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and W.B. Sherman
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Illustration and design Katrina Vitkus Sr. Art/Publication Production Specialist, Educational Media and
Services, University of Florida, Institute of Food and Agricultural Sciences.
J.G. Williamson is associate professor and extension horticulturist, Horticultural Sciences, University of
Florida, Gainesville; P.C. Andersen is professor and research horticulturist, North Florida Research
and Education Center, University of Florida, Monticello; W.B. Sherman is professor and plant breeder,
Horticultural Sciences, University of Florida, Gainesville.
nectarine (Prunus) cultivars with the low
chilling needs of a mild climate has greatly
expanded the potential for commercial
peach and nectarine production in north and
north-central Florida. Deciduous fruits, such as
peach and nectarine, require accumulated expo-
sure to cool temperatures during winter dor-
mancy for budbreak and the resumption of
normal growth the following spring. The mini-
mum amount of accumulated cool temperature
exposure needed for normal growth, which
varies by cultivar, is referred to as its chilling
Because temperate-zone cultivars have higher
chilling requirements than can be satisfied in
Florida's mild climate, the University of Florida
initiated a Prunus breeding program in 1953 to
develop low-chill, early-ripening peach and
nectarine cultivars with quality characteristics
equal to temperate-zone cultivars. Most of the
cultivars released by this program, beginning in
1970, carry the prefixes "Florda" for peach and
"Sun" for nectarine.
The 10 peach and 4 nectarine cultivars discussed
here have potential for commercial and home-
owner use in Florida. Table 1 (p. 7) lists their
tree, flower, and leaf characteristics. The cultivars
are grouped according to estimated chilling
requirement, which is given in chill units (cu)
(low chill = less than 300 cu; medium chill = 300
to 450 cu). One chill unit is equal to one hour of
exposure to the optimum chilling temperature
(about 43F). Fractions of chill units result from
one hour's exposure at temperatures either
slightly above or below the optimum.
Within each group, the cultivars are listed in
order of anticipated ripening. Their chilling
requirements were estimated by comparing
their bloom and leafing dates with those of
older, standard cultivars with known chilling
Mean January temperatures necessary for normal
budbreak and foliation are related to chilling
requirement and may be used by growers to
judge the suitability of peach and nectarine
cultivars for a given location based on weather
records. Cultivars with a cu requirement of up to
250 are adapted to central Florida, and cultivars
with a cu requirement of 300 to 400 are adapted
to north-central and north Florida. This translates
to mean January temperatures of 160 to 17.8 C
(610 to 640 F) for central Florida and 13.50 to 15
C (570 to 590 F) for north-central and north
Florida. Flordaglobe, with an estimated chilling
requirement of 450 cu (mean January temperature
of 56' F), should be planted only in north Florida
(north of Alachua County).
Both flower type and leaf gland shape are useful
for cultivar identification purposes. Flower type
(showy or nonshowy) refers to the presence or
absence of conspicuous petals. Leaf gland shape
is either reniform (kidney-shaped) or globose
Bacterial spot resistance and flower bud set
were based on subjective ratings. (Bacterial spot
resistance refers to infection of leaves; bacterial
spot on fruit rarely occurs under Florida's climatic
Fruit characteristics of the same peach and nectar-
ine cultivars are listed in Table 2 (p.8). Days from
full bloom to maturity, known as the fruit devel-
opment period (FDP), vary with accumulated
temperature. Fruit weights were determined from
yearly samples collected at commercial maturity
from properly thinned trees. Fruit size generally
increases with FDP. Consequently, during late
April peaches and nectarines averaging 80 g are
marketable, whereas by late May the minimum
marketable size increases to about 100 g.
Pit freeness depends on fruit type: The flesh of
semicling fruit clings to the pit at soft ripe; the
flesh of semifree fruit separates from the pit at soft
ripe; and the flesh of freestone fruit separates
from the pit when firm ripe.
Fruit color was rated visually. High percentages of
red overcolor and bright yellow background color
are desirable for high consumer acceptance.
Fruit shape, firmness, taste, and overall attractive-
ness were rated subjectively. Ideally, the shape of
the fruit should be round to slightly oblong.
Lower ratings were given to excessively oblong
fruits or to fruits with protruding tips or sutures.
High firmness scores were given to fruit with
uniform ripening, no evidence of premature
softening, and good firmness retention after har-
vest. Fruit with high aroma, moderate acidity, and
high sugar content were rated highest for taste.
Scores for flesh browning were based on the
degree of brown coloration that occurred over-
night on cut fruit surfaces. Overall attractiveness
takes into account all of the previously mentioned
variables of fruit attractiveness (i.e., size, shape,
color, and flesh browning).
Following are additional comments on each of the
peach and nectarine cultivars:
Peaches and Nectarines 1 "i&
Flordaprince. Standard for a low-chill,
early-ripening peach; susceptible to
bacterial spot. Flordastar can replace
Flordaprince in areas where bacterial spot
is a problem.
Flordaglo. Large fruit for its season; firm,
nonbrowning white flesh; ripens about 1
week after Flordaprince.
TropicBeauty. Excellent shape, color,
and firmness; susceptible to
TropicSweet. Fruit are very
sweet with sugar speckles,
which give a dull appearance;
moderately susceptible to
Rayon. Large, high quality,
attractive, freestone fruit; flesh
C 2 Peaches and Nectarines
Sunmist. An early, low-chill, white-fleshed
nectarine with excellent aroma and flavor.
Sunraycer. Large fruit for its season; excellent
color; fruit ripens about 5 days before Sunred
: i I I ''
18 9 C 60F
20.0 C 68-Mal
1 oC 70F
Average January temperatures. Adapted from
Weinberger, 1956 and Sharpe, 1970.
Peaches and Nectarines
Peaches and Nectarines 3 m's-'.
Flordadawn. One of the first commercially
shipped peaches to ripen in North America
(usually late April in north Florida); good
color, shape, and flavor; heavy, prolonged
bloom; blooms early; fruit are relatively small
but acceptable for their season.
Flordaglobe. Early ripening (with or before
Flordaking); blooms later than Flordaking;
good color, shape, and flavor; fewer split pits
than Flordaking; smaller fruit than Flordaking.
Flordaking. Industry standard for its season;
early ripening (usually early May); large fruit;
early bloom; light flower crop; poor color;
high incidence of split pits.
Flordacrest. Excellent color; good
shape; attractive; ripens about 1
week after Flordaking; fewer split
pits but smaller fruit than
FlordaRio. Large fruit; good
shape, color, and flavor; blooms
earlier than JuneGold.
- 4 Peaches and Nectarines
Sundollar. Early ripening; good size, color,
and shape; longitudinal splits may develop
on fruit of nonirrigated trees following
Suncoast. Large fruit with good color and
shape; excellent firmness retention; ripens
about 10 days after Sundollar; a new cultivar
with little grower experience.
--_~_ I ni "'0~
Estimated chill unit accumulation for Florida.
Adapted from Weinberger, 1956 and Sharpe, 1970.
Peaches and Nectarines 5 ~~L
Peaches and Nectarines 5
Proper cultivar selection is one of the most
important decisions determining success or
failure of a commercial peach orchard. Pro-
spective growers are encouraged to consult
their local county extension office for more
information or write the Cooperative Exten-
sion Service at the Horticultural Sciences
Department, P.O. Box 110690, Gainesville,
Fla. 32611-0690. The reader also may find
the following publications, upon which this
circular is based, helpful:
Andersen, P.C. and W.B. Sherman. 1995. New
low-chill peach and nectarine cultivars from the
~14 6 Peaches and Nectarines
University of Florida. Proc. Fla. State Hort. Soc.
Sharpe, R.H. 1970. Subtropical peaches and
nectarines. Proc. Fla. State Hort. Soc. 82:302-
Sherman, W.B., P.M. Lyrene, F.G. Gmitter, and
P.C. Andersen. 1988. Low-chill peach and nectar-
ine cultivars for trial in Florida. Proc. Fla. State
Hort. Soc. 101:241-244.
Weinberger, S.H. 1956. Prolonged dormancy
trouble in peaches in the Southeast in relation to
winter temperatures. Proc. Amer. Soc. Hort. Sci.
Table 1. Tree, flower, and leaf characteristics of low- and medium-chill peach and
vars adapted to north and north-central Florida.
Mean January Estimated
Estimated temperature, Flower Bacterial spot % Flower Leaf
Cultivar chill units (OF) ('C) typeb resistancec bud set glands
Flordaprince 150 64 17.8 S 4 8 R
Flordaglo 150 64 17.8 S 8 9 R
TropicBeauty 150 64 17.8 S 5 8 R
TropicSweet 175 62 16.7 S 8 9 R
Rayon 175 62 16.7 S 8 8 R
Sunraycer 250 61 16.0 NS 10 8 R
Sunmist 275 60 15.5 S 8 8 G
Flordadawn 300 59 15.0 S 10 9 R
Flordaglobe 450 56 13.0 NS 10 9 R
Flordaking 400 58 14.4 NS 10 6 G
Flordacrest 350 58 14.4 S 10 8 G
FlordaRio 400 58 14.4 NS 10 10 G
Sundollar 350 58 14.5 S 10 8 R
Suncoast 375 58 14.0 NS 10 9 R
aAdapted from Weinberger, 1956; Sharpe, 1970. Areas with this average January temperature, or a
lower one, will provide sufficient chilling to grow this cultivar successfully.
l =least resistant to 10=most resistant
Peaches and Nectarines 7
Peaches and Nectarines 7 Si""
Z' Table 2. Fruit characteristics of low- and medium-chill peach and nectarine cultivars adapted to north and north-central Florida.
FDP Weight Pit Color Flesh Overall
Cultivar days" (g) freenessb Fleshc Overred (%) Backgroundd Shapee Firmnesse Tastee browning attractiveness
Flordaprince 78 82 SC Y 80 Y 9 8 8 8 8
Flordaglo 78 94 SC W 80 CW 9 9 8 9 8
TropicBeauty 89 100 SC Y 80 BY 10 9 9 9 10
TropicSweet 94 122 SF Y 70 DY 10 9 10 8 7
Rayon 105 109 F Y 80 Y 8 7 8 10 8
Sunraycer 85 110 SC Y 90 BY 9 9 9 8 9
Sunmist 80 90 SC W 85 W 9 9 10 7 8
Flordadawn 60 80 SC Y 80 BY 8 9 9 9 8
Flordaglobe 62 85 SC Y 90 Y 9 9 8 8 8
Flordaking 68 96 SC Y 50 DY 7 7 7 9 9
Flordacrest 75 92 SC Y 80 BY 7 9 8 9 9
FlordaRio 95 130 SC Y 75 BY 7 9 9 9 9
Sundollar 70 90 SC Y 80 Y 9 9 8 6 8
Suncoast 77 110 SC Y 90 Y 8 9 9 8 9
aFDP=fruit development period (days from 50% bloom to first commercial harvest)
bSC=semicling, SF=semifree, F=free
dBY=bright yellow, Y=yellow, DY=dull yellow, CW=cream white, W=white
el =least desirable to 10=most desirable
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