V/ L
WATERMELON AND GRAPE INVESTIGATIONS LABORATORY
AGRICULTURAL EXPERIMENT STATIONS
INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES
UNIVERSITY OF FLORIDA
LEESBURG, FLORIDA
Mimeo Report WGL 69-3 June 11, 1969
WATERMELON FIELD DAY PROGRAM
1:30 P.M.
Welcome to Lake County and the Watermelon Field Day. Royce C.
Williams, Associate County Agent.
Introduction of Visitors. Mason E. Marvel, Associate Vegetable
Crops Specialist, Florida Agricultural Extension Service, Gainesville
Grape Studies at the Watermelon and Grape Investigations Laboratory.
J. A. Mortensen, Associate Geneticist.
Peach Studies at the Watermelon and Grape Investigations Laboratory.
C. Balerdi, Assistant Horticulturist.
Fungicide Trial
N. C. Schenck, Plant Pathologist
Leaf Miner Control
Insecticide Trial
Insecticide Screening Trial
Epidemiology of Watermelon Mosaic
Watermelon Mosaic Survey, 1969
W. C. Adlerz, Associate Entomologist
Herbicide Trial
Fertilizer Trial
Control of Female Flowering in Cucurbits
Agrifoam Date of Planting Trial
Cantaloupe Variety Trial
G. W. Elmstrom, Assistant Horticulturist
Watermelon Breeding
Watermelon Variety Testing
Calcium Fusarium Wilt Trial
J. M. Crall, Plant Pathologist and Head
Tour of Plots. Members of Staff
200 copies
-2-
SUMMARIES OF EXPERIMENTAL WORK
1. Herbicide Trial (Elmstrom)
Purpose: To evaluate various materials for pre-emergence control
of weeds in watermelon plots.
Date of Plantings: February 14.
Variety: Charleston Gray
Procedure: Herbicides were applied February 2
bed. April 23 the middles were thrown out and
applied to the remaining 6 1/2 feet of bed. A
ments were replicated three times.
to a 3 1/2' x 20'
herbicide was
total of 13 treat-
Treatment
Rate
(lbs. active/acre)
Incorporation
Control-unweeded
Hoed
Alanap-3 (NPA)
Dacthal (DCPA)
Treflan (trifluralin)
Prefar (bensulide)
Sinbar
Alanap-3
Prefar
Dowpon
Vegadex (CDEC)
Vegadex
Randox
Hand pulled
Planavin (Nitralin)
4
6
1
6
0.8
4
--
No
Yes
Yes
Yes
No
Yes
Yes
No
No
No
No
Yes
*Applied post-emergence April 4.
Results: Weed control with Sinbar and Planavin was most promising.
2. Calcium-Fusarium Wilt Trial (Crall and Elmstrom)
Purpose: To determine the effect of calcium and pH
of Fusarium wilt.
on development
Design: Split-split plot
Main plots: Races I and II, Fusarium wilt fungus
Sub plots: Calcium sources and rates
Number
1
2
3
4
5
6
7
8
9
10
11
12
13*
-3-
None
High calcium limestone @ 3000# Ca/acre
High calcium limestone @ 6000# Ca/acre
Gypsum @ 3000# Ca/acre
Gypsum @ 6000# Ca/acre
Sub-sub plots: Varieties
Florida Giant
Charleston Gray
Texas W-5
Results of previous work and summary of current trial:
There is a slowing down of development or a reduction in
expression of wilt symptoms resulting from applications of lime
or gypsum. Under our conditions, differences with a susceptible
variety such as Florida Giant are not apparent. With a moderately
resistant variety such as Charleston Gray both lime and gypsum,
especially at the higher rates, reduce wilt development,
especially with Race 1; reduction with Race 2 is less apparent;
lime is perhaps more effective than gypsum. With a highly
resistant line such as Texas W-5, little wilt develops from
Race 1, so that calcium effect is not apparent; with Race 2 wilt
in Texas W-5, there was an apparent reduction in wilt with both
lime and gypsum in 1968, but only with gypsum in 1969.
3. Fungicide Trial (Schenck)
Purpose: To compare fungicides for control of fungus foliar
diseases on watermelon.
Procedures: Treatments (white stakes) applied at weekly intervals
at 200 psi using a boom-sprayer with 10 Tee Jet nozzles at 1-foot
intervals.
Treatments
D) Benlate
K) Mandate D
C) Benlate + Manzate D
F) Benlate + Manzate D
N) Dithane M-45
B) Dithane M-22 Special
L) Manzate + Parzate
A) Dithianon
E) Difolatan 4 Flo
G) Daconil
I) Dithane M-45 + Nu-Film 17
M) Colloidax
J) Polyram
H) Tribasic Copper Sulfate
O) Untreated
P) Tribasic Copper Sulfate
+ Daconil
Q) Tribasic Copper Sulfate
+ Difolatan 4 Flo
Rate Der 100 gal.
1 lb.
1.5 lb.
1 lb. + 1 lb.
0.5 lb. + 0.5 lb.
1.5 lb.
1.5 lb.
1 lb. + 1 lb.
1.5 lb.
2.5 pt.
2.0
1.5 lb. + 2 pts.
3.5 lbs.
1.5 lbs.
3 lb.
3 lb. + 2 lb.
3 lb. + 2.5 pt.
-4-
Results: Incomplete for printed program.
4. Insecticide Trial (Adlerz)
Purpose: To evaluate various materials for control of rindworm
on watermelon.
Date of planting: March 21, 1969.
Variety: Texas W-5
Treatments: The experiment was designed for 6 to 8 applications
at weekly intervals beginning prior to fruit set. First application
May 6. The plots are marked with yellow stakes.
Insecticides
Oz. active/A
Thuricide 90TS 2 quarts/100 gal.
Biotrol BTB 183 3 pounds
Thuricide 90TS 1 quart
Lannate 90WD
Lannate 90WD + 4 oz. surfactant
Lannate 90WD + 4 oz. surfactant
Du Pont 1642 90WD
Du Pont 1642 90WD + 4 oz. surfactant
Monitor 6S
Azodrin 3.2WS (25 gal/acre)
Azodrin 3.2WS
Biotrol BTB 183 2 pounds
Manzate D
8.0
8.0
16.0
8.0
8.0
16.0
16.0
16.0
Results: Early evaluations of this test indicate that the best
treatments were Thuricide 90TS at 1-2 quarts and Biotrol BTB
183 at 3 pounds. Good control will probably be obtained with
several other materials but complete evaluations are not available
at this time.
5. Insecticide Screening Trial (Adlerz)
This trial is marked by green stakes in the field. Details of
operation are similar to the Insecticide Trial, but this test
includes some newer materials.
Insecticide
Oz. active/A
Abate 5% biweekly
Abate 5% biweekly
Thuricide 90TS 2 quarts/100 gal.
Fundal 98WS
Thuricide 90TS 1 quart + Nu Film BT
-5-
Insecticide Oz. active/A
F. VCS 506 16
G. UC 34096 16
H. BTB 183 1 pound + Molasses
I. Monitor 6S 16
J. Niran 6-3 9
K. Niran 6-3 18
Results: Early evaluations of this test indicate that the best
treatments were Fundal, Thuricide plus Nu Film BT, Thuricide 90TS
at 2 quarts, and Monitor.
C. 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. Promising lines of
four distinct fruit types are in advanced generations: Leesburg-
type, Watson-type, Round green stripe, and Round gray.
More recently an intense red flesh color from certain Peacock
lines has been incorporated into a number of different fruit types.
This season we have begun a series of crosses between our better
lines and various small-fruited varieties. The aim of this part
of the breeding program is to develop small-fruited varieties
with combined resistance to Fusarium wilt and anthracnose, deep
red flesh color, and other desirable fruit qualities.
7. Control of Female Flowering in Cucurbits (Elmstrom)
The effect of ETHREL, ALAR (B-9) and a cytokinin, SD 4901, on
the initiation of female flowers on cucumber, pumpkin, cantaloupe,
watermelon and squash plants was studied. Growth regulators
were applied either at the 2-4 true leaf stage or to running
vines. Some of the treated plants developed mature fruit earlier
than the control plants. However, many of the female flowers
that developed early on the treated plants did not set fruit.
Female flowering was not altered on any of the treated watermelon
plants.
8. Foam Application Demonstration (Elmstrom and Crall)
The liquid concentrate from which the foam is generated and the
mobile unit designed to produce the foam were donated by Laurentian
Concentrates Limited of Canada. The protein based concentrate is
added to water in the ratio of 5 parts concentrate to 95 parts
water. A 100 gallon mixture will expand 30 times by volume and
therefore produces 3000 gallons of foam compound at a cost of
about $20, or less than 14 per gallon.
-6-
9. CIntaloupe Variety Trial (Elmstrom and Crall)
Purpose: To compare promising breeding lines and new varieties
with commonly used varieties.
Observational Trial Entries:
1. Ac-67-124
2. C-.77
3. C-880
Replicated Trial Entries:
VBL-67-7
VBL-67-1 (Planter's Jumbo)
VBL-67-2
Edisto
Hales Best Jumbo
L-39-1
7.
8.
9.
10.
11.
12.
AC-63-11
AC-67-14
AC-67-59
AC-67-17
Saticoy Hybrid
Samson Hybrid
Borders SJ 45
10. Watermelon Variety Trial (Crall and Elmstrom)
Purpose: Comparison of promising breeding lines from Florida,
Kansas, USDA Vegetable Breeding Laboratory (Charleston), American
Seedless (Goshen), and standard commercial varieties.
Design: Randomized blocks, 4 replications; borders, Texas W-5.
Entries:
Charleston Gray
Crimson Sweet
Sweet Princess
Jubilee
Garrisonian
F68-1
F68-2
F68-3
9.
10.
11.
12.
13.
14.
15.
16.
Kansas 66-1
Kansas 66-12
Summerfield (UBL60-27)
VBL Tetra 2
VBL-W872 (Tetraploid)
Tri-Xl (313)
Tri-X2 (Super Sweet)
Tri-X3 (Goshen Gem)
Varietal recommendations: Charleston Gray, Jubilee, and Crimson
Sweet are all recommended for commercial watermelon production in
Florida. Sweet Princess is recommended for trial.
11. Fertilizer Trial (Elmstrom)
Purpose: To evaluate the timing, rate and placement of fertilizer
application for optimum growth and yield of watermelon.
-7-
.'tte of planting: March 18
Procedure: Fertilizer was applied to disked land prior to bedding.
Sources of N, P and K were sewage sludge (30% of total N), nitrate
of potash (13-0-44), nitrate of soda (16-0-0), and regular
superphosphate. Placement was either in 10" band or broadcast
over the 40" bed area.
Treatment
Number
Timing*
()
50-50
50-50
50-50
50-50
50-50
50-50
50-50
50-50
75-25
75-25
75-25
75-25
75-25
75-25
75-25
75-25
Placement
Broad Band
Broad Band
Broad Band
Broad Band
Broadcast
Broadcast
Broadcast
Broadcast
Broad Band
Broad Band
Broad Band
Broad Band
Broadcast
Broadcast
Broadcast
Broadcast
Rate
(NPK)
120-120-120
240-120-240
120-240-120
240-240-240
120-120-120
240-120-240
120-240-120
240-240-240
120-120-120
240-120-240
120-240-120
240-240-240
120-120-120
240-120-240
120-240-120
240-240-240
*First number refers to per cent of total applied March 13.
Second number refers to per cent applied May 2.
12. Agrifoam-Date of Planting Test (Elmstrom and Crall)
Purpose: Comparison of Agrifoam and Hotkaps for cold protection.
Design: Split plot, 4 replications
Main plots: dates of planting
January 24; replanted February 27
January 30; replanted March 6
February 6; replanted March 13
February 13
February 20
Sub plots
a. Agrifoam (applied as needed for frost protection)
b. Hotkaps (applied as needed for frost protection)
c. no protection
-8-
Results: Although killing frosts did not occur, plant stand was
poor and growth slow due to continuous cold weather. Foam was
applied five times and the following lowest temperatures were
recorded:
Foam Applied Low Temperature (oF)
Control Hot Kap Foam
3/4 42 45 49
3/10 41 47 49
3/11 37 45 50
3/13 37 45 51
3/27 40 -- 56
13. Leafminer control (Adlerz)
Purpose: To determine the effectiveness of some experimental
insecticides in controlling leaf miner.
Date of planting: December 16, 1968 at Immokalee, Florida. The
work was done with the cooperation of Dr. Paul H. Everett at the
South Florida Field Laboratory.
Variety: Charleston Gray
Treatments: Treatments 4 through 8 were granular formulations
of systemic insecticides banded at seed level, and 3 inches to
one side of the seed furrow at planting. Spray materials were
applied weekly from January 13 to March 4. Samples were taken
January 22 and February 5.
Insecticide Oz. active/A
Azodrin 3.2WS 4
Azodrin 3.2WS 8
Cygon 267E 4
Temik 10G 4
Temik 10G 8
Temik 10G 16
TH 427I 5G 8
TH 4271 5G 24
Fundal 98WS 8
Fundal 98WS 16
TH 4271 2E 8
Untreated
Results: Evaluations were based on the sampling of January 22;
in this sample pupae were reared from 5 whole plants from each
plot.
The Azodrin and Cygon treatments and Temik at 8 and 16 ounces
gave essentially complete control.
-9-
The infestation had declined by the second date of sampling
(February 5) and there were no leaf miners on March 5. Infestations
of leaf miner have never been sustained long enough in these
tests to determine the duration of Temik's effectiveness following
preplanting application.
Fundal in this formulation was phytotoxic.
|