Group Title: Watermelon field day.
Title: Watermelon field day. 1966.
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 Material Information
Title: Watermelon field day. 1966.
Series Title: Watermelon field day.
Physical Description: Serial
Language: English
Publisher: Watermelon and Grape Investigations Laboratory, University of Florida
Publication Date: 1966
Spatial Coverage: North America -- United States -- Florida
 Record Information
Bibliographic ID: UF00076045
Volume ID: VID00008
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 144617905

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Mimeo Report WGL 66-1 June 1, 1966


1:30 P.M.

Welcome to Lake County and the Watermelon Field Day, Earl Kelly,
Lake County Agricultural Agent.

Introduction of Visitors. J. M. Montelaro, Vegetable Crops
Specialist, Florida Agricultural Extension Service, Gainesville.

Grape Studies at the Watermelon and Grape Investigations Laboratory,
J. A. Mortensen, Assistant Geneticist.

Soil Fumigation.
Fungicide Trial,
Compatibility Trial.
Watermelon Diseases in Florida in 1965.
Epidemiology of Watermelon Diseases.
N. C. Schenck, Associate Plant Pathologist.

Pollination Study.
Insecticide Trial.
Leafminer Control.
Aphid Repellents for Mosaic Control.
Mosaic Survey for 1966.
W. C. Adlerz, Assistant Entomologist.

Watermelon Nutrition, with Particular Reference to Copper
Deficiency in Some Florida Soils. S. J. Locascio, Associate
Horticulturist, Vegetable Crops Department, Gainesville.

Watermelon Breeding and Variety Testing.
Studies on Pusarium Wilt of Watermelon.
Watermelon Mosaic in Florida in 1966 and Current Status of
Research on this Problem.
Cantaloupe Breeding and Variety Testing.
J. M. Crall, Plant Pathologist and Head

Careers in Agriculture. F. E. Myers, Assistant Director,
Florida Agricultural Extension Service, Gainesville.

Tour of Plots. Members of Staff


1. Fungicide Trial (Schenck)

Purpose: To compare fungicides for control of fungus foliar
diseases on watermelon.

Procedures; Fungicide treatments (white stakes) were randomized
with insecticide (yellow stakes) and compatibility treatments
(green stakes) in one large test area. All treatments were
applied at weekly intervals at 200 psi using a boom-sprayer
with 10 TeeJet nozzles at 1-foot intervals.


Maneb + zineb
Difolatan 80W
HOE 2866
Tribasic CuSO4
Calumet BCO
Dithane M-22 Sp. +
Dithane Z-78
Daconil 2787
Calumet M-20
Dithane M-45
Daconil 2787
HOE 2846
Brestan 60
Difolatan 80W

Rate per 100 gal.

1 lb. + 1 lb.
2 lb.
3/4 lb.
3 lb.
3 lb.

1 lb. + lb.
2 lb.
1 1/2 lb.
1 1/2' b.
1 1/2 lb.
3/4 lb.
1/2 lb.
1 1/2 lb.
2 lb.

Results. 1965. Downy mildew and gummy stem blight occurred
in moderate amounts. Daconil 2787, Manzate D, Dithane M-45,
maneb plus zineb, Difolatan 80W, Dithane M-22 Sp. were equally
effective in control; TC-90, Dupont 4472, and Miller 658
were not as effective.

Recommendations: Manzate D ( 1 1/2 lb.); Dithane M-45
(1 1/2 lb.); Dithane M-22 Sp. (1 1/2 lb.); maneb (1 lb.)
plus zineb (1 lb.).

2. Insecticide Trial (Adlerz)

Purpose: To evaluate various materials for control of rind-
worm on watermelon.

Date of planting: March 7.

Variety: Charleston Gray

Treatments: Six to eight applications are planned at weekly
intervals beginning prior to fruit set. Field letters on
yellow markers.


A. Nia 10242 50W
B. Nia 10242 50W
plus Thuricide 90TS
C. Parathion 8E
D. Parathion 8E
plus Thuricide 90TS
E. Mevinphos 2E
F. Mevinphos 2E
plus Thuricide 90TS
G. Thuricide 90TS
H. Thuricide 90TS
I. Guthion 2E
J. Endosulphan 50W
K. Dimethoate 267E
L. Kepone 4% bait
M. Kepone 4% bait
N. GS 10128 50W
0. GS 13005 40E
P. Ortho 9006

Amount/100 gal./acre

1.0 lb.
0.5 lb.
1.0 pt.
0.5 pt.
0.25 pt.
1.0 pt.
1.0 qt.
1.0 pt.
1.0 pt.
1.0 qt.
2.0 qts.
1.0 qt.
1.0 lb.
1.0 pt.
40.0 Ibs. weekly
40.0 lbs. biweekly
2.0 lb.
1.0 pt. (approx.)
1.0 pt. (approx.)

Results: 1966 data incomplete. Tobacco budworms began
working in the crop early and were present at the rate of
1-4 per 120 watermelon flowers during the week of May 16-20.

1965. Best results were obtained with Nia 10242,
parathion plus Thuricide 90TS, parathion, mevinphos plus
Thuricide 90TS, guthion, Thuricide and CP 43858. The latter
was phytotoxic.

3. Compatibility Trial (Schenck, Adlerz)

Purpose: To compare various pesticide mixtures for their
effects on disease and insect control and yield of watermelon.

Procedure: 25 treatments (green stakes) consisting of promis-
ing fungicides and insecticides combined with the presently
recommended materials; weekly applications as for fungicides
and insecticides.


Thuricide 90TS (1 qt.)

Nia. 10242 (1 lb.)


+ Dithane M-22 SP. (1 1/2 Ib.)
+ Manob (1 lb.) + zineb (1 lb.)
+ Dithane M-45 (1 1/2 lb.)
+ Daconil 2787 (2 lb.)
+ Difolatan 80W (2 lb.)
+ Dithane M-22 Sp. (1 1/2 lb.)
+ Maneb (1 lb.) + zineb (1 lb.)
+ Dithane M-45 (1 1/2 lb.)
+ Daconil 2787(2 lb.)
+ Difolatan 80W (2 lb.)


Daconil 2787 (2 lb.')

Difolatan 80W (2 lb.)

Manzate D (1 1/2 lb.)


+ Parathion 8E (1/2 pt.)
+ Guthion 2E (1 qt.)
+ Endosulfan 50W (1 Ib.)
+ Dimethoate 267E ( 1 pt.)
+ Mevinphos 2E ( 1 qt.)
+ Parathion 8E (1/2 pt.)
+ Guthion 2E (1 qt.)
+ Endosulfan 50W (1 lb.)
+ Dimethoate 267E (1 pt.)
+ Mevinphos 2E (1 qt.)
+ Parathion 8E (1/2 pt.)
+ Guthion 2E (1 qt.)
+ Endosulfan 50W (1 lb.)
+ Dimethoate 267E (1 pt.)
+ Mevinphos 2E (1 qt.)

Results: 1965. Fungicidal effectiveness of Difolatan was
reduced by Guthion and endosulfan; the effectiveness of Daconil
was reduced by Guthion and mevinphos.
Insecticidal effectiveness of Niagara 10242 was reduced by
Dithane M-22 Special.

4. Watermelon Replicated Trial (Crall)

Purpose: Comparison of two F-l hybrids from the Vegetable
Breeding Laboratory with Charleston Gray.

Date of Planting: March 9

Replicates: 4


Charleston Gray Rows Al5, 19, 23, 25
WX11 Rows A16, 20, 21, 24
WX15 Rows A17, 18, 22, 26

Varietal Recommendations: Charleston Gray, Jubilee, and
Crimson Sweet are all recommended for commercial watermelon
production in Florida. None of the Peacock lines under test
for several years have proved consistent enough in quality to
merit recommendation for trial in commercial production.

5. Watermelon Observational Selection Trial (Crall)

Purpose: Comparison of promising breeding lines from our
program and those from other watermelon breeders.

Date of planting:


Rows Al 14

March 9

Replicates: 2 and 4

WX16 F-L hybrid (VBL, Andrus)
W618 wilt resistant Graybelle (VBL, Andrus)
W915A wilt resistant Sugar Baby (VBL, Andrus)
L92-2 (Louisiana, Taylor)
Ark. cl-64-1 Charleston Gray-type (Arkansas, Watts)
U714 Black Diamond-type (Texas, Fuque)
U256-5 small-fruited, dark green (Texas, Fuqua)

Rows A15 C46

Selections of various types from program here; most
with combined resistance to Fusarium wilt and

6. Watermelon Breeding Plots (Crall)

A program was initiated in 1961 to combine the Summit-type
resistance to Fusarium wilt with anthracnose (Race 1)
resistance in a high quality shipping-type watermelon. Most
promising lines in this trial are from crosses between
Charleston Gray and Texas W-5. Other varieties used as
parents in this program are Summit, Peacock #132, Fairfax,
Jubilee, Crimson Sweet, and NC62-C7M. Testing of promising
lines for resistance to anthracnose and Fusarium wilt is
carried out in the greenhouse from late fall through late
spring. Most advanced lines are in the fourth selfed
generation in this planting.

7. Soil Fumigation: (Schenck)

Purpose: To determine the effect of soil fumiSants and
fungicides on the soil fungi, weeds, and yield of watermelon
on old land.

Procedure: Materials applied January 18, 19; plots planted
with Charleston Gray (wilt resistant) and Florida Giant
(wilt susceptible) varieties February 14.

Treatment Broadcast rate/acre Application method

A. Lanstan 4EC 10 gal. rototill-- Triox *
B. Vorlex 35 gal. injection-- Vapam*
0. EP 201 35 gal. injection
D. Vapam 40 gal. rototill-- Triox*
E. Lanstan 4EC 20 gal. robotill--Vapam*
F. Untreated
G. Vapam 40 gal. Rototill-- Vapam*
H. Vapam (6-foot wide) 40 gal. rototill
J. Vorlex 35 gal. injection

*Applied at edge of treated area on April 5 to roots from
growing beyond the treated area.

Results: 1965. Vorlex gave excellent early weed control but
weeds became a serious problem about mid-season; no plants of
Florida Giant survived to harvest; growth of Charleston Gray
was reduced below normal in all plots and yields were abnormal-
ly low; most promising treatments were Vorlex, EP-297, Vapam,
and Lanstan.

1966. No Florida Giant plants remain in treatments A, D, F,
G, H; Charleston Gray plants surviving in untreated areas
are considerably less vigorous than those plants in treated

8. Pollination Study (Adlerz)

Purpose: A time of planting experiment is being conducted to
determine whether certain phenomena observed in the past can
be reproduced three times in one season. Bee activity is
being related to flower production, and nectar amounts and

Dates of planting: M.a-ch 11, March 25, April 8

Plot No. Plant-ing Date Plot No. Planting Date

1 3 7 2
2 2 8 3
3 1 9 1
4 1 10 3
5 3 11 1
6 2 12 2

Variety: Charleston Gray

Results: Highest numbers of bees, total blossoms and female
blossoms were found on May 14, 64 days after the first plant-
ing; and highest numbers of total blossoms and females were
found on May 19, 55 days after the second planting (Third
planting data not available).

9. Fertilizer Source and Copper Rate Study. (Locascio and J. G.
Fiskell, Soils Department)

Purpose: To determine whether deficiency of copper in soils
might be affecting yield and quality of watermelon production
in central Florida.

Treatments: Fertilizer equivalent to 1600 Ibs. of 6-8-8
applied -in bands in 2 applications.

1. 15-20-20
2. 15-20-20 + 4 lbs. Cu/acre from CuSo4
3. 6-8-8
4. 6-8-8 + 4 lbs. Cu/acre from CuSo4
5. 15-20-20 + 30 Ibs. Cu/acre from Frit 503
6. 15-20-20 + 60 Ibs. Cu/acre from Frit 503

DatpF nof nW an-M1-) *-) q

11 1/-'- h


10. Epidemiology Studies: (Schenck)

Purpose: To evaluate the effect of environment on the
sporulation of the pathogen and the spread of disease.


1. Wetness recorder; to measure periods of rain and dew.
2. Hygrothermograph; to record temperature and humidity.
3. Spore trap; to record periods of fungus sporulation.
4. Anemometer and wind vane; to record wind velocity and

Results; Spores of gummy stem blight pathogen are usually
ejected at night after a dew or for a few hours after a rain;
spores of the downy mildew pathogen are released in the
mornings after dews, not after rains during the day; spores
of Cercospora and Alternaria are released during the day in
highest numbers during periods of greatest wind velocities.

11. Dolomite-Lime-Ca-Mg Trial (Crall)

Purpose: To determine the effect of applications of dolomite,
hydrated lime, calcium nitrate (Pril-Cal) and magnesium sulfate
Emjeo) on watermelon culture under conditions of low pH
4.5-5.3) and limiting Ca and Mg.

Results and previous years' trials: In 1962, there was a
significant yield response to mixed applications of dolomite
and hydrated lime at pH levels below 5.0. In subsequent years,
at slightly higher pH levels (at or slightly above 5.0), yield
responses to dolomite or lime were not significant. In
several years, however, there were apparent yield responses to
applications of calcium nitrate plus magnesium sulfate,
especially where dolomite or lime applications were not made.
In one year, concomitant with increased yields was a lowering
of melon quality as measured by color, flavor, and sugar

Recommendation on liming: Where soil tests indicate acidity
of pH 5.0 or less and low levels of Ca and Mg, applications of
dolomite or high calcium lime at least 6 months prior to plant-
ing are recommended. If lime application is not made, yield
response to Ca and Mg fertilizers may be expected under some

1966 Treatments (Split plot)

Main treatments (11 rows) (Feb. 10, 1966)

Dolomite at 1 ton/acre
Hydrated lime at 1600 lbs/acre
No dolomite or lime

Sub-treatments (3 rows)


Calcium nitrate at 225 Ibs. CaO/acre
Magnesium sulfate at 90 Ibs. MgO/acre

Date of planting: February 22

Varieties: Charleston Gray, Crimson Sweet (Texas W-5 in sub-
plot separator rows and main-plot borders)

12. Cantaloupe Breeding Plots (Mortensen)

The main objective has been to obtain cytoplasmic male
sterility for use in the economical production of F-l hybrid
seed. Sterility in "Male-sterile 2" cantaloupe from G. W.
Bohn in California is inherited as a nuclear gene, thus re-
quiring careful roguing of about 50 percent of the plants in
the seed production field (segregation each generation).
Cytoplasmic male sterility, if found, would not require roguing.

Selections at Leesburg from backcross progenies that derived
their cytoplasm from exotic ;ypes of Cucumis melo have shown
a type of male sterility in which the anthers fail to dehisce
pollen when the flowers open. Whether this functional male
sterility is cytoplasmic or nuclear in inheritance is still
unknown, but recessive nuclear inheritance is suspected because
fertility was restored in the F-l when crossed with Seminole.

13. Cantaloupe Variety Trial (Crall)

Purpose: To compare promising breeding lines and new varieties
with commonly used commercial varieties; included in test are
several particularly promising F-l hybrid varieties.

Observational Trial Entries (2 replicates)

Fla. 84
Fla. 67

8. AC64-100
9. AC64-22
10. Male-sterile #1
11. Honeydew #601
12. Burpee's 64-1
13. Burpee's 65-1
Borders Danza (Whitner)

Replicated Trial Entries (4 replicates)

Golden Perfection
Fla. 64-14
Fla. 4-4
Fla. 42


Edisto 47
VBL 58-8
Fla. F134-Fl
Samson Hybrid (F-l)
Saticoy Hybrid (F-l)


10. AMSC-1 23. Supermarket (F-l)
11. AC63-11 24. Burpee's F-1
12. AHD64-18 25. Topmark
13. Delta Gold Borders Danza (Whitner)

14. Nitrogen Sources and Minor Elements (Crall)

Purpose: To determine response of watermelon to N from
various fertilizer sources and to several minor elements
applied as foliar sprays, using Rayplex (Chelatex) as the
mebal-complexing agent.

Methods: N-fertilizers applied in the bed and as side-dresser.
Minor elements applied in 5 applications at weekly intervals
beginning about 2 weeks after emergence.

Treatments (Split plot)

Main plots (N sources) (5 rows)

A. All NH4 (urea in bed; NH4S04 side-dress)
B. 1/2 NH4; 1/2 NO3 (NH4N03)
C. All N03 (13-0-44 plus Pril-Cal)
D. Commercial mix (6-10-6, 30% nat. org. N, wo/minors)
E. Treatments D (bed) plus C (side-dress)

Sub-plots (Minor elements) (1 row)

1. No minor elements
2. Combination (Fe, Zn, Mn, Cu, Bo, Mb)
3. Copper
4. Boron
5. Sodium molybdate

Date of planting: Feb. 24, March 14

Variety: Charleston Gray
(Texas W-5 in main-plot separator and border rows)

15. Watermelon Breeding Search for Resistance to Watermelon
Mosaic (Crall)

Over 800 accessions of Citrullus species (watermelon and its
relatives) from the Plant Introduction Station at Experiment,
Georgia have been grown in the field here for screening for
resistance to watermelon mosaic. DevTelopment of the disease
was general in the field planting made in April 1965 and 4
lines were selected as most resistant to infection. A back-
cross with Fairfax was obtained on one of them. These lines
are planted in the field this year and additional backcrosses
to them are being made. Only a few scattered mosaic-
infected plants are present in the field plots at this time.


16. Watermelon Breeding Search for Cytoplasmic Male Sterility

Initial crosses between watermelon and distant relatives of
watermelon were made in 1960 and first backcrosses to the F--1
were made in 1961. In each subsequent year additional back-
crosses have been made, using commercial varieties (Charleston
Gray, Dixie Queen, Crimson Sweet, others) exclusively as the
male parent. In 1965 some progenies were segregating indi-
vidual lines with as much as 50% abnormal pollen. Back-
crossing to individual plants with the highest percentage
of pollen abnormalities is being continued.

17. Leafminer Control (Adlerz)

Purpose: To determine the effectiveness of some experimental
insecticides in controlling leafminer.

Date of planting: January 28 at Immokalee, Florida. This
work was done with the cooperation of Dr. Paul Everett at
the South Florida Field Laboratory.

Variety: Charleston Gray.

Treatments: The first six treatments were preplanting ap-
plications of granules. Applications of treatments 6 to 11
were made weekly beginning February 21 (guthion twice weekly).
Samples taken February 16 and March 30.

Seeds were planted in the granule furrow and two inches to
the side of the furrow so that information on toxicity of
materials to germinating seed could be obtained.

Material Oz. active/A

Nia 10242 10G 16
Nia 10242 10G 32
Nia 10242 10G 64
UC 21149 10G 16
UC 21149 10G 32
UC 21149 10G 64
Dimethoate 267E (Cygon) 4
UC 20047 A 50W 8
UC 20047 A 50W 16
Guthion 2E 8
Azodrin (SD 9129) 32WS 8

Results: When seeds were planted in contact with granular
insecticides UC 21149 reduced stand, drastically at the two
higher rates, and Nia 10242 caused retarded seedling growth.
The insecticides did not adversely affect seeds planted 2"

Best control of leafminers was obtained with UC 21149 at all
rates, Cygon, Azodrin, and Guthion. UC 21149 treatments


gave almost perfect control for 61 days which was the limit
of the evaluation period.

18. Aphid Repellents for Mosaic Control (Adlerz)

Purpose: To evaluate aluminum and white plastic mulches as
aphid repellents for mosaic control.

Date of planting: January 18 at Immokalee, Florida. This
work was done with the cooperation of Dr. Paul Everett on
a commercial growers field.

Treatment: 1. 50" wide aluminum mulch. 2. 60" wide white
polyethylene mulch.. .... 3. no mulch. Treatments were
applied in large plots that totalled nearly 7 acres. Aphids
were trapped daily in each plot.


1. Damping off was severe in these plots, and the problem
was greatly aggravated by aluminum mulch.

2. Up to April 15 five percent of the aphid catch was over
aluminum, 51 percent over white plastic and 44 percent
over bare ground. In the next 15 days comparable figures
were 20 percent, 47 percent, 33 percent.

3. When used as a mulch, repellent effectiveness of the
materials decreases as foliage cover increases.

4. Preliminary evaluation indicated that mosaic incidence
may have been delayed by aluminum.


Spray Program for Florida Dooryard Grapes
John A. Mortensen
Watermelon and Grape Investigations Laboratory

Teaspoons Days
Amount spreader- before DEC 10 i33
per sticker har- Time to
Material Formulation gallon per gallon vestl spray For control ot
Basic copper 53% WP 2 TBS. 0 0 mid-winter ...:..
sulfate -----
Lime-sulfur commercial 1 pint 0 0 mid-winter anthracnose
Maneb with zinc 80% WP 1 TBS. 1/2 7 spring, beginning anthracnose,
sulfate3, when shoots are 3" black rot, bitter
or captain 50 to 80% WP 2 TBS. 1/2 0 long, thereafter rot, ripe rot,
every 2 weeks (espe- leaf spot and
cially during bloom) downy mildew
for clean fruit
Halathion 50-57% EC4 2 tsp. 1/2 3 when insect damage aphids,
25% WP 4 TBS. 1/2 3 occurs, except caterpillars,
during bloom and leafhoppers
DDT 50% WP 2 TBS. 1/25 40 when insect damage flea beetles.

occurs, except
during bloom

caterpillars and
Seafh nnPrs

Sevin 50% WP 2 TBS. 1/2 0 when insect damage caterpillars, fruit
80% WP 4 tsp. 1/2 0 occurs, except beetles, wasps, and
23-25% liquid 2 TBS. 1/2 0 during bloom leafhoppers
Dithane M45, or 80% WP 1 TBS. 1/2 66 non-bearing vines: anthracnose,
maneb with zinc any time needed. black rot
sulfate3, or 80% WP 1 TBS. 1/2 7 bearing vines: any downy mildew, and
captain 50 to 80% WP 2 TBS. 1/2 0 time needed after har- leafspot
vest for clean vines
Karathane 25% WP 1 tsp. 1/2 21 any time powdery powdery mildew
mildew appears,
except within 3
weeks of harvest
Chlordane 44% EC 2 tsp. 0 any time ants are apply as drench to
damaging foliage ant beds, not plants,
1to control ants.
1 This is the recommended minimum number of days between last application of the pesticide and harvest.
2 WP = u-N +- 1- 1 A

3 Manzate D, Dithane M22 Special, or similar product
4 EC = emulsifiable concentrate.
5 Do not use a sticker with DDT after the buckshot stage

Mimeo Report WGL 68-1, September 30, 1968

of the berries.

Note: TBS = tablespoon
tsp = teaspoon

I H------wI"7E -IrV

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