• TABLE OF CONTENTS
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 Title Page
 Table of Contents
 Acknowledgement
 Introduction
 Methods and materials
 Results
 Discussion
 Summary and conclusions
 Literature cited
 Tables














Group Title: Bulletin - University of Florida. Agricultural Experiment Station ; no. 604
Title: A survey of the mineral nutrition status of Valencia orange in Florida
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00027230/00001
 Material Information
Title: A survey of the mineral nutrition status of Valencia orange in Florida
Series Title: Bulletin University of Florida. Agricultural Experiment Station
Physical Description: 59 p. : ; 23 cm.
Language: English
Creator: Koo, R. C. J ( Robert Cheng Jen ), 1921-
Reitz, H. J
Sites, J. W ( John Wilbur ), 1912-
Publisher: University of Florida Agricultural Experiment Station
Place of Publication: Gainesville Fla
Publication Date: 1958
 Subjects
Subject: Oranges -- Nutrition -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
bibliography   ( marcgt )
non-fiction   ( marcgt )
 Notes
Bibliography: Bibliography: p. 43-44.
Statement of Responsibility: R.C.J. Koo, H.J. Reitz and J.W. Sites.
General Note: Cover title.
General Note: "A contribution from the Citrus Experiment Station"--T.p.
 Record Information
Bibliographic ID: UF00027230
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: aleph - 000927028
oclc - 18287668
notis - AEN7731

Table of Contents
    Title Page
        Page 1
    Table of Contents
        Page 2
    Acknowledgement
        Page 2
    Introduction
        Page 3
    Methods and materials
        Page 4
        Page 5
        Page 6
        Page 7
    Results
        Page 8
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
    Discussion
        Page 20
        Page 21
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
    Summary and conclusions
        Page 41
        Page 42
    Literature cited
        Page 43
        Page 44
    Tables
        Page 45
        Page 46
        Page 47
        Page 48
        Page 49
        Page 50
        Page 51
        Page 52
        Page 53
        Page 54
        Page 55
        Page 56
        Page 57
        Page 58
        Page 59
        Page 60
Full Text



Bulletin 604


December 1958


UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATIONS
J. R. BECKENBACH, Director
GAINESVILLE, FLORIDA
(A contribution from the Citrus Experiment Station)











A Survey of the Mineral Nutrition Status

of Valencia Orange in Florida


R. C. J. Koo, H. J. REITZ AND J. W. SITES









TECHNICAL BULLETIN









Singles copies free to Florida residents on request to
AGRICULTURAL EXPERIMENT STATION
GAINESVILLE, FLORIDA









CONTENTS
Page

INTRODUCTION .. ......- ....-...---.. ....... --------------- .. -.. 3
METHODS AND MATERIALS .. ...... ... ........- ... ------------ ------- 4
Selection of Groves ... ..........- ....... -- ------------------- 4
CollecLion and Preparation of Samples ......-.....----- ---- .....- --- 5
M methods of A analysis .. .......... ............... .... ----
Mineral Composition of Leaves and Fruits ........---------- -.-.. 6
Soil A naly is .. ...... .... .... ......--- .............--- 7
Fruit Qualities .......... ....... .......--..--------- 7
RESULTS .................. ----------....... 8
Field Data .............. ..... ........-- -------- 8
Soil Type ....... .......... ....... .... ... ...... ------- 8
Age .... .............. ...----------- -- ------ 9
Planting Distance ... ..... ........-.... --------- -e--- 9
Fruit Production .... .... ................--- -- --- -------- 11
Fertilization Practices .... --..... ---------------- 11
Spray and Dust Programs ........ ... ------------.- --- 15
Irrigation -. ............ ... ......-- -------- 15
Laboratory Data ... ..... .. .- ---------------- -- 16
External Fruit Quality ...... ............ .. ...--- ------ .. 16
Internal Fruit Quality ... ..... .... ..... ------------ 17
Mineral Composition of Leaves .... .. ....... ...---- -------- --..-- 19
Mineral Composition of Fruit ...... -.. ......------- --..- 19
Mineral Composition of Soil .. ..- .... -.......-. -- -------------- 20
DISCUSSION ..... ....... ..........-..... ...- ..... ..- --------- 20
Influence of Planting Distance ................... ... .... -- ------------- 22
Influence of Fertilization Practices ... -......---. ----------------------- 24
Fruit Production .- -.. .- ... ....... -- -----------------24
Fruit Qualities .................----.. .------ 25
Leaf, Fruit, and Soil Composition ...... ------------------ -- --..-. 27
Influence of Soil Reaction ... ...... .......--- -------- 29
Influence of Copper in Soil ...... ...... -----------. ---- ...... 31
Influence of Spray and Dust Program ...........-.......----- ..- 32
Influence of Irrigation ....... ...............- .... -.-.... ...- ------ ---- 33
Relation of Mineral Composition of Fruit and Leaf to Fruit Quality.... 36
Relation Between Mineral Compositions of Leaf and Fruit ...........-.... 38
The Roles of Leaf, Fruit and Soil Analysis in Studying the
Mineral Nutrition of Citrus ...............- .. ----.------... 40
SUMMARY AND CONCLUSIONS ........ -...--- ......--- ---. ....- ..... -------.. 41
LITERATURE CITED -..... ....... ... ...... ---------- ------------------ .. 43
A PPEN DIX .......... .... --- -...- -. ...- ...-...... .... ..- -- ...- 45



ACKNOWLEDGMENTS

1. This study was financed in part by a grant from the International
Minerals and Chemical Corporation of Chicago, Illinois.
2. The authors wish to express their appreciation to the many pro-
duction managers and independent growers for their generous cooperation
in supplying groves and records which made this study possible.









CONTENTS
Page

INTRODUCTION .. ......- ....-...---.. ....... --------------- .. -.. 3
METHODS AND MATERIALS .. ...... ... ........- ... ------------ ------- 4
Selection of Groves ... ..........- ....... -- ------------------- 4
CollecLion and Preparation of Samples ......-.....----- ---- .....- --- 5
M methods of A analysis .. .......... ............... .... ----
Mineral Composition of Leaves and Fruits ........---------- -.-.. 6
Soil A naly is .. ...... .... .... ......--- .............--- 7
Fruit Qualities .......... ....... .......--..--------- 7
RESULTS .................. ----------....... 8
Field Data .............. ..... ........-- -------- 8
Soil Type ....... .......... ....... .... ... ...... ------- 8
Age .... .............. ...----------- -- ------ 9
Planting Distance ... ..... ........-.... --------- -e--- 9
Fruit Production .... .... ................--- -- --- -------- 11
Fertilization Practices .... --..... ---------------- 11
Spray and Dust Programs ........ ... ------------.- --- 15
Irrigation -. ............ ... ......-- -------- 15
Laboratory Data ... ..... .. .- ---------------- -- 16
External Fruit Quality ...... ............ .. ...--- ------ .. 16
Internal Fruit Quality ... ..... .... ..... ------------ 17
Mineral Composition of Leaves .... .. ....... ...---- -------- --..-- 19
Mineral Composition of Fruit ...... -.. ......------- --..- 19
Mineral Composition of Soil .. ..- .... -.......-. -- -------------- 20
DISCUSSION ..... ....... ..........-..... ...- ..... ..- --------- 20
Influence of Planting Distance ................... ... .... -- ------------- 22
Influence of Fertilization Practices ... -......---. ----------------------- 24
Fruit Production .- -.. .- ... ....... -- -----------------24
Fruit Qualities .................----.. .------ 25
Leaf, Fruit, and Soil Composition ...... ------------------ -- --..-. 27
Influence of Soil Reaction ... ...... .......--- -------- 29
Influence of Copper in Soil ...... ...... -----------. ---- ...... 31
Influence of Spray and Dust Program ...........-.......----- ..- 32
Influence of Irrigation ....... ...............- .... -.-.... ...- ------ ---- 33
Relation of Mineral Composition of Fruit and Leaf to Fruit Quality.... 36
Relation Between Mineral Compositions of Leaf and Fruit ...........-.... 38
The Roles of Leaf, Fruit and Soil Analysis in Studying the
Mineral Nutrition of Citrus ...............- .. ----.------... 40
SUMMARY AND CONCLUSIONS ........ -...--- ......--- ---. ....- ..... -------.. 41
LITERATURE CITED -..... ....... ... ...... ---------- ------------------ .. 43
A PPEN DIX .......... .... --- -...- -. ...- ...-...... .... ..- -- ...- 45



ACKNOWLEDGMENTS

1. This study was financed in part by a grant from the International
Minerals and Chemical Corporation of Chicago, Illinois.
2. The authors wish to express their appreciation to the many pro-
duction managers and independent growers for their generous cooperation
in supplying groves and records which made this study possible.









A Survey of the Mineral Nutrition Status

of Valencia Orange in Florida

By
R. C. J. Koo, H. J. REITZ AND J. W. SITES

INTRODUCTION
Fertilization of citrus trees is the largest single expense in
producing citrus in Florida. Many approaches have been tried
to determine guides for applying the most economical amounts
of fertilizers. One of the means used most extensively to study
this problem has been leaf analysis. There is considerable in-
formation available from experimental plots showing the range
of the various elements in citrus leaves from trees growing with
various supplies of nutrients. The purpose of this survey was
to determine the nutrient content of Valencia orange leaves and
fruit from a large number of commercial groves, and compare
the levels found with those obtained from experimental plots.
A rather comprehensive review of the factors which may in-
fluence leaf composition, and their relation to deficiency and tox-
icity symptoms, yield and fruit quality has been prepared by Reu-
ther and Smith (17).2 Reuther et al. (20) compared the mineral
composition of Valencia orange leaves from central Florida
with the other citrus producing areas of the United States and
found that, with the exception of calcium and copper, all the ele-
ments studied were higher in central Florida than elsewhere. In
a similar study for Valencia orange leaves from the Indian River
section, Reitz and Long (13) found closer similarity between
leaves from the Indian River area and other citrus producing
sections than between Indian River and central Florida. In
both studies no attempt was made to correlate leaf analysis with
fruit quality characteristics or yield.
Fragmentary information (2,4,7,25) available on the min-
eral composition of whole fruit in Florida indicated that the
possibility of using samples of whole fruit as an index to the
mineral nutrition of the entire tree is worthy of investigation.

SRespectively Assistant Horticulturist and Horticulturist-in-Charge,
Citrus Experiment Station, Lake Alfred; Head, Fruit Crops Department,
University of Florida.
Italic figures in parentheses refer to Literature Cited.






Florida Agricultanral Experiment Stations


A survey of 168 commercial Valencia groves in the State was
initiated in 1955. This survey was conducted to obtain informa-
tion on (1) the present nutritional status of the Valencia variety
in central Florida, as indicated by leaf, fruit and soil analysis;
(2) the existence of correlations between the mineral composi-
tion of leaves and whole fruit, and yield, fruit quality and the
fertilizer practices followed, thus seeking confirmation of trends
indicated in field experiments; (3) the possibility of applica-
tion of leaf, fruit and, to a lesser degree, soil analyses as guides
to fertilizer practice under commercial grove conditions.

METHODS AND MATERIALS
SELECTION OF GROVES
Only central Florida groves were included in the survey.
Because of the differences in soil types and rootstocks, groves
of the Indian River area were omitted, since it was felt they
would unduly complicate interpretation.
The 1954 census (21) was used as a guide to determine the
proportionate distribution of the survey groves by counties as
shown in Table 1.

TABLE 1.-DISTRIBUTION OF VALENCIA SURVEY GROVES BY COUNTIES.

County Groves County Groves
No. i No.
Polk -... ..- --. I 77 Pinellas ............ 4
Lake .. .... .. 27 Hernando -...-..-...- 3
Orange ....... 25 Seminole ...... ...- 2
Pasco ............- --- I 11 Hardee .............. 1
Highlands ...... ... 10 Osceola .. ..-..- 1
Hillsborough ...... 7 TOTAL -.... 168


The total number of groves involved in the survey represents
approximately 4 percent of the bearing Valencia trees over 15
years of age in the State (21). Only groves with apparently
accurate records were included in the study. Because of the
difficulty in securing accurate records, the number of groves
operated by independent growers was not as large as originally
anticipated. The survey groves were managed by 44 different







Mineral Nutrition Status of Valencia Orange 5

citrus cooperatives, caretakers and independent growers. The
names of the cooperators are listed in the Appendix (Table C.).
All the trees were on rough lemon rootstock and were be-
tween 14 and 47 years old. Most of the groves were situated
on well-drained acid sandy soil. The size of the groves ranged
from five to 20 acres. To obtain representative samples, groves
larger than 20 acres were subdivided into smaller blocks and
separate samples were collected from each block.

COLLECTION AND PREPARATION OF SAMPLES

The sampling procedure followed was similar to the one used
by Wilson et al (31). The sampling area, which consists of 20
trees in a diamond shape, covered an area of approximately two
to three acres, depending on the spacing of the trees in the block.
A diagram of a sampling area is shown below:

(10


(a Ia
(7 '?
(6 '14-

_4 16)

IsB)
9)
20)
x
X = Tagged tree.
( = Side of tree where samples are collected.

The sampler started from the tree diagonally to the left of
the tagged tree and proceeded according to the diagram until he
finished up at the tagged tree, thus taking equal portions of the
sample from the specific side of each tree as shown in the dia-
gram. On a small number of blocks which were long and nar-
row, the sampler started from the tagged tree and proceeded
diagonally as shown in the diagram until the tenth tree was
reached. Instead of turning right at that point as shown in
the diagram, he turned 90 degrees left and proceeded for five
more trees before turning right again for the last five trees.






Florida Agricultural Experiment Stations


Foliage samples were collected between July 25 and August
11, 1955. Five leaves per tree were taken at random from the
middle of non-fruiting spring-flush twigs, making a total of 100
leaves for each composite sample. Each sample was washed
or scrubbed with cheesecloth, depending on the amount of foreign
material on the leaves, in a 2.5 percent neutral detergent. The
leaves were then rinsed three times with tap water and once
with deionized water. After the samples had been air dried,
they were placed in an oven at approximately 70' C. for not less
than 48 hours. A Wiley mill was used to grind the leaves and
the ground material was stored in air-tight jars.
Soil samples were collected at the same time as leaf samples.
One core was taken to a depth of six inches just outside the leaf
drip and on the same side of each tree from which leaves were
taken. Twenty cores made a complete sample. The samples
were air dried, screened through a sieve with openings about
one-eighth inch in diameter and then thoroughly mixed.
Fruit samples were collected between March 12 and March
20, 1956, and totaled 161 samples from 155 groves. The fruit
crop was harvested before samples could be taken in 13 of the
groves. Four fruits were picked at random from each of the 20
trees, making a total of 80 fruits for each sample. Fruits of late
bloom were avoided. Fruits were washed and measured for ex-
ternal qualities. Each sample was then randomly divided into
two equal subsamples. One subsample was analyzed for min-
eral composition and the other for juice quality.
For study of mineral composition one subsample was ground
in a comminuting machine through a quarter-inch screen. To
determine the moisture content, approximately 50 grams of the
comminuted material was weighed into an evaporating dish and
dried in an oven at 60 C. for not less than 96 hours and re-
weighed. A second portion of about 500 grams of the com-
minuted material was first dried in an oven at 600 C., then ground
in a Wiley mill and stored in an air-tight jar.

METHODS OF ANALYSIS
Mineral Composition of Leaves and Fruits.-Except for total
nitrogen, the samples were digested in 100 ml. volumetric flasks
with an acid solution containing 1 part of 60 percent perchloric
acid to 4 parts of nitric acid. Nitrogen was measured by means.
of the "semi-micro Kjeldahl procedure" (29), and phosphorus
by ammonium molybdate and amino-naphthol-sulfonic acid






Mineral Nutrition Status of Valencia Orange


(6). A Beckman Model DU Flamephotometer with hydrogen-
oxygen flame and photo-multiplier was used for analysis of potas-
sium and calcium. A compensating solution was used to elim-
inate errors in the flame determination of calcium due to the pres-
ence of interfering anions. The "Rapid 8-Quinolinol" method
(30) was followed to measure magnesium.
Soil Analysis.-Available phosphorus was extracted with a
solution composed of 0.03 N sulfuric acid and 0.03 N ammonium
fluoride, as proposed by Miller and Axley (8) with slight modifi-
cation. A 10-gram soil sample was shaken with 50 ml. of the
above extracting solution for 30 minutes and filtered through
Whatman No. 42 paper. Phosphorus was then determined with
the same method used for leaves and fruits. Extractable cal-
cium and magnesium were extracted from the soil with sodium
acetate solution having a pH of 4.8 and determined by methods
described by Peech and English (10). Copper content of the
soil was estimated with the rapid method described by Spencer
(27). A Model M Beckman pH meter with glass electrode was
used to measure the soil reaction.
Fruit Quality.-External fruit quality was measured by three
characteristics: color, texture and size. Rind color was expressed
in percent of green fruit. Any fruit showing even a slight trace
of green was classified arbitrarily as a green fruit. On this basis
the percent of green fruit was high for most of the samples.
Smoothness at stem end was used as an index to express the
general texture of the rind. Each fruit was classified as being
either rough or smooth, and the results were expressed as per-
cent fruit smooth at stem end. Commercial packinghouse sizers
were used to measure size and this was expressed in inches of
diameter.
To study internal fruit quality, juice was extracted by a
"F.M.C. In-Line" juice extractor, strained through a fine sieve
to remove fragments of albedo and other solid particles, and
weighed. The percentage concentration of soluble solids in the
juice was measured with Brix hydrometers corrected for tem-
perature. Acidity was titrated against standard sodium hy-
droxide, using a Beckman Model K automatic titrator. Vitamin
C (ascorbic acid) was measured by titration against a standard-
ized sodium 2,6-dichloroindophenol dye. The "ratio" (soluble
solid/titratable acid) and the "percentage juice by weight" are
calculated values.







Florida Agricultural Experiment Stations


RESULTS

Results obtained from this study will be presented under two
general categories, field data and laboratory data. Results under
field data were obtained mostly from records furnished by collab-
orators and by actual measurements. Included in laboratory data
were the mineral composition of leaves and fruit, fruit quality
and certain phases of soil compositions. In view of the large
amount of data accumulated from the study, results for each
grove are listed in Tables A and B in the Appendix. Table A
includes the location, soil series, age, spacing, production and
fruit quality characteristics. Table B shows the mineral compo-
sitions of leaf, fruit and soil of each grove. Data shown in the
main text represent mostly the average values used primarily
to express distribution and various trends observed. Statistical
analyses where applied are based on the entire data.

FIELD DATA

Soil Type.-The soils planted to citrus in Florida may be di-
vided into two major groups-well-drained soils and imperfectly
to poorly drained soils (11). Most of the groves used in the
present study were situated on soils of well-drained series. The
type of soil on which each individual grove was situated was
determined from existing county soil maps.

TABLE 2.-THE DISTRIBUTION OF VALENCIA ORANGE GROVES
SITUATED ON DIFFERENT SOILS.

Soil Series Groves Distribution
No. /C
Lakeland ..... ............. ---.- 133 79.2
Blanton ......-.......... .. ......------ 9 5.3
Gainesville ............................... .. 9 5.3
Eustis ........ ........ ......-...........- 8 4.8
Orlando ......... ..... ...-.-...- ----..- 3 1.8
Lakewood ......................... .......-. 3 1.8
St. Lucie ................. .. -.. 1 0.6
Leon and Portsmouth ............ 1 0.6
Scranton .............-- ---. .......... 1 0.6

TOTAL ............-. ..-- ... ..------- 168


Table 2 shows that nearly 80 percent of the groves were situ-
ated on soils of the Lakeland series. Of the remaining 20 per-






Mineral Nutrition Status of Valencia Orange


cent two groves were on the Scranton and Leon and Portsmouth
series of soil, which may be classified as somewhat poorly drained
sand. Another four groves were located on excessively or well-
drained deep sands (St. Lucie and Lakewood). Most of the
groves in Pasco and Hernando counties were located on Gaines-
ville series, a well-drained sand mixed with phosphatic materials.
The native fertility of most of these soils has been described by
Peech and Young (11).
Age.-Of the records supplied by the collaborators in the
survey, the age of the groves was probably the least accurate.
In addition to 22 groves where no information was available,
only the approximate age was obtained for a number of others
(Table A, Appendix). Table 3 shows that the range in age
varied between 14 and 47 years, with over 75 percent of the
groves in the age group between 21 and 35.

TABLE 3.-THE DISTRIBUTION OF VALENCIA ORANGE GROVES
BASED ON AGE.

Age Groves Distribution

No.
14-15 ................................ ........ 11 7.5
16-20 ...................................... ... 16 10.9
21-25 .....~.............. ........... ...... 26 17.8
26-30 ................-............... ....... 56 38.4
31-35 ..... ..... .. -.. .......- .-- ...... 29 19.9
36-40 ...... ......-. ..... ............. ....... 5 3.4
41-47 ........... .... ............... 3 2.1


Planting Distance.-Wide variations in the spacing of trees
were observed from grove to grove. Double set groves were
avoided whenever possible during the selection. Nevertheless
approximately 7 percent of the groves had more than 90 trees
to the acre (Table 4). The more commonly used spacings, when
found in 10 or more groves, are in bold type. The 25 x 25 foot
spacing (70 trees per acre) was found to be most common in
the present study. It was followed by 25 x 30 foot spacing (58
trees per acre).







Florida Agricultural Experiment Stations

TABLE 4.-THE DISTRIBUTION OF VALENCIA ORANGE GROVES
BASED ON PLANTING DISTANCES.


Trees/
Acre


45 .............

47 ........

48 ........

50 ............

52 ...........

54 .... .....


Planting
Distance
Feet

30x32

30x31

30x30

27x32

29x29

27x30

28x28

25x30

27x27

26x27

26x26

25x26


Groves
No.

2

1

13

2

2

3

14

30

6

3

14


The more commonly used spacings are in bold tye.


TABLE 5.-A SUMMARY OF VALENCIA ORANGE PRODUCTION BASED ON
THE AVERAGE OF THREE YEARS (1953-1955).


Production

Boxes/
Tree

2.45- 3.50

3.51- 4.50

4.51- 5.50

5.51- 6.50

6.51- 7.50

7.51- 8.50

8.51-10.48


Groves


No.

6

11

28

35

30

21

6


A average ...............

R ange ...............


Distribution


%
4.4

8.0

20.4

25.6

21.9

15.3

4.4

Boxes/Tree

6.14

2.45-10.48


Standard deviation ....


Production


Boxes/Acre

166-250

251-320

321-390

391-460

461-530

531-600

601-734


Grove Distribution


No. %

7 5.1

26 19.0

27 19.7

39 28.5

29 21.2

4 2.9

5 3.6

Boxes/Acre

400

166-734


Trees/ Planting
Acre Distance
Feet

70 25x25

73 20x30

76 23x25

81 18x30

82 23x24

90 22x22

91 20x24

97 15x30

99 21x21

100 15x29

116 15x25

TOTAL


Groves
No.

40

13

4

2

1

1

1

6

1

5

2

168


1.52






Mineral Nutrition Status of Valencia Orange


Fruit Production.-Records of fruit production for a three-
year period (1953-54 to 1955-56) were obtained from the collabo-
rators (Table A, Appendix). In view of the wide variations
in planting distance observed from grove to grove, which may
influence fruit production, the data were expressed on the basis
of boxes per tree as well as per acre.
Complete production records were not available on some
groves. Consequently, fewer groves were used when the aver-
age yield of all three years was considered.
Fruit production from the survey groves showed a very wide
range, whether expressed in boxes per tree or per acre. Ap-
proximately 83 percent of the groves produced between 4.5 and
8.5 boxes per tree. On the acre basis, 89 percent of the groves
produced between 251 to 530 boxes.
Fertilization Practices.-Among the different cultural prac-
tices followed in the survey groves, fertilization showed the
least agreement among the growers. The majority of the groves
had been adequately, if not heavily, fertilized. Undoubtedly
such practices were influenced to a certain extent by the favor-
able market price of Valencia oranges during the survey period.
Less than 20 percent of the groves were fertilized with rates
below the adequate range.
Most of the groves were fertilized three times a year, while
11 groves (6.67%) received two applications and two groves
(1.2%) were fertilized four times a year. Approximately two-
thirds of the groves which were fertilized three times a year
received one of the applications as a single nitrogenous com-
pound, usually in the fall.
Very few growers were using less than 0.5 pound of nitrogen
for every box of fruit produced. A few were using as high as 1
pound of nitrogen per box of fruit. The nitrogen application
ranged from 1.39 to 5.85 pounds per tree per year, with the
majority receiving 2.5 to 4.5 pounds. On the acre basis, nitro-
gen application ranged from 67 to 448 pounds, with the majority
between 200 to 250 pounds per acre per year. Because of the
differences in tree spacing, a grove which received large quanti-
ties of nitrogen based on pounds per tree did not necessarily fall
into the same category when the application was expressed in
pounds per acre. In general, more nitrogen was applied to each
tree in groves with wide space-setting than those in which the
trees were closely planted. However, when the data were ex-






Florida Agricultural Experiment Stations


pressed as pounds per acre, the highest rates were usually found
in groves with trees closely planted.
While the majority of the groves under study used chemical
fertilizer exclusively, approximately one in every five groves
added some form of organic nitrogen, usually with the summer
application. Most of the groves in that group used 25 percent
organic nitrogen and a small number of groves used 40 percent
organic nitrogen in summer applications. In 12 groves some
form of organic nitrogen (usually 25 percent) was mixed in
all the fertilizer applications. In 1955 single applications of
sludge, tobacco stems or cyanamid were applied to 10 of the
groves in place of the summer fertilizer applications. Among
the inorganic nitrogenous compounds used in separate applica-
tions, sodium nitrate was most commonly used (50 groves). It
was followed closely by calcium nitrate (43 groves). Thirteen
groves used ammonium nitrate in separate applications. Po-
tassium nitrate was used as a single compound in 29 of the
groves one time or another during the three-year period. The
distribution of groves in relation to the amount of applied nitro-
gen is summarized in Table 7.
Wide variations in the use of phosphorus were observed from
grove to grove. Approximately 14 percent of the groves did not
receive any phosphorus between 1953 and 1955. The other 86
percent were fertilized with amounts varying from 0.1 to 3.8
pounds of P20O per tree per year, or from 9 to 233 pounds per
acre (Table 7).
The quantity of potassium used in different groves ranged
from 0.72 to 4.80 pounds per tree, or 72 to 310 pounds per acre.
Analysis of various data accumulated from the survey indicated
that results concerning potassium can be interpreted only on the
basis of its usage in relation to the quantity of nitrogen applied
and the nitrogen-potassium ratio used in the fertilizer. The dis-
tribution of groves using various quantities of nitrogen and
potassium is shown in Table 6.
More potassium than nitrogen was used in 20 percent of the
groves, while another 27 percent of the groves received equal
quantities of both. In general, less nitrogen was applied to
groves receiving higher rates of potassium and vice versa, al-
though there are exceptions. Also, nearly half of the groves
under study received more potassium than the present recom-
mended rates (12).






Mineral Nutrition Status of Valencia Orange


TABLE 6.-THE DISTRIBUTION OF VALENCIA ORANGE GROVES BASED ON THE
QUANTITY OF NITROGEN AND POTASSIUM APPLIED (AVERAGE OF 3 YEARS).

Ratio Groves Distribution Average Quantity Applied
Pounds per Tree Pounds per Acre
N:K No. I N KO N K-0
1:114 ..... 28 20.1 2.61 3.28 164 206
1:1 .......... 37 26.6 3.39 3.37 230 229
1:% ........ 13 9.4 3.28 2.90 234 210
1: ........ 36 25.9 3.65 2.68 229 168
1:% ....... 14 10.1 3.90 2.35 262 156
1:% ........ 11 7.9 4.13 1.83 282 126


The use of water-soluble magnesium in fertilizer covered a
range from zero to 2.91 pounds per tree, or 181 pounds per acre.
In 20 of the groves no water-soluble magnesium was used be-
tween 1953 and 1955. In general, growers calculate magnesium
rates on the basis of nitrogen applied. It varied between two-
thirds and one-half of the quantity of nitrogen used in the mixed
fertilizer. The distribution of groves using different quantities
of water-soluble magnesium together with nitrogen and phos-
phorus is summarized in Table 7.
Minor elements were applied to the trees in fertilizers and in
nutritional sprays. The wide variations in rates that were
found among the major and secondary elements were not ob-
served with minor elements. With very few exceptions growers
followed closely the recommended rates (12). Manganese and
zinc were used in practically all groves. The use of copper in
regular fertilizer programs was found in only a few of the
younger groves. Annual application of 0.2 to 0.3 unit of borax
(as BOs3) was observed in about one-third of the groves under
study. The use of molybdenum in nutritional spray and iron
chelate as a soil application was not a part of the regular fertili-
zation program in most of the groves. Apparently these two
elements were used whenever the trees showed signs of need.
The rate and frequency of liming was usually determined by
the results of soil pH measurement which were taken annually
in most of the groves. Liming materials were usually applied
either annually or biennially. In general, the rates were doubled
if applications were made every other year. In groves receiving
annual application of liming material, the rates of one-half to one
ton of dolomite or calcium limestone were most commonly used.










TABLE 7.-THE DISTRIBUTION OF VALENCIA ORANGE GROVES BASED ON ANNUAL NITROGEN, PHOSPHORUS AND
MAGNESIUM APPLICATIONS. (AVERAGE OF 3 YEARS.)


Nitrogen Phosphorus

Groves Distribution Rates iGroves
No. Percent Lbs./Tree No.

22 15.8 0 20

24 17.3 0.01-0.50 18

27 19.4 0.51-1.00 36

30 21.6 1.01-1.50 24

23 16.5 1.51-2.00 17

13 9.4 2.01-3.80 24


Lbs. /Acre

10 7.2 0 20

44 31.7 1-50 37

47 33.8 51-100 43

21 15.1 101-150 19

13 9.4 151-200 12

4 2.8 201-233 8


Distribution Rates
Percent Lbs./Tree

14.4 0

12.9 0.01-1.00

25.9 1.01-1.50

17.3 1.51-2.00

12.2 2.01-2.50

17.3 2.51-3.08


Rates
Lbs./Tree

1.39-2.50

2.51-3.00 ..

3.01-3.50 _.

3.51-4.00

4.01-4.50

4.51-5.85


Lbs./Acre

67-150 ....

151-200 ....

201-250 ....

251-300 ..

301-350 ....

351-448 ....


Magnesium

Groves Distribution
No. Percent

20 14.4

16 11.5

18 12.9

53 38.1

26 18.7

6 4.3


Lbs./Acre

0

1-40

41-80

81-120

121-160

161-205






Mineral Nutrition Status of Valencia Orange


However, the practice varied from a low of one-half ton of dolo-
mite per acre every third year to two tons of calcium limestone
per acre annually. Dolomite was used much more extensively
than calcium limestone. The latter was used in less than 15 per-
cent of the groves under study. Basic slag was also used in a
few scattered groves occasionally to supplement either dolomite
or calcium limestone.
Spray and Dust Programs.-The spray and dust records from
145 groves indicated that the growers followed closely to the
recommendations listed in the Better Fruit Program (1). More
than half of the groves (56 percent) were sprayed with oil as
the summer scalicide. Parathion was used in 23 groves (16
percent). In 41 groves (28 percent) parathion and oil were
either applied in two separate applications or were combined
in a single application. There was a notable switch from para-
thion to oil in 1955 by a number of growers, probably because
of the inability of parathion to control mites and greasy spot.
A mixture of copper-oil applied during the regular melanose
spray in spring and followed with a summer scalicide was used
in 21 (14 percent) groves. The number of sulfur applications
for the control of rust mite varied from two to seven, with 48
percent of the groves receiving four applications a year. Two
and three applications of sulfur were made to 26 (18 percent)
and 33 (23 percent) of the groves, respectively, while 13 groves
(9 percent) were sprayed or dusted five times a year. There
were three (2 percent) groves that received six to seven sulfur
applications in 1955. Almost without exception one application
of DN (dinitro-o-cyclohexylphenol), used either alone or in com-
bination with wettable sulfur, was made in the fall for control of
mites. Two applications of DN were used in a small number of
groves. Aramite, Ovex and Systox were used in about 5 percent
of the groves during 1955. The records also showed that ap-
proximately 10 percent of the groves used concentrated spray
in 1955.
Irrigation.-Approximately 75 percent of the groves under
study had facilities for irrigation. However, only one-half of
the groves were irrigated in the spring of 1955 despite the below-
normal rainfall in all the areas studied (3). The annual rainfall
for the several years preceding 1955 was "adequate," which may
have influenced the thinking of some of the growers as to the im-
portance of irrigation. The quantity of water applied varied
from one to 15 inches with the majority of the groves receiving






Florida Agricultural Experiment Stations


one to three inches. In general, the rainfall deficit was larger in
the part of the citrus belt south of Lake Alfred than in the
northern part. As a result, more groves were irrigated in the
area south of Lake Alfred.

LABORATORY DATA
External Fruit Quality.-External fruit quality was evalu-
ated by measuring three characteristics-color, texture and size
(Table 8).

TABLE 8.-PERCENT DISTRIBUTION OF GROVES BASED ON EXTERNAL
FRUIT QUALITIES OF SIZE, COLOR AND TEXTURE.

Distribu- Distribu- Distribu-
Size of tion Green tion Smooth tion
Fruit of Groves Fruit of Groves Fruit of Groves
Inches 2.74-2.85 .. .. 8.6 25-49 1.9 0-20 57.3
2.86-2.95 ....-.- 40.7 50-74 4.3 21-40 19.7
2.96-3.05 ......... 35.8 75-84 19.9 41-60 11.9
3.06-3.15 ......... 11.7 85-94 33.5 61-80 7.7
3.16-3.27 ......... 3.1 95-100 40.4 81-100 3.4
Mean
2.960.09 ........ 8912.76 29-22.30


The average fruit size was 2.96 inches in diameter, with a
range from 2.74 to 3.27 inches. Nearly 75 percent of the groves
had fruit that averaged between 2.85 and 3.05 inches in diameter.
These sizes expressed to the nearest commercial packinghouse
size are as follows: The average size was 200 ranging between
126 and 250, with 75 percent of the groves averaging between
176 and 216. Close to 90 percent of the fruit showed some trace
of green, although a number of samples had excellent orange
color. There was not a single sample that did not contain a few
fruits showing traces of green. Samples with more than three-
fourths of the fruit showing traces of green were found in 95
percent of the groves studied. Samples collected from 35 groves
showed some traces of green on every fruit. In the study of
rind texture, 92 samples (57.3 percent) showed less than 20
percent of the fruits smooth at stem end. Only one out of 161
samples did not have a single fruit rough at the stem end. Per-
cent fruit smooth at stem end was negatively correlated to fruit
size and percent green fruit.







Mineral Nutrition Status of Valencia Orange


Internal Fruit Quality.-Internal fruit quality was measured
by determining percent juice by weight, soluble solids, titratable
acid, ratio of soluble solids to acidity and vitamin C. The aver-
ages and the distribution of groves based on these characteristics
are presented in Table 9.

TABLE 9.-PERCENT DISTRIBUTION OF GROVES BASED ON
INTERNAL FRUIT QUALITY.

Range Grove Distribution

Percent Percent
Juice by weight 42.9-48.0 3.8
48.1-51.0 28.1
51.1--54.0 41.2
54.1-57.0 20.6
57.1-60.8 6.3
Mean 52.5+- 2.87

Brix

Soluble solids 9.70-10.50 11.2
10.51 11.00 15.5
11.01-11.50 23.0
11.51-12.00 27.3
12.01-13.30 23.0
Mean 11.50- 0.72



Titratable acid 0.73- 0.90 10.5
0.91- 1.00 16.0
1.01- 1.10 30.2
1.11- 1.20 27.2
1.21- 1.51 16.1
Mean 1.09- 0.13

Brix/Acid

Ratio 8.71-10.00 26.1
10.01 11.00 41.0
11.01 12.00 19.9
12.01 13.00 9.9
13.01-14.38 3.1
Mean 10.71+ 1.09

mg./100 ml. Juice

Vitamin C 35.5-40.0 6.2
40.1-45.0 17.4
45.1-50.0 38.5
50.1 55.0 27.3
55.1-60.0 10.6
Mean 48.7- 5.11












TABLE 10.-THE AVERAGE MINERAL CONTENT OF VALENCIA ORANGE LEAVES AND THE DISTRIBUTION
OF SAMPLES ACCORDING TO THE NUTRITIONAL STANDARDS OF REUTHER AND SMITH (17).


M ean .... ..... ......
R ange .............. ...
Standard Deviation
Coefficient of
Variation .........


Reuther and Smith
Nutritional Class


Deficient
Low ........
Optimum
High ......
Excess ..


Nitrogen

Percent

2.96
2.24-3.29
0.155

5.24


Phosphorus Potassium

Percent Percent

0.133 1.84
0.104-0.160 1.04-2.77
0.014 0.333

10.85 18.10


Nutritional Nutritional
Standard Sample Standard Sample


( ? -2.05)
(2.06-2.35)
(2.36-2.95)
(2.96-3.55)
(3.56- ? )


- I ( ? -0.085)
2 (0.086-0.115)
85 (0.116-0.165)
94 (0.166-0.295)
- (0.296- ?


6
175
-
_i


Calcium

Percent

2.99
1.84-4.18
0.486

16.25


Nutritional Nutritional
Standard Sample Standard Sample

No. No.

(? -0.60) ( ? -1.55) -
(0.61-1.15) 4 (1.56-2.95) 91
(1.16-1.75) 67 (2.96-5.55) 90
(1.76-2.35) 100 (5.56-6.95) -
(2.36- ? ) 10 (6.96- ? )


Magnesium

Percent

0.423
0.228-0.655
0.080

18.95


Nutritional
Standard San


( ?
(0.156-
(0.296-
(0.651-
(1.101-


0.155)
0.295)
0.650)
1.100)
? )


ple

No.


10

70
1 ?"
cc













cc






Mineral Nutrition Status of Valencia Orange


Mineral Composition of Leaves.-Five-month-old spring-flush
leaves of non-fruiting stems were analyzed for their mineral
contents. Data in Table 10 show the mean, range, standard devi-
ation and coefficient of variation for the different elements. A
tentative set of standards proposed by Reuther and Smith (17)
for classification of the nutrient status of orange trees based on
leaf analysis is also included in Table 10, to facilitate comparison
between the status of the groves under study and these stand-
ards.
Based on the Reuther and Smith standards, the mineral con-
tents of leaves obtained from the groves under study covered a
relatively narrow range. None of the samples analyzed were in
the deficient or excessive ranges, with the exception of 10 po-
tassium samples classified in the excess range. The high potas-
sium and nitrogen in leaves would indicate that most of the
groves have been heavily fertilized with nitrogen and possibly
potassium.
The Mineral Composition of Fruit.-The mineral composition
of whole fruit was determined to explore the possibility of using
it to supplement leaf analysis in studying the mineral nutrition
of orange trees. The mineral contents for each sample of whole
fruit can be found in Table B (Appendix). The mean, range,
standard deviation and coefficient of variation of the elements
studied are presented in Table 11.

TABLE 11.-THE AVERAGE MINERAL CONTENTS OF VALENCIA ORANGE
FRUITS FROM COMMERCIAL GROVES (DRY WEIGHT BASIS).
S-tandard Coefficient
Element Mean Range Deviation of Variation
Percent Percent Percent Percent
Nitrogen ........... 0.90 0.72 -1.12 0.085 9.44
Phosphorus ....... 0.100 0.075-0.136 0.012 12.13
Potassium ........ | 1.34 1.00 -1.63 0.115 8.55
Calcium .......... 0.284 0.165-0.425 0.054 18.95
Magnesium ....... 0.113 0.087-0.145 0.012 11.09


The average nitrogen, calcium and magnesium contents in
the whole fruit were much lower than those of the spring-flush
leaves, while the differences in the phosphorus and potassium
contents between fruit and leaves were considerably smaller.
A comparison of the coefficient of variation between the mineral






Florida Agricultural Experiment Stations


composition of leaf and fruit analysis indicated that smaller vari-
ations were found in the potassium and magnesium, but some-
what larger variations in the nitrogen, phosphorus and calcium
contents of fruit samples.
Mineral Composition of Soil.-Soil samples from the 0-6 inch
depth were analyzed for available phosphorus, extractable cal-
cium and magnesium, copper and soil reaction (pH). In gen-
eral, the variations in phosphorus, calcium and magnesium con-
tents covered a much wider range in soil than in either leaf or
fruit. It should be pointed out that the data reported represent
only the quantity of these elements extracted by certain acid
solutions. It is not the total quantity nor does it tell what frac-
tion was extracted.
Copper content in soil is expressed as pounds per acre, with
50 pounds considered as low, 100 pounds as medium and 200
pounds as high or excessive. The average and standard devia-
tion for copper were not calculated in Table 12. Because of
the manner of expressing the data, such calculations will serve
no useful purpose. The soil reaction of the groves under study
covered a range from pH 4.8 to 6.8. Approximately 85 percent
of the groves were in a pH range of 5.4 to 6.2, which is recom-
mended for growing citrus on acid sandy soil (12).

DISCUSSION
The following discussion represents the authors' interpreta-
tions of some of the trends observed. It should be pointed out
that in any survey type of study, where conditions are not con-
trolled, wide variations can be expected among the individual
cases, related not only to the variables studied but also to other
variables for which no measure may be available or which are
unrecognized. The lack of control of the variables and the non-
uniformity of unmeasured factors may obscure the true rela-
tions, so that much caution is necessary in interpreting the re-
sults. Conclusions drawn from the present study are subject to
these reservations, and should not be mistaken for the more pre-
cise results of controlled experiments. It is felt that enough
groves were included in the present survey to be representative
of grove conditions in the State, and to allow the detection of
obviously significant trends. Some of the variables, such as
rootstock and variety and to a lesser extent soil type and tree
age, were elimniated during the selection of groves.









TABLE 12.-THE AVERAGE SOIL COMPOSITION AND PERCENT DISTRIBUTION OF GROVES BASED ON RESULTS OF SOIL ANALYSIS.

Phosphorus Calcium Magnesium Copper pH

Range Distribution Range Distribution Range Distribution Range Distribution Range Distribution

Lbst Lt I Lbs./
Lbs./Acre Percent Lbs./Acre Percent Lbs./Acre Percent Acre Percent Percent
109-250 13.7 170-300 3.7 15-50 8.7 50 2i.5 4.75-5.05 1.7
251-350 14.3 301-500 32.3 51-70 22.4 100 40.1 5.05-5.35 7.3
351-450 ... 24.8 501-700 31.1 71-90 22.4 200 33.3 5.35-5.65 18.6
451-550 18.0 701-900 14.9 91-110 19. 5.65-5.95 36.2
551-650 14.9 901-1100 9.9 111-130 16.1 5.95-6.25 29.9
651-750 5.0 1101-2370 8.1 131-167 10.5 -- 6.25-.85 6.2
751-1230 .3 -- _
Mean
462=_193.. 6753(69 8930 -- -5.80-0.;i9
_|






Florida Agricultural Experiment Stations


The variables are evaluated from the standpoint of fruit pro-
duction, fruit quality and the mineral compositions of foliage and
fruit. As was pointed out earlier, the data have been classified
into groups and the mean of each group listed in tables. The
tables were used primarily to illustrate the trends observed.
Only those trends indicated by statistical analysis to be signifi-
cant will be treated in the discussion. It should be mentioned
also that information obtained from surveys should not be taken
as conclusive evidence, unless it can be substantiated by compari-
son with results of controlled experiments. However, there are
other observations for which no data from controlled experi-
ments are available at present for comparison. These findings
should merely be treated as trends observed in a large number of
Valencia orange groves. They may serve as guides for future
studies.
INFLUENCE OF PLANTING DISTANCE
The statistically significant relations (26) of tree spacing
to other variables were compiled in Table 13. The soluble solids
content of juice was also included to illustrate the source from
which the Brix/acid ratio is derived. The groves were classified
into groups based on the number of trees per acre and the aver-
age values of the characteristics measured were listed for each
group. Only seven groves were planted with between 75 and 84
trees per acre and fruit samples were obtained from six of them.
Because of the small number of groves used to make up the aver-
age values, some of the figures may not be entirely in line with
the trends observed. In order to compensate for some of the dif-
ferences found from one year to another, the averages over a
three-year period were used for fruit production when possible.
There was very little difference in fruit production when the
data were expressed in boxes per tree in the range from 45 to 84
trees per acre. The yield per tree was approximately 30 percent
less in the group with 85 to 116 trees per acre. However, when
the data are expressed as boxes per acre, the increase in yield
is proportional to the number of trees planted on an acre up to
the 75 to 84 trees per acre range. Further increase in the num-
ber of trees per acre resulted in lower yield. The average pounds
of nitrogen applied to groves in each group was also included in
Table 13. These data indicated that nitrogen was applied at the
rate of approximately 200 pounds per acre in the majority of
the groves. Close to 300 pounds per acre of nitrogen were used







Mineral Nutrition Status of Valencia Orange 23


in groves with close plantings. However, the additional use of
nitrogen did not result in corresponding increase in fruit pro-
duction.

TABLE 13.-THE RELATION OF NUMBER OF TREES PER ACRE TO
FRUIT PRODUCTION, QUALITY AND MINERAL COMPOSITION.


Avg. trees/acre

No. groves ......


Yield
(Boxes/tree)

N. appl.
(lbs./tree) .....

N. appl.
(lbs./box) .....

Yield
(boxes/acre) .

N. appl.
(lbs./acre) ......




Number groves.

Juice (percent
by wt.) ...........

Brix (percent) ..

Acid (percent)

Ratio
(Brix/acid) ....




N (percent) ......

P (percent) ........

Statistical symbo


Range (Trees/Acre)

45-54 55-64 65-74 75-84

49 59 71 78

17 58 41 7


Production (Avg. 1953-1955)


6.49 6.48 6.39


3.72 3.49 3.39


0.57 0.54 0.53


316 384 449


182 205 238


Quality (1955)

21 62 55


53.2 52.8 52.3

11.57 11.49 11.52

1.04 1.07 1.09


11.31 10.90 10.67


Mineral Composition of

0.84 0.89 0.92


Is:


0.091 0.100 0.100

n.s. no significant difference.


6.28


2.89


0.46


490

228


6


54.0

11.50

1.13


10.24


Fruit

0.94

0.106


* significant difference at 5% level.
** significant difference at 1% level.


Signifi-
cance


85-116

100

14


4.13


2.95


0.71


411

295


17


50.4

11.42

1.18


9.78


0.94

0.100


I






Florida Agricultural Experiment Stations


Increase in the number of trees per acre resulted in lower
juice content of the fruit and no significant change in soluble
solids, but higher acid content and consequently lower Brix/
acid ratio. Exception to the trend was seen in the juice content
of fruit from groves planted between 76 and 85 trees per acre,
but because of the small number (six) of samples involved, the
values may not be entirely representative. The intensity of
light may have influenced the juice and acid contents of the
fruits. In closely planted groves the crowding of the canopy
results in less exposure of foliage and fruit to light. Trends
in fruit quality noted in comparing open groves with close set
groves parallel the trends noted in comparing fruit from the out-
side of a tree's foliage with fruit from the interior of the
tree (14).
The nitrogen and phosphorus contents in fruit were the only
elements affected by different planting distance. Even in these
two elements the magnitude of variation is rather small. The
pattern of variation, if it can be explained on the basis of ex-
posure to light, is in accordance with that reported by Koo and
Sites (7).
INFLUENCE OF FERTILIZATION PRACTICES
Fruit Production.-Nitrogen was the only element directly
related to fruit production (Table 14). Increase in the quantity
of nitrogen applied was accompanied by increase in fruit pro-
duction, but the relationship was not linear. Increase in yield
became proportionally smaller as more nitrogen was added.

TABLE 14.-THE RELATION OF RATES OF NITROGEN APPLICATION TO
FRUIT PRODUCTION OF VALENCIA ORANGE.

Nitrogen Yield Nitrogen
Range Average Groves Range Average Applied

Pounds/Acre/Year No. Boxes/Acre Lbs./Box
67-150 133 10 166-488 328 0.40
151-200 176 44 232-518 385 0.46
201-250 225 47 239-616 400 0.56
251-300 271 21 278-618 429 0.63
301-350 318 13 245-615 434 0.74
351-488 402 4 377-734 541 0.74






Mineral Nutrition Status of Valencia 0r''.-


The present recommendation by the Citrus Experiment Sta-
tion for nitrogen (12) is 0.4 pound for every box of oranges pro-
duced. The fact that the majority of the growers used 0.5
pound or more nitrogen per box of fruit produced would seem
to indicate that most of the growers either anticipated a much
higher yield when the fertilizer was applied or believed that the
recommendation was too low. The subnormal rainfall in 1954
and 1955 undoubtedly affected the fruit production in many
groves, but it must be recognized that many growers are using
more nitrogen than recommended. Whether the slight increase
in yield associated with the additional use of nitrogen can com-
pensate for the extra cost would be determined largely by the
relative market price of fruit and the cost of nitrogen.
There was no consistent trend between fruit production and
the various quantities of phosphorus applied in the fertilizer.
Phosphorus applications tend to accumulate in these soils and,
as a result, a considerable reserve has been built up in many
groves through fertilizer programs over the years (5,9,28).
Use of additional phosphatic fertilizer has not been shown to
serve any useful purpose.
Variations in the quantities of potassium and magnesium
involved in this study had no detectable effects on fruit produc-
tion. Results from controlled experiments with phosphorus, po-
tassium and magnesium (15, 19, 22) indicated that these ele-
ments have little influence on fruit production, except when
trees are markedly deficient. Most of the groves under study
were in the sufficient range from the nutritional point of view.
As a result, the effects of these elements, if any, cannot be dem-
onstrated in the relatively narrow range covered in the study.
Fruit Qualities.-Very few fruit quality characteristics were
related to the rates of different mineral elements applied. It
will be pointed out in subsequent discussions that fruit quality
is much more closely related to the mineral composition of fruit
than to fertilizer treatments. Only those characteristics of
fruit quality showing statistical significance in relation to fer-
tilizer practices were included in Tables 15 and 16.
The percentage of fruit smooth at stem end, a measure of
rind texture, was inversely proportional to the quantity of nitro-
gen applied. No other relation was found between fruit quality
and the nitrogen applied. No significant difference was observed
in fruit quality that could be attributed to the quantity of phos-
phorus or water-soluble magnesium applied.







Florida Agricultural Experiment Stations


TABLE 15.-THE INFLUENCE OF NITROGEN APPLIED ON RIND TEXTURE.

Nitrogen Range Grove Smooth Fruit

Lbs./A ................ ........... ............... No. Percent
67-150 .............. ........ .................. 7 49
151-200 .... ..... ... .............. 29 35
201-250 ......... ........ .. ... ........... 29 30
251-300 ............ .... ... .............. 14 24
301-350 ....... ....... .... ......... .... 13 16
351-448 ......... ......... .................. 5 14
Statistical significance ......- .. '**


No significant relation in fruit quality was observed when
potassium rates alone were considered. However, when po-
tassium was considered together with nitrogen, highly signifi-
cant differences were found in fruit size, juice acidity and Brix/
acid ratio of the juice. Fruit size increased as the nitrogen-
potassium ratio in fertilizer became smaller, the increase being
approximately one commercial packinghouse size over the entire
nitrogen-potassium range (sizes 200 to 176). The titratable acid
was lowest at the widest nitrogen-potassium ratio, which re-

TABLE 16.-THE INFLUENCE OF NITROGEN AND POTASSIUM RATIO
IN THE FERTILIZER ON FRUIT QUALITY.

Nitrogen-Potassium Rates Size Acid I Ratio
Ratio N K..O Grove

N/KO2 Pounds/Acre No. Inches I Brix/Acid
1:11 ...... 164 206 22 3.03 1.05 I 10.9
1:1 ........... 230 229 41 3.01 1.10 10.6
1: % ...... 234 210 18 2.97 1.12 i 10.3
1: ...... 229 168 44 2.95 1.12 10.3
1:% ... 262 156 18 2.93 1.10 10.7
1:% .. ... 282 126 16 2.92 0.99 11.6


Statistical significance ...-.... ..-............ ** *:;






Mineral Nutrition Status of Valencia Orange


suited in the highest Brix/acid ratio at that range. These data
are in general agreement with results reported by Reuther and
Smith (16) and Sites and Deszyck (22).
Leaf, Fruit and Soil Composition.-The quantity of nitrogen,
phosphorus and potassium added in the fertilizer was usually
reflected in one or more components studied. The results are
presented in Table 17. Applications of magnesium in the water-
soluble form were not reflected in the magnesium contents of
leaves, fruits or soil. The nitrogen content in leaves was re-
lated to the quantity of nitrogen in the fertilizer, particularly
more apparent in the lower ranges of applied nitrogen. No sig-
nificant relation was found between the nitrogen content of fruit
and the rate of nitrogen application.
The rate of phosphorus used in the fertilizer, on the other
hand, was reflected in the phosphorus content of fruit and in
the available phosphorus content of soil but not of leaves. A
relationship was observed between phosphorus applications and
soil acidity. A similar relation also existed between the avail-
able phosphorus content of soil and the pH (not shown in Table
17). It had also been observed in controlled experiments by
Smith (24).
The data were too erratic to prove any correlation between
the rate of potassium applied and the potassium content of leaves
or fruit. Other factors may have confounded the results due to
potassium so that its significance was not revealed. In order
to find out if the nitrogen applied in the fertilizer had any effect
on potassium, multiple regressions were calculated for the po-
tassium contents of leaf and fruit. The amounts of nitrogen
(X1) and potassium (X2) in the fertilizer were used as inde-
pendent variates on which the potassium content of leaf (Y1)
and fruit (Y2) were dependent. Highly significant correlation
coefficients were found. The regression equation for leaf po-
tassium content (Yi = 1.838-0.125X, + 0.137X2) indicated that
the average leaf-potassium content expressed in percent of dry
weight decreased 0.125 with each pound of nitrogen applied to
the tree, but increased 0.137 with each pound of potassium ap-
plied. The influence of nitrogen on the potassium content of
fruit was about one-half that of the potassium applied (-., =
1.247-0.033X +- 0.070X,). In simple analysis when only one
element is considered, interrelation with another element cannot
be identified. It is possible that a grove fertilized with a large
quantity of potassium may also receive nitrogen at a high rate.














TABLE 17.-THE RELATION BETWEEN RATES OF APPLICATION OF NUTRIENTS AND THE
MINERAL COMPOSITIONS OF LEAVES, FRUIT AND SOIL.


Phosphorus


Nitrogen-Potassium


Range

Lbs.iA.

67-150 ..

151-200

201-250 ._

251-300 ..

301-350

351-448


Groves

No.

11

45

48

20

16

5


Statistical significance


Leaves

Percent

2.86

2.92

2.96

3.00

3.03

2.93


**


Range

Lbs./A.

0

1-50

51-100

101-150

151-200

201-233


Groves

No.

23

35

38

19

15

8


Fruit

Percent

0.092

0.096

0.099

0.102

0.104

0.111


Soil pH

Lbs./A.

378 6.0

446 5.9

495 5.8

519 5.6

539 5.7

634 5.4


L** **


Ratio

N/KO

1:1

1:1

1:%

1:%



1:%


Groves
l____1
No.

22

37

19

34

16

15


Leaves

% K

2.02

1.93

1.85

1.82

1.73

1.49


Fruit

%K

1.43

1.34

1.34

1.33

1.29

1.17 Ci


C'
Cs


Nitrogen






Mineral Nutrition Status of Valencia Orange


As a result, the potassium contents of leaf and fruit may be rela-
tively low because of the suppressing effects of nitrogen on po-
tassium. An erroneous conclusion may then be drawn that high
rates of potassium application had no effect on the potassium
contents of leaf and fruit. However, when the rates of both ni-
trogen and potassium are taken into consideration, the potassium
contents of leaf and fruit are significantly different at various
levels of application.
The fact that the quantity of water-soluble magnesium ap-
plied in the fertilizer was not related to fruit production, quality
or the magnesium content of leaf, fruit and soil would seem to in-
dicate that it was not the only source of magnesium. Records
showed that approximately 85 percent of the groves used dolo-
mite for control of soil acidity. This led to the belief that dol-
omite may be an important source of magnesium. A compari-
son of the average magnesium content of leaf, fruit and soil
between groves using calcium limestone and dolomite substanti-
ated the belief. On the average, less water-soluble magnesium
was applied to groves which used dolomite than those using cal-
cium limestone and yet, the average magnesium content of leaf
and fruit was higher for the former. The difference in the ex-
tractable magnesium of the soil was negligible, as shown in
Table 18.

TABLE 18.-A COMPARISON OF THE AVERAGE MAGNESIUM CONTENT OF LEAF,
FRUIT AND SOIL IN GROVES LIMED WITH DOLOMITE AND CALCIUM LIMESTONE.

Material Percent Avg. MgO" Magnesium Content
Groves Applied Leaf Fruit Soil
Percent lbs./A. Percent Percent lbs./A.
Calcium
Limestone ........ 15 111 0.390 0.109 92
Dolomite .............. 85 89 0.428 0.114 89

a. Water-soluble magnesium applied as magnesium sulfate.

INFLUENCE OF SOIL REACTION
The range of soil pH covered in the present study did not
correlate directly with fruit production. Characteristics that
were related to soil pH are summarized in Table 19. Only two
characteristics of fruit quality were related to soil reaction.
Fruits of smoother rind and higher solids were produced on
soils with lower pH. Magnesium was the only element studied
for which leaf or fruit analysis was related to soil reaction. The






Florida Agricultural Experiment Stations


magnesium content in both leaf and fruit showed a steady in-
crease from pH 4.8 to 5.9, and then gradually decreased as soil
pH continued to increase. It was pointed out in the previous
section that the quantity of water-soluble magnesium applied in
the fertilizer showed no significant effect in the magnesium con-
tent of leaf and fruit. Therefore, it seemed that dolomite ap-
plications have more influence on the magnesium content of leaf
and fruit than the water-soluble magnesium applied through
fertilizer.

TABLE 19.-THE INFLUENCE OF DIFFERENT SOIL PH ON QUALITY AND
MINERAL COMPOSITIONS OF LEAF, FRUIT AND SOIL.

Soil pH Rind Texture Groves Soluble Magnesium
Groves Smooth Solids Leaf Fruit
Range No. % No. Brix % %
4.75-505 .. 2 45.5 2 12.18 0.322 0.097
5.05-5.35 9 42.9 11 11.71 0.367 0.103
5.35-5.65 .. 20 32.7 30 11.54 0.407 0.111
5.65-5.95 .. 44 27.5 62 11.39 0.446 0.114
5.95-6.25 .. 36 26.6 48 11.15 0.428 0.113
6.25-6.75 .. 6 24.8 8 11.15 0.410 0.108

Statistical I
significance ** **


Calcium is the predominating base in the soil colloidal com-
plex. Magnesium, though present in much smaller quantity, is
of equal importance. The amounts of exchangeable calcium and
magnesium found in the soil are closely correlated to the ex-
change capacity at approximately the same pH values (11). For
the same reason the extractable calcium and magnesium should
increase with pH of soil with similar exchange capacity. The
data presented in Table 20 represent the average values of ex-
tractable calcium and magnesium based on different pH ranges.
The data were further divided on the basis of groves that re-
ceived dolomite and those that used calcium limestone. Highly
significant differences in the extractable calcium content at dif-
ferent pH ranges were observed for groves using dolomite as
well as those using calcium limestone. The same was true also
of the extractable magnesium content for groves using dolomite,






Mineral Nutrition Status of Valencia Orange


but in groves receiving calcium limestone the level of signifi-
cance between exchangeable magnesium and soil reaction reached
only the 5 percent level.

TABLE 20.-RELATION BETWEEN SOIL REACTION AND EXTRACTABLE
CALCIUM AND MAGNESIUM CONTENTS.

Soil Dolomite Limestone
Reaction Groves Groves
Extractable Extractable
Calcium Magnesium Calcium Magnesium
pH No o. Lbs A. Lbs.A. No. Lbs.A. Lbs./A.
4.75-5.05 2 263 34 1 365 39
5.05-5.35 10 370 49 3 444 72
5.35-5.65 28 403 66 6 525 79
5.65-5.95 54 606 89 8 798 90
5.95-6.25 40 754 112 14 965 103
6.25-6.75 9 1319 109 2 1750 124

Statistical
significance ...... ** -:* *

The extractable calcium was consistently higher in groves
which received calcium limestone when compared to those using
dolomite at the same pH range. Higher solubility of residual cal-
cium carbonate compared to dolomite by the extracting solution
may have been a factor.
Peech and Young (11) contended that a calcium-magnesium
ratio between 8 and 10 to 1 was desirable and necessary to pre-
vent magnesium deficiency. Such a ratio was found in all the
pH ranges except in groves where the pH was 6.3 or above. The
average calcium-to-magnesium ratio in this range was 12 to 1
for groves receiving dolomite and 14 to 1 for those using calcium
limestone and showed no attending magnesium deficiency.

INFLUENCE OF COPPER IN SOIL
The effects of soil copper content on the characteristics meas-
ured are summarized in Table 21. Fruit quality was not affected
by the copper content in soil. Fruit production increased with
soil copper content. It was highly doubtful that soil copper con-
tent caused increase in fruit production. Increase in the nitro-
gen applied undoubtedly contributed to higher yield. The par-
allel increase in the available soil phosphorus and copper would






Florida Agricultural Experiment Stations


indicate older groves, which may be another factor. In the ab-
sence of controlled conditions, the data should not be interpreted
as indicating soil copper was related to fruit production, espe-
cially in view of the complications which may arise from high
copper content in soils (18). The potassium content of both
leaf and fruit varied directly with the soil copper content, while
the magnesium content showed an inverse relationship.

TABLE 21.-THE AVERAGE FRUIT PRODUCTION AND MINERAL CONTENTS OF
LEAF AND FRUIT AT DIFFERENT LEVELS OF COPPER IN SOIL.
SAver- Nitro-
Copper Groves age gen Fruit Leaf Soil
Yield Applied I N K Mg K I Mg P
Lbs./A. No. Boxes/ Lbs./A. % / % % % %c Lbs./
A. A.
50 .... 32 363 198 0.85 1.27 0.118 1.78 0.463 350
100 ...... 56 404 235 0.91 1.34 0.111 1.86 0.415 462
200 ...... 50 425 228 0.93 1.38 0.108 1.87 0.397 531
I I
Statistical
significance ** **

INFLUENCE OF SPRAY AND DUST PROGRAM
Since the present study is concerned primarily with the min-
eral nutrition status of the Valencia orange, a detailed study of
the influence of spray and dust programs was not attempted. As
an exploratory study on the possible effects of certain spray ma-
terials on fruit and leaf characteristics, all of the groves were
divided into three groups: those using oil, oil-parathion and para-
thion. No significant difference was found in fruit production,
fruit quality or mineral composition of leaf and fruit that could
be attributed directly to any of these sprays. If any influence
did exist, it was obscured by other factors.
Since the annual rainfall in 1955 was considerably below
normal, with the rainfall deficit varying widely in different sec-
tions of the citrus belt, the groves were further divided into two
groups according to moisture deficit. Groves in group "A" are
those in which soil moisture conditions were near the long-time
average, either through rainfall alone or with irrigation. Group
"B" represented those where the moisture deficit was appreci-
able. When the groves were classified on that basis (Table 22),
no difference was observed in fruit production from the use of
different scalicides as long as the supply of moisture was "ade-






Mineral Nutrition Status of Valencia Orange


quate". However, in group "B" where the supply of moisture
may have been a limiting factor, lower fruit production was
seen in groves sprayed with oil.

TABLE 22.-THE INFLUENCE OF OIL AND PARATHION ON THE FRUIT
PRODUCTION OF VALENCIA ORANGE (1955-1956).

Material Group "A" Group "B"
Groves 1 Average Yield I Groves Average Yield
Boxes/ Boxes/ xes Boxes/ Boxes/A.
No. Tree A. No. Tree
Oil ..... 44 6.72 449 36 4.60 290
Parathion-oil 15 6.75 448 26 5.02 331
Parathion ..... 11 6.75 442 12 5.25 347

Statistical significance n.s. n.s.
"A"-Groves received 42 to 50 inches of water either through precipitation or supple-
mental irrigation.
"B"-Groves received 32 to 41 inches of water either through precipitation or supple-
mental irrigation.

One of the precautions in using oil is "do not apply oil spray
when trees are wilting or near wilting" (1). It is doubtful if trees
in any of the groves were actually in that stage at the time of
oil application, as most growers are quite conscious of the pre-
caution. Possibly the wilting of the trees in days following the
oil spray, together with the duration of the residual effects of oil,
brought about the observed effect on yield.

INFLUENCE OF IRRIGATION
The supply of adequate moisture was probably one of the
most important factors limiting fruit production during the
1955-56 season. Supplemental irrigation was applied to about
half the groves under study. The majority of the irrigated
groves yielded well, but some yielded better than others. It
is obvious that, among other factors, local weather conditions
and time and rate of irrigation may have influenced crop yield.
Because of the wide variations observed in annual rainfall, it
seemed desirable to group the groves according to geographi-
cal locations and compare the effects of supplemental irriga-
tion within each area. It was apparent from the data in Table
23 that the effects of supplemental irrigation were closely re-
lated to the rainfall. In areas where the annual rainfall was
low, as in Highlands County and parts of Polk, benefit derived
from supplemental irrigation was much more pronounced. Light
irrigation, although it produced more fruit than non-irrigation,















TABLE 23.-THE INFLUENCE OF SUPPLEMENTAL IRRIGATION ON FRUIT PRODUCTION OF VALENCIA ORANGE, 1955-1956.


Area


Lake Placid-Frostproof ..
(Avon Park)* .................


Babson Park-Waverly ....
(Lake Wales) .......


Waverly-Davenport .........
(Lake Alfred) ................


Avalon-Dr. Phillips ....
(Windermere) .......


Winter Garden-Plymouth
(Orlando) .. ...... ..


Annual Treatment
SRainfall
Inches

32.39 No Irrigation
(-19.83)$ Light Irrigation**
Heavy Irrigationt

40.36 No Irrigation
(-10.21) Light Irrigation
Heavy Irrigation

33.84 No Irrigation
. (-19.14) Light Irrigation
Heavy Irrigation

43.89 No Irrigation
(- 4.67) Light Irrigation
Heavy Irrigation

42.26 No Irrigation
(- 8.97) Light Irrigation
Heavy Irrigation


Number Production
Groves
Boxes/tree Boxes/Acre

5 3.90 225
6 4.34 253
6 6.49 377

13 4.98 300
8 5.00 323
7 5.99 396

10 4.54 300
9 5.99 342
9 7.07 451

6 5.18 391

7 6.56 411

7 7.80 512
3 7.24 491
i i












TABLE 23.-THE INFLUENCE OF SUPPLEMENTAL IRRIGATION ON FRUIT PRODUCTION OF VALENCIA ORANGE, 1955-1956. (Cont.)


Area


Annual
Rainfall
Inches


Mt. Dora-Leesburg ..
(Eustis) .........


Montverde-Groveland
(Clermont) .. ......


Dade City-Brooksville
(St. Leo) ...... .....


Lutz-Clearwater ......
(Tarpon Springs) ....


44.50
- 3.07)


42.26
- 6.29)


45.02
-10.48)


40.52
-10.68)


Treatment



No Irrigation
Light Irrigation
Heavy Irrigation

No Irrigation
Light Irrigation
Heavy Irrigation

No Irrigation
Light Irrigation
Heavy Irrigation

No Irrigation
Light Irrigation
Heavy Irrigation


Number
Groves


9


Boxes/tree

6.31
7.73


8 6.43
6 5.89


11 6.45
4 5.30


4 4.14

6 5.34


* Location of the U. S. Weather Bureau rain gauge.
** Groves irrigated with 1-2 inches were arbitrarily classified as light irrigation.
f The range in heavy irrigation varied from 3 to 15 inches.
. Annual rainfall deficit.


Production


Boxes/Acre

420
459


3(369
385


475
457


253

386






Florida Agricultural Experiment Stations


was considerably less effective than heavy irrigation. On the
other hand, in areas where the rainfall deficit was small, as in
Orange and Lake counties, difference in fruit production between
the irrigated and non-irrigated groves was negligible. These
evidences point to the fact that irrigation facilities can be uti-
lized more beneficially when local weather conditions are taken
into consideration.
No consistent difference was observed in fruit quality or min-
eral composition of leaf and fruit between the irrigated and non-
irrigated groves. Differences in fruit quality characteristics as
reported by Sites et al. (23) due to irrigation were found in only
a few very heavily irrigated groves, when compared to non-
irrigated groves in the same vicinity. Outright comparisons
between the irrigated and non-irrigated groves were of little
value because of the differences in quantity and distribution of
rainfall as well as supplemental irrigation in different areas.
RELATION OF MINERAL COMPOSITION OF FRUIT AND LEAF
TO FRUIT QUALITY
Attempts were made to find out if any correlation existed
between leaf and fruit mineral composition and fruit quality.
Correlations between various fruit quality characteristics and
different mineral elements in leaf and fruit were tested. Pair-
ings which showed highly significant correlations (r) were used
to calculate linear regression coefficients (i). The results were
summarized in Table 24.
In general, fruit quality is more closely associated with the
mineral composition of fruit than of the leaf. Data in Table 24
showed highly significant relation between certain characters
of fruit quality and the mineral contents of fruit, but not of leaf.
In other cases where fruit quality is related to both leaf and
fruit, the latter is more strongly correlated, as indicated by the
larger "r" values. It should be pointed out that some of the
correlations are rather weak even though statistically significant,
indicating that factors other than those measured have consid-
erable influence on fruit quality.
Rind texture, which was expressed as percentage of fruit
smooth at stem-end, is the only external characteristic meas-
ured that was related appreciably to the mineral contents of leaf
and fruit. The percent smooth fruit varied directly with the
nitrogen and phosphorus contents of fruit, but inversely with
the magnesium content of both leaf and fruit. No consistent
trend was observed in the variation of fruit size and color that







Mineral Nutrition Status of Valencia Orange


can be attributed to any one element. However, a highly signifi-
cant correlation was found between fruit size and the .itrgen
and potassium contents of fruit. The influence of nitrogen-po-
tassium ratio discussed earlier in relation to leaf analysis was
also observed in fruit size. The multiple regression equation
(Y = 3.001-0.293X, + 0.163X,) indicated that increased nitro-
gen content (X,) of fruit inhibited fruit size, whereas increased
potassium content (X,) increased fruit size. The influence of
nitrogen is nearly twice as strong as that of potassium. .-
erally speaking, fruits high in potassium and low in nitrogencon-
tents had the largest size. The next largest sizes were composed
of fruits relatively low in both nitrogen and potassium contents,
followed by fruits high in both elements. Finally, the smallest
fruits are those with low potassium and high nitrogen contents.

TABLE 24.-A SUMMARY OF THE CORRELATIONS AND REGRESSIONS OF FRUIT
QUALITY ON MINERAL CONTENTS OF LEAF AND FRUIT BASED ON 161 PAIR
OF VALUES.


Fruit
Quality (Y)

Rind texture*





Soluble Solids




Acid .................


Ratio


Mineral
Element

Nitrogen

Phosphorus

Magnesium


Nitrogen

Phosphorus

%/ Dry Matter

Phosphorus

Magnesium

; Dry Matter


......... 1 Potassium

Magnesium


Vitamin C ......


Nitrogen

Phosphorus

Potassium


Com-
ponent

Leaf
Fruit
Leaf
Fruit
Leaf
Fruit

Leaf
Fruit
Leaf
Fruit
Fruit

Leaf
Fruit
Leaf
Fruit
Fruit

Leaf
Fruit
Leaf
Fruit

Leaf
Fruit
Leaf
Fruit
Leaf
Fruit


Correlation
Coeffi-
cient (r)

0.058 n.s.
0.456**
0.086 n.s.
0.388**
-0.519**
-0.626**

-0.080 n.s.
-0.273**
-0.279**
-0.557**
0.735**

-0.341**
S-0.383** I
-0.210**
-0.247**
0.713"**

-0.016 n.s.
-0.583:**
0.276**'
0.302**

0.011 n.s.
-0.595** "
-0.330**
-0.736**'
-0.197 n.s. I
-0.205** '


Regression (i)


26.30 +

26.71 +
28.62-
28.69 -


11.71 -
14.08 -
14.84 -
4.36 +

1.67-
1.51-
1.23-
1.38-
-0.21 +


1.216X

7.018X
2.830X
11.310X


2.298X
19.222X
33.783X
0.382X

4.389X
4.348X
0.346X
2.640X
0.069X


18.08 5.542X
9.15 + 3.687X
7.78 + 26.200X

80.62 35.302X
70.09-160.833X
80.67-322.957X

64.67 12.009X


The calculations of rind texture and
on 117 pair of values.
** Statistical significance.
n.s. Not significant.


mineral compositions of leaf and fruit were based






Florida Agricultural Experiment Stations


From the standpoint of internal fruit qualities, no consistent
trends were observed in the juice content, as affected by the
mineral composition of leaf and fruit. The soluble solids con-
tent, on the other hand, was inversely proportional to the phos-
phorus content of fruit and to a lesser degree that of the leaf.
The nitrogen content also affected the soluble solids of juice,
but the influence was not as strong as that of phosphorus. It
was pointed out earlier that no significant correlation was found
between the nitrogen content of fruit and the nitrogen applied in
the fertilizer, which seriously limited the practical application
of the data. The acid content of the juice was affected by the
phosphorus and magnesium contents of both leaf and fruit.
Juice with low acids generally was found associated with high
phosphorus and magnesium contents in both leaf and fruit.
The Brix/acid ratio varied directly with the magnesium con-
tent of fruit and leaf and inversely with the potassium content
of fruit. The inverse relationship between the acid content of
juice and the magnesium contents of leaf and fruit resulted
in a higher ratio at higher ranges of magnesium content. The
soluble solids and acid content of the juice varied to some extent
with the potassium content of the fruit. Neither correlation
was highly significant when considered alone. The regression
observed for ratio is probably the accumulative effects of both
Brix and acid.
The relation between vitamin C (ascorbic acid) content of
the juice and the mineral composition of leaf and fruit follows a
pattern similar to that of acid content. Vitamin C varied in-
versely with nitrogen, phosphorus and potassium contents of
fruit and also the phosphorus content of leaves.
It was also found that both the soluble solids and acid con-
tents of the juice were very closely correlated to the percent dry
weight of the fruit.

RELATION BETWEEN MINERAL COMPOSITIONS OF
LEAF AND FRUIT
In order to study the relation between the mineral composi-
tions of leaf and fruit, correlations were calculated for the ele-
ments under study. Leaf analysis was used as a basis for classifi-
cation in Table 25, to express the average values. Correlation co-
efficients were calculated on the entire 161 samples. Because of
the large number of groves involved, the degree of freedom at
which the "r" value would have been significant was also given to












TABLE 25.-RELATION BETWEEN MINERAL COMPOSITION OF LEAF AND FRUIT BASED ON 161 PAIRINGS.

Avg. of Range Cot
Component (Based on Leaf Content) Co


s







i-i


S Leaf
Fruit

Learf
Fruit

S Leaf
Fruit

Leaf
Fruit

Leaf
Fruit


2.61
0.95

0.115
0.091

1.35
1.25

2.23
0.249

0.272
0.096


2.74
0.88

0.121;
0.095

1.60
1.31

2.72
0.276

0.345
0.102


2.85
0.92

0.135
0.0990

1.81
1.32

3.10
0.283

0.411
0.109


Element




Nitro ni ..


I'hos1horiu


Potassium


Calcium ...


Mag/nesiun


0.154
0.110

2.29
1.41

3.88
0.306

0.570
0.128


relation
efficient


0.144
0.105

2.02
1.36

3.48
0.296

0.484
0.119


0.45
28 d.f.

= 0.212 *
145 d.f.

=0.475 *
2( d.f.

= 0.765
8 d.f.






Florida Agricultural Experiment Stations


illustrate the extent of parallel fluctuations between the mineral
compositions of leaf and fruit.
There was no significant correlation between the nitrogen
contents of leaf and fruit. The potassium contents of leaf and
fruit were only weakly correlated, even though statistically sig-
nificant. This is probably due to the non-stability of potassium
level in the leaves. Phosphorus and calcium contents showed
about the same degree of correlation between leaf and fruit.
The magnesium contents of leaf and fruit were very closely
related. This was also indicated by their similarity in relation
to fruit quality.

ROLES OF LEAF, FRUIT AND SOIL ANALYSES IN
STUDYING THE MINERAL NUTRITION OF CITRUS
Although leaf analysis has been extensively used by research
workers in studying the mineral nutrition of citrus, its applica-
tion in commercial groves has not been fully tested. One of the
objects of this survey was to explore the possibility of applying
leaf analysis under commercial conditions. Phosphorus is prob-
ably the only element of the five studied whose status cannot
be satisfactorily determined on the basis of leaf analysis. One
of the more useful functions of leaf analysis, which was not
included in the present study but should be followed up, is to
study the trends in the mineral nutrition of groves in relation
to their fertilizer programs and to predict the approach of any
deficiencies or excesses so that necessary corrections can be
made.
Fruit analysis to study the mineral nutrition of citrus has
not been widely used. Results obtained from the survey indi-
cated that fruit analysis is a valuable tool that can be used to
supplement leaf analysis. Sampling error can be reduced greatly
when fruit analysis is employed. This can be very useful in
the latter part of the year when it is almost impossible to inter-
pret the data of leaf analysis due to inability to accurately de-
termine age of leaf. In general, the mineral composition of
fruit is more closely correlated to fruit quality than leaf analysis.
It was pointed out in earlier discussion that the phosphorus con-
tent of fruit is a more satisfactory index than leaf in studying
phosphorus nutrition of citrus. There is, at present, insufficient
data to set up standards for fruit analysis as has been done in
leaf analysis. With sufficient data accumulated similar standards
could also be set up for fruit. These standards will be especially
useful for fruit quality control studies.






Mineral Nutrition Status of Valencia Orange


Soil analysis has been used to a limited extent in Florida for
a number of years, on a routine basis, for the determination of
phosphorus, calcium and magnesium as well as soil reaction. Re-
sults of the present study indicated a good possibility of applying
soil analyses together with leaf and fruit analyses in the study
of mineral nutrition of citrus if sufficient research was conducted
to correlate the analytical data with field conditions of response.

SUMMARY AND CONCLUSIONS
1. A survey of 168 commercial Valencia orange groves from
the major citrus producing areas of Florida was undertaken in
1955. The object of the survey was to study the mineral nutri-
tion status of the groves in relation to fruit production and
quality by means of foliage, fruit and soil analyses.
2. All the trees were budded on rough lemon rootstock be-
tween the ages of 14 and 47, with more than 85 percent of the
trees between the ages of 16 and 35. By far the majority of
the groves (80 percent) were situated on soils of Lakeland series.
The number of trees planted to an acre ranged from 45 to 116,
with 85 percent of the groves having between 48 and 73 trees
per acre.
3. Fruit production over a period of three years averaged
6.14 boxes per tree, covering a range from 2.45 to 10.48 boxes;
or 400 boxes per acre, with a range from 166 to 734 boxes.
4. In general, most of the groves were adequately fertilized,
although both types and rates of material varied widely. Ni-
trogen was the only nutrient element under study that could be
directly related to fruit production, while phosphorus, potassium
and magnesium, in the amounts used, did not appear to be re-
lated to variations in fruit production. Correlations were found
between the nitrogen content of leaf and the nitrogen applied
in the fertilizer. Phosphorus application was related to phos-
phorus content of fruit and the available phosphorus in soil. Po-
tassium, when considered together with nitrogen, was signifi-
cantly correlated to the potassium content of leaf and fruit. The
fact that the water-soluble magnesium applied in the fertilizer
was not related to the magnesium content of leaf and fruit or
the extractable magnesium content of soil would suggest that it
was not the only source of magnesium. Evidence suggests that
dolomite is an important source of magnesium. The use of






Florida Agricultural Experiment Stations


minor elements by most of the growers corresponded closely to
recommendations.
5. Over 80 percent of the groves had a soil reaction ranging
between pH 5.4 and 6.2, which is generally accepted as satis-
factory for growing citrus on acid sandy soil. Both the extract-
able calcium and magnesium contents of the soil varied directly
with the soil reaction, whether dolomite or calcium limestone was
used as the amendment. Soil reaction seemed to affect the mag-
nesium content of leaf and fruit more than other elements.
Highest magnesium content was found in the proximity of pH 5.9.
6. The groves were well distributed among the different
ranges of soil copper content. The influence of soil copper on
fruit quality was of no practical importance. The available
phosphorus content of soil varied directly with copper. Potas-
sium and magnesium contents in leaf and fruit were affected by
soil copper content.
7. Records showed that growers followed closely the recom-
mendations with respect to timing and dosages in their spray and
dust schedule. A comparison of leaf analysis and fruit quality
in relation to use of the common scalicides (oil, oil-parathion and
parathion) did not reveal any significant effects, but production
was somewhat curtailed in groves sprayed with oil where the
supply of soil moisture may have been inadequate.
8. Rainfall in 1955 was considerably below normal. Supple-
mental irrigation where adequately applied was highly benefi-
cial to fruit production. The majority of the irrigated groves
did not receive enough irrigation, which was reflected in lower
yields. Only groves that were heavily irrigated were able to
uphold the fruit production records of previous years. Increased
yield due to irrigation was less pronounced where the rainfall
deficit was smaller and the distribution more favorable.
9. Fruit quality was more closely related to the mineral com-
position of fruit than that of the leaf. It seems desirable to set
up standards of fruit composition for control of fruit quality, in
view of the poor correlation between fruit quality and mineral
elements used in the fertilizer.
10. The practical application and limitations of leaf, fruit
and soil analyses were discussed.







Mineral Nutrition Status of Valencia Orange


LITERATURE CITED

1. Better fruit program. Spray and dust schedule for Citrus. Florida
Citrus Commission. 1955.
2. BRYAN, O. C. The quality of citrus fruit as affected by cultural prac-
tice. Proc. Fla. Sta. Hort. Soc. 53: 98-100, 1940.
3. Climatological data, Florida section. U. S. Dept. of Commerce. Weather
Bureau Vol. 57-59. 1953-1955.
4. FUDGE, B. R. Relation of magnesium deficiency in grapefruit leaves
to yield and chemical composition of fruit. Fla. Agri. Expt. Sta.
Bull. 331. 1939.
5. JONES, D. W., N. GAMMON and R. B. FORBES. Leaching of fertilizer
phosphorus in acid sandy soils as affected by lime. Fla. Agri. Expt.
Sta. Circ. S-32, 1952.
6. KING, E. J. The colorimetric determination of phosphorus. Biochem.
Jour. 26: 292-297. 1932.
7. Koo, R. C. J., and J. W. SITES. Mineral composition of citrus leaves
and fruit as associated with position on the tree. Proc. Amer. Soc.
Hort. Sci. 68: 245-252. 1956.
8. MILLER, J. R., and J. H. AXLEY. Correlation of chemical soil tests for
available phosphorus with crop response, including a proposed
method. Soil Sci. 82: 117-127. 1956.
9. NELLER, J. R. Mobility of phosphates in sandy soils. Soil Sci. Soc.
Amer. Proc. 11: 227-230. 1946.
10. PEECH, M., and L. ENGLISH. Rapid microchemical soil tests. Soil Sci.
57: 167-195. 1944.
11. PEECH, M., and T. W. YOUNG. Chemical studies on soils from Florida
citrus groves. Fla. Agri. Expt. Sta. Bull. 448. 1948.
12. REITZ, H. J., C. D. LEONARD, J. W. SITES, W. F. SPENCER, I. STEWART,
and I. W. WANDER. Recommended fertilizers and nutritional sprays
for citrus. Fla. Agri. Expt. Sta. Bull. 536. 1954.
13. REITZ, H. J., and W. T. LONG. Mineral composition of citrus leaves
from the Indian River area of Florida. Proc. Fla. Sta. Hort. Soc.
65:32-38. 1952.
14. REITZ, H. J., and J. W. SITES. Relation between position on tree and
analysis of citrus fruit with special reference to sampling and meet-
ing internal grades. Proc. Fla. Sta. Hort. Soc. 61: 80-90. 1948.
15. REUTHER, W., and P. F. SMITH. A preliminary report on the relation
of nitrogen, potassium, and magnesium fertilization to yield, leaf
composition and the incidence of zinc deficiency in oranges. Proc.
Amer. Soc. Hort. Sci. 56: 27-33. 1950.
16. REUTHER, W., and P. F. SMITH. Relation of fertilizer treatment to fruit
quality of Valencia oranges. Proc. Fla. Sta. Hort. Soc. 64: 29-35.
1951.







Florida Agricultural Experiment Stations


17. REUTHER, W., and P. F. SMITH. Leaf analysis of citrus. Mineral nu-
trition of fruit crops. Chap. 7: 257-294. Horticultural Publications,
Rutgers University. 1954.
18. REUTHER, W., and P. F. SMITH. Toxic effects of accumulated copper in
Florida soils. Proc. Fla. Soil Sci. Soc. 14: 17-23. 1954.
19. REUTHER, W., F. E. GARDNER, P. F. SMITH, and W. R. ROY. Phosphate
fertilizer trials with oranges in Florida. I. Effects on yield, growth,
and leaf and soil composition. Proc. Amer. Soc. Hort. Sci. 53:
71-84. 1949.
20. REUTHER, W., F. E. GARDNER, and A. W. SPECHT. A comparison of
the mineral composition of Valencia orange leaves from the major
producing areas of the United States. Proc. Fla. Sta. Hort. Soc.
62: 38-45. 1949.
21. SCHULER, P. E., and J. C. TOWNSEND, JR. Florida Citrus Fruit. An-
nual Summary, 1954. U. S. Dept. of Agri., Agri. Marketing Serv.
1954.
22. SITES, J. W., and E. J. DESZYCK. Effect of varying amounts of potash
on yield and quality of Valencia and Hamlin oranges. Proc. Fla.
Sta. Hort. Soc. 65: 92-98. 1952.
23. SITES, J. W., H. J. REITZ, and E. J. DESZYCK. Some results of irriga-
tion research with Florida citrus. Proc. Fla. Sta. Hort. Soc. 64:
71-79. 1951.
24. SMITH, P. F. Effect of phosphate fertilization on root growth, soil
pH, and chemical constituents at different depths in an acid sandy
Florida citrus soil. Proc. Fla. Sta. Hort. Soc. 69: 25-29. 1956.
25. SMITH, P. F., and W. REUTHER. Mineral content of oranges in relation
to fruit age and some fertilization practices. Proc. Fla. Sta. Hort.
Soc. 66: 80-85. 1953.
26. SNEDECOR, G. W. Statistical methods. Iowa State College Press. 1950.
27. SPENCER, W. F. A rapid test for possible excesses of copper in sandy
soils. Fla. Agri. Expt. Sta. Bull. 544. 1954.
28. SPENCER, W. F. Distribution and availability of phosphates added to a
Lakeland fine sand. Soil Sci. Soc. Amer. Proc. 21(2): 141-144.
1957.
29. WILLSON, A. E. Analysis of citrus tissues. Unpublished. Progress
Report: 340. Fla. Agri. Expt. Sta. 1950.
30. WILLSON, A. E. Rapid 8-quinolinol procedures for determination of
magnesium. Anal. Chem. 23: 754. 1951.
31. WILLSON, A. E., W. J. AREY, and F. W. BISTLINE. Errors in citrus soil
and leaf sampling procedures. Proc. Fla. Sta. Hort. Soc. 68:
107-112. 1955.






APPENDIX

TABLE A.-FRUIT PRODUCTION AND QUALITIES OF VALENCIA ORANGE.


Grove






A-1-1
A-1-2
A-1-3
A-2-1
A-2-2
A-2-3
A-2-4
A-2-5
A-2-6
A-2-7
A-2-8
A-2-9
A-3-1
A-3-2
A-3-3
A-4-1
A-4-2
A-4-3
A-4-4
A-4-5
A-4-6
A-4-7


Location






Lake Wales
Dundee
Lake Wales
Auburndale
Lake Alfred
Lake Wales
Davenport
Davenport
Lake Garfield
Winter Haven
Haines City
Lake Wales
Lake Alfred
Lake Alfred
SLake Alfred
SLake Wales
Lake Wales
I Lake Wales
Lake Wales
Waverly
Lake Wales
Lake Wales


Soil series






Lakelandl
Lakeland
Lakeland
Blanton
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Blanton
Lakeland
Lakeland
SLakeland
Lakeland
Lakeland
Blanton
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland


C)
i0
uI-


Age

Fi



30 601
28 58
31 64
25 58|
30 701
30 64
27 52
27-30 48
28-30 48
26 82
25 58
30 56
23 81
40 70
23 81;
35 100
30 70;
35 64
30-35 100
35 521
35 100
25-30 73


Production Fr


1n 1 ?

0


Boxes/tree

68 5.77 6.00 100
191 (.24 5.401
42 7.4( (6.13 100
14 7.00 6.28 95
96 3.95 3.35 95
34 6.42 5.73 100
06 5.85 5.53 84
74 9.44 8.30 94
(63 7.14 3.57 70
70 4.95 5.06 86
25 5.27 3.84 28
50 5.92 4.06 100
40 5.90 6.00 91
90 (.22 3.40 100
45 5.70 5.34 821
6( 3.43 3.47 901
12 (.37 4.33 --
16 6.09 5.31 100
05 1.52 2.78 94
34 4.87 4.80 -
19 3.13 2.42 89
80 4.60 3.51 100


E
u


External
lit Quality










3.04 53.2
52 2.85 52.2
I-








86; 2.74 52.9
2.98 500 9
'*1 iInches | 'I







29 2.95 49.5
2.88 48.31

3.04 53.2|
52| 2.85 52.2|
8(1 2.74 52.9;

491 2.81 50.3
29| 2.95 49.51
S 2.92 54.6
--! 2.93 58.3
3.00 50.8
43 2.91 50.9
16 2.84 48.7
2.88 53.7
3.19 50.7
2.92 48.81
--- --
2.91 49.5|
(i 2.95 50.3i
--I -- i---
211 2.92 54.71
2.84 50.7


4.
7.
8.
7.
4.
7.
7.
9.
8.
7.
3.
5.
6.
7.
4.
1.
7.
8.
3.'
11.:
5.
6.:


Internal Fruit Quality



Y) 0



mg./
S Brix/ 100 ml
Said juice
10.75 1.051 10.241 49.2

9.70 0.87 11.15 37.0
11.85 1.18 10.04 52.3
12.75 1.30 9.17 55.4
10.20 1.10 9.27 46.1
12.801 1.37 9.34 57.8
11.90 1.32 9.02 57.8
12.30 1.39 8.85 57.8
12.15 1.32 9.20 44.4
12.40 1.22 10.16 53.8
10.85 1.04 10.43 47.7
12.05 1.18 10.20 53.8
11.15 1.04 10.72 38.5
10.25 0.97 10.57 40.0
11.95 1.23 9.72 50.8

10.851 1.051 10.33 46.1
12.15 1.20 10.31 49.2

12.20 1.17 10.43 46.1
10.95| 1.101 9.95 52.3









Table A. (contd.)


Grove






A-4-8
A-4-9
A-6-1
A-6-2
A-6-3
A-7-1
A-7-2
A-7-3
A-7-5
A-7-6
A-7-7
A-7-8
A-7-9
A-7-11
A-7-12
A-7-13
A-7-14
A-7-15
A-7-16
A-8-1
A-8-2
A-8-3
A-8-4
A-8-5


Soil series Age


Location






Lake Wales
Waverly
Winter Haven
Winter Haven
Hesperides
Frostproof
Frostproof
Frostproof
Lake Wales
Lake Wales
Lakeland
Lakeland
Auburndale
Lucerne Park
Lucerne Park
Lucerne Park
Davenport
Davenport
Davenport
Haines City
Haines City
Haines City
Haines City
Haines City


30-35
35
30
30-35
25
25
25











30
30
22 & 30
20
30


Production







Boxes/tre


8.45
11.35
9.14
9.17'
6.02



6.81


6.77
6.92
6.721
3.90
6.00
9.71
5.02
7.44
8.82
10.48
6.64
9.10o


7.99
5.41
6.79
8.89
5.87
5.79
5.79
3.99
3.99
5.33
6.84
7.01
4.09
3.79
3.79
3.79
5.02
5.02
5.02
8.93
6.83
11.30o
6.08
10.04


Fry



I s



e %

4.64 89
5.99 82
5.43 100
6.47 94
5.05 --
4.67 96
4.67 91
5.46 86
4.60 63
6.19 97
9.60 100
9.65 94
4.23 100



951
92
92
5.01 97'
7.46 -
4.74--
2.86 100
6.37 76


External
lit Qual:
- 1-


In


ity

>.




ches %

2.88 54.3
2.87 51.4
2.99 53.4
3.05 56.5

3.02 50.7
3.14 49.0
2.88 51.0
3.00 49.6
2.89 52.2
2.98 52.7
2.88 51.9
2.98 51.4
2.92 52.3|
2.88 51.6|
2.96 55.4
3.01 55.1
3.03 50.7
2.88 49.8
2.89 51.2


3.05 52.9
2.96 53.5


Internal Fruit Quality


%


12.25'
13.00
10.35
11.10

10.90|
11.00
11.75
12.15
11.65|
10.95
11.55
11.65
12.70
12.50
12.45
12.25
11.85
11.95
11.45


11.55
12.451


S 0



% Brix/
I acid
1.17 10.47
1.17 11.11
0.87 11.90
1.14 9.74[

1.12| 9.73
1.03 10.681
1.30 9.04
1.11 10.95
1.12 10.40
1.09 10.05
1.05 11.00
1.09 10.69
1.20 10.581
1.09 11.47
1.12 11.12
1.17 10.47
1.10 10.77
1.22 9.80
1.18 9.70,


1.05 11.001
1.18 10.55


C-)


mg./
100 ml
juice
50.8
56.9
43.1
41.5

48.9
48.9
50.8
49.2
46.1
52.3
53.8
43.1
50.8
41.5
50.6
53.8
55.4
58.4
53.8


53.8
52.3


Lakeland
Lakeland
Lakeland
Lakeland
Blanton
Lakeland
Lakeland
Blanton
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
SLakeland
Lakeland
SLakeland
SLakeland
SLakeland
Lakeland
Lakeland
I Lakeland











Grove Location






A-8-6 Haines City
1-8-7 Loughman
A-8-8 Haines City
A-9-1 Babson Park
A-9-2 Babson Park
1-9-3 Lake Wales
A-10-1 Frostproof
1-10-2 Frostproof
A-10-3 Frostproof
A-11-1 Lake Hamilton
A-11-2 Lake Hamilton
A-11-3 Winter Haven
A-12-1-a Dundee


A-12-1-b
A-12-3
A-13-1
A-13-2
A-15-1
A-16-1
A-16-2
A-16-3
A-17-1
A-17-2
A-18-1
A-19-1


Dundee
Winter Haven
Dundee
I Winter Haven
Lake Wales
Lake Wales
Lake Wales
Lake Wales
Lake Wales
Lake Wales
Lake Wales


Soil series Age


Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland

Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland


14
15
35
38
38
35
27
30
27
30
30
40+
25

40
27
34
30+
30
30
30
31
31
30
33


Table A. (contd.)
External
Production Fruit Quality



a) ca ~ ~ o-o a

,- 2 S cC


Boxes/tree

4.57 3.76
4.56 4.66
8.33 6.80
6.34 7.16
5.35 5.58
5.72 5.37
4.56 5.17
4.08 4.47
4.52 5.32
9.84 6.89


6.12 5.62

8.59 7.22
8.48 6.38
10.12 6.07
8.22 7.25
4.84 6.54
5.51 4.86
6.15 5.01
7.65 7.90
6.80 6.19
6.54 6.97
7.25 3.65


%

3.36 97
4.44 89
8.72 96
4.60 87
3.87 87
3.25 97
4.20 96
3.45 100
4.43 100
7.00 851
-- 81

5.81 961
94
5.52 87
5.73 97
9.16 100
4.40 96
3.81 100
5.70-
5.64 100
8.55 100
7.44 100
6.09 95
4.44 100


I I


Intern







% %

56.1 11.90
54.3 11.45
54.0 12.00
54.5 11.25
53.1 11.35
51.5 11.75
51.4 12.15
54.1 11.65
53.4 10.95
50.0 12.30
52.9 12.45

53.4 12.45
55.3 12.25
49.6 12.75
50.7 11.15
50.5 11.15
49.9 11.05
51.2 11.45

54.5 11.55
54.9 10.70
49.3 10.75
53.6 11.75
52.1 10.50


al Fruit Quality



2 Z


mg./
% Brix/ 100 ml
acid juice
0.95 12.53 53.8
0.97 11.80 53.8
1.10 10.91 53.8
1.15 9.78 47.7
1.10 10.32 43.1
1.09 10.78 50.4
1.14 10.66 51.8
1.01 11.53 45.9
0.97 11.29 41.5
1.23 10.00 53.8
1.20 10.38 56.9
-
1.07 11.64 53.8
1.09 11.24 55.4
1.25 11.20 49.2
1.08 10.32 46.1
1.02 10.93 44.4
1.03 10.73 44.4
1.18 9.70 53.8

0.97 11.91 47.7
1.13 9.47 48.9
1.10 9.77 46.1
1.09 10.78 50.8
0.93 11.29 38.5


i

Ji
i
1
i
i



1
i


S Inches

17 2.93
32 2.99
14 2.97
3.10
3.19
2.99
2.96
2.96
3.02
2.99
2.96

17 2.89
15 2.97
36 2.87
3.01
2.86
-- 2.94
2.89
--[
451 2.88
--1 2.93
--I 2.82
351 2.94
-1 2.91









Table A. (contd.)


Grove





A-19-2
A-20-1
A-20-2
A-20-3

B-1-1
B-1-2
B-1-4
B-1-5
B-2-1
B-2-2
B-2-3
B-3-1
B-3-2
B-3-3
B-3-4-a
B-3-4-b
B-3-6
B-4-1-a
B-4-1-b
B-5-3
B-5-4
B-5-5
B-5-6
B-5-7


Location





Babson Park
Alturas
Alturas
Waverly

Clarcona
Clarcona
Lake Sherwood
Clarcona
Windermere
Windermere
Windermere
Dr. Phillips
Dr. Phillips
Dr. Phillips
Turkey Lake

Ocoee
Windermere

Forest City
Plymouth
Plymouth
Plymouth
Plymouth


Soil series





Lakeland
Lakeland
Lakeland
Lakeland

Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
St. Lucie
Orlando

Orlando
Lakeland

Lakeland
Lakeland
Lakeland
Lakeland
SLakeland


Age





38
30
30
30

23

25+

31
32
47
20
25
15


30

30
35
15
30
20


external
lit Quality


Internal Fruit Quality


a A b *8-Eo a i
CO r-~ Cr


E
Production Fr







Boxes/tree %

56 4.94 5.75 3.33 941
56 8.72 6.98 8.00 70
641 9.07 6.63 9.001 940
70 8.55 5.32 6.00 100


641 8.45 6.49 7.99 92
70 7.82 6.66
70 7.46 5 70
Boxes/tree 00




64 64.94 5.75 3.33 94
45 6.0172 6.98 8.00 7
64 9.07 6.63 9.001 9




991 4.67 3.68 4.82 83
70 8.55 5.32 6.001 100
641 8.45 6.49 7.99 92



70 7.03 7.82 6.66 9
0 7.46 5.9 7.08 87
564 6.45 5.4 91
45 6.01 6.32 7.13 77
45 7.70 9.36 9.915


99 43.7 3.629 8.37
70 4.59- 6.49 81
70 4.53 5.82 96
60 -- 7.23[ 5.90 87
58 3.47 91
96
70 3.92 7.29 8.37 100
701 6.49 81
95
70 11.16 9.80 10.48 85
70 8.13 9.56 8.57 82
58 5.48 6.62 5.54 90
56 5.20 10.98 9.24 96
73 5.79 6.59 7.50 79


% %
52.9 11.25
53.5 11.75
46.8 10.70
54.8 11.70

58.1 11.35
55.9 11.75
51.9 11.05
47.0 11.70
53.1 11.60
52.9 11.80
46.5 13.30
52.6 11.80
52.2 11.25
51.4 11.05
55.7 11.50
50.6 11.05
49.8 11.15
49.5 10.20
51.4 10.90
43.7 11.20
55.7 11.30
53.3 12.00
53.9 10.90
57.8 11.10


% Brix/
acid
0.94 11.97
1.14 10.31
1.12 9.95
1.03 11.36

1.11 10.23
1.17 10.04
1.00 11.05
1.10 10.46
1.02 11.37
1.13 10.44
1.51 8.81
0.86 13.72
0.85 13.241
0.87 12.70
0.94 12.231
0.87 12.701
1.07 10.42,
0.98 10.41J
1.01 10.79
0.921 12.171
0.98 11.53
1.06 11.32
1.08! 10.09
0.97 11.44


Inches

2.91
2.98
3.01
2.97

2.86
2.80
2.98
2.98
2.93
3.04
2.80
2.92
2.81
2.95
2.89
2.96
2.93
2.96
2.99
2.93
2.97
2.80
2.87
2.89


0



mg./
100 ml
juice
46.1
56.9
44.6
47.7

49.2
52.3
49.2
49.2
45.9
48.9
56.3
49.2
43.1
49.2
47.7
46.1
46.1
45.9
42.9
43.1
49.2
55.4
53.8
49.2










Grove





B-5-8
B-7-1
B-7-2
B-7-3
B-7-4
B-7-5
B-7-(;
B-9-1

C-1-1
C-1-2
C-1-3
C-1-4
C-1-5
C-2-1
C-2-2
C-3-1
C-4-1
C-4-2
C-4-3
C-4-4
C-6-1
C-6-2
C-6-3
C-6-4


Location





Avalon
Avalon
Avalon
Avalon
Avalon
Windermere
Forest City
Tangerine

Tavares
Grand Island
Lane Park
Clermont
Howey-in-the-Hills
Groveland
Ferndale
Montverde
Montverde
Montverde
Montverde
Clermont
Eustis
Leesburg
Mt. Dora
Mt. Dora


Soil series Age





,Lakeland 30
ILakeland 14
Lakeland 27
Lakeland 31
Lakeland 27
Lakeland 44
Lakeland 20
Lakeland 23

Eustis 25
Eustis 28
Eustis 32
Lakeland 24
Lakeland 25
Lakeland -
Lakeland -
Lakeland 15
Eustis 15
Eustis 15
Eustis 18
Lakeland 15
Blanton 25
Lakeland 30
Lakeland 25
Lakeland 25


Table A. (contd.)

Production FI
Fru







Boxes/tree %
97 5.38 15.02 4.64 100

70 5.34 4.12 3,.;2 82

70 7.00 5.89 5.80 82
70 5.58 4.59 6.91 100
64 8.50 10.08 10.31 -
7) G.51 8.3) 6.50 --


56, 8.01 6.90 5.03 821
64 7.49 8.10 6.37 91
48 7.64 8.28 8.38 !
73 11.79 4.77 6.70 85
48 3.1 .49 90 o
48- 4.31 5.64 950
70 5.66 8.76 5.75 92
73 -- 4.59 5.51 100
Boxes/tree '/o









7 5- 5.02 4.69 100
(;4 4.(i7; 3.73^ (i.0(; 100
70 5.:4 4.12 3.(;2 82!








70 5.58 4.51 .1 100
(64 8.50( 10.08 10.31











74 46.51 83.3 5.35 (;(
56 8.01 6.58 5.03 82
64 7.49 8.10 6.37 91
48 7.(;4 8.28 8.38 951




73 11.73 4.77 i.703 85
(4 7.0110.04 6.8735
48 3.1 6.49 901
48 4.31 5.64 95
70 5.(66l 8.76 5.75 92
73 4.59 5.65 100
73 6.70 5.32 5.57 95
73 4.69 100
(;0 -- 4.51 5.81 100
i4 4.86 3.91 5.35 6;6|
73 4.99 6.58 7.08 82
70 6.73 4.56 9.63 87
70 4.18( 5.41 6.35 -


External
itQalty Internal Fruit Quality
it Quality




U1

SInches % /0 e Brix/ 100
acid jui
1 3.15 50.4 10.(5 1.081 .86( 4'
5; 3.08 48.8 10.50 0.881 11.931 4!
8 3.11 49.9 10.90 1.08 10.09| 5
7 3.12 48.7 10.90 1.07 10.19[ 4.
61 3.14 45.9 10.95 1.04 10.53 1 4
61 3.12 53.7 10.25 1.05 9.761 3



7 3.15 48.9 11.70 0.94 12.451 5
9 3.10 56.7 11.95 1.05 11.381 5:
19 3.02 55.5 10.50 0.84 12.50 4,
80 2.87 54.9 11.55 0.96 12.03 4:

37] 2.93 55.3 10.35 0.7( 13.62 4
24| 2.89 54.7 11.40 0.92 12.391 5:
12 3.07 51.4 11.30 0.95 11.89 4
12 2.97 55.4 11.30 0.99 11.41 4
14 3.04 55.2 11.00 0.97 11.34[ 5
20; 2.96 53.0 11.00 0.9G(; 11.46, 4
11 3.03 51.0 11.35 0.8(6 13.20 5
311 2.92 58.2 12.25 1.15 10.65 5:
24| 2.91 58.2 11.901 1.10; 10.82 5
111 2.96 56.2 10.90 0.96 11.35 4


5



;*./
ml
ce

4.4
1.8
4.4
8.9
5.5














Location


Soil series


Grove





C-7-1
C-7-2
C-7-3
C-7-4
C-8-1
C-8-2-a
C-8-2-b
C-9-1
C-9-2
C-9-3
C-9-4
C-9-5

D-l-l-a
D-l-l-b
D-2-1
D-2-2
D-2-3
D-3-1
D-3-2
D-3-3
D-5-1
D-6-1

E-4-1


Age





30
18
21
16
35
30

30
30
30
30
30

25


Table A. (contd.)

Production










70 4.13 5.03 -
76 5.58 5.95 6.(
100 5.84 6.52 6.
48 8.90 8.54 4.1
73 7.09 5.82 6.1
50 5.56 5.76 5.-
58 5.97 6.18 76.
56 7.24 5.11 5.!
54 8.28 7.41 8.,
62 6.46 6.42 6.'

73 3.96 3.:

54 3.75 1.,
48 4.66 10.1
58 6.96 3.,
58 6.00 6.45 5.:
58 8.38 9.26 6.'
64 7.67 8.62 7..
58 6.70 6.31 5.1
60 3.95 5.46 4.!

761 8.511 8.07 7.:


nal Fruit Quality


External
Fruit Quality Inter


o 4'



%9 % Inches % %

89 441 2.77 57.3 13.15

83 34 2.92 56.3 12.15
79 13 2.98 52.6 11.10
93 251 2.94 56.0 10.20
67 20 3.03 53.4 11.65
75 16 3.09 49.7 11.85
83 16 2.94 51.1 12.00
54 44 3.01 53.0 10.95
81 161 2.98 57.0 12.15
85 36 2.88 53.4 11.65
64 20 2.87 51.6 12.65

91 2.99 53.1 12.50
95 2.90 53.5 12.50
100 -- 3.00 53.7 10.50
92 2.92 51.6 12.40
881 -- 2.89 59.8 12.10
100 3.27 49.5 10.00
100 3.07 49.5 10.00
95 -- 3.15 55.0 10.90
90 2.96 51.9 11.80
86 2.99 53.7 11.80

86] 341 2.93 52.3 11.401


%

1.21

0.99
0.94
0.82
1.08
1.14
0.97
0.87
1.12
0.97
1.09

1.25
1.20
0.73
1.11
1.13
0.85
0.79
0.86
1.35
1.10

1.161


Leesburg Orlando
Grand Island Eustis
Tavares i Eustis
SPlymouth Lakeland
Sorrento Blanton
Groveland I Lakeland

Howey-in-the-Hills Lakeland
Minneola Lakeland
Howey-in-the-Hills Lakeland
Howey-in-the-Hills Lakeland
Howey-in-the-Hills Lakeland

Avon Park Lakeland

Avon Park Lakeland
DeSoto City Lakeland
Avon Park Lakeland
Lake Placid Lakewood
Lake Placid Lakewood
Lake Placid Lakewood
Avon Park Lakeland
Avon Park Lakeland

SPlant City Scranton


o


mg./
Brix/ 100 ml
acid I juice
10.87 56.9

12.27 56.9
11.81 49.2
12.44 46.1
10.79 49.2
10.39 53.8
12.37 53.8
12.59 47.7
10.85 53.8
12.01 49.2
11.61 60.0

10.00 50.4
10.42 54.8
14.38 41.5
11.17 56.3
10.71 50.4
11.76 35.5
12.66 37.0
12.67 37.0
8.74 53.3
10.73 47.4

9.83 48.9





Table A. (contd.)


Grove





E-5-1
E-5-2
E-5-3
E-5-4
E-5-5
E-5-6

F-2-1
F-2-2
F-2-3-a
F-2-3-b
F-2-4-a
F-2-4-b
F-2-5
F-2-6
F-2-7
F-2-8
F-2-9
F-2-10
F-2-11
F-2-12
F-4-1
F-4-2-a
F-4-2-b


Location


Soil series





Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland

Lakeland
Lakeland
Gainesville

Gainesville

Lakeland
Gainesville
Gainesville
Gainesville
Gainesville
Gainesville
Gainesville
Lakeland
Gainesville
Lakeland


SLutz
Lutz
Lutz
Lutz
Lutz
Lutz

Dade City
Dade City
Trilby

Trilby

Dade City
Dade City
Dade City
Dade City
Dade City
Dade City
Dade City
Dade City
Brooksville
Dade City


Age





25 76
30 70
30 64
18 48
30 70
18 64

17 116
17 116
15 100

15 97

28 70
21 & 31 70
35 70
26 70
21 70
17 70
26 67
22 67
18 58
18 58


Production FExteral Internal Fruit Quality
Fruit Quality


? o? ? 0
So tO 2 I *


mg./
Boxes/tree % % Inches % % % Brix/ 100 ml
acid juice
6.76 5.73 4.43 97 77 2.90 57.8 11.00 1.17 9.40 41.5
6.34 6.35 4.88 80 33 2.94 54.2 11.30 1.21 9.34 48.9
7.23 7.68 7.54 84 96 2.86 58.0 11.50 1.23 9.35 45.9
3.86 4.03 3.95 --I -
7.49 7.44 4.21 97 14 3.08 50.7 11.60 1.07 10.84 40.0
8.12 4.59 7.67 17 89 2.86 55.4 11.80 1.16 10.17 44.4

2.56 2.86 3.47 89 16 2.95 54.9 11.60 1.24 9.35 47.4
2.69 3.36 4.42 90 20 2.95 51.6 12.00 1.24 9.68 48.9
6.72 5.85 6.44 75 17 3.06 51.2 11.20 1.13 9.91 50.4
75 9 3.03 52.4 11.10 1.13 9.82 45.9
5.43 5.05 5.69 77 12 2.96 47.4 11.55 1.32 8.75 48.9
86 15 3.12 51.2 10.40 1.08 9.63 44.4
10.36 5.99 6.81 92 54 3.03 52.6 11.20 1.15 9.74 44.4
7.81 5.55 6.75 99 20 2.84 50.6 11.60 1.31 8.85 47.4
6.90 5.12 6.45 100 19 2.89 48.1 11.50 1.32 8.71 42.9
8.26 6.53 7.83 84 19 3.12 50.7 11.60 1.24 9.35 49.2
8.43 6.05 7.05 92 12 2.98 51.1 11.60 1.25 9.28 47.4
8.64 5.11 6.82 100 56 2.90 48.8 11.80 1.23 9.59 44.4
7.81 7.17 7.61 96 15 2.98 48.2 12.30 1.20 10.25 48.9
6.00 4.86 5.53 82 39 2.96 49.5 11.00 1.02 10.78 44.6
5.36 4.81 4.00 79 67 2.87 56.3 11.50 1.08 10.65 49.2
4.94 4.51 5.50 79 57 3.00 48.4 11.10 1.16 9.57 49.2
85 47 3.07 54.7 11.20 1.11 10.09 45.9









Table A. (contd.)


Production


Location






Indian Rock
Largo

Indian Rock

Groveland
Lake Wales
Dunedin
Frostproof
Frostproof
DeSoto City
Wauchula
Kathleen


Soil series






Lakeland
Leon and
Portsmouth
Lakeland

Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Lakeland
Blanton
Blanton


Internal Fruit Quality


Age






20-25 97

15-20 70
20-30 90

33 73
31 58
35 4
30 70
35 70%
31 48
21 70
48Z


External
Fruit Quality
4-


- (V


c% I 7 Inches %

1001 70 2.89 52.9

91 631 2.90 53.7
100 751 2.96 48.2

92 0! 3.17 51.5
95 42| 2.97 53.3
25 100! 2.86 60.8
100 171 3.11 52.1
97 4 3.24 51.1
82 74 2.80 52.2
84 641 2.79 51.8
. .- )


-09



(C
%

10.20

11.10
10.60

11.80
12.35
10.25
11.20'
10.50
13.20
13 05


1.10

1.13
1.03

1.10,
1.18
1.00
1.05
0.89
1.19
1 .23


* Samples for fruit quality study were collected between March 12 and 20, 1956.
** Any fruit showing trace of green was considered a green fruit.
t Smoothness at stem-end was used as an index to express the general texture of the rind.


Grove


G-l-1
G-1-2

G-1-3

P-312
P-117
P-417
P-517
P-520
P-510
P-537
P-125


Boxes/tree

2.24 2.64 2.47

3.91 5.07 4.47
3.48 2.46 4.98

6.29 4.16 4.25
5.95 4.23 5.49
3.24 3.131 3.97
5.00 6.15 4.13
7.00 -- 7.64
7.44 6.85 5.15
5.00 7.001 6.00
7.00 4.061 7.36


Brix/
acid
9.27

9.82
10.29

10.73
10.47
10.25
10.671
11.80
11.09
10.611


mg./
100 ml
juice
41.5

44.4
38.5

50.0
52.3
46.1
46.1
41.5
58.4
52.3





TABLE B,-CHEMICAL COMPOSITION OF LEAVES, FRUITS AND SOILS FROM VALENCIA ORANGE GROVES.


Grove



A-1-2
A-1-3
A-2-1
A-2-2
A-2-3
A-2-4
A-2-5
A-2-6
A-2-7
A-2-8
A-2-9
A-3-1
A-3-2
A-3-3
A-4-1
A-4-2
A-4-3
A-4-4
A-4-5
A-4-6
A-4-7
A-4-8
A-4-9
A-6-1
A-6-2
A-6-3
A-7-1
A-7-2
A-7-3


Leaf Composition
(Percentage of Dry Weight)
N P I K Ca I Mg

3.08 0.141 2.19 2.50 0.430
3.06 0.134 2.56 2.15 0.381
3.05 0.147 2.04 2.86 0.42(;
2.81 0.119 1.63 3.34 0.345
2.90 0.111 1.15 4.07 0.359
2.89 0.135 2.07 3.24 0.295
3.02 0.12( 1.62 2.81 0.407
3.05 0.129 1.54 3.12 0.384
2.87 0.127 2.09 3.56 0.287
3.03 0.141 2.04 3.12 0.308
2.89 0.125 1.75 3.12 0.266
2.94 0.145 2.13 3.12 0.328
2.88 0.123 2.05 2.51 0.37(;
3.12 0.146 1.92 2.39 0.466
3.00 0.139 2.37 2.09 0.411
2.93 0.130 1.87 2.64 0.363
2.95 0.126 1.35 3.24 0.484
2.86 0.129 2.12 3.06 0.382
3.16 0.125 1.54 2.81 0.332
3.07 0.127 1.50 3.51 0.330
3.03 0.134 1.70 2.81 0.422
2.93 0.129 2.13 2.81 0.450
2.88 0.135 2.05 2.76 0.361
3.18 0.124 1.40 3.06 0.328
2.94 0.160 2.66 2.69 0.346
3.05 0.159 2.24 2.69 0.328
2.95 0.127 2.30 2.64 0.399
3.00 0.133 1.95 2.15 0.431
3.16 0.142 1.57 1.95 0.544
3.16 0.145 1.70 2.99 0.480


Fruit Composition
(Percentage of Dry Weight)


N


4, Dry
Matter


16.8

15.5
20.0
20.0
16.9
21.2
19.1
20.7
20.0
20.2
17.6
17.9
17.5
16.5
19,3

18.2
19.0

21.3
10.6
19.7
20.6
1(.8
17.5

17.8
18.9
18.5


K I


P

0.114

0.123
0.095
0.093
0.119
0.081
0.085
0.085
0.109
0.090
0.103
0.095
0.13(6
0.114
0.098

0.093
0.085

0.099
0.091
0.089
0.089
0.111
0.125

0.094
0.092
0.102


Ca

0.270

0.293
0.300
0.290
0.375
0.293
0.328
0.353
0.308
0.343
0.373
0.238
0.225
0.205
0.331

0.308
0.250

0.275
0.263
0.295
0.338
0.225
0.233

0.250
0.298
0.153


Soil Composition
(Pounds per Acre)


I


Mg

0.123

0.115
0.102
0.091
0.100
0.112
0.103
0.092
0.087
0.093
0.097
0.103
0.110
0.111
0.103

0.099
0.094

0.109
0.118
0.102
0.095
0.101
0.099

0.141
0.129
0.116(


P

41(;
421
55(;
482
620
534
38(6
372
501
558
315
548
410
81(;
432
393
299
281
5(61
529)
456
207
344
425
525
514
338
134
109)
215


Ca

618
547
668
1080
1130
960
775
1070
812
852
853
1260
467
730
078
402
495
620
490
420
600
512
395
342
445
450
1300
328
348
463


Mg

107
92
108
140
128
105
121
1019
90
80
107
106(
63
77
91
48
83
76
58
62
79
94
53
57
70
75
135
70
91
88


Cu

100
100
200
200
200
200
100
50
50
200
100
200
200
200
100
100
200
100
100
200
100
50
50
200
100
100
200 1
50
50
50








TABLE B. (Contd.)


Grove


A-7-5
A-7-6
A-7-7
A-7-8
A-7-9
A-7-11
A-7-12
A-7-13
A-7-14
A-7-15
A-7-16
A-8-1
A-8-2
A-8-3
A-8-4
A-8-5
A-8-6
A-8-7
A-8-8
A-9-1
A-9-2
A-9-3
A-10-1
A-10-2
A-10-3
A-11-1
A-11-2
A-11-3
A-12-1-a
A-12-1-b


% Dry
Matter
____


Leaf Composition
(Percentage of Dry Weight)
N P K ICa Mg

3.28 0.158 2.04 2.20 0.530
2.91 0.158 1.79 3.05 0.444
2.94 0.127 1.37 3.69 0.385
3.03 0.134 1.55 2.64 0.488
3.20 0.135 1.79 2.32 0.473
3.00 0.131 1.67 2.20 0.483
3.07 0.131 1.27 2.69 0.524
2.87 0.144 1.63 2.76 0.632
2.95 0.133 1.92 2.20 0.540
3.19 0.133 1.82 2.02 0.424
3.11 0.130 1.60 2.09 0.527
2.96 0.123 1.79 3.12 0.445
2.89 0.127 2.07 2.45 0.388
2.82 0.118 1.50 3.12 0.402
2.87 0.113 1.52 2.64 0.406
2.75 0.116 1.44 3.57 0.416
2.86 0.137 2.07 2.32 0.535
3.03 0.146 1.96 2.15 0.549
2.94 0.122 1.80 2.69 0.455
3.05 0.139 2.05 2.57 0.339
3.10 0.139 2.19 2.69 0.366
3.20 0.134 1.88 2.81 0.412
2.94 0.133 2.29 2.64 0.361
2.95 0.145 2.10 2.64 0.384
2.78 0.145 2.07 2.89 0.385
3.03 0.128 1.84 2.72 0.353
2.97 0.117 1.47 2.62 0.374
2.90 0.131 1.54 3.51 0.354
3.00 0.125 1.87 3.04 0.364
3.03 0.133 1.62 3.37 0.327


I


19.4
19.5
17.5
17.8
17.8
19.8
19.5
19.6
20.2
19.9
19.7
18.7

18.3
20.1
19.8
16.8
20.4
19.2
19.5
20.1
19.3
18.7
18.1
20.6
19.9

20.5
19.1


0
0
0
0
1
0
0
0
0
0
0
0

0
0
0
0
0
C

0
I


Fruit Composition
(Percentage of Dry Weight)
N P K Ca Mg

.89 0.102 1.33 0.230 0.134
.97 0.110 1.33 0.250 0.110
.80 0.100 1.38 0.348 0.119
.87 0.094 1.37 0.283 0.122
.01 0.109 1.34 0.240 0.115
.78 0.092 1.33 0.308 0.144
.96 0.095 1.22 0.243 0.107
.87 0.091 1.41 0.270 0.128
.82 0.086 1.39 0.243 0.128
1.76 0.084 1.33 0.278 0.120
.72 0.075 1.25 0.258 0.112
.87 0.085 1.33 0.290 0.101

.77 0.084 1.25 0.265 0.111
.93 0.086 1.41 0.270 0.116
.78 0.104 1.32 0.180 0.124
.77 0.098 1.23 0.195 0.118
).85 0.088 1.36 0.255 0.124
).92 0.103 1.39 0.380 0.104
).91 0.110 1.37 0.408 0.111
).89 0.094 1.34 0.375 0.106
).87 0.088 1.32 0.295 0.102
).89 0.099 1.28 0.325 0.108
).94 0.111 1.32 0.348 0.101
).77 0.079 1.27 0.338 0.095
).76 0.079 1.22 0.333 0.106
- i- -
3.81 0.085 1.25 0.368 0.103
0.77 0.080 1.19 0.375 0.091


Soil Composition
(Pounds per Acre)
Ca Mg Cu

418 127 50
690 98 200
1075 150 200
400 76 100
930 87 200
840 117 200
1160 126 100
1063 158 50
538 93 50
560 74 100
795 76 50
675 101 100
580 105 200
720 165 200
560 78 50
423 113 200
530 168 50
373 117 50
340 100 100
430 96 200
325 60 200
272 30 100
630 53 100
555 50 50
905 156 100
2260 112 100
850 57 50
1140 56 100
580 107 100
1435 98 200





TABLE B. (Contd.)


Leaf Composition
(Percentage of Dry Wei)
N P K Ca


Grove


A-12-3
A-13-1
A-13-2
A-15-1
A-16-1
A-16-2
A-16-3
A-17-1
A-17-2
A-18-1
A-19-1
A-19-2
A-20-1
A-20-2
A-20-3

B-1-1
B-1-2
B-1-4
B-1-5
B-2-1
B-2-2
B-2-3
B-3-1
B-3-2
B--3-
B-3-4-a
B-3-4-b
B-3-
B-4-1-a


3.06
3.16
2.97
2.91
3.03
2.83
2.91
3.03
3.01
3.06
2.97
3.01
2.74
2.87
2.74

2.89
3.01
3.03
3.11
3.29
2.57
2.81
3.10
3.10
2.94
3.10
3.08
3.08
2.73


0.129
0.133
0.139
0.130
0.122
0.133
0.119
0.128
0.138
0.144
0.142
0.136
0.142
0.151
0.144

0.114
0.122
0.136
0.128
0.131
0.125
0.104
0.149
0.143
0.136
0.145
0.137
0.142
S0.128


ght)
Mg-

0.398
0.423
0.352
0.384
0.362
0.472
0.430
0.400
0.367
0.386
0.380
0.321
0.329
0.320
0.364

0.534
0.508
0.428
0.509
0.480
0.436
0.405
0.544
0.560
0.523
0.655
0.645
0.505
0.481


Fruit Composition
(Percentage of Dry Weight)
N I P K Ca Mg


~ Dry
Matter


20.8
18.6
17.0
16.6
20.5

17.6
17.6(
17.8
17.5
17.0
18.5
19.5
17.3
17.0

18.9
21.3
17.3
20.7
18.8
19.1
19.2
19.1
17.3
19.6
18.8
19.2
19.9
18.1


0.085
0.092
0.117
0.096
0.086

0.087
0.104
0.102
0.085
0.124
0.106
0.091
0.107
0.110

0.091
0.102
0.108
0.093
0.085
0.093
0.090
0.108
0.118
0.096
0.107
0.107
0.115
0.089


0.348
0.255
0.325
0.270
0.388

0.343
0.295
0.285
0.270
0.228
0.235
0.300
0.425
0.285

0.303
0.245
0.270
0.298
0.285
0.250
0.278
0.263
0.278
0.310
0.250
0.245
0.268
0.250


0.096
0.100
0.102
0.096
0.104

0.122
0.111
0.104
0.098
0.105
0.106
0.096
0.094
0.104

0.136
0.134
0.132
0.135
0.115
0.126
0.131
0.131
0.127
0.132
0.142
0.145
0.134
0.116


Soil Composition
(Pounds per Acre)
Ca Mg Cu

1010 138 200
365 68 200
358 49 200
2035 80 100
520 128 100
735 149 100
470 111 100
493 112 200
470 83 200
560 64 200
370 70 200
383 60 100
385 52 50
515 81 100
690 77 200

660 138 100
560 121 100
860 151 50
430 99 100
1052 129 200
787 83 200
1205 61 200
345 95 50
690 126 100
410 102 50
395 100 50
480 102 50
627 60 200
595 70 200









TABLE B. (Contd.)


Grove


B-4-1-b
B-5-3
B-5-4
B-5-5
B-5-6
B-5-7
B-5-8
B-7-1
B-7-2
B-7-3
B-7-4
B-7-5
B-7-6
B-9-1

C-1-1
C-1-2
C-1-3
C-1-4
C-i-5
C-2-1
C-2-2
C-3-1
C-4-1
C-4-2
C-4-3
C-4-4
C-6-1
C-6-2
C-6-3
C-6-4


Leaf Composition
(Percentage of Dry Weight)
N P K Ca Mg

2.96 0.139 1.79 3.62 0.503
2.92 0.144 1.54 3.42 0.393
2.96 0.128 1.60 3.31 0.454
2.67 0.123 1.39 3.04 0.576
3.10 0.121 1.46 3.57 0.291
2.91 0.122 1.39 3.87 0.337
3.12 0.118 1.42 3.97 0.301
2.84 0.138 1.59 3.59 0.583
2.74 0.126 1.60 3.82 0.360
2.78 0.126 1.75 4.04 0.409
2.83 0.123 1.75 3.72 0.331
2.61 0.125 1.89 3.41 0.454
3.02 0.144 1.64 3.17 0.550
2.96 0.148 2.49 2.51 0.365

2.97 0.129 1.84 2.72 0.335
2.89 0.129 2.27 2.67 0.319
3.15 0.145 2.20 3.29 0.376
3.04 0.152 2.37 3.19 0.450
2.69 0.136 2.32 2.64 0.347
3.00 0.146 1.74 3.23 0.506
2.97 0.133 1.70 3.29 0.444
2.97 0.140 2.25 2.61 0.342
3.18 0.151 2.55 2.04 0.460
3.23 0.144 2.10 2.25 0.456
3.24 0.158 2.55 2.54 0.424
3.18 0.151 2.04 2.47 0.577
2.75 0.131 1.35 3.87 0.506
2.81 0.128 2.00 2.94 0.460
2.78 0.137 2.09 3.44 0.499
3.01 0.142 2.14 2.86 0.546


Fruit Composition
(Percentage of Dry Weight)
N P K I a M M


% Dry
Matter


17.9
17.7
18.9
18.8
18.7
18.2
19.1
16.2
18.4
17.6
18.0
17.0


21.0
20.6
17.6
18.5

16.7
19.4
21.0
20.6
19.5
18.4
18.8
18.8
18.6
17.4


0.91
0.99
0.88
0.82
0.84
0.83
0.96
0.89
0.81
0.88
0.86
1.01
-


0.81
0.80
0.82
0.99

0.91
0.83
0.83
0.95
0.93
0.92
0.81
0.89
0.92
0.89
- I


0.089 1.37
0.112 1.27
0.095 1.20
0.090 1.14
0.084 1.08
0.080 1.19
0.096 1.20
0.113 1.36
0.101 1.37
0.102 1.25
0.101 1.28
0.121 1.50



0.095 1.23
0.093 1.41
0.098 1.32
0.120 1.44
S- I
0.108 1.19
0.086 1.35
0.101 1.23
0.103 1.36
0.095 1.20
0.099 1.34
0.106 1.14
0.096 1.38
0.100 1.44
0.097 1.45
-- -


0.1
0.1
0.1
0.1
0.0
0.1
0.1
0.1
0.1
0.1
0.1
0.1


23
02
17
36
99
01
10
25
09
09
12
13


0.270
0.263
0.328
0.285
0.405
0.365
0.388
0.253
0.413
0.323
0.365
0.270



0.320
0.308
0.330
0.178

0.185
0.348
0.185
0.220
0.270
0.225
0.228
0.228
0.250
0.270


I ~ ~~ ~ 1 U I'


0.113
0.105
0.102
0.103

0.123
0.120
0.102
0.123
0.121
0.117
0.136
0.118
0.127
0.106


Soil Composition
(Pounds per Acre)
P Ca Mg Cu

567 645 83 100
518 688 58 100
439 673 97 100
128 323 52 50
457 1077 45 200
285 540 39 100
480 1315 58 100
109 418 67 50
253 2370 100 200
352 2115 71 200
232 2145 72 50
949 1400 167 100
295 540 109 50
372 318 44 200

548 305 60 100
762 400 42 200
401 470 80 50
495 560 88 100
331 353 61 100
176 678 134 50
261 440 80 100
367 285 35 100
232 590 94 100
244 590 1 105 50
545 740 92 100
124 390 99 50
600 535 114 50
573 405 98 50
758 573 113 200
471 475 92 50





TABLE B. (Contd.)


Leaf Composition
(Percentage of Dry Weig
N P K ) Ca


C-7-1
C-7-2
C-7-3
C-7-4
C-8-1
C-8-2-a
C-8-2-b
C-9-1
C-9-2
C-9-3
C-9-4
C-9-5

D-l-l-a
D-1-1-b
D-2-1
D-2-2
D-2-3
D-3-1
D-3-2
D-3-3
D-5-1
D-6-1

E-4-1
E-5-1
E-5-2
E-5-3
E-5-4
E-5-5
E-5-6


2.93
2.93
3.02
3.05
2.67
2.78
2.94
2.91
3.13
2.98
2.96
2.93

2.94
2.86
2.96
3.19
2.91
2.85
2.72
2.75
3.10
3.18

2.85
2.86
3.08
2.91
2.24
2.70
3.18


0.137
0.142
0.140
0.134
0.140
0.112
0.137
0.13(;
0.148
0.149
0.135
0.133

0.137
0.119
0.141
0.131
0.12(;
0.154
0.122
0.130
0.130
0.126(

0.120
0.138
0.131
0.130
0.137
0.138
0.135


Grove
I


% Dry
Matter


20.9

19.7


1.94
2.30
1.80
2.00
1.609
1.39
1.94
2.07
2.27
2.02
1.70
2.10

2.17
2.05
1.45
1.99
1.45
2.77
2.05
2.27
1.87
1.52

1.25
2.07
1.90
1.67
2.15
2.05
2.00


Soil Composition
(Pounds per Acre)


ht)
Mg

0.228
0.249
0.479
0.411
0.378
0.412
0.452
0.390
0.3(i3
0.475
0.447
0.42(;

0.485
0.512
0.007
0.450
0.48(;
0.366
0.398
0.325
0.390
0.399)

0.453
0.333
0.251
0.240
0.438
0.474
0.309


Fruit Composition
(Percentage of Dry Weight)
N P K Ca M

0.90 0.094 1.27 0.310 0.0!

0.81 0.093 1.22 0.308 0.1
0.88 0.09( 1.36 0.278 0.1
0.85 0.098 1.17 0.365 0.1
0.88 0.084 1.22 0.375 0.1
0.88 0.084 1.22 0.375 0.1
0.78 0.093 1.20 0.250 0.1,
0.96 0.107 1.3(; 0.245 0.1
0.82 0.094 1.33 0.263 0.1
0.84 0.092 1.32 0.300 0.1]
0.87 0.092 1.42 0.253 0.11

0.85 0.088 1.38 0.285 0.1]
0.89 0.086 1.30 0.270 0.1:
0.92 0.113 1.33 0.175 0.1]
0.83 0.073 1.21 0.325 0.1'
0.88 0.08( 1.34 0.310 0.1(
0.94 0.130 1.50 0.255 0.11
0.86 0.12( 1.33 0.253 0.1;
0.82 0.122 1.3(; 0.255 0.11
0.78 0.083 1.22 0.350 0.0!
0.86 0.093 1.09 0.370 0.1

0.92 0.101 1.33 (0.320 0.11
1.03 0.121 1.42 0.173 0.0!
0.94 0.10( 1.31 0.278 0.0O
0.99 0.12 1.44 0.250 0.1
I -
1.06 0.131 1.52 0.250 0.1
1.03 0.107 1.41 0.203 0.1


g


95

27
20
00
30
01
22
02
15
18
15

17
23
14
22
)4
10
12
17

08

17
98
87
01

28
)0


P

630
571
289
595
452
452
377
371
489)
394
389
317

418
410
177
233
187
511
400
479
327
279

643
850
645
746
458
852
750


Ca Mg


I


Cu

50
100
50
100
50
50
50
100
200
100
50
100

200
100
100
200
200
200
200
200
100
50

100
100
200
200
50
200
100










TABLE B. (Contd.)


Grove


F-2-1
F-2-2
F-2-3-a
F-2-3-b
F-2-4-a
F-2-4-b
F-2-5
F-2-6
F-2-7
F-2-8
F-2-9
F-2-10
F-2-11
F-2-12
F-4-1
F-4-2-a
F-4-2-b

G-1-1
G-1-2
G-1-3

P-312
P-117
P-417
P-517
P-520
P-510
P-537
P-125


% Dry
Matter
J ___


Leaf Composition
(Percentage of Dry Weight)
N P K Ca Mg

3.10 0.129 1.95 2.39 0.406
2.95 0.141 1.95 2.34 0.447
3.08 0.145 1.77 2.99 0.458
3.14 0.128 1.71 3.14 0.431
2.81 0.125 2.51 3.89 0.573
2.88 0.127 1.74 3.62 0.418
2.93 0.146 2.05 3.29 0.488
3.12 0.147 1.52 3.22 0.507
3.25 0.131 1.52 2.79 0.378
3.06 0.145 1.79 3.21 0.428
3.11 0.155 1.79 3.21 0.519
2.87 0.140 1.85 3.49 0.522
3.01 0.141 1.92 3.01 0.445
2.92 0.153 1.39 3.37 0.402
2.61 0.115 1.44 3.97 0.381
2.84 0.129 2.20 3.49 0.293
2.92 0.128 2.14 3.01 0.294

2.98 0.139 1.82 2.97 0.466
2.99 0.125 1.59 3.11 0.361
2.97 0.139 1.79 3.22 0.410

2.48 0.122 1.87 2.77 0.543
2.82 0.117 1.64 2.72 0.429
3.11 0.136 1.94 2.87 0.355
2.81 0.111 2.04 3.17 0.373
2.96 0.126 1.87 2.82 0.401
2.55 0.131 1.57 2.92 0.467
2.87 0.133 1.77 2.54 0.378
2.95 0.140 1.97 3.17 0.502


Fruit Composition
(Percentage of Dry Weight)
N T P K Ca Mg

1.00 0.098 1.32 0.245 0.116
0.95 0.096 1.33 0.220 0.113
0.85 0.099 1.31 0.250 0.105
0.87 0.097 1.33 0.220 0.104
0.87 0.100 1.19 0.263 0.116
0.91 0.102 1.44 0.275 0.115
0.93 0.102 1.44 0.245 0.118
1.08 0.102 1.27 0.258 0.111
1.11 0.090 1.33 0.258 0.105
0.87 0.096 1.35 0.283 0.112
0.97 0.105 1.36 0.238 0.115
0.99 0.104 1.42 0.300 0.121
1.01 0.095 1.48 0.238 0.113
1.04 0.105 1.23 0.343 0.105
0.99 0.105 1.50 0.275 0.112
0.92 0.109 1.55 0.253 0.099
0.90 0.112 1.44 0.228 0.099

0.98 0.113 1.22 0.325 0.115
1.05 0.098 1.17 0.293 0.097
1.04 0.116 1.28 0.288 0.104

0.75 0.098 1.28 0.308 0.127
0.91 0.097 1.37 0.360 0.128
0.94 0.104 1.31 0.230 0.104
0.90 0.097 1.30 0.318 0.106
0.96 0.106 1.31 0.268 0.115
0.86 0.084 1.31 0.253 0.111
0.88 0.105 1.17 0.193 0.113
-I -


Soil Composition
(Pounds per Acre)
Ca Mg Cu

720 79 200
923 120 100
550 46 100
937 79 200
992 85 100
720 62 200
750 121 200
810 141 100
520 101 200
625 115 100
500 82 100
710 132 50
595 124 200
820 137 100
368 22 100
410 40 100
315 53 100

1072 126 50
1200 126 100
1005 156 50

672 120 100
632 138 100
612 85 50
805 64 200
765 66 200
650 88 100
170 23 50
395 85 50


19.2
20.3
17.6
17.7
19.3
17.0
18.6
19.2
19.1
19.5
18.7
19.2
20.6
16.8
18.1
16.9
17.2

15.6
17.3
15.8

19.8
19.4
16.1
20.1
17.9
20.1
19.5


r







Mineral Nutrition Status of Valencia Orange


TABLE C.-NAMES OF COLLABORATORS ARRANGED IN ALPHABETICAL ORDER.


Name


Organization


Location


Mr. Dallas W. Adams ..

Mr. W. S. Arrington ..

Mr. R. J. Barben .....
Mr. Paul Beauchamp .
Mr. Cecil Bishop ....

Mr. F. E. Blackburn .
Mr. Tom Brown ......
Mr. Henry Bullard ......
Mr. Wilbur G. Charles ...

Mr. Frank Chase ........
Mr. R. W. Clark ......
Mr. James C. Cooper ......

Mr. Alfred Estes -..-....
Mr. J. E. Evans, Jr......
Mr. Tom E. Evans ........
Mr. Charles F. Fawcett, Jr.
Dr. J. T. Griffiths .....-.
Mr. John F. Harris ........
Mr. Robert P. Heidbrink
Mr. Jack Huey .........
Mr. Ellis Hunt......
Mr. J. B. Huppel
Mr. Don Kemp ..........
Mr. C. D. Kime .....
Mr. A. G. Kirtley ....
Mr. Frank T. Laird -...
Mr. N. A. Lockett ......
Mr. E. L. Mathews .....

Mr. A. C. Mathias .

Mr. B. B. Register .. ....
Mr. Frank Rich .....

Mr. Charles A. Root ..........
Mr. W. V. Schock ........
Mr. J. E. Smoak ..........
Mr. Harvey Snively ..........

Mr. Kingswood Sprott .....
Mr. L. E. Tisdale ........
Mr. Frank Thulberry -.....

Mr. Howard Thulberry .....

Mr. G. F. Ward .-.......-
Mr. Henry C. Whitesell ...
Dr. A. E. Willson ....
Mr. Earl Wirt, Jr. .--.
Mr. W. W. Others .-


Fosgate Citrus Concentrate Co-
operative
South Lake Apopka Citrus
Growers Association ..........
S. Y. Hartt & Son, Inc...........
R. W. Burch, Inc. ..............
Brooksville Citrus Growers
A association ..... ..................

Brown & Company .................
Bullard, Inc....................
Florence Citrus Growers
Association ... ......
Chase Grove, Inc. ...............
W. H. Clark Fruit Company
Mount Dora Growers


..... Orlando

..... Oakland
. Avon Park
...Plant City

...Brooksville
......Wauchula
....Frostproof
.Lake Wales

lorence Villa
.Windermere
........ Lutz


Cooperative ............................. Mount Dora
Estes Grove Properties, Inc.....Winter Haven
Evans Properties, Inc. ...............Dade City
Evans Grove Service ..............Lake Alfred
................ ... .......-................ O rla n d o
Eloise Groves Association ......Winter Haven
Slough Grove Company, Inc........... Dade City
Heidbrink Groves ..................... .....Orlando
L. M. Hawes ............. ... ........... Dade City
Hunt Brothers Cooperative ........Lake Wales
R. D. Keene, Inc ..... .............WWinter Garden
Lake Region Packing Association......Tavares
Waverly Growers Cooperative ........Waverly
.............. ...................... .- W inter H aven
.-.-...... -. -. ......- .................. Groveland
Foremost Fertilizer Company ........Leesburg


Plymouth Citrus Growers
Association .............
Haines City Citrus Growers
A association ..............
Register Brothers ...................
Winter Haven Citrus Growers
Association ......... ..-...........
Lykes Brothers, Inc. .............
.. ... ...-- ..--- ..-- .....- ......--


......Plymouth

.. Haines City
...........A lturas

Winter Haven
Winter Garden
Winter Haven
.Lake Placid


The Lake Hamilton
Cooperative, Inc ....................Lake Hamilton
Sprott Groves, Inc. ............ .........Lake W ales
Lake Placid Groves ...................Lake Placid
Highland Park Service
Company ...............................Lake Wales
Superior Fertilizer and Chemical
Company ....- ...-..-........Lake Wales
Ward's Nursery .........................Avon Park
Clearwater Growers Association.. .Clearwater
Minute Maid Corporation ................ Plymouth
---............-.... ..- .. ..- .. -- ... Babson Park
-- .......-..........Orlando


.







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