Watermelon and Grape Investigations Laboratory- Mimeo-ep0rt-61-1
WATERMELON FIELD DAY
WATERMELON AND GRAPE INVESTIGATIONS LABORATORY
UNIVERSITY OF FLORIDA AGRICULTURAL EXPERIMENT STATIONS
May 24, 1961, 1:30 P.M.
Welcome to Lake County and the Watermelon Field Day,
Nixon, Assistant County Agent, Lake County.
Introduction of Visitors. James Montelaro, Associate Vegetable
Orops Specialist, Florida Agricultural Extension Service.
Grape Studies at the Watermelon and Grape Investigations
Laboratory. J. Mortensen, Assistant Geneticist and L. H.
Stover, Assistant in Horticulture.
Tour of Plots, J. A. Mortensen: W. C. Adlerz, Assistant
Entomologist; N. C. Schenck, Assistant Plant Pathologist;
J. M. Call, Plant Pathologist in Charge
S'AIAHIEI OF EXPERIMENTAL WORK
1. Watermelon Observational Trial (Crall)
Date of Planting: March 3
WR Peacock 132
WR Klondike 155
# Char. Gray
#Southern Regional entry.
-Lxtreme susceptibility to Fusarium wilt.
Observations to Date: The soil in which this trial is
plan-td is rather uniformly heavily infested with the
Ralarium wilt fungus. This trial demonstrates clearly the
need to use resistant varieties on old land (this field
was last planted in melons at least 7 to 10 years ago).
Pronounced differences in resistance among varieties can
2. BreedinR Plots (Crall)
F1 and segregating progenies. Various lines are being
utilized in a breeding program aimed at the development
of conraercially desirable types with resistance to the more
important diseases. Evaluaticn of various Fl combinations
is also being made.
3. Pollination Study (Adlerz)
Puro;oe: To evaluate the effects of various field con-
centiations of bees on yield of watermelon.
Planting Date: February 20 to February 23, 1961.
Variety: Charleston Gray
Pvul*'- of 1960 Bee Visitation Study: Treatments were 2,
-4 aind' visits and hand and open pollination. The
lowest number of visits required for adequate pollination
was six. The most effective pollination occurred between
the hours of 8 and 9 A.M.
1961 Treatments: An attempt has been made to vary the field
concentrations of honey bees by varying the number of
colonies per acre. Treatments include one colony per acre,
one colony per two acres and one colony per four acres,
Measures of bee activity close to the hives and 1000 1200
feet from the hives have been made and are to be correlated
with yield. Results are incomplete.
4. hFasarium Wilt Test (Schenck)
Purpose: To test various watermelon varieties for resist-
ance to Fusarium wilt.
Design: Randomized block: 3 replications.
Varieties: Percent wilted plants (- date)
lo Dixie Queen W.R. 4.3
2. Charleston Gray 11.6
3. Shipper 2.7
4. Kleckley Sweet 45.2
5. Charleston Gray 12.5
6. Fairfax 5.5
7. Dixie Queen W.R. 1.9
80 Charleston Gray 4, 5
90 Blackstone 12.3
10, Florida Giant 81,3
ll Garrisonian 41,6
12o Calhoun Sweet 1.3
Results: Wilting percentages this year are higher than in
any previous test; results incomplete.
5. Surfactant Test (Schenck)
Purpose: To determine the effect of various surfactants on
the coverage and adherence of foliar fungicides.
Methods: Phosphorescent chemical applied with all treatments.
Ten leaf samples collected at various intervals from each
plot and examined under ultra-violet light for fluorescence.
Distribution of fluorescence on leaf indicates spray coverage;
fungicide adherence determined by amount of fluorescence
after several days weathering.
Treatments: Rate/100 gals,
1, Triton B-1956 6 oz.
2. Plyac 6 oz.
3. Elvanol 72-60 2 Ibs.
4. PEPS / X-77 6 oz. / 6 oz.
5. Colloidal X-77 6 oz.
6. Untreated -
7. Rhoplex 6 oz.
8. Colloidal Z-1 W, 4 oz.
9, Ortho-Spray 6 oz.
10. PEPS 6 o,..
11. Glyodin 6 oz.
12. Fungicide alone
1960 Results: No difference in initial retention of
fungicide among treatments. After rainfall PEPS, Ortho-
Spray, Rhoplex, and Plyac retained greater amounts of
fungicide than other treatments. After 1.25 inches of
rain 75 percent of fungicide was removed from upper surface
of leaf and 25 percent from lower surface. No difference
among treatments in disease control.
6. Fungicide Spray Trial (Schenck)
Purpose: To determine effectiveness of various fungicides
in the control of leaf diseases.
Design: Randomized block, 4 replications.
Variety: Charleston Gray
Treatments: 3 applications at 7 day intervals beginning
May 4 (only slight amounts of anthracnose and gummy stem
Dithane A-40 / ZnSo4
Zineb alt. maneb
Thylate / maneb
Phaltan alt. maneb
Captan 50 / maneb
Dyrene / maneb
1 lb. / 34 lb.
2 Ibs. alt. 11 lbs.
1 lb. / 1 lb.
2 lbs. alt. 1l Ibs.
1 lb. / 1 lb.
1 lb. 1 3/ lb.
1960 Results: Best control of gummy stem blight with
Phaltan, Captan 80, zineb / maneb. Excellent disease control
persisted two weeks after last fungicide application with
Phaltan and Captan 80. Foliage injury resulted after 7th
application of Phaltan.
Present Recommendations for Control of Watermelon Foliage
Maneb alternate zineb
Maneb plus zineb
1- Ibs ; 2 lbs.
3/4 lb. plus 1 lb.
7. Replicated Watermelon Variety Trial (Grall)
Purpose: To compare several new varieties and breeding
lines with Charleston Gray.
Date of Planting: February 23
1. Garrisonian 6. WR Peacock #132
2. F59-3 7. WR Klondike #155
3. Charleston Gray 8. USDA 59-7
4. Fl Hybrid 9. Summit
5. Tri X-313 10. Shipper
1960 Results, Summit and FP9-3 were highly resistant to
Fusarium wilt, Charleston Gray was moderately resistant,
and USDA 59-7 and Garrisonian were moderately to highly
susceptibleS USDA 59-7 was very early) Charleston Gray
and Summit early and P59-3 and Garrisonian later in
maturing* USDA 59-7 and Garrisonian were significantly
lower yielding than other entries in this trial.
1961 Resultst Incomplete at this time) but highly wilt
susceptible varieties Garrisonianp Tri X-313 and USDA 59-7
will obviously be lower yielding WR Peacock, and WR
Klondike (California lines)'made poor early season growth.
No variety in this trial appears to have sufficient overall
merit to warrant recommendation as a replacement for
Charleston Gray for commercial production.
8. Compatibility Test (Schenck, Adlerz)
Purpose: To determine if various insecticide, fungicide
and foliar fertilizer mixtures are safe for use on watermelon*
Treatments: Each material listed below used in combination
with each other material once (24 treatments).
Insecticide Rate Fungicide Rate Fertilizer Rate
Phosdrin 25WP 1 lb. Zineb / maneb 1/3/4 lb.Nu-Green 4 lbs.
Thiodan 1 lb. CGptan 50 2 Ibs. 15-0-14 lbs.
Diazinon 25WP 1 lb. Tribasic CuSo4 3 lbs.
Dibrom 8E 1 pt.
9. Leafminer Control (Adlerz)
Purpose: To evaluate various materials for control of
leafminers on watermelon.
Date of Planting: February 2, 1961, at Immokalee, Florida.
Variety: Charleston Gray
Treatments: Seven applications were made on a twice weekly
schedule between 2/28/61 and 3/21/61. Plots were evaluated
3/9/61 and 3/23/61.
Materials: Amount (100 gal.)
Diazinon 25WP 1 lb.
Diazinon 25WP 2 lbs.
Djazinon 25WP (plus Colloidal K-77) 1 lb. (2 oz.)
Dibrom"8E 0.5 pt.
Dibrom 8E 1.0 pt.
Guthion 25WP 2.0 lbs.
S.D. 3562 4S 1.0 qt.
Ros-ults: The best control resulted from SD3562, Dibrom
at one pint and Guthion. The addition of Colloidal
Products X-77 did not improve control with Diazinon.
Dibrom and Guthion are not presently cleared for use
on watermelon. SD3562 is not presently on the market.
A leafminer spray trial was planned for the Leesburg area,
but there was no infestation.
10. Salt Marsh Caterpillar Control (Adlerz)
Purpose: To evaluate various materials for control of salt
Date of Planting: February 23, 1961
Variety: Charleston Gray
Treatments: Applications were made at the rates indicated
on 4/13/61 and at half these rates on 4/8/61.
Materials: Rate (100 gals.)
1. Parathion 15WP 4 lbs.
2. Dylox 50WP 4 Ibs.
3. Phosdrin 25 WP 4 lbs.
4. Endrin 16E 2 pts.
5. DDT 50uP 4 lbs.
6. Thiodan 50WP 4 lbs.
7. Thiodan 50WP 2 lbs.
8. Dibrom 8E 2 pts.
9. Unsprayed check
Results: Best control was obtained wi~ treatments 3,8,2,5,
and 1, in that order. Treatment 4 was superior to the check.
11. Search for Cytoplasmic Male Sterility in Watermelon (Crall,
Crosses are being made between watermelon and distant
relatives of the watermelon in an effort to obtain a plant
with sterile male but functional female flowers. This
characteristic would then be incorporated into existing
lines of watermelon. Such male-sterile plants would be
used in producing hybrid seed without the expense of hand-
Initial crosses were made in 1960. Bockcrosses to the F1
progenies are being made this season.
12. Inheritance of Rcsist:.ncc to ijcrilum wilt in Watermelon
(Crall ) .. -.
Crosses are being made between highly resistant (Summit,
Calhoun Sweet), highly susceptible (Garrisonian, Florida
Giant) and intermediately resistant (Charleston Gray,
The F1 progenies and backcross progenies to them will be
tested for resistance,
13. Factors Affecting Watermelon Yield and Quality (Crall)
Purpose: To determine the effect of various factors on
watermelon yield and quality.
Date of Planting: February 21
1. Spacing: 4' VS 8'
2. Dolomite at 1 ton/A plus Frits 501 at .30 lbs/A VS none
3. Nitrogen (25% natural organic N): 80 lbs/A VS 120 Ibs/A
4. Potash: 80 lbs/A VS 120 lbs/A
Phosphate as super phosphate and triple super phosphate at
1959: No effect of spacing at 4' or 8' on yield. More.
blossom end rot at 4' than at 8t. Yields were significantly
higher at 120 lbs N and 120 lbs. K than at 60 lbs. of each.
Clay amendments and hydrated lime had no significant effects.
1960: Significantly higher yields at 4' spacing than at 8'.
Significantly higher yields at 120 lbs. N and 120 Ibs. K
than at 60 lbs. of each. Clay amendments and hydrated lime
had no significant effects.
14. Cultural Practices Affecting Water melon Maturity. (Crall)
Purpose: To determine the effect of various cultural
practices on early maturity.
1. Polyethylene plastic mulch
2. South-sloped beds VS no slope
3. Dates of planting or transplanting
a. Planted February 17
b. Planted February 27
c. Planted March 9
d. Transplanted March 1
1959: Immediate watering following planting resulted in
higher early yields, but emergence top-dressing and south-
sloped beds were not effective in promoting earlier maturity.
1960: Clear polyethylene plastic mulch and south-sloped
beds both promoted more vigorous early season growth and
increased early yields. Total yields also were larger
fiom mulched beds. Early season soil temperatures were
higher under clear plastic mulch and in sloped beds. Better
moisture and fertilizer retention may also have been
effected under plastic. Effects of planting date and
t r.ansplanting were not decisive.
1961: Incomplete, but early results indicate higher early
yields from Feb. 17 planting and transplanted plots.
Also, early yields will be lower from plots covered with
black plastic mulch.
15. Replicated and Observational Cantaloupe Trials. (Crall)
Purpose: To compare maturity, quality, and yield of
cantaloupe varieties and breeding lines.
Date of Planting: March 14
S. Car. 25
S. Car. 180
(All except Beplicated entries 8,
Southern Regional Trials)
Florida 134 (Fl)
9, and 10 are from
Results (1960): Most promising last season were Seminole,
Delta Gold, Rio Gold, W57-123D and L30 C-58, all of which
compared favorably with Hale's Jumbo and PMR 45 in quality,
and the latter 3 of which compared favorably also in yield.
All entries were superior to Haleb Jumbo and PMR 45 in
resistance to leafspots.
Recommended for Commercial Production
Suggested for Limited Trial
16. Search for Cytoplasmic Male-Sterility in Cantaloupe (Mortensen)
Crosses are being made between cantaloupes and various
cantaloupe relatives from foreign countries in an effort
to obtain plants with sterile male, but functional female
flowers This characteristic would then be incorporated
into existing lines of cantaloupe. Such male-sterile
plants would be used in making hybrid seed without the
expense of hand-pollinationo
Initial crosses are being made this season.
17. Soil Fumigation (Schenck)
Purposes To evaluate soil fumigants for their control of
nematodes and fungi associated with failure of watermelon
culture on old land,
Treatment Date: January 31 Planting:S February 23
Replanting April 6
Varieties Charleston Gray and Florida Giant interplanted.
Application: All treatments injected 6-8" deep except allyl
alcohol (drench), Immediately after treatment all plots
rebedded with 4-5" of soil to seal treated areas. One day
prior to planting, surface soil remove from beds to expose
the treated areas.
1. Mylone 85W 50 Ibs.
2. Nemagon 50E.C. 1 gal.
3. VPM 25 gals.
4. Nemagon / AA 1 gal. / 25 gals.
6. Allyl alcohol 25 galso
7,p Mencs 8 gals.
Results: No plants remaining in Nemagon or untreated plots.
Vine growth best in VPM and allyl alcohol treated plots.
Fungus populations reduced most in VPM treated plots.