• TABLE OF CONTENTS
HIDE
 Historic note
 Front Cover
 Agenda
 Watermelon breeding
 Icebox watermelon variety...
 Watermelon variety trial
 Cantaloupe variety trial
 Watermelon breeding
 Weed control in cucurbits
 Squash breeding
 Biological control of Fusarium...
 Cantaloupe fungicides
 Squash fungicides
 Watermelon fungicides
 Aphid transmission of watermelon...
 Back Cover














Group Title: Watermelon field day.
Title: Watermelon field day. 1986.
ALL VOLUMES CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00076045/00017
 Material Information
Title: Watermelon field day. 1986.
Series Title: Watermelon field day.
Physical Description: Serial
Language: English
Publisher: Watermelon and Grape Investigations Laboratory, University of Florida
Publication Date: 1986
 Subjects
Spatial Coverage: North America -- United States -- Florida
 Record Information
Bibliographic ID: UF00076045
Volume ID: VID00017
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 144617905

Table of Contents
    Historic note
        Unnumbered ( 1 )
    Front Cover
        Front Cover
    Agenda
        Page 1
    Watermelon breeding
        Page 2
    Icebox watermelon variety trial
        Page 3
        Page 4
        Page 5
    Watermelon variety trial
        Page 6
        Page 7
    Cantaloupe variety trial
        Page 8
        Page 9
    Watermelon breeding
        Page 10
    Weed control in cucurbits
        Page 11
        Page 12
    Squash breeding
        Page 11
    Biological control of Fusarium wilt of watermelon
        Page 13
    Cantaloupe fungicides
        Page 14
    Squash fungicides
        Page 15
    Watermelon fungicides
        Page 16
    Aphid transmission of watermelon mosaic virus 2 and zucchini yellow mosaic virus
        Page 17
        Page 18
    Back Cover
        Back Cover
Full Text





HISTORIC NOTE


The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
(EDIS)

site maintained by the Florida
Cooperative Extension Service.






Copyright 2005, Board of Trustees, University
of Florida








a I


SUNIVERSITY OF FLORIDA

AGRICULTURAL RESEARCH
EDUCATION CENTER, LEESE
BOX 388
TELEPHONE: 904/787-3423
(GAINESVILLE LINE 392-727


UNIVERSITY OF FLORIDA

INSTITUTE OF FOOD AND AGRICULTURAL SCIENCES

21 'I I ... -
AND LEESBURG, FLORIDA 32749-0388
URGrrM A R7!

2) IB 908 ,-df i


June 4, 1986


Gary W. Elmstrom, Center Director






FLORIDA


WATERMELON


Leesburg AREC Research Report (LBG 86-10)
200 copies


COLLEGE OF AGRICULTURE


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.
i







1






WATERMELON FIELD DAY

University of Florida, IFAS
Agricultural Research and Education Center, Leesburg

Wednesday, June 4, 1986
1:30 5:00pm




Terry Courneya, Lake County Extension Director Moderator

James Crall, Plant Pathologist, Leesburg
Watermelon Breeding Program
Newly released cultivars (Charlee, Minilee, and Mickylee)
Lines recommended for release in 1986 (BC Jubilee and BC
Charleston Gray lines)
Lines for future release (small seeded Dixielee line, dwarf
(short-internode) lines, gummy stem blight resistant and
mosaic resistant lines)

Gary Elmstrom, Horticulturist, Leesburg
Cucurbit variety evaluation
Muskmelon breeding
Squash breeding

Jim Gilreath, Assistant Horticulturist, Bradenton
Weed control in watermelon

Don Hopkins, Plant Pathologist, Leesburg
Biological control of Fusarium wilt
Cantaloupe fungicide test
Squash fungicide test
Watermelon fungicide test

Warren Adlerz, Entomologist, Leesburg
Aphid transmission of watermelon mosaic virus 2 and zucchini
yellow mosaic virus


Refreshments (Courtesy of Foremost Fertilizer Company)


Tour of research plots, Don Maynard, Extension Vegetable
Specialist, Bradenton, Presiding












1. WATERMELON BREEDING (Crall)


Release of three new cultivars has recently been made from this
Center. Charlee produces fruits of exceptionally high quality
and uniformity and similar in size, shape, and weight to those of
Charleston Gray. It has resistance to anthracnose (race 1) and a
high level resistance to Fusarium wilt.

Minilee and Mickylee are icebox-type cultivars with excellent
fruit quality and resistance to anthracnose and Fusarium wilt.
We think that they will fill the need for a small-fruited type
watermelon cultivar for Florida that has existed for many years.

Florida produces about 1/3 of the U.S. watermelon crop and that
production is an important segment of the state's total vegetable
production value. Since their introduction, Florida's watermelon
industry has been based largely on the varieties Charleston Gray,
introduced in 1954, and Crimson Sweet and Jubilee (from this
Center), both introduced in 1963. While total production in
Florida has been increasing over the past 15 years and more, per
capital consumption of watermelons in the U.S. has declined 30% in
the past 20 years. We view this decrease in per capital
consumption as resulting at least in part from smaller family
sizes and the lack of small watermelons in the market. The
release of the two icebox cultivars, Minilee and Mickylee, could
help remedy this situation.

Two other breeding lines from this program have been recommended
for release as cultivars in 1986-87. A line from our Jubilee
backcross program (S84NW[E]) has performed well in both
replicated field trials and grower tests. It is resistant to
both anthracnose and Fusarium wilt and produces good yields of
high quality, shipping-type melons. A second line from our
Charleston Gray backcross program (S84GS[S], also tested as our
SW4 line) has done well in both replicated and grower tests. It
is resistant to both anthracnose and Fusarium wilt. It also
produces good yields of high quality, shipping-type melons that
are somewhat larger than those of Charlee. Melon size approaches
that of Jubilee.

There are a number of other lines that are further in the future
with regard to eventual release as cultivars. A small-seeded
Dixielee-type has been tested with some growers and recommended
by them for evaluation as a striped icebox cultivar. There are
several Crimson Sweet-type and Dixielee-type lines in early
stages of evaluation. Additionally, there is a group of lines
being evaluated for resistance to watermelon mosaic virus and
another group being screened for resistance to gummy stem blight.
Dwarf (short internode) progenies are in early stages of
evaluation, but have interesting long-range potential.








Initiated this year is a project, in cooperation with the
U.S.D.A., to evaluate and increase seeds of Plant Introduction
progenies that might be useful in programs of other watermelon
research workers.

The breeding field and evaluation tests portions of this year's
field plots include Ranges A through M and WN through WQ. Ranges
E through M encompass a replicated Advanced Selections trial that
includes Charlee, the Charleston Gray backcross line SW4, and
Jubilee backcross line S84NW(E) as well as several others; a
replicated Icebox-Spacing trial that includes Minilee, Mickylee,
and the small-seeded Dixielee line; and a race 1 anthracnose
inoculation test of Charlee, Charleston Gray, Calhoun Gray,
Charleston Gray #5, and Charleston Gray #6 (ranges E-J, rows
27-30). Ranges WN through WO (at the extreme west end of this
years field) encompass the Plant Introduction progenies, mostly
from Africa.

Watermelon mosaic resistant lines may be found in Range A, Rows
1-40. Dwarf lines may be found in Range B, Rows 1-20. Gummy
stem blight resistant lines are in Range B, Rows 21-40. Large
round stripe and Crimson Sweet lines are in Range C, Rows 1-40.

Recently released cultivars and those recommended for release may
also be found in Variety Trials being conducted by Dr. Elmstrom.
The Watermelon Fungicide Trial (Dr. Hopkins) is planted with the
new release Charlee.


2. ICEBOX WATERMELON VARIETY TRIAL (Elmstrom & Crall)


Replicated

R-l Minilee Leesburg AREC
R-2 Mickylee Leesburg AREC
R-3 Baby Fun Petoseed
R-4 Bush Jubilee Musser

Over the last few years trials have been conducted on watermelon
varieties which produce "icebox" (small size) watermelons and
have vines that are not as prolific as are the vines of standard
commercial varieties. Some of these varieties have a short
internode (bush type) habit of growth. Traditionally, Florida
has met the needs of consumers of early spring watermelons by
growing cultivars producing large melons of 20-25 pounds or more.
Several new "icebox" watermelon cultivars including 'Baby Fun'
and two IFAS releases, 'Minilee' and 'Mickylee', typically
produce melons in the 5 to 15 pound range. These "icebox"
cultivars may have an impact on this traditional production.
Cultural practices for the icebox cultivars differ slightly from
those for large-fruited melons. In plant population studies from
1981 to 1983, fruit yields were highest in rows 5 ft apart and a
2 ft in-the-row spacing.





4


The production of icebox watermelons might reverse the decline in
per capital watermelon consumption in the U.S. by providing a
product size better suited to the small family. In addition to a
fruit size more appealing to today's smaller families, several
other characteristics make 'Minilee' and 'Mickylee' well suited
to the supermarket trade. Fruits are sweet and attractive when
cut, with few small black seeds. They are exceptionally uniform
in both sweetness and firmness of flesh texture. Fruits hold
prime quality for reasonably long periods in storage. Small
melons are well adapted to shipment in cartons to both domestic
and foreign markets.








Yield, mean melon weight, and soluble solids content
of icebox watermelon cultivars at Leesburg, 1981-1985.


Cultivar Marketable yield (cwt/acre)y Melon Soluble
Earlyz Total weight solids
(lb./fruit) (%)



1981
Mickylee 296 a 411 a 7.2
Yellow Baby 233 ab 336 a 4.5 -
Petite Sweet 102 c 237 b 5.7 -
Sugar Baby 164 bc 211 b 6.5 -

1982
Mickylee 437 a 8.3 -
Yellow Baby 344 ab 3.8 -
Minilee 328 ab 4.7 -
Sweet Baby 282 b 8.1

1983
Minilee 321 b 573 a 5.8 -
Mickylee 317 b 538 a 6.7 -
Sweet Baby 443 a 508 ab 7.8 -
Yellow Baby 244 bc 382 b 5.2 -
Sugar Baby 185 cd 256 c 7.4 -
Petite Sweet 133 de 193 cd 5.5 -
Garden Baby 90 e 94 d 4.2 -

1984
Baby Fun 245 a 428 a 10.3 10.6
Mickylee 205 ab 407 a 9.1 10.2
Minilee 147 ab 358 ab 8.9 10.4
Sugar Baby 214 ab 330 ab 6.3 9.9
Yellow Baby 209 ab 322 ab 7.8 10.6
Bush Charleston Gray 108 bc 273 ab 5.1 9.7
Bush Jubilee 21 c 217 b 5.3 9.5

1985
Baby Fun 289 a 334 a 11.6 11.4
Mickylee 252 a 318 a 8.8 11.2
Minilee 127 b 275 a 7.0 11.5
Yellow Baby 179 b 242 a 5.7 11.3

ZFirst 2 harvests each year.
YMean separation within columns for each year by Duncan's New
Multiple Range Test, 5% level.










3. WATERMELON VARIETY TRIAL (Elmstrom & Call)


Two-row plots were planted February 24 in randomized blocks with three
replications.

REPLICATED


Charleston Gray
Jubilee
SCWT 239
SCWT 244
SCWT 249
SCWT 250
SCWT 256
SCWT 257
SCWT 266
SCWT 267
Delta Queen
Sweet Charlie
Crimson Tide
PSX 26883


Asgrow
Asgrow
Leesburg AREC
Northrup King
Leesburg AREC
Leesburg AREC
Northrup King
Leesburg AREC
Northrup King
Leesburg AREC
Ferry-Morse
Northrup King
Northrup King
Petoseed


R-15
R-16
R-17
R-18
R-19
R-20
R-21
R-22
R-23
R-24
R-25
R-26
R-27
R-28


PSX 26983
Royal Sweet
Royal Jubilee
Prince Charles
Southern Belle
Huck Finn
Rebel Queen
MOX 1568
Oasis
Calsweet
Charleston Gray #5
Charleston Gray #6
HSR 221
Crimson Sweet


Petoseed
Petoseed
Petoseed
Petoseed
Ferry-Morse
Ferry-Morse
Ferry-Morse
Harris-Moran
Harris-Moran
Abbott & Cobb
Hollar
Hollar
Hollar
Asgrow


OBSERVATIONAL


Charleston Elite
NVH 4260
NVH 4262
NVH 4267
NVH 4272
AVX 5500
AVX 5501
X-7-F1
82-2478
84-5059
84-5756
84-9495
85-9295
PSR 30284
PSR 38985
PSR 39385
PSR 39585
PSR 39785
PSR 40785
Mirage
Sunshade
Madera
AU-Jubilant
AU-Producer
Dixielee
HSR 222
HSR 224
HSR 276


Northrup King
Northrup King
Northrup King
Northrup King
Northrup King
Agrigenetics
Agrigenetics
Burrell
Nickerson-Zwaan
Nickerson-Zwaan
Nickerson-Zwaan
Nickerson-Zwaan
Nickerson-Zwaan
Petoseed
Petoseed
Petoseed
Petoseed
Petoseed
Petoseed
Asgrow
Asgrow
Asgrow
Hollar
Hollar
Hollar
Hollar
Hollar
Hollar


0-29
0-30
0-31
0-32
0-33
0-34
0-35
0-36
0-37
0-38
0-39
0-40
0-41
0-42
0-43
0-44
0-45
0-46
0-47
0-48
0-49
0-50
0-51
0-52
0-53
0-54
0-55
0-56


HSR 277
HSR 278
HSR 279
HSR 289
HSR 290
HSR 1718
HSR 2314
Charlie I
All sweet
lopride
Sugarlee
SCWT 252
SCWT 261
SCWT 268
SCWT 269
SCWT 270
SCWT 281
SCWT 272
SCWT 273
S85 NE
S84 NW(E)
F85 SW
Sugar Baby
SCWT 274
Sugarama
PSR 39885
PSR 39985
SCWT 276


Hollar
Hollar
Hollar
Hollar
Hollar
Hollar
Hollar
Abbott & Cobb
Willhite
Willhite
Willhite
Leesburg AREC
AL AES
Leesburg AREC
Leesburg AREC
Leesburg AREC
AL AES
AL AES
AL AES
Leesburg AREC
Leesburg AREC
Leesburg AREC

Northrup King
Northrup King
Petoseed
Petoseed
Northrup King


R-1
R-2
R-3
R-4
R-5
R-6
R-7
R-8
R-9
R-10
R-11
R-12
R-13
R-14


0-1
0-2
0-3
0-4
0-5
0-6
0-7
0-8
0-9
0-10
0-11
0-12
0-13
0-14
0-15
0-16
0-17
0-18
0-19
0-20
0-21
0-22
0-23
0-24
0-25
0-26
0-27
0-28










Results: 1984, 1985.

Twenty-eight watermelon varieties and breeding lines were
evaluated in a replicated trial in 1984. The earliest maturing
were 'Mickylee', 'Royal Charleston', XPH 957 (Asgrow), and
'Crimson Sweet'. Total marketable yield was highest for 'Royal
Jubilee', Fla 78SW4 (Florida), NVH 4254 (Northrup King), and
'Charleston Gray No. 5'. Soluble solids content was highest in
'Dixielee', 'Oasis', 'Royal Peacock', NKX 4253 (Northrup King),
and XPH 957 (Asgrow).

In a similar trial in 1985, the most productive entries were
'Royal Jubilee', 'Carmen', 'Prince Charles', 'Royal Sweet', and
F82 NW (Florida). Earliest maturing entries were 'Mickylee',
'Crimson Sweet', 'Sugar Baby', and NVH 4265 (Northrup King).
Soluble solids content was highest in 'Smokylee', 'Dixielee', and
'Sugarlee'.










4. CANTALOUPE VARIETY TRIAL (Elastrom)


Single-row plots were
replications.


planted February 24 in randomized blocks with three


REPLICATED


Nova
Challenger
Explorer
FL 86-3M
84 M 114
Columbia
Star Performer
XPH 913
Summet
Hiline
PSX E680
Saticoy
Supermarket
Earlidew


Northrup
Northrup
Northrup
Leesburg
Musser
Twilley
Twilley
Asgrow
Asgrow
Asgrow
Petoseed
Petoseed
Petoseed
Petoseed


King
King
King
AREC


R-15
R-16
R-17
R-18
R-19
R-20
R-21
R-22
R-23
R-24
R-25
R-26
R-27


Magnum .45
Gold Star
Star Producer
Earligold
Rocky Sweet
HSR 241
HSR 244
HSR 11790
XPH 5094
Superstar
FL 86-1M
FL 86-2M
FL 86-4MXL


Petoseed
Harris-Moran
Twilley
Hollar
Hollar
Hollar
Hollar
Hollar
Asgrow
Harris-Moran
Leesburg AREC
Leesburg AREC
Leesburg AREC


OBSERVATIONAL


HXP 3587
HXP 3590
HMX 5588
HMX 5589
HMX 5607
85 M 103
Ambrosia
4 W 7106
4 M 754
84-3436
84-3533
84-3837
84-3944
84-4631
84-4736
PSR 285
PSR 2385
PSR 2485
PSR 2685
PSR 2785
PSR 8085
PSR 11285
PSR 12485
PSR 15785
PSR 17985
Vacant
Vacant


Harris-Moran
Harris-Moran
Harris-Moran
Harris-Moran
Harris-Moran
Musser
Burpee
Agrigenetics
Agrigenetics
Nickerson-Zwaan
Nickerson-Zwaan
Nickerson-Zwaan
Nickerson-Zwaan
Nickerson-Zwaan
Nickerson-Zwaan
Petoseed
Petoseed
Petoseed
Petoseed
Petoseed
Petoseed
Petoseed
Petoseed
Petoseed
Petoseed


0-28
0-29
0-30
0-31
0-32
0-33
0-34
0-35
0-36
0-37
0-38
0-39
0-40
0-41
0-42
0-43
0-44
0-45
0-46
0-47
0-48
0-49
0-50
0-51
0-52
0-53
0-54


Market Star
HSR 227
HSR 228
HSR 245
Green Ice
PMR 45
PMR 6
Camelot
Mayan Sweet
FL 85-1, 2M
FL 85-3, 4M
Edisto 47
Planters Jumbo
AC-70-154
WC 11
WC 12
WC 13
N/A
AC-75-16-H
AC-75-59-H
AC-82-33-4-H
AC-82-38-H
AC-82-43-H
AHDO-82-43
AHDO-82-46
AC-75-71-H
AC-82-45-A


Twilley
Hollar
Hollar
Hollar
SC AES


Asgrow

Leesburg AREC
Leesburg AREC
Burrell
Burrell
AL AES
TX AES
TX AES
TX AES


AES
AES
AES
AES
AES
AES
AES
AES
AES


R-I
R-2
R-3
R-4
R-5
R-6
R-7
R-8
R-9
R-10
R-1
R-12
R-13
R-14


0-1
0-2
0-3
0-4
0-5
0-6
0-7
0-8
0-9
0-10
0-11
0-12
0-13
0-14
0-15
0-16
0-17
0-18
0-19
0-20
0-21
0-22
0-23
0-24
0-25
0-26
0-27









Results: 1984, 1985


The highest yielding varieties in the 1984 replicated trial were
'Gretel', 'Gold Star', 'Superstar', and 'Magnum .45'. Earliest
maturing were 'Market Pride', 'Gold Star', and 'Superstar'.
Downy mildew resistance was best in 'Gretel', 'Sampson', 'Castle
Rock', and 'Hiline'; varieties most resistant to powdery mildew
were 'Gretel', 'Magnum .45', 'Summet', 'Saticoy', and 'Camelot'.
Soluble solids were highest in 'Venus', 'Green Ice', 'Honeygrow',
and 'Saticoy'.

In the 1985 replicated trials the highest yielding entries were
'Camelot', AC-70-154 (Alabama), and AC-75-1 (Alabama). The
earliest ones were 'Burpee Hybrid', 'Gold Star', 'Camelot', and
'Summet'. Downy mildew resistance was best in HXP 3587 (Harris
Moran), 'Planters Jumbo', and FL 85-2M (Florida); varieties
susceptible to powdery mildew were 'Burpee Hybrid', 'Superstar',
and 'Gold Star'. Soluble solids exceeded 13% in 'Edisto 47',
'Saticoy', and FL 85-1M (Florida).

In addition to the watermelon and cantaloupe variety evaluation,
trials of squash and cucumber varieties have been conducted since
1977. Results of these trials are included in the following
publications which are available upon request:




1. Cucurbit Variety Evaluation, 1985. Leesburg AREC
Research Report (LBG 85-3).

2. Watermelon Variety Evaluation, 1977-1985. Leesburg AREC
Research Report (LBG 86-1).

3. Cantaloupe Variety Evaluation, 1977-1985. Leesburg AREC
Research Report (LBG 86-2).

4. Fresh-Market Cucumber Variety Evaluation, 1977-1985.
Leesburg AREC Research Report (LBG 86-3).

5. Pickling Cucumber Variety Evaluation, 1977-1985.
Leesburg AREC Research Report (LBG 86-4).

6. Summer Squash Variety Evaluation, 1977-1985. Leesburg
AREC Research Report (LBG 86-8).

7. Winter Squash Variety Evaluation, 1979-1985. Leesburg
AREC Research Report (LBG 86-7).








5. MUSKMELON BREEDING (Elmstrom)

Purpose: To evaluate the combining ability of some varieties and
breeding lines and to develop parental lines with genetic
properties suitable for Fl hybrid seed production.

Procedure: Almost without exception, the highest quality
muskmelon fruits are produced by hybrid varieties. However there
is a reluctance on the part of growers to plant hybrid seed since
the cost is 10 to 15 times greater than that of open-pollinated
varieties. The high price of seed is the result of the need for
hand emasculation and hand pollination to produce hybrid seed.
At present, I am attempting to incorporate various characters
into parental lines which would make them more suitable for
parental lines and reduce the cost of hybrid seed. A new
male-sterile gene was released to seed companies during 1983 by
the AREC Leesburg. Studies are continuing on the usefulness of
either the monooecious or gynoecious flowering habit for
production of hybrid muskmelon seed.

Gynoecious. The goal is to incorporate the gynoecious flowering
habit into an inbred line adapted to Florida. WI 998 is
essentially a 100% gynoecious line in Florida and is being
utilized in this program. F2 plants of a cross of WI 998 with
one of my inbred lines were planted in Spring 1985. None of the
1000+ seedlings was 100% gynoecious. The most gynoecious were
selfed. In the future I will make crosses between the plants
that are closest to being gynoecious. Since this is a multiple
gene character, I might recover genes by crossing that I might
otherwise lose by selfing. Silver thiosulfate application
induced male blossoms on WI 998.

Monoecious. As above, the goal is to incorporate the monoecious
flowering habit into inbred lines. In Spring 1985 I planted seed
from 10 lines that are monoecious and have round fruit.
Width/length measurements were made on fruit from all plants.
The ratio of width to length varied from 0.73 (oval) to 1.54
(oblate). Crosses were made between these plants and my inbred
breeding lines. Seeds from these crosses will be planted this
fall. Plants will be selfed. Selection for roundness will be
done in Spring 1986 and will require large plant populations.

Male Sterile. In Fall 1984 and Spring 1985, Fl seed was produced
for 6 different selections at AREC Leesburg using ms-3 and roguing.
Four of these Fl's were tested in the Southern Cooperative
Muskmelon Variety Trial. In Spring 1985, a program to incorporate
increased downy and powdery mildew resistance into my male-sterile
inbred was initiated. Crosses between 11 sources of mildew
resistance and my inbred line are being evaluated this fall.

Zucchini Yellow Mosaic Virus. I am attempting to incorporate the
ZYMV resistance/tolerance from PI 371795 and PI 414723 into my
male-sterile breeding lines. A number of Fl and F2 seed were
produced in Spring 1985 and will be evaluated this fall.
Horticultural qualities are very poor in most of this material.









6. SQUASH BREEDING (Elmstrom)


Powdery mildew. Resistance to powdery mildew has been
transferred from Cucurbita martinezii to C. pepo. An inbred line
of a zucchini type and a yellow S.N. type were planted as
observational rows in my summer squash variety trials in Spring
1985. PM resistance was outstanding. Further selection for
improved fruit type will be done this fall and next spring.
Release of PM resistant inbreds of zucchini, yellow S.N., and
yellow C.N. should occur within the next few years.

Zucchini yellow mosaic virus. Attempts to transfer ZYMV
resistance from C. ecuadorensis to C. pepo are continuing.
Sterility factors and lack of male blossoms on Fl plants are
causing problems in completing this transfer. Over 150 lines are
in the field this fall for evaluation.



7. WEED CONTROL IN CUCURBITS (Gilreath)

Over the past five years, weed control trials have been conducted
at the Gulf Coast R.E.C. in Bradenton and at the Immokalee R.E.C.
to identify new herbicides with potential for use in cucumbers,
squash, and watermelons. This work has focused on both
preemergence and postemergence herbicides. Currently, only
Prefar and Alanap are suggested for use on these cucurbits in
Florida, whereas Amiben is labeled for use only on squash and
pumpkin. Paraquat can be used preemergence on watermelon and as
a directed spray. Last year Sonalan and Devrinol also were
labeled for use with several of the cucurbits; however, the
respective manufacturers have removed cucurbits from their labels
since that time.

In the area of preemergence weed control there is only one new
herbicide, Cinch, which has shown promise in Florida. Cinch is
highly effective on annual grasses prior to germination and has
produced no injury on any cucurbits in trials to date, whether
applied prior to crop emergence or over the top of the vines.
Researchers in N.C. have reported good results with another new
compound, Command, which has provided excellent grass control and
good broadleaf weed control.

There are a number of postemergence herbicides for controlling
emerged grasses which have shown promise for use on cucurbits.
The most well known of these are Poast and Fusilade, which have
provided excellent grass control with little to no injury in most
tests. Under conditions of high temperature and high relative
humidity Fusilade 2000 has been injurious in some tests in the
Southeastern U.S., including one at Bradenton last year. Assure,
another postemergence herbicide for grass control, has been
injurious to cucurbits in all tests at Bradenton.






12


Additional work which has been conducted at Bradenton involves
the effects of tank mixes of Fusilade 2000 and the biostimulants
Burst and Keyplex on cucumber and squash. No yield increase was
observed with these biostimulants, nor was Fusilade 2000 more
phytotoxic when applied in combination. Some improvement in
crabgrass control was observed when Fusilade 2000 was combined
with the 2X rate (2 pints/acre) of Burst.

Evaluation of new herbicides for weed control in cucurbits will
continue as industry makes products available. Control of
nutsedge and aggressive broadleaf weeds, such as nightshade
probably will continue to be a problem. Cinch and postemergence
products, such as Poast and Fusilade 2000, will hopefully be
registered in the not too distant future and will provide growers
with highly effective means of grass control.









6. SQUASH BREEDING (Elmstrom)


Powdery mildew. Resistance to powdery mildew has been
transferred from Cucurbita martinezii to C. pepo. An inbred line
of a zucchini type and a yellow S.N. type were planted as
observational rows in my summer squash variety trials in Spring
1985. PM resistance was outstanding. Further selection for
improved fruit type will be done this fall and next spring.
Release of PM resistant inbreds of zucchini, yellow S.N., and
yellow C.N. should occur within the next few years.

Zucchini yellow mosaic virus. Attempts to transfer ZYMV
resistance from C. ecuadorensis to C. pepo are continuing.
Sterility factors and lack of male blossoms on Fl plants are
causing problems in completing this transfer. Over 150 lines are
in the field this fall for evaluation.



7. WEED CONTROL IN CUCURBITS (Gilreath)

Over the past five years, weed control trials have been conducted
at the Gulf Coast R.E.C. in Bradenton and at the Immokalee R.E.C.
to identify new herbicides with potential for use in cucumbers,
squash, and watermelons. This work has focused on both
preemergence and postemergence herbicides. Currently, only
Prefar and Alanap are suggested for use on these cucurbits in
Florida, whereas Amiben is labeled for use only on squash and
pumpkin. Paraquat can be used preemergence on watermelon and as
a directed spray. Last year Sonalan and Devrinol also were
labeled for use with several of the cucurbits; however, the
respective manufacturers have removed cucurbits from their labels
since that time.

In the area of preemergence weed control there is only one new
herbicide, Cinch, which has shown promise in Florida. Cinch is
highly effective on annual grasses prior to germination and has
produced no injury on any cucurbits in trials to date, whether
applied prior to crop emergence or over the top of the vines.
Researchers in N.C. have reported good results with another new
compound, Command, which has provided excellent grass control and
good broadleaf weed control.

There are a number of postemergence herbicides for controlling
emerged grasses which have shown promise for use on cucurbits.
The most well known of these are Poast and Fusilade, which have
provided excellent grass control with little to no injury in most
tests. Under conditions of high temperature and high relative
humidity Fusilade 2000 has been injurious in some tests in the
Southeastern U.S., including one at Bradenton last year. Assure,
another postemergence herbicide for grass control, has been
injurious to cucurbits in all tests at Bradenton.







8. BIOLOGICAL CONTROL OF FUSARIUM WILT OF WATERMELON (D. L. Hopkins)


Purpose: To evaluate watermelon cultivars with different levels of resistance to Fusarium wilt in a
watermelon cultivar monoculture.
Procedure: Ten watermelon cultivars with different levels of resistance to wilt have been planted in
the same plots for 8 years.
Results:



1985 1986
Cultivars Z wilt Yield (tons/acre) Z wilt


Crimson Sweet 7 a 12.4 a 7 a
Smokylee 23 a 8.0 b 26 b
Charleston Gray 55 b 6.0 b 66 c
Calhoun Gray 61 bc 5.4 b 62 c
Dixielee 73 bc 1.2 c 60 c
Jubilee 71 bc 1.0 c 72 c
Sugarlee 75 bc 0.9 c 65 c
Congo 70 bc 0.8 c 80 c
Sugar Baby 75 bc 0 c 62 c
Florida Giant 77 c 0 c 66 c


After 8 years of monoculture, all
commercial yield except Crimson Sweet.
such as Florida Giant and Sugar Baby.


cultivars wilted severely and failed to
There was as much wilt in Calhoun Gray


produce an adequate
as in susceptible cultivars


In greenhouse studies with soil from the Crimson Sweet monoculture plots, we found a biological control
agent that prevents Fusarium wilt from developing. The biological control agent could be eliminated by heat
treatment (>65C) and by fumigation. Apparently Crimson Sweet is uniquely able to promote the accumulation
of this agent in the soil. We hope to utilize this agent to develop a biological control program for
Fusarium wilt of watermelon.

We do not recommend growing Crimson Sweet in a monoculture! Large losses to wilt can occur with
Crimson Sweet.







9. CANTALOUPE FUNGICIDES (D. L. Hopkins)


Date of Planting: February 27, 1986
Variety: Gold Star
Procedure: Sprays were applied in 100 gallons of dilute spray per acre at a pressure of 150 psi,
using a boom sprayer. Spray application dates were April 24, May 1, 8, 16, 22, and 29.
Results:


Disease rating
Treatment Rate (ant/acre) DM PM


(N) Topsin M 70WP + Bravo 500 0.5 Ib + 3.0 pts 2.0 0.1
(L) Bayleton + Dithane M-45 + Penetrator 0.25 Ib + 3.0 lbs + 0.5 pt 3.3 0.5
(W) Bayleton + Bravo 500 0.25 lb + 3.0 pts 2.5 0.1
(D) Bravo 720-A 2.0 pts 3.1 4.3
(0) Topsin M 4.5F + Bravo 500 10.0 oz + 3.0 pts 2.8 0.4
(C) Bravo 500-C 2.75 pts 2.8 3.1
(B) Bravo 500-B 2.75 pts 3.2 2.8
(K) Bayleton + Dithane M-45 0.25 Ib + 3.0 Ibs 4.2 0.8
(A) Bravo 500-A 2.75 pts 2.7 2.3
(E) Bravo 720-B 2.0 pts 3.5 3.4
(J) Bayleton + Dithane M-45 + Penetrator 0.12 lb + 3.0 lbs + 0.5 pt 3.8 0.8
(X) Bayleton + Ridomil MZ-58 alt. with Bravo 500 0.25 lb + 2.0 lbs 2.75 pts 5.2 0.1
(R) Topsin M 4.5F + Penncozeb 80WP 10.0 oz + 2.0 lbs 5.4 1.3
(S) Systhane + Dithane M-45 + Triton B-1956 1.0 oz ai + 3.0 lbs + 2 oz 3.9 0.1
(F) SDS-63049 1.0 lb 4.3 4.6
(V) Benlate + Manzate 200 0.5 lb + 2.0 Ibs 5.0 0.3
(P) Topsin M 70WP + Penncozeb 80WP 0.5 Ib + 2.0 Ibs 5.7 1.4
(T) Systhane + Dithane M-45 + Triton B-1956 1.5 oz ai + 3.0 lbs + 2 oz 5.3 0.2
(G) SDS-63049 2.25 lbs; 14-day 4.0 5.4
(M) Bayleton + Ridomil MZ-58 + Penetrator 0.12 lb + 2.0 Ibs + 0.5 pt; 14-day 5.5 1.7
(H) Ridomil MZ-58 2.0 Ibs 5.3 5.9
(I) Rovral 50W 2.0 lbs 6.2 5.1
(U) Untreated 6.8 6.0


= downy mildew and


Barratt-Horsfall rating system: 0 = no disease, 6 = 50% disease, 11 = 100% disease. DM
PM = powdery mildew. DM was rated on May 23 and PM on May 22.







10. SQUASH FUNGICIDES (D. L. Hopkins)

Date of Planting: February 27, 1986
Variety: Early Butternut
Procedure: Materials were applied at a pressure of 150 psi and in 100 gallons of dilute spray per
acre, using a boom sprayer. Treatments were applied April 22, 29, May 6, 13, and 20.
Results:



Disease rating
Treatment Rate (ant/acre) DM PM


(H) Systhane (14-day) + Dithane M-45 + Triton B-1956 2.0 oz ai + 3.0 lbs + 2 oz 1.4 0.5
(G) Systhane + Dithane M-45 + Triton B-1956 1.5 oz ai + 3.0 lbs + 2 oz 1.7 0
(J) Topsin M 4.5F + Bravo 500 10.0 oz + 3.0 pts 1.9 0.5
(A) Dithane M-45 + Karathane + Triton B-1956 3.0 Ibs + 0.75 lb + 2 oz 2.0 3.9
(F) Systhane + Dithane M-45 + Triton B-1956 1.0 oz ai + 3.0 Ibs + 2 oz 2.0 0.1
(C) Maneb 80WP 3.0 lb 2.1 4.6
(0) Bayleton + Bravo 500 + Penetrator 0.12 lb + 3.0 pts + 0.5 pt 2.3 0.9
(B) Maneb F4 2.5 qts 2.5 4.8
(E) Topsin M 4.5F + Penncozeb 80WP 10.0 oz + 2.0 lbs 2.5 2.4
(I) Topsin M 70WP + Bravo 500 0.5 lb + 3.0 pts 2.5 0.6
(N) Bayleton + Bravo 500 + Penetrator 0.25 lb + 3.0 pts + 0.5 pt 2.5 0.3
(D) Topsin M 70WP + Penncozeb 80WP 0.5 lb + 2.0 lbs 2.9 2.8
(P) Bayleton + Bravo 500 0.25 lb + 3.0 pts 3.1 0.9
(S) Bayleton + Ridomil MZ-58 alt. with 0.25 Ib + 2.0 lbs 3.0 lbs + 2 oz 3.4 2.2
Dithane M-45 + Triton B-1956
(T) Benlate + Manzate 200 0.5 lb + 2.0 lbs 4.0 2.9
(R) Bayleton + Ridomil MZ-58 + Penetrator 0.12 Ib + 2.0 lbs + 0.5 pt 5.4 3.2
(K) Spotless 25WP 0.1 Ib 5.5 0
(L) Spotless 25WP 0.2 lb 6.5 0
(M) Unsprayed 7.6 5.5

Barratt-Horsfall rating system: 0 = no disease, 6 = 50% disease, 11 = 100% disease. DM = downy mildew and
PM = powdery mildew. DM was rated on May 20 and PM on May 21.








11. WATERMELON FUNGICIDES (D. L. Hopkins)


Date of Planting: February 28, 1986
Variety: Charlee
Procedure: Treatments were applied at a pressure of 150 psi and in 100 gallons
of dilute spray per acre, using a boom sprayer. Spray application dates were
April 30, May 7, 14, 21, 28, and June 3.


Treatments


Rate (amt/100 gal/acre)


Rovral 50W
Rovral 50W
Rovral 50W
Maneb F4
Maneb 80W
Topsin M 70W + Penncozeb 80W
Topsin M 4.5F + Penncozeb 80W
Topsin M 70W + Bravo 500
Topsin M 4.5F + Bravo 500
Dithane M-45 + Triton B-1956
Benlate 50W + Manzate 200
Difolatan 80
Bravo 500
Unsprayed


1.0 lb
1.5 lbs
2.0 lbs
2.5 qts
3.0 Ibs
0.5 lb + 2.0 lbs
10 oz + 2.0 Ibs
0.5 lb + 3.0 pts
10 oz + 3.0 pts
3.0 lbs + 2 oz
0.5 lb + 2.0 lbs
2.0 lbs
3.0 pts


(A)
(B)
(C)
(D)
(E)
(F)
(G)
(H)
(I)
(J)
(K)
(L)
(M)
(N)


Results: Results are not available yet. Plots may be observed on the field tour.
Many of the treatments listed above are not yet cleared for use on watermelon.












12. APHID TRANSMISSION OF WATERMELON MOSAIC VIRUS 2 AND ZUCCHINI
YELLOW MOSAIC VIRUS (Adlerz)


Purpose: Detection and identification of alate aphids naturally
infected with viruses in cucurbit plots.

Procedure: From 1981 to 1983 aphids flying near cucurbit plots
were trapped alive either in yellow pans, or in a suction trap or
on a vertical screen. Live aphids were transferred singly to
healthy 'Dixie' squash to determine rate of natural infection
among migrant aphids. In all, 2433 aphids were tested.

In 1984 and 1985 alate aphids trapped alive in the field when
there was no infection present in crop plants were fed singly on
sources of watermelon mosaic virus 2 (WMV-2) and zucchini yellow
mosaic virus (ZYMV) and transferred to healthy test plants to
determine their transmission efficiency in controlled conditions.

Results: Only 4 of 40 species of aphids trapped alive were found
to be naturally infective with plant virus. The infective aphids
were Aphis citricola, Aphis middletonii, Aphis illinoisensis, and
Myzus persicae. Of these, 92% of all infective aphids were 2
species, Aphis citricola 52% and Aphis middletonii 40%.

Calculated on the basis of proportion of infective aphids after
the first infective aphids were found each season, the most
efficient of the 40 aphid species tested were Aphis middletonii
13.6% and Aphis citricola 4.3%. The average efficiency of all
aphids transmitting virus was 5.9%.

In the controlled transmission tests of 1984 and 1985 in which
trapped alate aphids were fed on virus sources, 7 of 23 species
of aphids tested transmitted virus. Of these, 93.1% of
transmission were by 3 species: Aphis citricola 48.3%, Myzus
persicae 17.2%, and Aphis middletonii 27.6%. Their transmission
efficiency rates were 18.3%, 23.8%, and 30.8% respectively.

Zucchini yellow mosaic transmission was more efficient than WMV-2
transmission in these tests with alate aphids:



Transmission rates of 2 viruses
by aphids trapped alive

WMV-2 ZYMV
1984 6.9% 14.9%
1985 12.4% 27.9%






18


Significance: According to the literature, at least 38 species
of aphids are known to transmit WMV-2. The evidence from live
trapping studies is that only 2 or 3 species are likely to be
very important vectors of cucurbit viruses in the area. In the
event that virus control strategies are developed that are
centered on vector control, the 2 or 3 species to be controlled
have been identified.

Evidence has been presented in earlier research that ZYMV spreads
more quickly than WMV-2. Evidence presented here is that the
rate of spread of ZYMV may be twice that of WMV-2. This helps
explain why ZYMV has become more prevalent than WMV-2 in many
central Florida cucurbit fields.









































































































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