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UNIVERSITY OF FLORIDA
AGRICULTURAL RESEARCH AND
EDUCATION CENTER, LEESBURG
(GAINESVILLE LINE 392-7272)
LEESBURG, FLORIDA 32749-0388
MUSCADINE GRAPE FIELD DAY
August 22, 1986
Leesburg AREC Research
COLLEGE OF AGRICULTURE
Report (LBG 86-12)
AGRICULTURAL EXPERIMENT STATION
COOPERATIVE EXTENSION SERVICE
SCHOOL OF FOREST RESOURCES AND CONSERVATION
CENTER FOR TROPICAL AGRICULTURE
The Institute of Food and Agricultural Sciences is an Equal Employment Opportunity Affirmative Action Employer authorized to provide research,
educational information and other services only to individuals and institutions that function without regard to race, color, sex, or national origin.
UNIVERSITY OF FLORIDA
INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES
SI 4UIMF LIBRARY
Dr. Mary C. Halbrooks, Fruit Crops Department Moderator
to Register (no cost), sample grape juices.
9:30 Taste Test Panel of cultivars and experimental
selections. Your evaluations are used in the research
10:15 Taste test panel review by Dr. John Mortensen.
10:20 Dr. Gary Elmstrom, Center Director, AREC Leesburg.
10:25 Dr.John Mortensen, AREC Leesburg.
Breeding Muscadine Grapes for Florida.
10:35 Dr. Don Hopkins, AREC Leesburg.
Disease Control in Florida Grapes.
10:45 Dr. Mary Halbrooks, Fruit Crops.
Grape Root Borer Update.
10:50 Dr. Bob Bates, Food Science and Human Nutrition.
Popularizing Southern Grapes: Activities in Other
11:00 Dr. Charles Sims, Food Science and Human Nutrition.
Research Opportunities in Muscadine Grape Processing.
11:05 Tour of the research vineyard. Stops will include new
walk-in cooler, muscadine varieties, vineyard sprayer in
operation and maxi-jet irrigation.
Breeding Muscadine Grapes for Florida. (J. A. Mortensen)
It was 1959 when we began testing muscadine cultivars and
selections obtained from breeding programs in Mississippi,
Georgia, and North Carolina. We have continued testing and
evaluating available muscadine material to date for longevity,
fruit yields, disease resistance, and adaptability to mechanical
harvest. Since 1972 we have made crosses at Leesburg to increase
emphasis on resistance to PD, uniformity of ripening, high
percentage dry scar, and fruit quality for fresh use or wine.
Increased berry size is demanded by pick-your-own and fresh
market outlets; thus, larger-berried parents such as Granny Val,
Summit, Dixieland, Jumbo, or Nesbitt have been used as sources of
size. Seedlessness is needed in muscadines, and at least one
seedless selection developed by the late Mr. B. O. Fry of
Griffin, Georgia is currently of interest. Use of fertile
hybrids between bunch and muscadine grapes to transfer
seedlessness from bunch grapes to muscadines is under
investigation. A North Carolina cultivar of interspecific hybrid
makeup is seedless -- N.C. 74C039-1. Crosses were made with
pollen of this cultivar with Nesbitt, CA9-37, and CA9-50
muscadines and with AA12-3 interspecific hybrid. Wine cultivars
with good color and quality retention through fermentation are
being developed in cooperation with Dr. Bates. Resistance to
berry rot during the period of ripening has received increased
selection pressure in recent years among our muscadine
Table 1 gives the 14 currently recommended muscadines for various
purposes and uses. Best for white wine are Welder, Doreen, and
Dixie; for red wine Noble and Regale. Best pick-your-own
bronze-fruited varieties are Triumph, Summit, Fry, Dixie, and
Dixiered. The best pick-your-own black-fruited varieties are
Nesbitt and Jumbo. Only two cultivars appear suitable for fresh
market: Nesbitt and Summit. Other varieties either lack size,
ripen unevenly, or have a wet stem scar when harvested
Table 2 lists the 31 muscadine varieties not currently
recommended for Florida and the reasons why they are not. Carlos
is excellent for uniformity of ripening and dry stem scar but
several vines have died of PD at Leesburg and at other Florida
locations. PD susceptibility is the reason we do not recommend
Carlos. Magnolia makes good white wine but the fruit ripens so
unevenly in Florida, and its susceptibility to ripe rot is so
evident that we cannot recommend it. Higgins was a fine old
female variety but susceptible to ripe rot, so is no longer
recommended. Sugargate has excellent fruit quality but yields so
poorly it is not recommended (See Table 2).
Below are listed 12 newer muscadine selections from our breeding
program that are being tested around the state as possible new
varieties for Florida growers.
Fla. AA10-9 A cross of Southland with Dixie, black, with 4.6 g
berries, 87% dry scar, ripening uniformly about August 18 in
Leesburg, with 36 g bunches averaging 8 berries per cluster that
do not shell off readily. Vine vigor medium, productive.
Possible wine or juice grape.
Fla. AA12-3 A cross of Summit with Florida P9-15; black, with
6.3 g oval berries, dry scar, ripening uniformly about August 16,
with good flavor but slightly tough pulp. Leaf shape resembles
bunch x muscadine hybrids. Vine vigorous and productive, with
37 g clusters averaging 6 berries per cluster. Possible wine or
Fla. AA12-64 A cross of U.S.4, a uniform ripening black
selection, with Florida AD3-42, a highly productive bronze
selection derived from a Carlos x Welder combination. Fruit is
black, with 6.4 g berries and 49 g clusters averaging 8 berries
per cluster. Scar is relatively dry. Fruit ripens uniformly
about August 17, with high levels of productivity and vine vigor.
Bloom is early and probably should be harvested about August 10
or 12 for wine use.
Florida AB5-60 A cross of Magoon with Dixie, pink fruited, with
8.4 g berries on 65 g clusters averaging 8 berries per cluster.
Relatively dry scar and less rot than the usual bronze-fruited
variety. The selection has excellent vigor and productivity,
with good-flavored fruit, but pulp is too tough for fresh market
use. Ripens about August 25, possibly useful for wine.
Florida AD2-38 A cross of Nesbitt with Carlos, black, with 8.3 g
berries on 46 g clusters averaging 5 berries per cluster.
Relatively dry scar, productive, ripening about August 22 with
good-flavored fruit that may be of interest for pick-your-own,
dooryard, or fresh market.
Florida AD3-42 A cross of Carlos with Welder, bronze, with 5.3 g
berries on 40 g clusters averaging 7.6 berries per cluster. Scar
is occasionally wet when harvested mechanically but ripening is
uniform about August 16, with highly productive, vigorous vines
at several locations across Florida. Quality of fruit is juicy
and very good, but berries probably are smaller than desired for
fresh market. Very resistant to diseases. Possible use for wine
Florida CA4-46 A cross of Fla. H13-11 (a Vitis munsoniana x
Magoon combination) with Dixie. Fruit is black, with 4.4 g
berries on 72 g clusters averaging 17 berries per cluster.
Flavor is good and clusters are well-filled with juicy berries
that are highly pigmented. Vines have excellent vigor and
production, ripening uniformly about August 27 with pH 3.3,
titratable acidity of .42, and soluble solids of 16.6%. A
natural for red wine production.
Florida CA9-37 A cross of Fry with Southland. Bronze fruit with
11.3 g berries on 75 g clusters averaging 6.5 berries per
cluster. This selection is a female and will require a
self-fertile pollinator nearby. Fruit quality resembles Fry but
picks with a relatively dry scar. Vine vigor and productivity
are medium. Possible use for pick-our-own or fresh market.
Florida CA9-48 Another cross of Fry with Southland. Fruit is
black, with 7.7 g berries on 51 g clusters averaging 7 berries
per cluster. Vines are vigorous and productive, ripening
uniformly about August 27. Fruit is good flavored with chewable
skin and tender pulp. Scar is about 50% dry. It is a natural
for pick-your-own and dooryard use.
Florida CA9-50 Still another Fry by Southland cross with bronze
fruit, 6.6 g berries on 38 g clusters averaging 6 berries per
cluster. Both the texture and flavor of the fruit is good to
excellent. Vine vigor and productivity are very good, ripening
fruit uniformly about August 27 at Leesburg. Usually 70% of the
fruit have dry stem scar when harvested mechanically. Potential
is for fresh market, wines (ph 3.4, titratable acidity .37,
soluble solids 18.3%), and dooryard use.
Florida DBl-65 A cross of Southland with Carlos. Fruit is
black, with 5.6 g berries on 44 g clusters averaging 7.6 berries
per cluster. This selection ripens uniformly, with 93% dry scar,
good texture, and very good flavor. Vines have medium vigor and
productivity, ripening about August 27 at Leesburg. Possible
fresh market or wine use.
Florida DB3-21 A cross of Southland with Dixie, black fruited,
with 6.0 g berries on 41 g clusters averaging 6.6 berries per
cluster. Fruit ripens uniformly with 95% dry scar, 18.8% soluble
solids, pH 3.3, and titratable acidity of .46. Pulp too tough
for fresh fruit. Possible wine or juice grape.
Table 1. Fourteen muscadine grape varieties recommended to Florida
White Red U-pick Fresh Juice, Home gardens
Variety wine wine Bronze Black mkt. jelly Bronze Black
Dixie X X XY X
Doreen X X
Nesbitt X X X
Noble X X
Regale X X
Summitz X X
Triumph X X
Welder X Xy
SFemale variety: requires a self-fertile muscadine nearby for good
fruit set (25 ft or less). Self-fertile varieties bear fruit well
without a different variety nearby.
YBlend juice with Noble or Regale for color.
Muscadine grape varieties not recommended for new
plantings in Florida.
Bronze muscadine grapes
Reason not recommended
susceptible to PD
low fruit yield
low fruit yield
lacks vine vigor
fruit rots, uneven ripening
susceptible to PD
uneven ripen, fruit rots
low yield, lacks quality
lacks quality, tight bunch
low yield, susceptible to PD
lacks vine vigor
low to medium yield
Black muscadine grapes
fruit shells off on ground
small size, low yield
lacks sugar, low yield
low yield, tenacious
lacks quality and yield
low yield,dry calyptra
small size, weak vigor
susceptible to PD
small size, female
susceptible to PD, low yield
Insect Control on Florida Muscadine Grapes (W. C. Adlerz)
Grape Root Borer
Grape root borer may be the most serious threat to grapes in
Florida, having the potential to kill both bunch and muscadine
vines. Root borers have been found in most varieties of
grapevines in Florida, (Table 3). Larvae tunnel in the roots,
reducing root diameters and girdling even large roots. Large
larvae often make their way into the crown of the plant. Marked
reductions in vine vigor and yield is cause to suspect root borer
activity. Detection is by exposing part of the root system to
inspect for larvae or damaged roots.
Larvae remain in the soil for about 22 months before coming to
the surface to pupate. The adult moths are active and can be
seen in the vineyard in the daytime. Adults are brown wasplike
moths with yellow markings. Females lay eggs on a variety of
plant materials or on the ground. Newly hatched larvae tunnel
through the soil to the roots.
The only available chemical control method is spraying the ground
to create a chemical barrier to newly hatched larvae that are
attempting to penetrate the soil surface to the grapevine roots.
Larval control with this method has been found effective in
Florida. The approved insecticide for this is Lorsban, which
should be applied according to label directions. Do not apply
less than the 2 quarts of dilute spray per vine called for on the
label. A concentration of 4.5 pints of Lorsban 4E/100 gallons of
finished spray is effective. The Lorsban label limits
applications to one per season. The insecticide label is the law
In Central Florida, root borer moths are active from about
mid-August to mid-November. Peak moth flights are late September
to early October. The single application of barrier spray that
is allowed by law should be made around the first of October to
vines on which harvest has been completed. Applications cannot
be made later than 35 days before harvest.
In the Tallahassee area it has been determined that moth adults
are active from late July through the end of September, peaking
around the first of September. Late August to the first of
September would be good timing for the barrier spray. If this is
in the harvest period, however, it will be necessary to count
back 35 days from the first anticipated day of harvest to apply
At this time, moth flight data have been compiled only for
Lakeland, Leesburg, and the Monticello-Tallahassee area. Short
distances between vineyards may result in large differences in
moth flight periods.
Occurrence of grape root borers on various grapes in
the laboratory research planting and a commercial
vineyard: cast pupal skins at the soil surface.
Pupal skins per vine
1979 1980 1981 1980 1981
Liberty (Lake Emerald)
Stover (Lake Emerald)
Norris (Lake Emerald)
L4-33 (Dog Ridge)
Average from 6 single-plant replications.
2Average from 5 to 15 plants of each variety.
Average from 5 to 15 plants of each variety.
Muscadine Tissue Culture (D. J. Gray)
Muscadine tissue culture research has centered on two main areas:
Micropropagation for rapid clonal multiplication and embryo
rescue for seedless cultivar development.
Micropropagation is useful for rapid increase of desirable
cultivars and is particularly applicable when demand for planting
stock exceeds the capacity of conventional nursery methods. We
have successfully micropropagated 'Carlos' and 'Dixie' as well as
a numbered selection, AD3-42 (Gray & Fisher, Proc. Fla. Hort.
Soc. 98:172-174, 1985). 'Carlos' increased at a rate of five
shoots per month. Each shoot could be rooted to produce a plant
or be recultured to produce five additional shoots. Assuming 40
initial cultures with a monthly proliferation rate of five shoots
per culture and serial reculture of all shoots, 625,000 plants
would result in only six months. Our continuing research is
studying micropropagation of 'Fry' and will attempt to carry
resulting plants to fruit.
Our embryo rescue research is attempting to cross muscadine
cultivars with various seedless bunch grapes. This cross is
typically very difficult to accomplish and resulting fertility is
low. We hope that our embryo rescue procedure will allow us to
coax the development of progeny that are normally not obtainable
with conventional breeding. The goal will be to incorporate
bunch grape genes for seedlessness into quality muscadine
cultivars. For 1986, we have crossed 'Nesbitt' with seedless
pollen from 'Himrod', 'Orlando Seedless' and NC-391, a
pre-existing seedless muscadine-bunch hybrid. The results of
these crosses look very promising. We should have progeny in
soil during the fall. First fruiting could occur as early as
Disease Control in Florida Grapes (D. L. Hopkins)
Disease control is an absolute necessity to successful bunch
grape production in Florida. The most severe fungal disease is
anthracnose, which affects both foliage and fruit. There are 3
other fungal fruit rots black rot, ripe rot, and bitter rot -
that must be controlled. A number of leafspot diseases become
serious problems during late summer. These diseases must be
controlled to prevent premature defoliation in the fall, thus
assuring a stronger vine in dormancy and better yields in the
A long growing season, high temperatures, abundant rainfall, and
high humidity make bunch grape disease very difficult to control
in Florida. Therefore, a vigorous spray program must be started
in the spring when buds are 2-6 inches long and continued
throughout the season. Fungicides should be applied every 10-14
days until a week before harvest, and every 3-4 weeks from
harvest through November or until dormancy. Spray intervals
should be shortened during rainy weather, and may be lengthened
during dry seasons.
Since muscadines are resistant to anthracnose, the first spray
can be delayed until just prior to bloom. As with bunch grapes,
fungicides should be applied every 2 weeks through harvest. One
or 2 postharvest applications are beneficial. The fungicides
recommended for grape disease control in Florida are listed in
the following table. A spreader-sticker may be included in the
spray. Please read the label for application instructions.
Remember, The Label is the Law.
Amt./100 gal. Amt. per
Fungicide per acre gal.
Manzate D 1 1/2 lb. 1 1/2 TBS1
Dithane M-22 Special 1 1/2 lb. 1 1/2 TBS
Captan 2-4 lb. 2-4 TBS
Phaltan 2-4 lb. 2-4 TBS
Benlate 1-1 1/2 lb. 1-1 1/2 TBS
TBS = tablespoon
Since the activity of these fungicides against specific diseases
varies, it is advisable to use combinations of materials in a
grapevine disease control program. For example, Benlate may be
tank mixed with either Orthocide captain ) or Manzate D or Dithane
M-22 Special. Orthocide and Manzate D or Dithane M-22 is also an
effective tank mix.
Pierce's Disease of Grapevine
Pierce's disease (PD) is caused by a small, xylem-limited
bacteria. The symptoms include decline of vigor, marginal
necrosis of leaves, and often death of the plant. This disease
limits grape production in Florida. Both European type (Vitis
vinifera) and American type (V. labrusca) bunch grapes succumb to
Presently, the only effective control for PD is resistance. To
be productive in Florida, grapes must be resistant to PD. Most
varieties of muscadine grape have a high level of resistance, but
some are susceptible. 'Pride', 'Carlos', 'Lucida', and
'Scuppernong' are examples of muscadine varieties that are
susceptible to PD in Florida. Among bunch grapes, only varieties
developed at the AREC, Leesburg have enough resistance to PD to
be productive in Florida. These include 'Stover', 'Lake
Emerald', 'Blue Lake', 'Suwannee', 'Daytona', 'Conquistador', and