above until it pressed onto the equato r of the berry, using an initial contact force not exceeding .03N (Fig. 2.1). Using a crosshead speed of 50 mm/min, each berry was deformed and the 3 mm deformation at 1 mm, 2 mm, and 3 mm depth were recorded (10 berries/clone). Figure 2.1. Instron machine with 8 mm probe.

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14 Results When berry firmness was plotted as a hi stogram (Fig. 2.2) the 99 clones appeared to give a normal distribution, except that the sample for FL 98-325 was separated from the others at the high end of the distribu tion. Firmness of FL 97-136, FL 98-325 and FL 00-270 fell within the top 10% of the array in firmness measured by the Instron (Table 2.1). One ‘Bluecrisp’ sample also was in the top 10% in firmness, but the other ‘Bluecrisp’ sample was less firm with a ra nking of 71 out of 100 samples. FL 98-325, a crisp-textured clone, was firmest and appeared to separate out from the rest of the clones in the histogram on page 31. A Tukey te st was preformed on the top 10% of the histogram to confirm these observations. The te st showed all clones to be similar to each other, except FL 98-325, at the five percent le vel. The unusual firmness of FL 98-325 in this test was not confirmed in subsequent tests (Table 2.2 and 2.3). It is not known why the firmness of FL 98-325 was so high in this test. Discussion Firmness is an important quality factor in blueberry. Several studies (4, 13, 16, 33, 34, 45) have been done on blueberry firmness, and methods of measuring firmness have varied. These studies have confirmed that blueberry firmness changes from harvest to harvest and from year to year. In ou r study, berry firmness of 99 southern highbush blueberry clones showed a bell-shaped distri bution. For the 99 clone s, the means force required to deform the berries 2 mm in an Instron instrument was 3.17 N (Table 2.1). Ehlenfeldt and Martin studied berry fi rmness in 87 highbush blueberry clones and hybrids using a FirmTech 1 firmness tester They found an average firmness of 1.34 N/mm deflection and values above 1.57 N/mm were considered superior (14). Our 99 clone test used an Instron 8600 to determine firmness, and got an average of 1.59 N/mm.

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15 Table 2.1. Meanz force (N) required to deform berri es by 2mm for 99 blueberry clones ranked from lowest to highest sampled in 2003. Cloney Mean (N) Standard deviation (N) Clone Mean (N) Standard deviation (N) Clone Mean (N) Standard deviation (N) FL 98-352 1.79 0.56 FL 98-375 3.04 0.43 FL 98-370 3.84 0.50 FL 98-17 2.06 0.44 FL 98-25 3.05 0.31 FL 98-370 3.90 0.43 FL 98-357 2.09 0.34 FL 95-209B 3.06 0.30 FL 98-385 3.92 0.50 FL 99-54 2.15 0.22 FL 96-96 3.12 0.45 FL 95-174 3.93 0.55 FL 96-90 2.20 0.31 FL 99-60 3.12 0.34 Bluecrisp2* 4.01 0.42 FL 99-74 2.25 0.25 FL 99-69 3.13 0.45 FL 98-384 4.04 0.39 FL 98-337 2.34 0.41 FL 99-51 3.13 0.29 Misty 4.08 0.38 FL 91-16 2.34 0.22 FL 98-369 3.13 0.65 FL 97-136* 4.17 0.48 FL 98-339 2.36 0.48 FL 95-50 3.14 0.38 FL 99-55 4.18 0.19 FL 98-338 2.38 1.03 Emerald 3.14 0.46 FL 98-363 4.22 0.48 FL 99-66 2.44 0.19 FL 98-402 3.16 0.52 Magnolia 4.35 0.58 FL 98-341 2.46 0.15 FL 95-174 3.19 0.66 FL 99-37 4.35 0.44 FL 98-351 2.47 0.28 FL 98-438 3.20 0.62 FL 98-436 4.50 1.39 FL Jewel 2.51 0.51 FL 98-433 3.22 0.17 FL 98-325* 5.49 0.62 FL 98-365 2.56 0.82 FL 98-388 3.25 0.66 Sapphire 2.59 0.20 FL 98-411 3.26 0.25 FL 98-437 2.60 0.30 FL 98-342 3.27 0.27 FL 99-48 2.63 0.22 FL 98-29 3.30 0.51 Overall Average 3.17 0.45 FL 99-59 2.66 0.39 FL 98-303 3.30 0.28 FL 99-56 2.66 0.40 FL 90-91 3.31 0.34 FL 99-65 2.67 0.30 FL 96-24 3.32 0.29 FL 98-423 2.67 0.51 FL 98-427 3.33 0.30 FL 98-401 2.67 0.32 FL 86-19 3.33 0.27 FL 98-27 2.67 0.37 FL 92-166-N 3.39 0.40 FL 97-118 2.68 0.54 FL 98-18 3.44 0.44 FL 98-414 2.69 0.32 FL 98-371 3.49 0.57 FL 98-415 2.71 0.30 FL 98-430 3.51 0.34 FL 98-372 2.72 0.27 Bluecrisp1*x 3.54 0.39 FL 98-421 2.72 0.30 FL 00-270 3.55 1.07 FL 98-428 2.74 0.36 FL 97-63 3.57 0.27 FL 98-431 2.78 1.07 Southern Bell 3.57 0.53 FL 96-43 2.82 0.57 FL 98-358 3.59 0.65 FL 99-45 2.83 0.63 FL 98-381 3.62 0.20 Legacy 2.84 0.48 FL 98-297 3.62 0.32 FL 98-125 2.87 0.37 Star 3.62 0.27 FL 95-197 2.90 0.40 FL 99-50 3.64 0.25 FL 98-416 2.90 0.28 FL 98-356 3.64 0.60 FL 98-439 2.98 0.26 FL 95-173 3.72 0.40 FL 93-171 3.00 0.33 Millennia 3.74 0.69 Sebring 3.00 0.26 FL 98-420 3.77 0.46 Sharpblue 3.02 0.34 FL 93-221 3.78 0.31 FL 98-383 3.03 0.49 FL 97-79 3.80 0.58 Windsor 3.03 0.41 FL 99-71 3.82 0.33 z Mean of 10 berries individually sampled. y The symbol following the clone name indicates th at it had been considered a crisp-textured clone previous to this experiment. x Bluecrisp 1 and 2 were from 2 different fields.

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16 Figure 2.2 Histogram of mean firmness of 99 test blueberry clones. Cl ass Interval 0.10 N. The value for each clone was the averag e of 10 berries individually tested. A direct comparison between the two e xperiments can not be made because different testers were used, but the averag e firmness, measured as N/mm deflection, for

PAGE 31

17 our 99 clone test was larger then the valu e Ehlenfeldt and Martin of the 87 highbush blueberry test considered to be superior in their tests. Further southern highbush testing using an Instron machine is needed to confirm the results from this test. Firmness Changes During Fruit Development Blueberry fruit change dramatically during final swell as the color changes from green to blue. Weight and SSC increase a nd TTA (26) and firmness decrease. Firmness decreases most between the white and pink stag es and less significantly thereafter. It had been hypothesized by Dr. Paul Lyrene that the crisp-textured clones soften more slowly then standard commercial clones. The purpose of this test was to determine if this hypothesis was right. For this experiment, normal and crisp text ured blueberries were harvested during several of the final stages of ripening and for several days afterward. Berries from four crisp-textured clones were used: ‘Bluecr isp’, FL 97-136, FL 98-325, and FL 00-59, and four commercial cultivars were used: ‘Emera ld’, ‘Millennia’, ‘Star’ and ‘Windsor’. 2003 Materials and Methods Five to eight bushes of the clones ‘Bluecrisp’, FL 97-136, FL 98-325, FL 00-59, ‘Emerald’, ‘Millennia’, ‘Star’ and ‘Windso r’ were netted (to exclude birds and berry harvesters) in a variety test attached to a commercial field. Once the berries had reached the white stage of development, 20 berries fr om each clone were harvested, placed into clamshells and transported in a cooler of ice back to the lab. At the lab the berries were warmed up to room temperature and their firm ness was tested. The white stage was after final swell had begun and 1 to 2 days before the berries turned pink then purple. Blueberries were also harveste d at the pink and blue stages of development (Fig. 1.1). The skins of some blueberries were marked w ith the date they first became blue using a

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18 paint marker (uniPAINT fine line PX21). Twenty berries were harvested from each clone at each of six sampling times: 3, 5, 7, 9, 12, and 15 days after they first turned blue. Berry firmness was tested using an Inst ron 8600 as described previously. All twenty berries harvested for each clone at each maturity level were tested for firmness. 2003 Results The firmness testing during fruit devel opment for 2003 was interrupted by pickers and some data were lost (Table 2.2). From the remaining data shown in Table 2.2 it can be seen that a dramatic decrease in firmne ss occurred from the white to pink stages of berry development. Changes in firmness afte r the pink stage of be rry development were small. Both “crisp” and “non-crisp” clones softened significantly during the transition from white to pink. The data failed to s how a major difference be tween the “crisp” and “non-crisp” clones in the soften ing that occurred as the berries went from white to blue. It had been hypothesized earlier that the high firmness of the “crisp” berries when fully ripe might be the result of less loss of firmne ss during the final stages of ripening, but this seems not to have been the case. ‘Bluecris p’ and FL 98-325 were less firm at the pink stage (Table 2.2) than in the fully ripened blue stage Table 2.1. This indicates that one or more non-genetic factors have a la rge effect on Instron firmness. 2004 Materials and Methods In 2004, FL 00-180 and FL 00-270 were added to the test as possible crisp-textured clones. Five to eight bushes of the cl ones ‘Bluecrisp’, FL 98-325, FL 00-59, FL 00-180, FL 00-270, ‘Emerald’, ‘Millennia’, ‘Sta r’ and ‘Windsor’ were netted in a

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19 Table 2.2. Meanz deformation force (2mm deformation) of fruit for eight blueberry clones sampled at 9 stages of maturity in 2003. 2mm Deformation Force (N) at Maturity Stage Cloney White Pink Blue Day 3x Day 7 Day 9 Day 12 Day 15 Bluecrisp* 7.77 ab 2.83 a 2.14 2.17 a 2.30 FL 97-136* 10.24 a 2.51 a 2.41 1.70 FL 98-325* 10.57 a 2.56 ab 2.82 2.97 FL 00-59* 9.03 abw 2.85 a 2.71 a Emerald 5.85 b 1.70 Millennia 8.34 ab 2.67 Star 9.88 a 1.73 b 0.84 Windsor 8.98 ab 1.77 b 2.12 a P > F 0.013 0.001 0.045 z Mean of 20 berries individually sampled. y Clones followed by a had been considered crisp textured x Days after berry first turned blue w Within columns means followed by th e same letter are not significantly different (P<0.05) by ANOVA and Tukey’s test. commercial field and allowed to ripen. Once the berries had reached the white stage of development, 20 berries from each clone were harvested, and their firmness was tested as previously described. Blueberries were also harvested at the pink and blue stages of development. To test the firmness of the be rries an Instron 8600 te sting machine with a 10 N load cell was used. The procedure was the same as previously described. 2004 Results All clones softened significantly between the white and pink stages (Table 2.3). The six “crisp” clones did not differ conspic uously in the pattern of firmness loss from the four “non-crisp” cultivars. Analysis of variance (Table 2.4) showed that clones, stages of ripening, and clone x stage interact ion all contributed signi ficantly to variances in the firmness of the samples.

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20 Table 2.3. Meanz deformation force of fruit for nine blueberry clones sampled at three stages of maturity in 2004. 2mm Deformation force(N) at maturity stage Cloney White Pink Blue Bluecrisp* 7.52 ab 3.20 abc 2.81 ab FL 98-325* 5.51 ab 3.76 a 2.80 ab FL 00-59* 7.79 abx 3.69 a 3.30 a FL 00-180* 7.32 ab 2.64 bc 2.39 bc FL 00-270* 7.27 ab 3.39 abc 1.87 c Emerald 4.78 b 2.45 c 1.97 c Millennia 9.24 a 3.49 ab 1.86 c Star 9.08 ab 2.84 abc 2.44 bc Windsor 5.06 ab 2.64 bc 2.14 bc Stage means 7.06 3.12 2.40 P > F 0.009 0.000 0.000 zMeans of 10 berries individually sampled. yClones followed by a are crisp textured x Within columns means followed by the same letter are not significantly different (P<0.05) by ANOVA and Tukey’s test. Table 2.4. ANOVA for mean deformation force of fruit for 9 blueberry clones sampled at three stages of maturity in 2004. Source DF Mean Square F value Pr > F Model 26 53.32 15.70 <0.0001 Clones 8 13.41 3.95 0.0002 Stages 2 566.95 166.93 <.0001 Stages x Clones 16 9.08 2.67 0.0007 Error 243 3.40 Discussion When “crisp” blueberries were originally observed by Dr. Lyrene theorized that the crisp texture in these new blueberries coul d be caused by a lack of polygalacturonase (PG) in the final stages of fruit developmen t (Lyrene, personal communication). PG is an enzyme that helps breaks down pectin, causing the cell walls to soften (39). Production of PG in other fruits has been inhibite d through genetic engineering, or by breeding creating such fruit as the non-melting flesh p each and the Flavor-Savor tomato (18, 43).

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21 Several studies (4, 46, 39) have shown th at during the final days of ripening blueberries soften as they change color from white to blue. The greatest decrease in firmness occurs from the pink to the blue st age and is caused by the synthesis of PG in the berry (39). The tests done in 2003 and 2004 showed a decrease in firmness of all clones as they ripened from white to blue, confirming previous studies. The fact that the “crisp” berries lost firmness rapidly ass they matured from green to blue suggests that PG levels are not related to the crisp textur e in “crisp” blueberri es. Further studies examining changes in PG levels as “crisp ” and “non-crisp” clones mature should be conducted to confirm these results. Shear-Cell Testing In an effort to detect a difference between berries of “crisp” and “non-crisp” clones, berries were tested using a Kramer shear-cell attached to the Instron. The Kramer shearcell is a multi-bladed fixture designed to produce shear stress in a spec imen that relates to firmness (22). The specimen is placed in to a metal box (82.5 mm x 98 mm) with a lid. The top and the bottom of the box have slits designed to allow ten, 3-mm blades to pass through them. The blades penetrate the t op of the box and then push through to the bottom. As the blades are moved through the box, the specimen is first compressed, then extruded, and finally sheared as the blades pe netrate the bottom slots (22). The forces needed for the blades to move through the box relate to berry text ure (22). The purpose of this experiment was to determine the ma ximum force needed to shear blueberries and to determine if this force is different for crisp textured selections and some standard cultivars.

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22 Materials and Methods In 2004, three clamshells of ripe berries (approximately 125 g of berries in each) were collected from April 30 through May 6 for each of the following clones: ‘Bluecrisp’ FL 97-136, FL 98-325, FL 00-59, FL 00-180, FL 00-270, ‘Emerald’, ‘Star’, ‘Windsor’ and ‘Millennia’. The clamshells were pla ced in a cooler and br ought to the lab where each clamshell was inspected to eliminate damaged or leaki ng berries. Approximately 70 g of sound berries were randomly selected and placed into a shear-cell box to make approximately two layers of berries. The sh ear-cell box, the lid and th e blades to the box were set in place on an Instron 8600 (Fig. 2.3). At a crosshead speed of 50 mm/min the blades were passed through the box of berries until they penetrated through to the other side of the box. The maximum force needed for the blades to pass through the box of berries was recorded. This procedure was repe ated for the other two clamshells of berries for a total of three re petitions per clone. On May 18 and May 19 of the same year the shear-cell procedure was repeated using the same clones and technique to obtai n a second set of data for each clone. The berries were harvested from the same bushes. The bushes had been harvested periodically before the samples were taken to insure that only newly ripened berries were included in the second samples. Means we re obtained from these repetitions and compared to the earlier shear-cell test results. Results There was good agreement between the shea r-cell tests run April 30 to May 6 and those run May 18 and 19 (Table 2.5, Fig. 2.4) ‘Bluecrisp’, FL 97-136 FL 00-59 and FL 00-180 had high shear-cell readings and FL 00-270, ‘Millennia’, ‘Star’ and ‘Windsor’ had lower readings (Table 2.5). The shearcell testing was done on six putative crisp-

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23 textured blueberry clones and four standard co mmercial clones. In th e early harvest, the firmest four clones in descending order we re FL 97-136, ‘Bluecrisp’, FL 00-59 and FL 00-180 (Fig. 2.4). At the 5% level ‘Bluecris p’, FL 97-136, and FL 00-59 were different from all other clones except FL 00-180. FL 00-59 was not significantly Figure 2.3. Instron 8600 with shear-cell attached. different from FL 00-180 but wa s significantly different from th e rest of the clones. The rest of the clones merge together and are not easily distinguished as seen from Tukey testing in Table 2.5. In the late season ha rvest there were not enough berries to do shearcell testing on FL 97-136, but all other clones were tested. In th e late-season shear-cell

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24 tests, ‘Bluecrisp’, FL 00-180 and FL 00-59 we re the top three clones and differed from the other clones at the 5% level of a Tukey test. There was a close relationship between the shear-cell force on the 1st and 2nd sample dates for the 9 clones that were sa mpled twice (Fig. 2.4). Clones FL 98-325 and FL 00-270, which had been thought to be cris p, had relatively low shear force, but the other four “crisp” clones were very high in shear-cell force. Although the second samples were harvested approximately 2 week s later in the season, shear-cell force did not dramatically change betw een the two sample dates (Tab le 2.5). Tukey testing done on the mean sample times confirmed ‘Bluecr isp’, FL 00-59 and FL 180 as the top three clones through out shear ce ll testing (Table 2.5). Table 2.5. Shear-cell meansz for 10 clones sampled at two different times during the 2004 growing season. Max force (N) Cloney First sample timex Second sample timew Mean sample times Bluecrisp* 458.0 av 433.7 a 445.84 a FL 00-59* 418.9 ab 393.7 a 406.34 ab FL 97-136* 477.5 a FL 98-325* 308.6 cdef 325.8 b 317.20 c FL 00-180* 360.4 bc 401.6 a 381.01 b FL 00-270* 270.1 def 293.5 bcd 281.79 cd Emerald 317.0 cd 313.2 bc 315.09 c Millennia 246.8 ef 288.0 bcd 267.38 d Star 219.9 f 252.5 d 236.21 d Windsor 269.1 def 257.8 cd 263.44 d P > Fu 0.0001 0.0001 0.0001 zMean of 3 shear-cell tests. y Clones followed by a had been considered crisp textured. xTime period was April 30 to May 6. wTime period was May 18 to May 19. vMeans followed by the same letter are not significantly different (P<0.05) by ANOVA and Tukey’s test. uProbability that the clones di d not differ in shear force.

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25 Discussion The Kramer shear cell was built to study th e texture of materials through a process of compression, extrusion and shearing of the ma terial. It has been used to assess the texture of many fruits and vegetables (1, 21, 22, 47), but extensive work with the shear cell has not been done with blueberries. A study published in 2005 examined shear stress in rabbiteye and highbush blueberries and dete rmined that rabbiteye blueberries (482 N) require more force then highbush berries ( 290 N) (44). A combination of certain 0 100 200 300 400 500 600 050100150200250300350400450500 Second date force (N)First date force (N) Bluecrisp FL 00-180 FL 00-59 FL 98-325 Emerald FL 00-270 Millennia Windsor Star Figure 2.4. Relationship between sh ear-cell forces of nine se lected blueberry cultivars and clones harvested at the blue stage in the first and second sampling dates of 2004.

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26 rabbiteye genes in the southe rn highbbush may be creating th e crisp texture. Further shear cell testing on southern and northern highbush, rabbiteye and lowbush blueberries should be conducted to determine if this is true. Standard deviations (SD) among berries within samples averaged 6% of the means, for shear-cell testing compared to eleven percent of the means for firmness testing. Furthermore, shear cell means fluctuated less from harvest to harvest than Instron firmness means (Table 2.1, 3.1) (4). Shear ce ll testing may be a more consistent way of comparing blueberries than firmness testing. Consumer Sensory Panel Study The crisp-textured clones had been sele cted based on the subjective opinions of growers and the blueberries bree ders at the University of Florida. To determine if the untrained public could distinguish the differe nce between the crisp-textured berries and standard commercial bluebe rries a consumer sensory panel study was conducted. ‘Bluecrisp’ and FL 00-59 repres ented crisp textured blueberr ies, and ‘Emerald’ and ‘Star’ represented standard co mmercial blueberries. 2003 Materials and Methods In a commercial field, 500 blueberries we re gathered from each of the following clones: ‘Bluecrisp’, FL 00-59, ‘Emerald’ and ‘S tar’. The berries from each clone were placed into 4-liter zip lock bags and placed on ice in a cooler for transport to a 2 C storage chamber where they we re kept overnight. The next day, the berries were taken out of storage and allowed to reach room temp erature (22 C). Each berry was inspected to eliminate immature and overripe berries and berries with cuts and leaks. The remaining berries were placed in zip lock ba gs and taken to the sensory panel facility operated by the University of Florida, Depart ment of Food Science and Human Nutrition.

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27 Each clone was assigned a random four-dig it number. The four-digit numbers were then randomly assigned to either the top left top right, bottom left or bottom right of a tray that was presented to the evaluators. For each clone, four berries were randomly selected and placed into a cup. The four c ups were randomly placed on the tray. Saltine crackers and a glass of water were also placed on the tray to cleanse the panelist’s palate between samples. When a panelist entered th e sensory panel chamber, he/she was seated at a booth that had a computer and a sma ll sliding window. The window was opened and a worker presented a tray with the cups of berries. The panelist then sampled the berries and answered the questions (listed in Tabl e 2.6) about each group of berries using the computer. Table 2.6. Questions asked for the 2003 taste panel study. Question number Berry attribute evaluated Evaluation scale 1 Appearance Ranked 1 (extremely disliked) to 9 (extremely liked) by number 2 Texture/firmness Ranked 1 (extremely disliked) to 9 (extremely liked) by number 3 Sweetness Ranked 1 (extremely disliked) to 9 (extremely liked) by number 4 Flavor Ranked 1 (extremely disliked) to 9 (extremely liked) by number 5 Overall acceptability Ranked 1 (extremely disliked) to 9 (extremely liked) by number 2003 Results The panelists preferred some clones over ot hers with respect to fruit appearance, texture/firmness, and sweetness, but showed no clonal preferences regarding flavor (Tables 2.7-2.11). In 2003, the pane lists tended to prefer the te xture of the “crisp” clones over that of ‘Emerald’ and ‘Star’ (Table 2.8). The questions presented with the 2003 samples were ambiguous in that they did not reveal whether the pa nelists could detect differences among the clones or whether they co uld detect differences but did not prefer one texture over another.

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28 Table 2.7. Overall appearance of panelists of four blueberry clones on a scale from 1 (dislike extremely) to 9 (lik e extremely) (n=90; 2003 study). Rating Clone 1 2 3 4 5 6 7 8 9 Mean Standard Deviation Tukey Test Bluecrisp 1 z 7 10 18 24 24 6 6.70 1.41 b FL 00-59 1 3 11 7 22 31 15 7.21 1.43 a Emerald 2 6 9 14 18 34 7 6.89 1.49 ab Star 2 8 8 15 12 19 18 8 6.18 1.87 c z The number of panelist who rated the clone. Table 2.8. Overall texture/firmness of panelists of four blueberry clones on a scale from 1 (dislike extremely) to 9 (lik e extremely) (n=90; 2003 study). Rating Clone 1 2 3 4 5 6 7 8 9 Mean Standard Deviation Tukey Test Bluecrisp 1z 3 8 7 17 31 15 8 6.54 1.57 ab FL 00-59 2 6 8 10 25 24 15 7.00 1.61 a Emerald 1 3 1 11 6 22 24 16 6 6.29 1.73 bc Star 2 2 3 9 10 27 22 10 5 6.02 1.72 c z The number of panelist who rated the clone. Table 2.9. Overall sweetness of panelists of four blueberry clones on a scale from 1 (dislike extremely) to 9 (lik e extremely) (n=90; 2003 study). Rating Clone 1 2 3 4 5 6 7 8 9 Mean Standard Deviation Tukey Test Bluecrisp 1z 1 4 12 13 8 26 16 9 6.30 1.84 Ab FL 00-59 1 1 4 7 7 10 13 29 18 6.92 1.92 A Emerald 1 3 7 7 10 19 21 18 4 6.08 1.84 B Star 5 7 11 10 22 15 18 2 5.82 1.83 B z The number of panelist who rated the clone. Table 2.10. Overall flavor of pane lists of four blueberry clones on a scale from 1 (dislike extremely) to 9 (like extremely) (n=90; 2003 study). Rating Clone 1 2 3 4 5 6 7 8 9 Mean Standard Deviation Tukey Test Bluecrisp 5z 4 10 11 17 17 18 8 6.16 1.91 A FL 00-59 1 4 4 7 6 15 19 15 19 6.59 2.06 A Emerald 3 4 5 3 17 17 18 15 8 6.03 2.02 A Star 1 3 6 8 14 18 16 16 8 6.08 1.91 A z The number of panelist who rated the clone.

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29 Table 2.11. Overall acceptability of panelists of four blueberr y clones on a scale from 1 (dislike extremely) to 9 (lik e extremely) (n=90; 2003 study). Rating Clone 1 2 3 4 5 6 7 8 9 Mean Standard Deviation Tukey Test Bluecrisp 1z 4 9 13 16 24 16 7 6.33 1.65 Ab FL 00-59 2 5 4 8 12 24 20 15 6.78 1.79 A Emerald 1 1 4 6 15 21 19 19 4 6.23 1.65 Ab Star 1 3 2 10 14 24 23 10 3 5.94 1.62 B z The number of panelist who rated the clone. 2004 Materials and Methods To resolve this ambiguity of the 2003 se nsory panel, the 2004 questionnaire was changed to directly ask each panelist if th ey could distinguish between the “crisp” and commercial berries. The 2004 panel was c onducted using the cris p-textured clones ‘Bluecrisp’ and FL 00-59, and the standard clon es ‘Star’ and ‘Windsor’. Each clone was placed through the same harvesting and tast e panel procedure that was used in 2003 except the questions were different (Table 2.12). Table 2.12. Questions asked fo r the 2004 taste panel study. Question number Question topic Evaluation scale 1 How often do you eat blueberries 1 (never), 2 (1-2 times a year), 3 (3-10 times a year), 4 (> 10 times a year) 2 Place in order solely based on firmness each group of berries 1 (softest) to 4 (crunchiest) by number 3 Rank each group of berries on texture/firmness. 1 (extremely disliked) to 9 (extremely liked) by number 4 Rank overall quality of each group of berries 1 (extremely disliked) to 9 (extremely liked) by number 2004 Results Forty four percent of the panelists w ho participated in the 2004 panel ate blueberries 1 to 2 times a year, 32% ate blueberr ies 3 to 10 times a year and the rest either never ate blueberries or ate them more then ten times a year (Table 2.13). From these

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30 data it could be said that most of these test subjects we re not regular blueberry eaters. The second question asked the panelist to ra nk the groups from softest to crunchiest. This question separated ‘Bluecrisp’ and FL 00-59 as being the crunchiest and ‘Emerald’ and ‘Star’ as being softer (Table 2.14). Base d on a sample of four berries per clone about 78% of the panelists chose one of the two “crisp” clones as bei ng crunchiest and only 22% chose one of the other two clones ( Ta ble 2.14). The third question (Table 2.15) asked panelists to indicate how well they liked the firmness of the gr oups of berries on a scale from one (extremely disliked) to nine (e xtremely disliked). Here the texture of the two crisp clones received the highest pr eference ratings (Table 2.15), although the preference for ‘Bluecrisp’ texture was not signif icantly higher than for ‘Star’. The forth and final question (Table 2.16) asked each paneli st to rank the overall de sirability of each group of blueberries. This question di d not reveal any major differenced among the groups, although FL 00-59 was ranked sign ificantly higher than ‘Star’. The difference between “crisp” and “non-crisp” clones was more consistent in firmness ranking than for firmness desirability (Table 2.14 versus Table 2.15). This implies that some panelist who could recognize crisp texture did not prefer it. Table 2.17 showed that how often a panelist ate blue berries was not correlated w ith the recognition of “crisp” berries. Overall, from these results it co uld be said that “crisp” berries can be distinguishable from regular commercial berrie s, and are often but not always considered more desirable than “non-crisp” berries. Table 2.13. Previous blueberry eating experience of the 95 panelists whom were part of the evaluation panel in 2004. Number of panelist w ho had eaten blueberries never 1-2 times/year 3-10 times/year >10 times/year 6 42 31 16

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31 Table 2.14. Firmness ranking of 4 blueberry cl ones by 95 panelists from 1 (softest sample) to 4 (crunchiest sample). Rank Clone 1 2 3 4 Rank total Tukey test Bluecrisp 10z 15 33 37 287 ay FL 00-59 9 16 32 38 289 a Star 30 39 17 9 195 b Windsor 46 25 13 11 179 b z Number of people who ranked the clone at that position. yTotals followed by the same letter are not significantly different (P<0.05) by ANOVA and TukeyÂ’s test. Table 2.15. Desirability of the berry firmness of 4 blueberry clones evaluated on a scale from 1 (dislike extremely) to 9 (like extremely) by 95 panelists. Desirability Clone 1z 2 3 4 5 6 7 8 9 Mean Standard deviation Tukey test Bluecrisp 2 y 3 4 10 9 13 23 21 10 6.34 1.982 abx FL 00-59 1 1 3 2 9 21 22 21 15 6.82 1.669 a Star 3 3 12 9 14 9 18 18 9 5.85 2.188 bc Windsor 2 6 8 16 11 16 15 12 9 5.63 2.124 c z Scale from 1(dislike extremely) to 9(like extremely) y Number of people who ranked the clone at that position. x Means followed by the same letter are not significantly different (P<0.05) by ANOVA and TukeyÂ’s test. Table 2.16. Overall desirability of the berry qu ality of 4 blueberry clones evaluated by 95 panelists. Desirability Clone 1z 2 3 4 5 6 7 8 9 Mean Standard deviation Tukey test Bluecrisp 5x 3 2 8 14 17 22 14 10 6.07 2.074 aby FL 00-59 3 2 6 9 21 18 20 16 6.71 1.768 a Star 1 1 7 12 9 23 15 17 10 6.17 1.877 ab Windsor 1 9 2 13 11 17 15 12 15 6.00 2.183 b z Scale from 1(dislike extremely) to 9(like extremely) y Means followed by the same letter are not significantly different (P<0.05) by ANOVA and TukeyÂ’s test. x Number of people who ranked the clone at that position.

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32 Table 2.17. Desirability of berry firmness a nd overall desirability of berries of 4 blueberry clones as judged by panelists with differing blueberry consumption histories. Firmness rank Desirability of firmness Overall desirability Clone Panelistsz Mean Standard dev. Tukey test Mean Standard dev. Tukey test Mean Standard dev. Tukey test FL 00-59 Never 2.67 1.37 a 6.00 1.26 a 6.00 2.28 a FL 00-59 1-2 times 3.00 0.96 a 6.67 1.95 a 6.45 1.84 a FL 00-59 3-10 times 2.97 0.91 a 7.48 1.23 a 7.39 1.45 a FL 00-59 > 10 times 3.31 1.08 a 6.25 1.39 a 6.31 1.70 a Bluecrisp Never 3.00 0.89 a 5.50 2.07 a 4.33 1.51 a Bluecrisp 1-2 times 3.12 0.99 a 6.10 1.66 a 6.07 1.67 a Bluecrisp 3-10 times 3.23 0.96 a 6.61 2.12 a 6.16 2.22 a Bluecrisp > 10 times 2.50 0.89 a 6.75 2.41 a 6.56 2.68 a Star Never 2.33 1.03 a 4.50 1.87 a 4.00 2.10 b Star 1-2 times 2.10 0.91 a 5.74 1.98 a 6.07 1.67 a Star 3-10 times 1.77 0.84 a 6.10 2.27 a 6.58 1.75 a Star > 10 times 2.38 1.09 a 6.19 2.61 a 6.44 2.13 a Windsor Never 2.00 1.26 a 4.67 2.66 a 4.17 3.06 a Windsor 1-2 times 1.79 1.02 a 5.29 2.04 a 5.81 1.95 a Windsor 3-10 times 2.03 1.08 a 5.90 2.20 a 6.58 2.13 a Windsor > 10 times 1.81 0.98 a 6.38 1.86 a 6.06 2.26 a zPrevious blueberry eating experience in a year Discussion Very little work has been done on blueberry taste as it pertains to consumer sensory panels. The Dave Wilson Nursery has done a taste panel study every year since 1992. In 2002 blueberries were added to this panel, and it was determined that new cultivars ‘Southmoon’, ‘Jubilee’, ‘Misty’ and ‘Ozark Blue ’ (scores ranging from 5.5 to 6.3 on their 10 point scale) tasted better than the older standard cultivars ‘O’Neal’, ‘Georgia Gem’ and ‘Bluecrop’ (scores ra nging from 4.8 to 5.4) (11). In the 2003 sensory panel study the “crisp” cl ones could not be distinguished from the “non-crisp” clones in any of the questions This was probably because panelists did not prefer the “crisp” clones over the “non-crisp” clones. Panelists were not asked

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33 whether they could distinguish between “crisp” and “non-crisp” clones. The 2004 sensory panel study directly asked the panelist s if they could detect a difference between the “crisp” and “non-cris p” clones, and if they preferred one type over another. We were able to determine that panelists could tell a difference but did not al ways prefer the crisptextured clones over the standard cultivars. The blueberries in our study were harveste d the day before each consumer sensory panel was conducted and kept in an ideal st orage condition until they were used. Most fresh blueberries eaten by consumers are sh ipped across the countr y, kept on the grocery shelf for several days and possibly stored in the home refrigerator for several more days before they are eaten. If the crisp-te xtured clones retain their “just-picked” characteristics longer than sta ndard commercial varieties, se nsory panel evaluations done on berries that had been subjected to commerc ial packing, transport, and sales might have separated the “crisp” and normal berries better than our test with just-picked berries. Further research should be conducted to determine if this is the case.

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34 CHAPTER 3 POSTHARVEST STORAGE TEST It was hypothesized that the “crisp” bluebe rries might store longer then standard commercial blueberries. Standa rd commercial blueberries can be stored at 2C in air for up to 2 weeks without serious degradation. To determine if “crisp” blueberries store longer then standard commercial berries, sel ected quality parameters of four “crisp” clones and four “non-crisp” clones determin ed during air and CA cold storage for 8 weeks in 2003 and 2004. 2003 Study Materials and Methods Five to eight blueberry plants of the “crisp” clones ‘Bluecrisp’, FL 00-59, FL 97136, FL 98-325 and the “non-crisp” clones ‘Emera ld’, ‘Millennia’, ‘Star’ and ‘Windsor’ were netted in a commercial field at the beginning of th e harvest season in April 2003. As the berries from each clone matured, they we re harvested at the blue stage and placed in 125 g plastic clamshells donated by Straughn farms Inc. For each harvest a minimum of three clamshells per clone were taken. A total of 15 clamshells were needed for each clone. The name of the clone, date of harves t and a storage time of 0, 2, 4, 6 or 8 weeks was written on each clamshell. The berries we re then placed in a cooler with ice for transport to a 2 C storage unit where they we re separated based on storage time. Berries harvested for 0 week storage were evaluated fo r initial quality factor s. Berries harvested for evaluations after 2, 4, 6 and 8 weeks storage were placed in the 2 C storage room for their designated length of time.

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35 At the end of the designated storage peri ods each blueberry was taken out of the clamshell and checked for mold, incident of shri vel, severity of shrivel, leaking/collapse, weight loss and firmness. To check for decay, each blueberry was visually inspected, and the total number of berries with decay was r ecorded. For incident of shrivel, each berry was examined for signs of shrivel starting at the scar end and going around the berry. The severity of shrivel was rated for each berr y using a 9 point scale, from 1 (no signs of shriveling) to 9 (severely shriveled). To ex amine leaking/collapse, the blueberries were checked for fluid leakage and cellular collapse not caused by decay. To check for weight loss, each clamshell was weighed before being placed into storage. When removed from storage the clamshells were reweighed and weight loss was obtained. To examine the firmness, ten blueberries were randomly taken from each clamshell and force deformation measurements with an Inst ron 8600 testing machine, as previously described, were taken. This process was re peated on all 10 berries for each group of berries that came out of cold storage. Once examined, the berries were poured into zip lock freezer bags and placed in a freezer at -30 C. The pH, SSC and TTA were later determined. All percentage data wa s converted to arcsin for analysis. To determine pH, SSC and TTA, the blueberr ies were taken out of -30 C storage, eight bags at a time. The frozen berries from each bag were placed in a glass jar. The jars were sealed and placed in a large plastic container with approximately 2 inches of tap water to thaw the berries. The berries were left in the containers for 1.5 hours to reach room temperature. Once at room temperat ure, the berries were blended for 10 s until reaching a paste-like consistence. Fifty grams was then placed into a tube and

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36 centrifuged at 34.02 gn for 20 minutes. The supernatant was then poured through cheese cloth into a small vial. From this supern atant, the pH, SSC and TTA were determined. Results Firmness of newly harvested blueberries differed among clones (Table 3.1). FL 98-325 was distinctively firmer than all other clones (Table 3.1). Of the four “crisp” clones, only ‘Bluecrisp’ had a firmness mean similar to the four “non-crisp” clones. Firmness declined for all clones during st orage (Table 3.1). The mean rate of softening ranged from 0.11 to 0.21 N per week for the eight clones. The “crisp” clones appeared to lose firmness as fast as the “non-crisp” cl ones. Overall there was a significant week x clone intera ction, but, the “crisp” clones did not maintain firmness better than the “non-crisp”. This is show n both by the slopes in Table 3.1 and by the Tukey test for firmness at week 8. All clones except ‘Star’ had some decayed be rries after 2 weeks storage at 2 C. Decay incidence increased in all clones over ti me during the storage te st (Table 3.3). The rate of increase in decay in cidence ranged from 0.08% to 2.86% per week (Table 3.3). Even though the week x clone interaction was significant the “crisp” clones did not show any consistent differences in the rate of decay development compared to the “non-crisp” clones. This is shown in the slopes a nd Tukey testing in Table 3.3. Clones FL 00-59 (“crisp”), ‘Emerald’ and ‘Mil lennia’ (“non-crisp”) had less decay over time th an the other clones (Tables 3.3 and 3.4). The number of leaking berries increase d with each clone over time during the storage test (Table 3.5). The Tukey test on week 8 and the sl opes reveled that the “crisp” clones did not develop leaking berries signifi cantly slower then th e “non-crisp” clones

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37 Table 3.1. Mean deformation forcez at 2mm depth for 8 blueberry clones stored in air for 8 weeks at 2C in 2003. 2mm Deformation Force (N) Clone Week 0 Week 2 Week 4 Week 6 Week 8 my Prob m = 0 Bluecrisp 2.37 dx 2.21 cd 1.95 b 1.36 c 1.17 c -0.16 bcw 0.0001 FL 97-136 3.02 bc 2.80 b 2.47 b 1.96 bc 1.79 b -0.17 b 0.0001 FL 98-325 4.18 a 4.55 a 4.18 a 3.72 a 2.74 a -0.19 cd 0.0017 FL 00-59 3.07 b 2.55 bc 2.35 b 2.11 b 1.74 b -0.15 bc 0.0001 Emerald 2.31 d 2.08 d 2.01 b 1.63 bc 1.26 bc -0.12 a 0.0001 Millennia 2.67 bcd 2.83 b 2.05 b 1.63 bc 1.26 bc -0.20 d 0.0001 Star 2.59 cd 2.65 b 1.89 b 1.52 bc 1.05 c -0.21 d 0.0001 Windsor 2.27 d 2.12 d 2.24 b 1.79 bc 1.36 bc -0.11 a 0.0014 P > F <.0001 <.0001 <.0001 <.0001 0.0001 zMean of 30 berries individually sampled, 10 from each of three clamshells. ym is the estimated change in force(N) per week based on linear regression analysis. xWeek means followed by the same letter are not significantly diffe rent (P<0.05) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not si gnificantly different (P <0.05) by two-sample t-tests Table 3.2. ANOVA for mean deformation force needed at 2mm for 8 blueberry clones stored for 8 weeks in 2003. Source DF Mean Square F value Pr > F Model 39 2.00 37.84 <.0001 Clones 7 6.87 129.76 <.0001 Weeks 4 6.68 126.11 <.0001 Weeks x Clones 28 0.119 2.25 0.0026 Error 80 0.053 R-Square 0.95 (Table 3.5). The week x clone interaction was not significant (Table 3.5). Overall there was an increase in leaking berries over ti me, but not significant interaction with the clones over time. All of the clones lost weight over time (Table 3.7). The week x clone interaction was significant showing that there were differences amongst the clones over time (Table 3.8). From the Tukey test and the slopes, ther e were no differences in the rate of weight

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38 loss between the “crisp” clones and the “ non-crisp” clones (Table 3.7). FL 00-59, ‘Emerald’ and ‘Millennia’ showed less weight loss than the other clones. Table 3.3. Incidence of decay (%) for eight blue berry clones stored for 8 weeks at 2C in 2003. Decay (%) Clone Week 0 Week 2 Week 4 Week 6 Week 8 mz Prob m = 0 Bluecrisp 0.00y 0.38 cx 4.08 ab 7.35 a 18.6 ab 2.22 abw <.0001 FL 97-136 0.00 0.81 c 5.20 ab 6.26 a 12.81 bc 1.55 c <.0001 FL 98-325 0.00 0.81 c 7.62 ab 9.46 a 24.31 ab 2.86 a <.0001 FL 00-59 0.00 7.80 ab 3.27 b 4.01 a 2.74 d 0.08 e 0.2928 Emerald 0.00 2.61 ab 7.44 ab 3.11 a 5.96 cd 0.62 de 0.0201 Millennia 0.00 14.24 a 8.56 ab 11.71 a 10.25 bcd 0.90 d 0.0167 Star 0.00 0.00 c 13.42 a 9.49 a 10.64 bcd 1.53 bc 0.0006 Windsor 0.00 14.24 a 4.57 ab 11.39 a 29.35 a 2.79 abc 0.0005 P > F <.0001 0.0951 0.1692 0.0004 zm is the estimated change in the percent of d ecaying berries per week based on linear regression analysis. yMean of 30 berries individually sampled, 10 from each of three clamshells. xWeek means followed by the same letter are not significantly different (P<0.05) by ANOVA and Tukey’s test. wSlopes followed by the same letter are not si gnificantly different (P <0.05) by two-sample t-tests Table 3.4. ANOVA for incidence of decay (%) of eight blueberry clones stored for 8 weeks in 2003. Source DF Mean Square F value Pr > F Model 39 252.03 13.84 <.0001 Clones 7 149.10 8.19 <.0001 Weeks 4 1500.86 82.40 <.0001 Weeks x Clones 28 99.36 5.46 <.0001 Error 80 18.21 R-Square 0.87 The number of shriveled berries increa sed dramatically over time during the storage test (Table 3.9). The week x clone interaction was significan t showing that there were differences amongst the clones over time (Table 3.10). However, in examining the Tukey test results and the slope s, these differences did not di stinguish the “crisp” clones

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39 from the “non-crisp” clones (Table 3.9). Over all, the amount of shriveling increased over time, but the “crisp” clones we re not significantly different from the “non-crisp” clones. The severity of shrivel for each clone incr eased over time during this storage test (Table 3.11). At week 2, “crisp” clones ‘Bluecrisp’, FL 97-136 and FL 98-325 showed less severity of shriveling then the other cl ones. This distincti on did not continue as storage time lengthened (Table 3.11). The week x clone inter action for shriveling severity was significant. Th e “crisp” clones did not devel op less shriveling than the “non-crisp” clones. Table 3.5. Incidence of leaking (%) for eight blueberry clones stored for 8 weeks at 2C in 2003. Leaking (%) Clone Week 0 Week 2 Week 4 Week 6 Week 8 mz Prob m = 0 Bluecrisp 0.00 y 0.00 ax 1.41 a 3.92 a 8.80 ab 1.08 cw <.0001 FL 97-136 0.00 0.00 a 0.74 a 2.52 a 10.61 ab 1.19 bd 0.0002 FL 98-325 0.00 0.00 a 3.86 a 5.54 a 18.26 ab 2.10 a <.0001 FL 00-59 0.00 0.00 a 0.65 a 5.97 a 6.24 b 0.92 d <.0001 Emerald 0.00 0.00 a 2.30 a 3.14 a 10.16 ab 1.17 bd 0.0008 Millennia 0.00 1.32 a 6.29 a 7.86 a 18.28 ab 2.15 a <.0001 Star 0.00 0.00 a 4.00 a 8.08 a 14.14 ab 1.82 ab <.0001 Windsor 0.00 1.32 a 3.94 a 9.58 a 25.65 a 2.98 a <.0001 P > F 0.0196 0.4777 0.3069 0.0337 zm is the estimated change in the percent of l eaking berries per week based on linear regression analysis. yMean of 30 berries individually sampled, 10 from each of three clamshells. xWeek means followed by the same letter are not significantly diffe rent (P<0.05) by ANOVA and Tukey’s test. wSlopes followed by the same letter are not si gnificantly different (P <0.05) by two-sample t-tests.

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40 Table 3.6. ANOVA for incidence of leaking (%) for eight blueberry clones stored for 8 weeks in 2003. Source DF Mean Square F value Pr > F Model 39 222.43 10.11 <.0001 Clones 7 108.01 4.91 0.0001 Weeks 4 1841.62 83.72 <.0001 Weeks x Clones 28 19.72 0.90 0.6169 Error 80 21.99 R-Square 0.83 Table 3.7. Incidence of weight loss (%) of eight blueberry cl ones stored for 8 weeks at 2C in 2003. Values for each week are the cumulative weight loss from week 0 to the week stated. Clone Week 0z Week 2z Week 4z Week 6z Week 8z My Prob m = 0 Bluecrisp 0.0x 2.0 dw 3.4 c 5.2 c 7.5 cd 0.91 cv <0.0001 FL 97-136 0.0 4.3 ab 5.6 a 7.7 a 9.3 bcd 1.09 b <0.0001 FL 98-325 0.0 4.4 ab 5.2 a 6.5abc 9.7 bc 1.08 b <0.0001 FL 00-59 0.0 3.7bc 5.6 a 5.7 bc 7.7 cd 0.87 d <0.0001 Emerald 0.0 3.4 bc 3.9 bc 5.3 bc 6.7 d 0.77 d <0.0001 Star 0.0 2.8 cd 5.9 a 7.7 a 10.5 ab 1.30 a <0.0001 Windsor 0.0 5.4 a 4.9 ab 7.3 a 12.7 a 1.37 a <0.0001 Millennia 0.0 5.4 a 5.2 a 6.6 ab 8.2 bcd 0.88 d <0.0001 P > F <.0001 <.0001 <.0001 0.0001 zLoss from original weight at week 0. ym is the estimated change in weight(g) per week based on linear regression analysis. xMean of 30 berries individually sampled, 10 from each of three clamshells. wWeek means followed by the same letter are not significantly different (P<0.05) by ANOVA and TukeyÂ’s test. vSlopes followed by the same letter are not signi ficantly different (P<0.05) by two-sample ttests. Table 3.8. ANOVA for incidence of weight loss (%) of eight blueberry clones stored for 8 weeks in 2003. Source DF Mean Square F value Pr > F Model 39 31.264 104.01 <.0001 Clones 7 10.341 34.40 <.0001 Weeks 4 267.89 891.23 <.0001 Weeks x Clones 28 2.691 8.95 <.0001 Error 80 0.301 R-Square 0.98

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41 Table 3.9. Incidence of shriveling (%) fo r eight blueberry clones stored for 8 weeks at 2C in 2003. Number of berries per 100 Clone Week 0 Week 2 Week 4 Week 6 Week 8 Mz Prob m = 0 Bluecrisp 0.00y 20.25 bx 88.95 bc 93.07 bc 99.58 ab 13.60 abw <.0001 FL 97-136 0.00 11.17 bc 75.30 bcd 84.32 c 96.45 bc 13.30 a <.0001 FL 98-325 0.00 2.08 c 58.57 d 42.91 d 90.07 c 11.05 bc <.0001 FL 00-59 0.00 12.93 bc 77.82 bc 94.00 abc 98.64 ab 13.92 bc <.0001 Emerald 0.00 26.33 b 73.71 cd 87.17 c 98.16 ab 12.86 c <.0001 Millennia 0.00 66.30 a 99.44 a 99.42 a 100.00 a 11.66 ab <.0001 Star 0.00 16.10 bc 90.39 b 98.97 ab 99.44 ab 14.09 ab <.0001 Windsor 0.00 66.30 a 79.23 bc 94.89 abc 100.00 a 11.43 abc <.0001 P > F <.0001 <.0001 <.0001 0.0001 zm is the estimated change in number of shrive led berries per week ba sed on linear regression analysis. yMean of 30 berries individually sampled, 10 from each of three clamshells. xWeek means followed by the same letter are not significantly different (P<0.05) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not significan tly different (P<0.05) by two-sample t-tests. Table 3.10. ANOVA for incidence of shriveling (%) of eight blueberry clones stored for 8 weeks in 2003. Source DF Mean Square F value Pr > F Model 39 3345.82 193.57 <.0001 Clones 7 1174.40 67.94 <.0001 Weeks 4 29112.66 1684.31 <.0001 Weeks x Clones 28 207.70 12.02 <.0001 Error 80 17.29 R-Square 0.99

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42 Table 3.11. Incidence of shrivel severityz of eight blueberry clones stored for 8 weeks at 2C in 2003. Index values Clone Week 0 Week 2 Week 4 Week 6 Week 8 my Prob m = 0 Bluecrisp 1.00x 1.51 cw 3.05 abc 3.60 bc 5.10 ab 0.62 av 0.0001 FL 97-136 1.00 1.23 c 2.74 bc 3.07 c 4.41 b 0.53 b 0.0001 FL 98-325 1.00 1.04 c 2.19 c 2.11 d 4.50 b 0.50 cd 0.0001 FL 00-59 1.00 3.95 a 2.85 bc 3.63 bc 4.34 b 0.42 d 0.0012 Emerald 1.00 3.93 a 2.96 bc 3.48 bc 4.85 ab 0.46 cd 0.0005 Millennia 1.00 4.23 a 4.03 a 4.49 a 5.60 a 0.57 abcd 0.0001 Star 1.00 3.11 b 3.55 ab 4.26 ab 5.13 ab 0.57 abc 0.0001 Windsor 1.00 4.24 a 2.99 bc 4.63 a 5.65 a 0.59 abc 0.0001 P > F <.0001 0.0008 <.0001 0.0011 zEach berry was rated on a scale from 1 ( no shriveling) to 9 (extreme shriveling). ym is the estimated change in shrivel severity per week based on linear regression analysis. xMean of 30 berries individually sampled, 10 from each of three clamshells. wWeek 8 means followed by the same letter are not significantly different (P<0.05) by ANOVA and Tukey’s test. vSlopes followed by the same letter are not si gnificantly different (P <0.05) by two-sample t-tests. Table 3.12. ANOVA for Incidence of shrivel severi ty of eight blueberry clones stored for 8 weeks in 2003. Source DF Mean Square F value Pr > F Model 39 6.781 83.17 <.0001 Clones 7 5.103 62.59 <.0001 Weeks 4 49.080 601.94 <.0001 Weeks x Clones 28 1.157 14.20 <.0001 Error 80 0.0815 R-Square 0.98 The pH, SSC and TTA for each clone at each week were tested. No significant differences were found between the “crisp” and “non-crisp” clones. For the pH, all clones increased slightly except ‘Windsor’, which decreased, but had a high probability of having a slope of zero (Table 3.13). All clones started with similar pHs and after 8 weeks differences among the clones could be seen, but the “crisp” and “non-crisp” clones did not stand out from each other (Table 3.13, 3.14).

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43 SSC of the freshly-picked berries ra nged from 7.47 to 12.83 among the clones (Table 3.15). SSC did not separate the “crisp” from the “non-crisp” clones (Table 3.15). There were no significant interactions among th e storage times and clones with respect to SSC (Table 3.16). All but three of the slope s showed a decrease in SSC with slopes not significantly different from zero, except for FL 97-136 and FL 98-325, which had a tendency to increase with time (Table 3.15). The initial TTA values ranged from 0.22 to 1.45 for the clones (Table 3.17). There was no distinction between the “crisp” and “noncrisp” clones. Only four clones showed significant changes in TTA over time (Table 3.17). The TTA decreased over time for these four. There were differences over storage time and clones and a significant variance for clones x weeks of storage (Table 3.18). Table 3.13. Meanz pH of eight blueberry clones stored at 2C over 8 weeks in 2003. Clone Week 0 Week 2 Week 4 Week 6 Week 8 my Prob m = 0 Bluecrisp 3.84 ax 3.84 a 4.06 a 3.96 a n/a 0.029 dw 0.0336 FL 97-136 3.45 bc 3.68 ab 3.73 bc 3.72 bc 3.83 b 0.043 cd 0.0047 FL 98-325 3.65 ab 3.85 a 3.92 ab 3.94 ab 4.06 a 0.047 cd 0.0124 FL 00-59 3.37 c 3.44 c 3.45 de 3.50 cd 3.63 cd 0.021 cd 0.0231 Emerald 3.11 d 3.20 d 3.22 e 3.24 e 3.23 e 0.019 b 0.0236 Millennia 3.47 bc 3.14 d 3.42 de 3.50 cd 3.54 cd 0.018 bc 0.4239 Star 3.38 c 3.51 bc 3.64 cd 3.60 cd 3.67 bc 0.039 cd 0.0066 Windsor 3.46 bc 3.68 ab 3.46 de 3.50 de 3.48 d -0.010 a 0.5135 P > F <.0001 <.0001 <.0001 <.0001 <.0001 zMean of 3 clamshells individually sampled. ym is the estimated change in pH per week based on linear regression analysis. xWeek means followed by the same letter are not significantly diffe rent (P<0.05) by ANOVA and Tukey’s test. wSlopes followed by the same letter are not signi ficantly different (P<0.05) by two-sample ttests.

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44 Table 3.14. ANOVA for mean pH of eight blueberry clones stored at 2C over 8 weeks in 2003. Source DF Mean Square F value Pr > F Model 39 0.176 31.39 <.0001 Clones 8 0.724 129.13 <.0001 Weeks 4 0.155 27.55 <.0001 Weeks x Clones 27 0.026 4.65 <.0001 Error 76 0.006 R-Square 0.94 Table 3.15. Meanz SSC of eight blueberry clones st ored at 2C over 8 weeks in 2003. Clone Week 0 Week 2 Week 4 Week 6 Week 8 my Prob m = 0 Bluecrisp 12.83 ax 14.27 a 14.37 a 12.67 a n/a -0.020 abcw 0.9531 FL 97-136 9.00 abc 9.40 b 11.00 a 11.77 a 9.80 ab 0.495 bc 0.0092 FL 98-325 8.47 bc 12.77 ab 12.47 a 12.07 a 13.05 a 0.525 c 0.0232 FL 00-59 11.83 ab 11.30 ab 11.30 a 11.20 a 12.30 a -0.095 bd 0.6377 Emerald 7.47 c 8.43 b 9.80 a 8.93 a 7.60 b 0.288 b 0.2774 Millennia 12.13 ab 10.73 ab 11.30 a 10.47 a 9.10 ab -0.222 a 0.0928 Star 8.93 bc 10.70 ab 12.47 a 10.60 a 10.40 ab 0.338 bc 0.1705 Windsor 9.60 abc 11.33 ab 10.67 a 10.65 a 8.77 ab 0.022 ad 0.9254 P > F 0.0012 0.0176 0.1736 0.3142 0.0143 zMean of 3 clamshells individually sampled. ym is the estimated change in SSC per week based on linear regression analysis. xWeek means followed by the same letter are not significantly diffe rent (P<0.05) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not signi ficantly different (P<0.05) by two-sample ttests. Table 3.16. ANOVA for mean SSC of eight blueberry clones stored at 2C over 8 weeks in 2003. Source DF Mean Square F value Pr > F Model 39 8.47 3.00 <.0001 Clones 8 25.04 8.87 <.0001 Weeks 4 9.08 3.21 0.0171 Weeks x Clones 27 3.19 1.13 0.3323 Error 76 2.82 R-Square 0.61

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45 Table 3.17. Meanz TTA of eight blueberry clones st ored at 2C over 8 weeks in 2003. Clone Week 0 Week 2 Week 4 Week 6 Week 8 my Prob m = 0 Bluecrisp 0.22 dx 0.28 d 0.21 d 0.25 c n/a 0.003 aw 0.6538 FL 97-136 0.52 bcd 0.37 cd 0.47 c 0.45 c 0.46 bc -0.005 ab 0.6493 FL 98-325 0.42 cd 0.36 cd 0.31 cd 0.30 c 0.28 c -0.020 de 0.0074 FL 00-59 0.58 bcx 0.51 c 0.48 c 0.43 c 0.47 bc -0.025 c 0.0010 Emerald 1.45 a 0.71 b 0.76 ab 0.81 a 0.95 a -0.093 e 0.0288 Millennia 0.61 bc 1.16 a 0.85 a 0.76 ab 0.80 ab 0.007 abcd 0.8389 Star 0.75 b 0.50 c 0.47 c 0.51 bc 0.48 bc -0.038 e 0.0299 Windsor 0.48 bcd 0.41 cd 0.52 bc 0.40 c 0.38 c -0.007 bcd 0.4907 P > F <.0001 <.0001 <.0001 <.0001 0.0013 zMean of 3 clamshells individually sampled. ym is the estimated change in TTA per week based on linear regression analysis. xWeek means followed by the same letter are not significantly diffe rent (P<0.05) by ANOVA and Tukey’s test. wSlopes followed by the same letter are not si gnificantly different (P <0.05) by two-sample t-tests. Table 3.18. ANOVA for mean TTA of eight blueberry clones stored at 2C over an 8 weeks in 2003. Source DF Mean Square F value Pr > F Model 39 0.198 17.69 <.0001 Clones 8 0.723 64.72 <.0001 Weeks 4 0.079 7.06 <.0001 Weeks x Clones 27 0.060 5.41 <.0001 Error 77 0.011 R-Square 0.90 In 2004, to better determine if crisp-textured blueberries are different from commercial blueberries, two atmospheres were used – one being normal air and the other a low O2 / high CO2 CA. Two new clones were also added that were believed to have crisp texture: FL 00-180 and FL 00-270. 2004 Study Materials and Methods Five to eight blueberry plants of each of the clones ‘Bluecrisp’, FL 97-136, FL 98325, FL 00-59, FL 00-180, FL 00-270, ‘Emerald’, ‘Millennia’, ‘Star’ and ‘Windsor’ were

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46 netted in a commercial field at Windsor, Florida at the begi nning of the harvest season. As the berries from each clone matured they we re harvested at the blue stage and placed in 125 g clamshells. For each harvest a minimum of three clamshells per clone were taken. A total of 15 clamshells per clone we re needed for the CA storage test, and 15 clamshells were needed for the air storage test The name of the clone, date of harvest, storage environment and the storage time were written on each clamshell. The clamshells were placed in a cooler of ice for transpor t to a 2 C storage unit, where they were separated based on storage environment and st orage time. Storage time for air was 2, 4, 5, and 6 weeks and CA storage was for 2, 4, 6, and 8 weeks. All the berries for a particular storage environment and storage time were placed into a sealed 5 gallon (79.49 L) bucket, which had one intake and one outlet hose attached to it. The buckets for the same atmosphere were then hooked together and a minimum flow rate of 81ml/min was established through the buckets using pressurized gasses and needle value flow meters to prevent CO2 buildup. For the CA, a mixture of 15% CO2, 2% O2 and 83% N with a relative humidity of 90–95% was delivered to th e buckets. For the air atmosphere, a pure flow of air with a relative humidity of 90–95% was delivered to the buckets. The outlet tubes from the end of the bucket lines were checked each day for flow rate, CO2 and O2 concentrations. As each storage time ended, the lids of the buckets were taken off and the clamshells were removed for post-storage ex amination. Berries harvested for week 0 storage were examined without storage. For evaluation, 10 blueberries were ra ndomly taken from each clamshell and checked for decay, number of berries that were shriveled, severity of shriveling, leaking/collapse and firmness. To check for decay, each blueberry was visually

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47 inspected. Of the 10 berries examined, the number with mold was recorded. The same berries were examined for signs of shrive ling, starting at the s car end and going around the berry. Berries were recorded as shriveled or not shriveled. The severity of shriveling was recorded for each berry using a 9 point scale, from 1 (no signs of shriveling) to 9 (severely shriveled). Ten random berries pe r clamshell were visually examined for leaking fluids or cellular colla pse not caused by disease. For firmness testing, a set of 10 different blueberries were placed through the same Instron testing procedure that was done in 2003. The pH, SSC and TTA for berries in each clamshell were determined using the same procedures as in 2003. Results Before storage, FL 00-59 was the firm est clone (Table 3.19). As a group, the “crisp” clones were not exceptionally firm at the beginning of the storage test. By week 2 “crisp” clones ‘Bluecrisp’, FL 98-325 and FL 00-59 had a higher firmness then the other clones. At week 6, Tukey’s test s howed three (‘Bluecrisp’, FL 00-59 and FL 00180) of the four “crisp” clones sampled at th at time to be significantly firmer than the “non-crisp” clones (Table 3.19). As indicate d by the slopes (Table 3.19), some clones became firmer during storage, others less firm ‘Bluecrisp’ gained the most in firmness and ‘Millennia’ lost the most. Decay incidence in the air atmosphere storage increased over time for all clones except FL 00-59, which still had no decay af ter 6 weeks (Table 3.21). The week x clone interaction showed significance, but the week 6 Tukey’s test and the slopes showed that the “crisp” clones did not fare better th e “non-crisp” clones (Tables 3.21 and 3.22). Among the slopes FL 00-59 was the only clone th at differed significantly from the others (Table 3.21).

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48 The percent of leaking berries increased in all clones over time, except for FL 0059, which had only one leaking berry in all th e samples (Table 3.23). The week x clone interaction was significant for number of leak ing berries, but the week 6 Tukey’s test and the slopes showed no consistent differences between the “crisp” and “non-crisp” clones (Tables 3.23 and 3.24). Among the slopes th e only clone to stand out as being significantly different from the rest was FL 00-59. The incidence of shriveling in the air atmo sphere increased with storage time in all clones (Table 3.25). The week x clone inte raction was significa nt, but the week 6 Tukey’s test and the slopes showed no cons istent differences amongst the “crisp” and “non-crisp” clones (Tables 3.25 and 3.26). ‘Bluecrisp’, FL00-59 and FL00-180 had the lowest rates of shriveling when compared to slopes of the other clones (Tables 3.25). The same trend could be seen in the severity of shrivel over time as was seen in the frequency of shriveled berries over time (Tables 3.27 and 3.28). The pH, SSC and TTA for the blueberries stored in the air atmosphere did not differ significantly for the “cris p” and “non-crisp” clones (T able 3.29). Slopes indicated that there were only small and inconsistent pH changes during th e weeks of storage (Table 3.29). The ‘weeks’ component of the ANOVA analysis for pH was nonsignificant (Table 3.30). There were significant differe nces in SSC among the clones at week 0 (Table 3.31), and these differences were maintained throughout. SSC was not a factor that distinguished the “crisp” from the standard clones. All slopes for the clones had high probabilities of being zero and there was not a significant clone x week interaction (Tables 3.31 and 3.32).

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49 Clones varied widely in TA at the beginning of the storag e test (Table 3.33). As a group, the six crisp clones had lower TA than the four standard clones. Overall there were only minor changes in TA during storage. Table 3.19. Mean deformation forcez at 2mm depth for 10 bluebe rry clones stored in air for 8 weeks at 2C in 2004. 2mm Deformation Force (N) Clone Week 0 Week 2 Week 4 Week 5 Week 6 my Prob m = 0 Bluecrisp 2.50 bcdx 3.49 a 3.66 a 3.53 a 3.13 a 0.20 aw 0.0022 FL 97-136 2.26 cde 2.58 b 2.04 d 2.39 bcd M* 0.02 b 0.5897 FL 98-325 2.88 b 3.51 a 3.33 ab 2.57 bc M -0.04 d 0.6251 FL 00-59 3.42 a 3.49 a 3.06 bc 2.96 ab 3.51 a -0.11 cd 0.0009 FL 00-180 2.35 cde 2.64 b 2.52 cd 2.46 bc 3.19 a 0.02 b 0.5337 FL 00-270 1.89 f 1.78 c 1.65 e 1.85 de 1.75 b -0.02 d 0.4183 Emerald 2.01 ef 2.18 bc 2.05 de 2.17 cd 1.93 b 0.02 e 0.5131 Millennia 2.09 def 2.40 b 1.82 e 1.36 e 2.07 b -0.15 e 0.0206 Star 2.54 bc 2.66 b 2.52 cd 2.31 cd 2.06 b -0.04 f 0.3348 Windsor 2.19 def 2.66 b 2.05 de 2.55 bc 1.72 b 0.02 bc 0.7014 P > F <.0001 <.0001 <.0001 <.0001 0.0001 zMean of 30 berries individually sampled, 10 from each of 3 clamshells. ym is the estimated change in force(N) per week based on linear regression analysis. xWeek means followed by the same letter are not significantly diffe rent (P<0.05) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not si gnificantly different (P <0.05) by two-sample t-tests *Data missing Table 3.20. ANOVA for mean force needed to deform the berries by 2mm for 10 blueberry clones stored for 6 w eeks in 2004. (air atmosphere). Source DF Mean Square F value Pr > F Model 47 1.051 18.61 <.0001 Clones 9 4.253 75.28 <.0001 Weeks 4 0.538 9.53 <.0001 Weeks x Clones 34 0.259 4.59 <.0001 Error 96 0.056 R-Square .90

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50 Table 3.21. Incidence of decay (%) for 10 blue berry clones stored for 6 weeks in air storage at 2C in 2004. Clone Week 0 Week 2 Week 4 Week 5 Week 6 mz Prob m = 0 Bluecrisp 0.00 y 0.00 ax 13.33 a 13.33 cd 10.00 cde 2.39 ew 0.0176 FL 97-136 0.00 6.67 a 13.33 a 60.00 a 63.33 ab 11.18 ab 0.0002 FL 98-325 0.00 6.67 a 10.00 a 40.00 ab 83.33 a 11.95 a 0.0003 FL 00-59 0.00 0.00 a 0.00 a 0.00 d 0.00 e 0.00 f FL 00-180 0.00 0.00 a 0.00 a 30.00 abc 3.33 de 2.44 e 0.1510 FL 00-270 0.00 0.00 a 13.33 a 53.33 ab 36.67 abcd 8.13 bc 0.0009 Emerald 0.00 0.00 a 13.33 a 23.33 abcd 33.33 bcd 5.69 c 0.0012 Millennia 0.00 0.00 a 23.33 a 26.67 abcd 43.33 abc 7.30 bc 0.0012 Star 0.00 0.00 a 6.67 a 16.67 abcd 20.00 bcde 3.56 de .0217 Windsor 0.00 0.00 a 0.00 a 3.33 cd 30.00 bcd 3.60 d 0.0554 P > F .0087 0.2514 .0002 <0.0001 zm is the estimated change in the percentage of de caying berries per week ba sed on linear regression analysis. yMean of 30 berries individually sampled, 10 from each of 3 clamshells. xWeek 6 means followed by the same letter are not significantly differe nt (P<0.05) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not signifi cantly different (P<0.05) by two-sample t-tests Table 3.22. ANOVA for incidence of decay (%) for 10 blueberry clones stored for 6 weeks in air storage in 2004. Source DF Mean Square F value Pr > F Model 49 929.40 10.27 <.0001 Clones 9 1068.95 11.81 <.0001 Weeks 4 5949.10 65.72 <.0001 Weeks x Clones 36 336.77 3.72 <.0001 Error 100 90.52 R-Square 0.83

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51 Table 3.23. Incidence of leaking (%) for 10 bl ueberry clones stored for 6 weeks in air storage at 2C in 2004. Clone Week 0 Week 2 Week 4 Week 5 Week 6 mz Prob m = 0 Bluecrisp 0.00 y 3.33 bcx 6.67 b 20.00 abc 16.67 bc 3.22 dw 0.0040 FL 97-136 0.00 30.00 a 16.67 ab 53.33 ab 50.00 ab 7.90 bc 0.0017 FL 98-325 0.00 20.00 ab 10.00 b 63.33 a 70.00 a 11.26 a 0.0004 FL 00-59 0.00 0.00 c 3.33 b 0.00 c 0.00 c 0.00 g 0.7920 FL 00-180 0.00 0.00 c 3.33 b 20.00 abc 30.00 c 1.84 f 0.1818 FL 00-270 0.00 0.00 c 46.67 a 53.33 ab 30.00 abc 8.25 ab 0.0039 Emerald 0.00 3.33 bc 13.33 ab 30.00 abc 20.00 abc 4.45 cde 0.0017 Millennia 0.00 0.00 c 46.67 a 46.67 ab 26.67 abc 7.41 bc 0.0056 Star 0.00 3.33 bc 10.00 ab 16.67 abc 16.67 abc 3.08 ef 0.0297 Windsor 0.00 0.00 c 10.00 ab 10.00 bc 56.67 ab 7.30 bc 0.0087 P > F <.0001 0.0016 0.0004 0.0002 zm is the estimated change in the percent of leaking berries per week based on linear regression analysis. yMean of 30 berries individually sampled, 10 from each of three clamshells. xWeek 6 means followed by the same letter ar e not significantly diffe rent (P<0.05) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not si gnificantly different (P<0.05) by two-sample t-tests. Table 3.24. ANOVA for incidence of leaking (%) for 10 blueberry clones stored for 6 weeks in 2004. Source DF Mean Square F value Pr > F Model 49 952.39 10.56 <.0001 Clones 9 1322.88 14.67 <.0001 Weeks 4 5397.03 59.84 <.0001 Weeks x Clones 36 365.92 4.06 <.0001 Error 100 90.19 R-Square 0.84

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52 Table 3.25. Incidence of shriveling (%) for 10 bl ueberry clones stored for 6 weeks in air storage at 2C in 2004. Clone Week 0 Week 2 Week 4 Week 5 Week 6 mz Prob m = 0 Bluecrisp 0.00 y 3.33 abx 16.67 ab 33.33 bc 33.33 cd 6.26 dw 0.0001 FL 97-136 0.00 30.00 a 53.33 ab 86.67 a 83.33 ab 14.89 a 0.0001 FL 98-325 0.00 20.00 ab 16.67 ab 76.67 ab 86.67 a 14.22 ab 0.0001 FL 00-59 0.00 0.00 b 3.33 b 6.67 c 0.00 e 1.55 e 0.2875 FL 00-180 0.00 0.00 b 6.67 b 63.33 ab 6.67 de 5.29 d 0.0993 FL 00-270 0.00 10.00 ab 63.33 a 86.67 a 63.33 abc 14.11 ab 0.0002 Emerald 0.00 3.33 ab 26.67 ab 46.67 abc 53.33 abc 9.68 bc 0.0001 Millennia 0.00 0.00 b 70.00 a 60.00 ab 63.33 abc 13.05 abc0.0002 Star 0.00 6.77 ab 26.67 ab 66.67 ab 40.00 bcd 9.37 c 0.0029 Windsor 0.00 6.77 ab 40.00 ab 50.00 ab 76.67 abc 12.67 b 0.0001 P > F .0104 .0024 <.0001 <0.0001 zm is the estimated change in the percent of shriveled berries per week based on linear regression analysis. yMean of 30 berries individually sampled, 10 from each of three clamshells. xWeek 6 means followed by the same letter ar e not significantly diffe rent (P<0.05) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not si gnificantly different (P <0.05) by two-sample t-tests. Table 3.26. ANOVA for incidence of shriveling (%) of 10 blueberry clones stored at 2C for 6 weeks in 2004. Source DF Mean Square F value Pr > F Model 49 1843.39 16.37 <.0001 Clones 9 2132.30 18.94 <.0001 Weeks 4 13789.26 122.47 <.0001 Weeks x Clones 36 443.85 3.94 <.0001 Error 100 112.59 R-Square 0.89

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53 Table 3.27. Incidence of shrivel severityz of 10 blueberry clones st ored for 6 weeks in air storage at 2C in 2004. Index values Clone Week 0 Week 2 Week 4 Week 5 Week 6 my Prob m = 0 Bluecrisp 1.00 x 1.13 bcw 1.50 abc 1.73 e 2.03 cd 0.17 dv 0.0021 FL 97-136 1.00 2.13 a 2.57 bc 5.70 a 4.60 ab 0.71 ab 0.0001 FL 98-325 1.00 1.87 ab 1.47 bc 4.43 abc 6.13 a 0.77 a 0.0002 FL 00-59 1.00 1.00 c 1.10 c 1.13 e 1.00 d 0.01 e 0.3732 FL 00-180 1.00 1.00 c 1.13 c 3.10 cde 1.17 d 0.17 d 0.1424 FL 00-270 1.00 1.10 bc 3.17 ab 4.90 ab 4.00 abc 0.66 b 0.0004 Emerald 1.00 1.13 bc 2.23 abc 2.70 cde 2.30 bcd 0.33 c 0.0001 Millennia 1.00 1.00 c 3.77 a 4.03 abcd 3.50 bcd 0.56 b 0.0004 Star 1.00 1.17 bc 1.63 bc 2.53 cde 2.37 bcd 0.27 c 0.0025 Windsor 1.00 1.07 c 2.00 abc 2.07 de 4.30 abc 0.48 b 0.0003 P > F 0 .0002 0.0004 <.0001 <.0001 zEach berry was rated on a scale from 1 ( no shriveling) to 9 (extreme shriveling). ym is the estimated change in shrivel severity per week based on linear regression analysis. xMean of 30 berries individually sampled, 10 from each of three clamshells. wWeek 8 means followed by the same letter are not significantly different (P<0.05) by ANOVA and TukeyÂ’s test. vSlopes followed by the same letter are not signi ficantly different (P<0.05) by two-sample ttests. Table 3.28. ANOVA for incidence of shrivel severi ty of 10 blueberry clones stored for 6 weeks at 2C in 2004. Source DF Mean Square F value Pr > F Model 49 5.90 16.98 <.0001 Clones 9 0.35 23.4 <.0001 Weeks 4 8.14 94.62 <.0001 Weeks x Clones 36 32.90 6.74 <.0001 Error 100 2.34 R-Square 0.89

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54 Table 3.29. Meanz pH of 10 blueberry clones in an air atmosphere over 6 weeks in 2004. Week 0 Week 2 Week 4 Week 5 Week 6 my Prob m = 0 Bluecrisp 4.10 abx 4.05 b 4.05 ab 3.99 a 4.09 a -0.013 cdew 0.5636 FL 97-136 4.41 a 4.40 a 4.08 ab n/av n/a -0.073 a 0.0272 Fl 98-325 4.16 ab 4.37 a 4.26 a n/a n/a 0.019 def 0.6462 Fl 00-59 3.95 bc 3.86 bc 3.79 bc 3.81 ab 3.82 b -0.041 bc 0.1162 FL 00-180 3.55 cd 3.46 gf 3.66 cd 3.54 c 3.54 c 0.029 e 0.2422 FL 00-270 3.65 cd 3.68 cde 3.63 cd 3.63 bc 3.61 bc -0.004 cde 0.7421 Emerald 3.61 cd 3.79 cd 3.67 cd 3.60 c 3.58 bc 0.015 d 0.4940 Millennia 3.65 cd 3.30 g 3.51 cd 3.62 c 3.51 c -0.036 cde 0.4707 Star 3.46 d 3.60 def 3.54 cd 3.61 c 3.68 bc 0.020 f 0.2797 Windsor 3.49 d 3.56 ef 3.42 d 3.27 d 3.42 c -0.016 b 0.4805 P > F <.0001 <.0001 <.0001 <.0001 <.0001 zMean of three clamshells individually sampled. ym is the estimated change in titratable acid per week based on linea r regression analysis. xWeeks followed by the same letter are not significantly different (P<0.05) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not signifi cantly different (P<0.05) by two-sample t-testsvBerries were too decayed to obtain any data. Table 3.30. ANOVA for mean pH of 10 blueberry clones in an air atmosphere over 6 weeks in 2004. Source DF Mean Square F value Pr > F Model 45 0.248 23.12 <.0001 Clones 9 1.070 99.75 <.0001 Weeks 4 0.014 1.26 0.2931 Weeks x Clones 32 0.028 2.60 0.0002 Error 89 0.011 R-Square 0.92

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55 Table 3.31. Meanz SSC 10 blueberry clones in an ai r atmosphere over 6 weeks in 2004. Clone Week 0 Week 2 Week 4 Week 5 Week 6 my Prob m = 0 Bluecrisp 12.70 abx 12.90 a 12.23 a 12.20 ab 11.70 ab -0.117 bcw 0.6620 FL 97-136 14.50 a 12.97 a 12.10 ab n/av n/a -0.600 de 0.1292 FL 98-325 10.13 bc 12.13 a 9.73 abcd n/a n/a -0.100 abcd 0.7843 FL 00-59 12.20 abc 12.00 a 11.50 abc 12.30 a 12.90 a -0.175 a 0.4884 FL 00-180 8.27 c 7.00 b 8.03 d 8.03 c 7.80 d -0.058 ab 0.7967 FL 00-270 9.87 bc 8.93 ab 9.13 cd 8.40 ac 8.83 cd -0.183 bc 0.4450 Emerald 11.30 abc 11.77 a 9.20 bcd 9.63 abc 9.00 cd -0.525 d 0.0705 Millennia 11.87 abc 11.50 a 10.37 abcd 12.07 ab 10.93 abc -0.375 bc 0.0891 Star 10.33 bc 11.93 a 10.33 abcd 10.87 abc 10.60 abc 0.000 abc 1.0000 Windsor 10.27 bc 10.70 ab 9.43 abcd 9.10 bc 9.80 bcd -0.208 ce 0.2189 P > F 0.0015 0.0009 0.0006 0.0012 <.0001 zMean of three clamshells individually sampled. ym is the estimated change in SSC per week based on linear regression analysis. xWeeks followed by the same letter are not significan tly different (P<0.05) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not signifi cantly different (P<0.05) by two-sample t-tests vBerries were too decayed to obtain any data. Table 3.32. ANOVA for mean SSC of 10 blueberry clones in an air atmosphere over 6 weeks in 2004. Source DF Mean Square F value Pr > F Model 45 8.24 5.87 <.0001 Clones 9 33.12 23.61 <.0001 Weeks 4 5.30 3.77 0.0070 Weeks x Clones 32 1.38 0.98 0.5054 Error 89 1.40 R-Square 0.75

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56 Table 3.33. Meanz TTA of 10 blueberry clones in an air atmosphere over 6 weeks in 2004. Clone Week 0 Week 2 Week 4 Week 5 Week 6 my Prob m = 0 Bluecrisp 0.24 bcdx 0.23 de 0.26 def 0.31 c 0.26 b 0.003 dw 0.6885 FL 97-136 0.14 d 0.13 e 0.20 ef n/av n/a 0.015 cd 0.0777 FL 98-325 0.15 d 0.13 e 0.14 f n/a n/a -0.003 e 0.4974 FL 00-59 0.23 cd 0.31 cde 0.31 cdef 0.29 c 0.35 b 0.021 c 0.0701 FL 00-180 0.30 abcd 0.55 b 0.35 bcdef 0.43 bc 0.46 ab 0.013 bcde 0.6631 FL 00-270 0.29 abcd 0.4 bcd 0.44 abcd 0.13 bc 0.47 ab 0.027 b 0.0008 Emerald 0.44 ab 0.35 cd 0.41 abcde0.48 b 0.46 ab -0.007 cd 0.5744 Millennia 0.42 abc 0.90 a 0.54 ab 0.51 b 0.65 a 0.03 bcde 0.5852 Star 0.46 a 0.43 bc 0.49 abc 0.42 bc 0.43 ab 0.006 e 0.7353 Windsor 0.43 abc 0.40 bcd 0.56 a 0.76 a 0.36 ab 0.027 a 0.2646 P > F <.0001 <.0001 <.0001 <.0001 0.010 zMean of three clamshells individually sampled. ym is the estimated change in TTA per week based on linear regression analysis. xWeeks followed by the same letter are not signi ficantly different (P<0.0 5) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not signifi cantly different (P<0.05) by two-sample t-tests vBerries were too decayed to obtain any data. Table 3.34. ANOVA for mean TTA of 10 blueberry clones in an air atmosphere over 6 weeks in 2004. Source DF Mean Square F value Pr > F Model 49 0.105 13.69 <.0001 Clones 9 0.423 55.28 <.0001 Weeks 4 0.025 3.24 0.0152 Weeks x Clones 36 0.034 4.46 <.0001 Error 100 0.008 R-Square 0.87

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57 In the C.A., the clones over time tended to decrease (Table 3.35). Examining the clones at week 0 showed no difference between the “crisp” clones and the “non-crisp” clones, except FL 00-59 was firmer than all other clones (Table 3.35). By week 8, however, the five firmest clones were all “cr isp”, and of the “crisp” clones, only FL 00270 was quite soft. Week x clone interaction was significant with respect to firmness in a C.A. (Table 3.36). Very few berries developed decay in th e C.A. (Table 3.37). The ANOVA showed significant differences in weeks and clones but no week x clone intera ction (Table 3.38). Under controlled atmosphere storage, the number of leaking berries did not increase significantly over time except in ‘Emerald’, ‘Millennia’ and ‘Windsor’ (Table 3.39). Clone, week and week x clone interac tion were all significant, but no difference could be seen between the “crisp” and “non-cr isp” clones at week 8 or in the slopes (Tables 3.39 and 3.40). The lack of decay a nd leaking berries after the C.A. storage indicates that the high CO2 and low O2 con centrations retarded berry degradation and mold growth (Tables 3.37, 3.38, 3.39 & 3.40). The number of shriveled berries increased for each clone over time (Table 3.41). The clone effect and the week x clone intera ction was significant, but the “crisp” clones did not stand out as being bette r when compared to the “non-crisp” at week 8 or in the rate of shriveling as indicated by the sl opes (Tables 3.41 and 3.42). The severity of shrivel for each clone (Table 3.44) followed the same trend as the number of shriveled berries (Table 3.43).

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58 Table 3.35. Mean deformation forcez at 2mm depth for 10 blueberry clones stored in C.A. for 8 weeks at 2C in 2004. 2mm Deformation Force (N) Clone Week 0 Week 2 Week 4 Week 6 Week 8 my Prob m = 0 Bluecrisp 2.50 bcdx 3.15 a 3.15 a 3.22 a 2.99 a 0.05 abw 0.1585 FL 97-136 2.26 cdef 2.07 bcd 2.07 b 1.75 bc 2.12 bc -0.03 bc 0.4125 FL 98-325 2.88 b 3.11 a 2.73 a 1.93 b 2.22 bc -0.12 cdef 0.0015 FL 00-59 3.42 a 3.16 a n/a 3.16 a 2.70 ab -0.07 cde 0.0124 FL 00-180 2.35 cde 2.31 b M* 1.69 bcd 2.33 abc -0.03 a 0.2765 FL 00-270 1.89 f 1.79 cd M 1.23 de 1.20 de -0.10 cde 0.0001 Emerald 2.01 ef 1.67 d 1.24 c 0.96 e 0.99 e -0.14 cde 0.0001 Millennia 2.09 def 2.30 b M 1.35 cde 1.08 de -0.15 ef 0.0002 Star 2.54 bc 2.45 b M 1.39 cde 0.90 e -0.22 f 0.0001 Windsor 2.19 def 2.22 bc 2.00 b 1.95 b 1.74 cd -0.06 d 0.0021 P > F <.0001 <.0001 <.0001 <.0001 0.0001 zMean of 30 berries individually sampled, 10 from each of three clamshells. ym is the estimated change in force(N) per week based on linear regression analysis. xWeeks followed by the same letter are not signi ficantly different (P<0.0 5) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not significan tly different (P<0.05) by two-sample t-tests. data missing Table 3.36. ANOVA for deformation force at 2 mm for 10 blueberry clones stored for 8 weeks in 2004. Source DF Mean Square F value Pr > F Model 44 1.40 22.72 <.0001 Clones 9 4.69 76.41 <.0001 Weeks 4 2.47 40.14 <.0001 Weeks x Clones 31 0.30 4.81 <.0001 Error 90 0.06 R-Square 0.92

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59 Table 3.37. Incidence of decay (%) for 10 bluebe rry clones stored for 8 weeks in C.A. storage at 2C in 2004. Clone Week 0 Week 2 Week 4 Week 6 Week 8 Mz Prob m = 0 Bluecrisp 0.00 y 0.00 bx 0.00 a 3.33 a 0.00 a 0.17 bw 0.5000 FL 97-136 0.00 0.00 b 6.67 a 6.67 a 0.00 a 0.33 ab 0.4455 FL 98-325 0.00 6.67 a 10.00 a 10.00 a 0.00 a 0.17 b 0.8162 FL 00-59 0.00 0.00 b 0.00 a 0.00 a 0.00 a 0.0 b FL 00-180 0.00 0.00 b 3.33 a 0.00 a 0.00 a 0.0 b 1.0000 Fl 00-270 0.00 0.00 b 0.00 a 0.00 a 0.00 a 0.0 b Emerald 0.00 0.00 b 0.00 a 3.33 a 0.03 a 0.50 a 0.1230 Millennia 0.00 0.00 b 3.33 a 0.00 a 0.00 a 0.17 b 0.5000 Star 0.00 0.00 b 0.00 a 0.00 a 0.00 a 0.0 b Windsor 0.00 0.00 b 6.67 a 0.00 a 0.00 a 0.0 b 1.0000 P > F 0.0047 0.1444 0.1165 0.4711 zm is the estimated change in the fraction of molding berries per week based on linear regression analysis. yMean of 30 berries individually sampled, 10 from each of three clamshells. xWeeks followed by the same letter are not significantly different (P<0.05) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not si gnificantly different (P <0.05) by two-sample t-tests. Table 3.38. ANOVA for incidence of decay (%) for 10 blueberry clones stored for 8 weeks in C.A. storage in 2004. Source DF Mean Square F value Pr > F Model 49 61.30 2.21 0.0004 Clones 9 106.68 3.84 0.0003 Weeks 4 152.27 5.48 0.0005 Weeks x Clones 36 39.84 1.43 0.0834 Error 100 27.79 R-Square 0.52

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60 Table 3.39. Incidence of leaking (%) for 10 blueberry clones stored for 8 weeks in C.A. storage at 2C in 2004. Clone Week 0 Week 2 Week 4 Week 6 Week 8 mz Prob m = 0 Bluecrisp 0.00 y 3.33 ax 6.67 a 6.67 ab 6.67 a 0.83 cw 0.2323 FL 97-136 0.00 13.33 a 13.33 a 23.33 ab 16.67 a 2.17 bc 0.1023 FL 98-325 0.00 16.67 a 13.33 a 20.00 ab 3.33 a 0.50 ce 0.6265 FL 00-59 0.00 0.00 a 0.00 a 3.33 ab 0.00 a 0.17 de 0.5000 FL 00-180 0.00 0.00 a 10.00 a 6.67 ab 10.00 a 1.33 bcd 0.1130 FL 00-270 0.00 16.67 a 16.67 a 10.00 ab 0.00 a -0.33 e 0.7442 Emerald 0.00 6.67 a 6.67 a 23.33 ab 13.33 a 2.17 b 0.0111 Millennia 0.00 3.33 a 10.00 a 36.67 a 16.67 a 3.33 a 0.0108 Star 0.00 10.00 a 10.00 a 3.33 ab 20.00 a 1.67 bcd 0.1280 Windsor 0.00 3.33 a 6.67 a 0.00 b 20.00 a 1.83 bc 0.0207 P > F 0.0611 0.5941 0.0105 0.233 zm is the estimated change in the fraction of leaking berries per week based on linear regression analysis. yMean of 30 berries individually sampled, 10 from each of three clamshells. xWeeks followed by the same letter are not significantly different (P<0.05) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not si gnificantly different (P <0.05) by two-sample t-tests Table 3.40. ANOVA for incidence of leaking (%) for 10 blueberry clones stored for 8 weeks in 2004. Source DF Mean Square F value Pr > F Model 49 302.82 2.91 <.0001 Clones 9 365.21 3.51 0.0008 Weeks 4 1269.06 12.21 <.0001 Weeks x Clones 36 179.87 1.73 0.0175 Error 100 103.93 R-Square 0.59

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61 Table 3.41. Incidence of shriveling (%) for 10 bl ueberry clones stored for 6 weeks in air storage at 2C in 2004. Clone Week 0 Week 2 Week 4 Week 6 Week 8 mz Prob m = 0 Bluecrisp 0.00y 3.33 bcx 13.33 ab 10.00 c 20.00 cd 2.33 fgw 0.0135 FL 97-136 0.00 23.33 ab 33.33 a 70.00 a 63.33 a 8.67 a 0.0001 FL 98-325 0.00 6.67 abc 16.67 ab 26.67 abc 30.00 bcd 3.50 eg 0.0040 FL 00-59 0.00 0.00 c 0.00 b 6.67 c 13.33 d 1.67 g 0.0008 FL 00-180 0.00 0.00 c 13.33 ab 13.33 bc 20.00 cd 2.67 d 0.0002 FL 00-270 0.00 26.67 a 33.33 ab 53.33 ab 43.33 abc 5.67 bcde 0.0006 Emerald 0.00 13.33 abc 20.00 ab 36.67 abc 50.000 ab 6.17 bc 0.0001 Millennia 0.00 3.33 bc 10.00 ab 36.67 abc 20.00 cd 3.67 cdef 0.0059 Star 0.00 10.00 abc 10.00 ab 16.67 bc 33.33 abcd 3.67 def 0.0001 Windsor 0.00 6.67 abc 13.33 ab 30.00 abc 50.00 ab 6.17 b 0.0001 P > F 0.0007 0.0239 0.0002 <0.0001 zm is the estimated change in the fraction of shrive led per week based on linear regression analysis. yMean of 30 berries individually sampled, 10 from each of 3 clamshells. xWeeks followed by the same letter are not signi ficantly different (P<0.0 5) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not si gnificantly different (P <0.05) by two-sample t-tests. Table 3.42. ANOVA for incidence of shriveling (%) of 10 blueberry clones stored at 2C for 8 weeks in 2004. Source DF Mean Square F value Pr > F Model 49 784.49 12.77 <.0001 Clones 9 1089.61 17.73 <.0001 Weeks 4 5929.63 96.49 <.0001 Weeks x Clones 36 136.53 2.22 0.0010 Error 100 61.46 R-Square 0.86

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62 Table 3.43. Incidence of shrivel severityz of 10 blueberry clones stored for 8 weeks in C.A. storage at 2C in 2004. Index values Clone Week 0 Week 2 Week 4 Week 6 Week 8 my Prob m = 0 Bluecrisp 1.00 x 1.07 aw 1.13 a 1.33 b 1.40 ab 0.05 ev 0.0326 FL 97-136 1.00 1.63 a 1.87 a 3.37 a 2.13 a 0.20 a 0.0096 FL 98-325 1.00 1.70 a 1.83 a 1.93 ab 1.47 ab 0.06 cdf 0.2302 FL 00-59 1.00 1.00 a 1.00 a 1.10 b 1.13 b 0.02 g 0.0024 FL 00-180 1.00 1.00 a 1.43 a 1.30 b 1.53 ab 0.07 cef 0.0220 FL 00-270 1.00 1.73 a 1.77 a 2.33 ab 1.77 ab 0.11 bef 0.0499 Emerald 1.00 1.27 a 1.50 a 1.10 b 1.90 ab 0.11 bd 0.0001 Millennia 1.00 1.07 a 1.20 a 2.10 ab 1.63 ab 0.12 bc 0.0005 Star 1.00 1.20 a 1.20 a 1.23 b 1.53 ab 0.06 e 0.0041 Windsor 1.00 1.27 a 1.40 a 1.50 b 2.27 a 0.14 b 0.0001 P > F 0.0069 0.0316 0.0009 0.0060 zEach berry was related on a scale from 1 ( no shriveling) to 9 (extreme shriveling). ym is the estimated change in the shrivel i ndex value per week based on linear regression analysis. xMean of 30 berries individually sampled, 10 from each of 3 clamshells. wWeeks followed by the same letter are not si gnificantly different (P<0.05) by ANOVA and Tukey’s test. vSlopes followed by the same letter are not si gnificantly different (P <0.05) by two-sample t-tests. Table 3.44. ANOVA for incidence of shrivel severi ty of 10 blueberry clones stored for 8 weeks at 2C in 2004. Source DF Mean Square F value Pr > F Model 49 0.66 6.25 <.0001 Clones 9 1.19 11.23 <.0001 Weeks 4 2.93 27.67 <.0001 Weeks x Clones 36 0.28 2.63 <.0001 Error 100 0.11 R-Square 0.75 No differences in the pH, SSC and TTA c oncentration were found that consistently separated the “crisp” from the “non-crisp” clones. The pH di d separate the three “crisp” clones ‘Bluecrisp’, FL 97-136 and FL 98-325 fr om the other seven clones at week 0 (Table 3.45). By the end of the 6 weeks in C.A. storage, the differences between these

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63 three clones and the others were no longer sign ificant (Table 3.45). Changes in pH with time in storage were inconsistent fr om one clone to another (Table 3.45). There were differences in the SSC of th e various clones (Table 3.47), but these did not consistently separate th e “crisp” clones from the “noncrisp” clones. Although SSC did not change greatly during the storage period, there was a highly significant week effect (Table 3.47) and the tendency was for SSC to decline slowly over time. Acid concentrations did not separate the “crisp” from the “non-crisp” clones at week 0, but in Table 3.49 (C.A.) as in Tabl e 3.33 (air storage e xperiment) the “crisp” clones ‘Bluecrisp’, FL 97-136, FL 98-325 and FL 00-59 and were much lower in TTA then ‘Emerald’, ‘Millennia’, ‘Star’ and ‘Windsor’. The ‘weeks’ effect was highly significant (Table 3.50), and most clones tended to increase in TTA over time, but this was not consistent among clones. Table 3.45. Meanz pH of 10 blueberry clones in a c ontrolled atmosphere over 8 weeks in 2004. Clone Week 0 Week 2 Week 4 Week 6 Week 8 my Prob m = 0 Bluecrisp 4.10 abx 3.91 b 3.78 bcd 3.82 bc 3.95 bc -0.016 dw 0.3126 FL 97-136 4.41 a 4.35 a 3.93 b 4.10 b 4.22 b -0.033 ef 0.4213 FL 98-325 4.16 ab 4.36 a 4.47 a 4.57 a 4.61 a 0.053 a 0.0062 FL 00-59 3.95 bc 3.69 bc 3.65 bcde 3.67 c 3.62 de -0.036 f 0.0088 FL 00-180 3.55 cd 3.35 de 3.44 e M* 3.42 e -0.010 cde 0.3669 FL 00-270 3.65 cd 3.49 cde 3.42 e M 3.52 de -0.012 de 0.1983 Emerald 3.61 cd 3.68 bc 3.83 bc 3.68 c 3.79 cd 0.024 b 0.0467 Millennia 3.65 cd 3.24 e 3.57 de 3.64 c 3.59 de 0.008 bc 0.7053 Star 3.46 d 3.50 cde 3.45 de M 3.34 e -0.018 de 0.0271 Windsor 3.49 d 3.54 cd 3.33 e 3.27 d 3.40 e -0.015 ef 0.2195 P > F <.0001 <.0001 <.0001 <.0001 <.0001 zMean of three clamshells individually sampled. ym is the estimated change in titratable acid per week based on linea r regression analysis. xWeeks followed by the same letter are not significantly different (P<0.05) by ANOVA and Tukey’s test. wSlopes followed by the same letter are not si gnificantly different (P <0.05) by two-sample t-tests. Missing data

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64 Table 3.46. ANOVA for mean pH of 10 blueberry clones in a controlled atmosphere over 8 weeks in 2004. Source DF Mean Square F value Pr > F Model 46 0.390 27.87 <.0001 Clones 9 1.757 125.54 <.0001 Weeks 4 0.060 4.32 0.0030 Weeks x Clones 33 0.054 3.83 <.0001 Error 94 0.014 R-Square 0.93 Table 3.47. Meanz SSC of 10 blueberry clones in a controlled atmosphere over 8 weeks in 2004. Clone Week 0 Week 2 Week 4 Week 6 Week 8 my Prob m = 0 Bluecrisp 12.70 abx 13.63 ab 12.37 a 11.80 ab 12.73 a -0.040 bcw 0.7219 FL 97-136 14.50 a 13.83 a 12.20 ab 12.97 a 12.40 ab -0.274 d 0.0215 FL 98-325 10.13 bc 10.47 cd 11.00 abc 10.47 abc 10.43 abcd -0.100 ab 0.4132 FL 00-59 12.20 abc 11.87 abc 12.60 a 12.43 ab 12.23 ab 0.024 a 0.7538 FL 00-180 8.27 c 8.40 d 7.77 d M* 8.10 d -0.034 bc 0.7010 FL 00-270 9.87 bc 9.93 cd 9.20 cd M 8.97 cd -0.128 c 0.1667 Emerald 11.30 abc 10.20 cd 9.50 cd 10.03 bc 8.73 cd -0.309 d 0.0072 Millennia 11.87 abc 12.07 abc 11.17 abc 12.10 ab 10.07 bcd -0.250 cd 0.0343 Star 10.33 bc 10.73 cd 10.93 abc M 9.63 cd -0.099 abc 0.5232 Windsor 10.27 bc 11.23 bc 9.33 cd 8.80 c 10.93 abc 0.031 bc 0.7512 P > F 0.0015 <.0001 <.0001 0.0008 <.0001 zMean of three clamshells individually sampled. ym is the estimated change in SSC per week based on linear regression analysis. xWeeks followed by the same letter are not significan tly different (P<0.05) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not significan tly different (P<0.05) by two-sample t-tests. Missing data Table 3.48. ANOVA for mean SSC of 10 blueberry clones in a controlled atmosphere over 8 weeks in 2004. Source DF Mean SquareF value Pr > F Model 46 7.76 7.55 <.0001 Clones 9 33.19 32.30 <.0001 Weeks 4 3.88 3.78 0.0068 Weeks x Clones 33 1.26 1.22 0.2251 Error 94 1.03 R-Square 0.79

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65 Table 3.49. Meanz TTA of 10 blueberry clones in a controlled atmosphere over 8 weeks in 2004. Clone week 0 week 2 week 4 week 6 week 8 my Prob m = 0 Bluecrisp 0.24 bcdx 0.26 cd 0.34 bc 0.30 cd 0.28 ef 0.004 dw 0.4769 Fl 97-136 0.14 d 0.15 d 0.31 bc 0.24 de 0.19 f 0.008 cdfg0.2948 Fl 98-325 0.15 d 0.13 d 0.12 c 0.12 e 0.12 f 0.004 e 0.0586 Fl 00-59 0.23 cd 0.32 bc 0.31 bc 0.34 cd 0.44 cde 0.025 b 0.0001 FL 00-180 0.30 abcd 0.45 b 0.40 ab M* 0.51 bcd 0.022 bc 0.0364 FL 00-270 0.29 abcd 0.44 b 0.45 ab M 0.41 cde 0.011 cdg 0.2002 Emerald 0.44 ab 0.37 bc 0.36 bc 0.46 bc 0.38 de -0.005 ef 0.4194 Millennia 0.42 abc 0.88 a 0.55 ab 0.51 ab 0.55 bc 0.001 eg 0.9773 Star 0.46 a 0.44 b 0.52 ab M 0.77 a 0.042 a 0.0024 Windsor 0.43 abc 0.39 bc 0.65 a 0.63 a 0.61 ab 0.021 b 0.0873 P > F <.0001 <.0001 <.0001 <.0001 <.0001 zMean of three clamshells individually sampled. ym is the estimated change in TTA per week based on linear regression analysis. xWeeks followed by the same letter are not significantly different (P<0.05) by ANOVA and TukeyÂ’s test. wSlopes followed by the same letter are not si gnificantly different (P <0.05) by two-sample t-tests *Missing data Table 3.50. ANOVA for mean TTA of 10 blueberry clones in a controlled atmosphere over 8 weeks in 2004. Source DF Mean SquareF value Pr > F Model 46 0.087 17.93 <.0001 Clones 9 0.329 67.90 <.0001 Weeks 4 0.058 12.04 <.0001 Weeks x Clones 33 0.025 5.06 <.0001 Error 94 0.005 R-Square 0.90 Discussion Postharvest storage of blue berries has been studied extensively over the past several decades (3, 5, 7, 30, 31, 35, 38, 46). From these studies it has been determined that low temperatures and CA storage can delay senescence in blueberries by several weeks. Our 2004 CA storage study confirms thes e results with the lack of decay (Table 3.37) and reduced severity of shrivel (Table 3.43) on blueberr ies during the 8 weeks they

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66 were stored. The 2004 air storage experiment (Table 2.31) confirms past research (4, 25, 29, 30, 32, 37) showing that blueberries kept at 1 to 5C in an air atmosphere can store for 2 weeks without decay. Air storage tests were done in 2003 and 2004. With respect to decay rates, the 2003 air experiment more closely resembles pr evious studies (5, 7, 23, 31) than the 2004 study. The constant air flow through the bucke ts in 2004 may be the reason for the lack of decay. Weight loss increased over time in the 2003 air storage test. The same was found by Miller and Mcdonald (30), and Sm ittle and Miller in 1988 (46). Firmness decreased over time in the 2003 air storage test and in the 2004 CA storage, as had been previously seen by Ferraz (15). Comparing the air and CA storage tests done in 2004 shows that the blueberries stored in air decayed faster (Tables 3.21 and 3.37) and shriveled more than berries stored in CA. These results agree with Ceponis and Cappellini’s study done in 1985 (7) and the Smittle and Miller study done in 1988(46). Co mparing the different parameters in each storage treatment to each other did not reve al any connection between them. Clone FL 00-59 was the only blueberry that did not s how any signs of decay (Tables 3.21 and 3.37) in the air and CA storage test. The clone also had the lowest levels of leaking and shriveling in both the air and CA storage tests. Reasons for its exceptional storage life are yet unknown. A few studies (30, 31) have shown that diffe rences in the storage life of blueberry clones can best be seen if the berries are kept at room temperature for a few days before examination. Tests should be conducted to determine if the “crisp” clones could be distinguished more easily from the “non-cris p” clones if this procedure was followed.

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67 The properties that cause the crisp textur e in blueberries is yet unknown. When the skin of one of the “crisp” clones is pealed away, the pulp has a cons istency very similar to that of “non-crisp” clones. Examination of the “crisp” and “noncrisp” blueberries at the cellular level could help uncover the prope rties responsible for the crisp texture in blueberry.

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68 CHAPTER 4 CONCLUSIONS One of the major goals of these experiments was to find some objective test that could distinguish the six clone s that had been subjectively identified as being “crisp” from other blueberry cultivars that had been identified as not “crisp”. The consumer sensory panel study in 2004 confirmed that most untrained subjects could recognize “crispness” in blueberries, alt hough they did not necessarily pref er it. This indicates that there is some objective realit y to the “crisp” phenotype. Shear-cell testing appeared to be the most promising objective test for the “crisp” phenotype clones. These tests had good repe atability over two sample dates and gave good separation between the “crisp” clones ‘Bluecrisp’, FL 00-59 and FL 00-180 and other clones in the test. However, putativ ely crisp clones FL 98-325 and FL 00-270 were not separated from conventional cultivars by shea r-cell testing. Another goal of the experiments was to see if “crisp” clones, when compared with “non-crisp” clones, showed a uni que softening pattern as they went from white to blue on the plant. Firmness decreased from white to pink stages among all clones, with a similar pattern for all the clones. This decrease in firmness matc hes that of previous studies done on blueberry ripening. In this study it was hypot hesized that “crisp” berries would soften less as they ripened when compared with “ non-crisp” clones, but th is was not the case. The next objective of this study was to see if the “crisp” texture could be distinguished by firmness testing. The resist ance to deformation of 99 clones was tested along with four of the six “crisp” clones. Th e only clone that was st atistically different

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69 from the other clones by this measure was th e “crisp” clone FL 98-325. From this it can be seen that the crisp characteristic is not closely associated with the resistance to deformation of the blueberry. The final objective of this study was to determine if the “cris p” characteristics contributed to longer postharvest life. In 2003, the “crisp” cl ones did not store longer in air than the “non-crisp” clones. In 2 004, the “crisp” clone FL 00-59 had a longer postharvest life than any of th e other clones in air storage. Also, the same “crisp” clones that distinguished themselves in the shearcell tests, ‘Bluecrisp’, FL 00-59 and FL 00180, also showed great resistan ce to shriveling in air storag e. A correlation between high shear-cell values and low shriveling during stor age is possible. Comparing the air storage and C.A. storage tests of 2004 showed that if the “crisp” characteris tic contributes to a longer postharvest life, it is onl y in an air atmosphere. When the “crisp” blueberries were placed into C.A. storage, their adva ntage over regular clones was lost.

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70 LIST OF REFERENCES 1. Abbott, J. A. and F. R. Harker. Textur e. Produce quality and safety laboratory. USDA. Last accessed 8/5/2005. www.ba .ars.usda.gov/hb66/021texture.pdf. 2. Adams, F. H. The uphill thrill of blueberri es. SunnyRidge farm, Inc. Last accessed 9/18/2004. http://www.sunnyridge.com/aboutus /uphill_thrill_of_blueberries.htm. 3. Ballinger, W. E. and L. J. Kushman. 1970. Relationship of stage of ripeness to composition and keeping quality of highbush bl ueberries. J. Amer. Soc. Hort. Sci. 95:239-242. 4. Ballinger, W. E., L. J. Kushman and D. D. Hamann. 1973. Factors affecting the firmness of highbush blueberries. J. Amer. Soc. Hort. Sci. 98:583-587. 5. Ballinger, W. E., E. P. Maness and W. F. McClure. 1978. Relationship of stage of ripeness and holding temperature to decay development of blueberries. J. Amer. Soc. Hort. Sci. 103:130-134. 6. Ballington, J. R., W. E. Ballington. Fr uit quality characteristics of 11 Vaccinium species. J. Amer. Soc. Hort. Sci. 109:684-689. 7. Ceponis, M. J., and R. A. Capellini. 1985. Reduce decay in fresh blueberries with controlled atmospheres. Hortscience. 20:228-229. 8. Crocker, T. E. and P. M. Lyrene. 1985. Su rvey of blueberry acreage in Florida. Proc. Fla. State Hort. Soc. 98:162-164. 9. Crocker, T. E. and L. Willis. 1989. Surv ey of southern highbush and rabbiteye blueberries in Florida. Proc. Fla. State Hort. Soc. 102:204-206. 10. Cross, Becky. 2002. Blueberry Statistic s. USDA Publication. Last accessed 9/18/2004. http://www.nass.usda .gov/nj/intern et0302info.pdf. 11. Dave Wilson Nursery. 2004. Fruit Tas ting Report. Last accessed 8/5/2005. www.davewilson.com/2004TasteReport.pdf. 12. Edwards, Jr., T. W., W. B. Sherman and R. H. Sharpe. 1970. Fruit development in short and long cycle blueberr ies. Hortscience. 5:274-275.

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71 13. Edwards Jr., T. W., W. B. Sherman and R. H. Sharpe. 1974. Evaluation and inheritance of fruit color, size, scar, firmness and plant vigor in blueberry. Hortscience. 9:20-22. 14. Ehlenfeldt, M. K., and R. B. Martin Jr 2002. A survey of fruit firmness in highbush blueberry and species-introgressed bluebe rry cultivars. Hortscience. 37:386-389. 15. Ferraz, A. C. O., S. A. Sargent and A. J. Fox. 2000. Delays to cooling and postharvest quality of fres h, Florida blueberries. Proc Fla. State Hort. Soc. 113:268-271. 16. Ferraz, A. C. O., S. A. Sargent and A. J. Fox. 2000. A nondestructive method for measuring firmness of blueberry fruit. Proc. Fla. State Hort. Soc. 114:138-142. 17. Finn, C. E., and J. J. Luby. 1992. Inheritance of fruit quality traits in blueberry. J. Amer. Soc. Hort. Sci. 117:617-621. 18. Food Directorate. Supressed polyga lacturonase activity Flavr SavrTM tomato. Canadian Food Inspection Agency. Last accessed 8/5/2005. http://www.hcsc.gc.ca/food-aliment/mh-dm/ofb-bb a/nfi-ani/e_ofb-095-048-a.html. 19. Galletta, G. J., W. E. Ballinger, R. J. Monroe, and L. J. Kushman. 1971. Relationship between fruit acidity and sol uble solids levels of highbush blueberry clones and fruit keeping quality. J. Amer. Soc. Hort. Sci. 96:758-762. 20. Giacalone, G., C. Peano, A. Guarinoni, G. Beccaro, and G. Bounous. 2002. Ripening curve of early, midseason, a nd late maturing highbush blueberry cultivars. Acta Hort iculturae. 574:119-121. 21. Harker, F. R., M. G. H. Stec, I. C. Hallett and C. L. Bennett. 1997. Texture of parenchymatous plant tissue: a comparison between tensile and other instrumental and sensory measurements of tissue streng th and juiciness. Postharvest Biology and Technology. 11:63-72. 22. Instron. Food texture fixtures Kramer shear cell. Instron Corper ation. Last accessed 8/5/2004. www.instron.com/wa/libra ry/streamfile2.aspx?sdoc=360. 23. Jackson, E. D., K. A. Sandfor, R. A. Lawrence, K. B. McRae and R. Stark. 1999. Lowbush blueberry quality changes in re sponse to prepacking delays and holding temperatures. Postharvest Bi ology and Technology. 15:117-126. 24. Kader, A. A, ed. Postharvest technology of horticultural crops. Oa kland: California. University of California Agricult ure and Natural Resources. 2002. 25. Kays, J. A Research Cornucopia. Ex plore. Fall 2003 vol. 8. Last accessed 9/18/2004. http://rgp.ufl.edu/publicati ons/explore/v08n2/feature_02.html.

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72 26. Kushman, L. J. and W. E. Ballinger. 1968. Acid and sugar changes during ripening in ‘Wolcott’ blueberries. J. Amer. Soc. Hort. Sci. 92:290-295. 27. Lyrene, P. M. 2002. Breeding southern hi ghbush blueberries in Florida. Acta Horticulturae. 574:149-152. 28. Lyrene, P. M. and W. B. Sherman. 1988. Cultivation of highbush blueberry in Florida. Proc. Fla. St ate Hort. Soc. 101:269-272. 29. Miller, W. R. and D. A. Smittle. 1987. Storage quality of hand and machine harvested rabbiteye blueberries. J. Amer. Soc. Hort. Sci. 112:487-490. 30. Miller, W.R., R. E. McDonald and T. E. Crocker. 1988. Fruit quality of rabbiteye blueberries as influenced by weekly ha rvests, cultivars, and storage duration. Hortscience. 23:182-184. 31. Miller, W. R. and R. E. McDonald. 1993. Quality of two Florida blueberry cultivars after packag ing and storage. Hortscience. 28:144-147. 32. Miller, W. R., E. J. Mitcham, R. E. McDonald, and J. R. King. 1994. Postharvest storage quality of Gamma-irradiated ‘Clim ax’ rabbiteye blueberries. Hortscience. 29:98-101. 33. NeSmith, D. S., S. E. Prussia and G. Krewer. 1999. Firmness of ‘Brightwell’ rabbiteye blueberry in response to vari ous harvesting and handling procedures. Blueberry Research at th e University of Georgia. Research Report No. 662. pp.1216. 34. NeSmith, D. S., S. Prussia, M. Tetteh and G. Krewer. 2002. Firmness of rabbiteye blueberries ( Vaccinium ashei Reade) during harves ting and handling. Acta Horticulturae. 574:287-293. 35. Nunes, M. C. N., J. P. Emond, and J. K. Brecht. 2004. Quality curves for highbush blueberries as a function of the storage termperature. Proc. 9th North Amer. Blueberry Research Conf. 423-439. 36. Oregon State University. Postharvest Hand ling of Blueberry. Northwest Berry and Grape Information Network. Lasted accessed 9/18/2004. http://berrygrape.oregonstat e.edu/fruitgrowing/berrycr ops/blueberry/postharv.htm. 37. Ourechy, D. K., and M. C. Bourne. 1968. Measurement of strawberry texture with an Instron Machine. Proc Am er. Soc. Hort. Sci. 93:317-325. 38. Perkins-Veazie, P., J. R. Clark, J. K. Collins and J. Magee. 1995. Southern highbush blueberry clones differ in postha rvest fruit quality. Fruit Variety Journal. 49:46-52.

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73 39. Proctor, Andrew and Terrence J. Miesle. 1991. Polygalacturonase and Pectinmethylesterase activities in deve loping highbush blueberries. Hortscience. 26:579-581. 40. Saltveit, M. E. and W. E. Ballinger. 1 983. Effects of anaerobic nitrogen and carbon dioxide atmospheres on ethanol production and postharvest quality of blueberries. J. Amer. Soc. Hort. Sci. 108:459-462. 41. Sato, Akihiko and M. Yamada. 2003. Berry texture of table wine, and dual-purpose grape cultivars quantified. Hortscience. 38:578-581. 42. Sharpe, R. H., and W. B. Sherman. 1971. Breeding blueberries for low-chilling requirements. Hortscience. 6:144-161. 43. Sherman, Wayne. New plants for Florida: stone fruit. EDIS. Florida Cooperative Extension Service Publication. Last accessed 8/5/2004. http://edis.ifas.ufl.edu/AG209. 44. Silva, Juan L., E. Marroquin, F. B. Matta, J. O. Garner Jr., and J. Stojanovic. 2005. Physicochemical, carbohydrate and sens ory characteristics of highbush and rabiteye blueberry cultivars. Journal of the Science of Food and Agriculture. 85:1815-1821. 45. Slaughter, D. C. and R. P. Rohrb ach. 1985. Developing a blueberry firmness standard. Transactions of the ASAE. 28:986-992. 46. Smittle, D. A. and W. R. Miller. 1988. Rabbiteye blueberry storage life and fruit quality in controlled atmospheres and ai r storage. J. Amer. Soc Hort. Sci. 113:723728. 47. Sousa, M. B. W. Canet, M. D. Alvarez and M. E. Torosa. 2005. The effect of the pre-treatment and long-term frozen stor age on the quality of raspberry (cv. Heritage). European Food Res earch and Technology. 221: 132-144. 48. U.S.D.A. Noncitrus fruits and nuts 2003 su mmary. National Agricultural Statistics Service. Last accessed 8/4/2005. http://jan.mannlib.cornell.edu/repo rts/nassr/fruit/pnf -bb/ncit0704.txt 49. Williamson, J. G. and P. M. Lyrene. 1991. Commercial blueberry production in Florida. Florida Cooperative Extens ion Service Publication, IFAS. 50. Williamson, J. G. and P. M. Lyrene. Bluebe rry varieties for Florida. EDIS, Florida Cooperative Extension Service Publi cation HS21500. Last accessed 9/18/2004. http://www.edis.ifas.ufl.edu/HS215.

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74 BIOGRAPHICAL SKETCH Les Padley Jr. was born in Largo, Flor ida, on January 9, 1980, to Les and Pam Padley. He graduated high school from the Center for Advanced Technologies in 1998, and received his Bachelor of Science de gree from Florida Southern College in environmental horticultural and business. Moving to Gainesville in 2002, he began studies for his Master of Scie nce degree in plant breeding at the University of Florida. On November 20, 2004, Les Padley Jr. was married to Michelle Cook in Gainesville, Florida. He plans on continuing his education with a PhD in the field of Horticulture studying plant breeding in cucurbits.