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Group Title: Bradenton GCREC research report - University of Florida Gulf Coast Research and Education Center ; BRA1993- 4
Title: Drip irrigation rates affect watermelon yields
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Permanent Link: http://ufdc.ufl.edu/UF00065258/00001
 Material Information
Title: Drip irrigation rates affect watermelon yields
Series Title: Bradenton GCREC research report
Physical Description: 8 p. : ; 28 cm
Language: English
Creator: Maynard, Donald N., 1932-
Clark, Gary A
Gulf Coast Research and Education Center (Bradenton, Fla.)
Publisher: Gulf Coast Research & Education Center, IFAS, University of Florida
Place of Publication: Bradenton FL
Publication Date: 1993
 Subjects
Subject: Watermelons -- Water requirements -- Florida   ( lcsh )
Microirrigation -- Florida   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: D.N. Maynard and G.A. Clark.
General Note: Caption title.
General Note: "February."
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Bibliographic ID: UF00065258
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 68623051

Table of Contents
    Historic note
        Historic note
    Front Cover
        Front cover
    Main
        Page 1
        Page 2
        Page 3
        Page 4
        Page 5
        Page 6
        Page 7
        Page 8
        Page 9
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




2(F 4AJ


Gulf Coast Research
and Education Center


SC eno


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5007 60th St. E., Bradenton, Florida 34203-9324
W Institute of Food and Agricultural Sciences
. .University of Florida








GULF COAST RESEARCH & EDUCATION CENTER
IFAS, UNIVERSITY OF FLORIDA
5007 60th Street East
Bradenton, FL 34203

Bradenton GCREC Research Report BRA1993-4 February

DRIP IRRIGATION RATES AFFECT WATERMELON YIELDS


D. N. Maynard and G. A. Clark'

Seasonal water requirements for watermelon vary from 16 to 24 inches. Early in
the season, the water requirement is approximately 40% of potential ET and during
fruit development may exceed 100% of potential ET (Doorenbos and Kassam, 1979;
Ritter et al., 1985).

The effects of drip and overhead irrigation on watermelon yields were compared
at Leesburg and Gainesville (Elmstrom et al., 1981). Early yields were increased
at Leesburg with drip irrigation compared to overhead or no irrigation. Total
yields were greater with irrigation, regardless of source, than with no
irrigation. There was no yield response to irrigation at Gainesville, presumably
because of the higher waterholding capacity of the acid, flatwoods soil used
there. Overall, water use was reduced by about 40% with drip compared to
overhead irrigation.

The objectives of this study were to determine the effects of three rates of drip
irrigation on watermelon yield, average fruit weight, soluble solids, and
hollowheart.

MATERIALS AND METHODS
Soil samples from the experimental area were obtained before fertilization and
analyzed by the IFAS Extension Soil Testing Laboratory (Hanlon and DeVore,
1989):pH = 7.6 and Mehlich I extractable P = 32, K = 12, Mg = 89, Ca = 631, Zn
= 94, Cu = 2.9, and Mn = 1.2 ppm. Soil at the site was EauGallie fine sand.

The experimental plot area was prepared in early February 1992 by incorporation
of 7 lb 0-20-0 and 3 lb 18-0-25 per 100 linear bed feet (Ibf). This preplant
application provided 26-68-36 lb N-P20-KO per acre. Beds were formed and
fumigated with methylbromide:chloropicrin (67:33) at 2.15 lb per 100 Ibf. Drip
irrigation tubing (Roberts Ro-Drip, 12-inch emitter spacing, 0.5 gpm/100 ft
nominal discharge) was installed during bed formation in the bed center
approximately 1-inch below the soil surface. The final polyethylene-mulched beds
were 24-inches wide and 8-inches high and were spaced on 9-ft centers, with four
beds between drainage ditches which were on 41-ft centers.

'Professor and Extension Vegetable Specialist and Associate Professor of
Agricultural Engineering and Extension Irrigation Specialist.








'Crimson Sweet,' 'Jack of Hearts,' 'Mickylee,' 'Royal Jubilee,' and 'Sangria'
watermelon seeds were planted in a peat-lite mix in No. 150 Todd planter flats
on 31 January and the transplants were grown by a commercial plant grower. The
plants were transplanted on 5 March in holes punched in the polyethylene at 3 ft
in-row spacing. The 36-ft long plots had 12 plants each and were replicated four
times in a randomized complete block design.
All plots were drip irrigated for 30 minutes per day (725 gal/acre/day) for 14
days for crop establishment. This run time was sufficient to allow applied water
to move from the dripper to the transplant location. For the remainder of the
season, all plots were drip irrigated at treatment levels IX, 2X, and 3X.
Scheduled applications were based on ratios of calculated Penman reference
evapotranspiration (ETo) (Burman et al., 1980) using atmospheric data collected
at a weather station approximately 50 feet from the experimental plots.
Calculated Penman ETo data, irrigation Level 1 target application ratio, and
applied irrigation amounts for Levels 1, 2, and 3, are shown in Table 1. Drip
irrigation applications for Levels 2 and 3 were approximately 2 and 3 times the
Level 1 application amount. Seasonal applied irrigation amounts totaled 3.8,
7.3, and 11.8 inches for the Level 1, 2, and 3 treatments, respectively.
Additional fertilizer was applied through the drip system to provide 120-0-120
lb N-P05O-K20 per acre. Total fertilizer application was 146-68-156 lb N-P20s-KO0
per acre. Watermelon fruit were harvested on 22 and 28 May and 5, 12, and 23
June. Marketable melons (U.S. No. I or better) according to the U.S. Standards
for Grades of Watermelons (USDA) were separated from culls and counted and
weighed individually. Soluble solids determinations were made with a hand-held
refractometer on two fruit from each replicate of the 12 treatments on every
harvest date when that variety was harvested, and the incidence and severity of
hollowheart were recorded for these fruits. The resulting data were subjected
to an analysis of variance and mean separation was by Duncan's multiple range
test.
RESULTS

Temperature and rainfall during the experimental period from 5 March to 23 June
(Table 2), approximated the 38-year averages (except for lower than normal
rainfall in May) (Stanley, 1992).

Early yields ranged from 0 cwt/acre for 'Royal Jubilee' to 297 cwt/acre for
'Sangria' (Table 3). Early yield of 'Mickylee' was similar to that of 'Sangria.'
Average fruit weight ranged from 12.1 lb for 'Mickylee' to 21.6 lb for 'Crimson
Sweet.' Soluble solids ranged from 11.6% for 'Sangria' to 12.3% for 'Jack of
Hearts,' exceeding the 10% specified for optional use in the U.S. Standards for
Grades of Watermelons (USDA). The incidence of hollowheart varied from 13% for
'Sangria' to 88% for 'Jack of Hearts;' 'Mickylee' and 'Crimson Sweet' were
intermediate in susceptibility to hollowheart with 48% and 55%, respectively.
The severity of hollowheart was greatest in 'Mickylee' and 'Jack of Hearts' with
0.79 inch and 0.83 inch wide cracks, respectively. 'Sangria' and 'Crimson Sweet'
fruit cracks were 0.04 inch and 0.16 inch wide, respectively.

Total yields ranged from 621 cwt/acre for 'Mickylee' to 929 cwt/acre for 'Royal
Jubilee' (Table 3). Average fruit weight for the entire season, ranged from 10.7
lb for 'Mickylee' to 25.1 lb for 'Royal Jubilee.' Soluble solids of all
varieties exceeded the optional requirement of 10% specified in the U.S.
Standards for Grades of Watermelons (USDA). The incidence and severity of








hollowheart was lowest in 'Sangria' and highest in 'Jack of Hearts.'
also had severe hollowheart.


'Mickylee'


The fruit weight distribution (Table 4) of the varieties included in this trial
are related closely to average fruit weight (Table 3). Fruit weights are
consistent with the inherent qualities of these varieties, i.e. 'Royal Jubilee'
> 'Crimson Sweet' > 'Sangria' > 'Jack of Hearts' > 'Mickylee.'

Significant quadratic yield responses at the 5% probability level occurred for
'Crimson Sweet' early and total yield. A quadratic response at the 1%
probability level occurred for 'Jack of Hearts', 'Mickylee', and 'Sangria' total
yield (Table 5). Average fruit weight of 'Royal Jubilee' responded to irrigation
levels in a quadratic mode for the total season (Table 6). The incidence of
hollowheart of 'Crimson Sweet' responded quadratically at the 1% level to
irrigation rate (Table 7). Severity of hollowheart (Table 8) and soluble solids
(Table 9) were not affected by irrigation level.

The performance of the five watermelon varieties included in this trial with
respect to yield, average fruit weight, soluble solids concentration and presence
and severity of hollowheart was in relation to performance in previous trials
(Maynard, 1992). Total yields were strongly affected by irrigation levels in
four of the five varieties with highest yields occurring at the 2X level which
was equivalent to 7.3 inches for the entire season. For the most part, other
parameters measured in this trial were not affected by irrigation level. The
experiment will be repeated and refined in the spring 1993 season to further
characterize the relationship between drip irrigation level and watermelon yields
and quality.

NOTE

The information contained in this report is a summary of experimental results and
should not be used as recommendations for crop production or water allocations.
Where trade names are used, no discrimination is intended and no endorsement is
implied.


LITERATURE CITED


Burman, R. D., P. R. Nixon, J. L. Wright, and
requirements (Chapter 6) in: M. E. Jensen
Farm Irrigation Systems, Monograph No.
Agricultural Engineers, St. Joseph, MI.


W. 0. Pruitt.
(ed.) Design and
3. American


1980. Water
Operation of
Society of


Doorenbos, J. and A.
Drain. Pap. 33.


H. Kassam. 1979. Yield response to water. FAO Irrig.
FAO, Rome.


Elmstrom, G. W., S. J. Locascio, and J. M. Myers.
drip and sprinkler irrigation. Proc. Fla.


1981. Watermelon response to
State Hort. Soc. 94:161-163.


Hanlon, E. A. and J. M. DeVore. 1989. IFAS extension soil testing laboratory
chemical procedures and training manual. Fla. Coop. Ext. Circ. 812.


Maynard, D. N. (ed.) 1992.
Fla. Agr. Expt. Sta.


Vegetable variety trial results in Florida for 1991.
Circ. S-384.








Ritter, W. F., T. H. Williams, and R. W. Scarborough.
for corn, soybeans, and vegetables in Delaware.
463.


Stanley, C. D. 1992.
Rept. BRA1992-2.


1985. Water requirements
Del Agr. Expt. Sta. Bul.


Temperature and rainfall report for 1991. GCREC Res.


U.S. standards for grades of watermelons. 1978.


U.S.D.A., Washington, DC.


Table 1. Treatment Level 1 irrigation application ratios, and average daily
levels of calculated Penman ETo and applied drip irrigation amounts
for Levels 1, 2, and 3. Spring 1992.

Weeks of Application Penman ETo Level 1 Level 2 Level 3
season ratio ---------------- gal/acre/da -----------------

3 & 4 0.10 3550 318 470 760
5 & 6 0.20 3780 700 930 1570
7 & 8 0.25 4400 1010 1840 3180
9 & 10 0.25 4600 1160 2200 3340
11 & 12 0.25 5430 1260 2590 4140
13 & 14 0.30 5450 1520 3250 5180
15 & 16 0.25 5860 1390 2930 4720






Table 2. Mean temperature and rainfall at the Gulf Coast Research and
Education Center from 5 March to 23 June 1992 and 1954-1991 monthly
averages (Stanley, 1992).


Average daily temperature
1992 1954-91 average Rainfall (in.)
Month (date) Max. Min. Max. Min. 1992 1954-91 average

March (5-31) 77 56 77 55 4.05 3.38
April 81 61 81 59 2.93 1.65
May 86 62 87 65 0.15 3.24
June (1-23) 91 72 89 70 5.39 7.58

1992 data are for the dates shown; 1954-91 averages are for the entire month.








Table 3. Yield, average fruit weight, soluble solids, and the incidence and
severity of hollowheart of five watermelon varieties averaged over
three drip irrigation rates. Gulf Coast Research and Education
Center. Spring 1992.

Early harvest'
Hollow-3
Avg. Soluble Hollow- heart
Weight fruit solids heart avg.
Variety (cwt/A)2 wt (lb) (%) (%) (in)

Royal Jubilee NH4 NH NH NH NH
Crimson Sweet 231 bc5 21.6 a 11.8 ab 55 b 0.16 b
Sangria 297 a 20.4 b 11.6 b 13 c 0.04 b
Jack of Hearts 207 c 14.1 c 12.3 a 88 a 0.83 a
Mickylee 277 ab 12.1 d 12.1 ab 48 b 0.79 a
Total harvest

Royal Jubilee 929 a 25.1 a 11.5 b 40 b 0.20 b
Crimson Sweet 747 b 21.0 b 11.5 b 49 b 0.24 b
Sangria 733 b 20.0 b 11.7 ab 20 c 0.12 b
Jack of Hearts 701 bc 12.3 c 12.0 a 75 a 0.75 a
Mickylee 621 c 10.7 d 11.8 ab 45 b 0.59 a

'Harvested 22 and 28 May.
2Acre = 4840 Ibf.
3Average width of fruit cracks of fruit with hollowheart.
4Not harvested.
5Mean separation in columns by Duncan's multiple range test, 5% level.



Table 4. Fruit weight distribution of the total harvest of five watermelon
varieties averaged over three drip irrigation rates. Gulf Coast
Research and Education Center. Spring 1992.

Fruit weight (Ib)
<5.0 5.1-10.0 10.1-15.0 15.1-20.0 20.1-25.0 25<
Variety Percentage of fruit
Crimson Sweet 0 b1 4 c 18 c 22 b 30 a 27 b
Jack of Hearts 0 b 31 b 45 a 22 b 2 c 0 d
Mickylee 9 a 41 a 36 b 13 c 2 c 0 d
Royal Jubilee 0 b 0 c 7 d 19 bc 23 b 52 a
Sangria 0 b 2 c 15 c 35 a 36 a 13 c

'Mean separation in columns by Duncan's multiple range test, 5% level.








Table 5. Early and total yields of five watermelon varieties grown at three
levels of drip irrigation. Gulf Coast Research and Education Center.
Spring 1992.

Irrigation Level
Variety 1 2 3 Response
Early' -------------(cwt/A) --------------

Crimson Sweet 280 276 140 Q*
Jack of Hearts 230 238 152 NS
Mickylee 28 289 254 NS
Royal Jubilee NH NH NH
Sangria 273 370 247 NS

Total
Crimson Sweet 767 862 612 Q*
Jack of Hearts 706 832 566 Q**
Mickylee 622 720 521 Q**
Royal Jubilee 863 1054 871 NS
Sangria 620 910 669 Q**

'Harvested 22 and 28 May.
2Acre = 4840 Ibf.
3Not harvested.
4NS = not significant, Q* = quadratic response at 5% probability level, Q** =
quadratic response at 1% probability level.


Table 6. Average fruit weight of five watermelon varieties grown at three
levels of drip irrigation. Gulf Coast Research and Education Center.
Spring 1992.

Irrigation Level
Variety 1 2 3 Response3
Early ----------------b)----------------

Crimson Sweet 20.8 22.6 21.4 NS
Jack of Hearts 13.5 15.5 13.4 NS
Mickylee 12 4 12.5 11.5 NS
Royal Jubilee NH NH NH
Sangria 20.8 19.9 20.5 NS

Total
Crimson Sweet 21.5 21.7 19.7 NS
Jack of Hearts 11.8 13.4 11.7 NS
Mickylee 11.1 10.8 10.2 NS
Royal Jubilee 23.3 28.0 24.0 Q*
Sangria 20.1 20.4 19.3 NS

'Harvested 22 and 28 May.
2Not harvested.
3NS = not significant, Q* = quadratic response at 5% probability level.







Table 7. Incidence of hollowheart of five watermelon varieties grown at three
levels of drip irrigation. Gulf Coast Research and Education Center.
Spring 1992.

Irrigation Level
Variety 1 2 3 Response3
Early' ------------------(%)------------

Crimson Sweet 100 15 50 Q**
Jack of Hearts 100 75 88 NS
Mickylee 59 44 50 NS
Royal Jubilee NH NH NH --
Sangria 25 13 0 NS

Total
Crimson Sweet 59 37 50 NS
Jack of Hearts 84 67 76 NS
Mickylee 45 44 47 NS
Royal Jubilee 25 31 63 NS
Sangria 25 27 9 NS

'Harvested 22 and 28 May.
2Not harvested.
3NS = not significant, Q** = quadratic response at 1% probability level.


Table 8. Severity of hollowheart of five watermelon varieties grown at three
levels of drip irrigation. Gulf Coast Research and Education Center.
Spring 1992.

Irrigation Level
Variety 1 2 3 Response
Early' ----------------(in.) --------------

Crimson Sweet 0.15 0.18 0.11 NS
Jack of Hearts 0.74 1.12 0.66 NS
Mickylee 0.60 0.95 0.84 NS
Royal Jubilee NH NH NH NS
Sangria 0.15 0.20 0 NS

Total
Crimson Sweet 0.19 0.31 0.19 NS
Jack of Hearts 0.72 0.93 0.55 NS
Mickylee 0.55 0.74 0.52 NS
Royal Jubilee 0.09 0.13 0.35 NS
Sangria 0.09 0.23 0.06 NS

"Harvested 22 and 28 May.
2Not harvested.
3Average width of fruit cracks of fruit with hollowheart.
4NS = not significant.








Table 9. Soluble solids of five watermelon varieties grown at three levels of
drip irrigation. Gulf Coast Research and Education Center. Spring
1992.
Irrigation Level
Variety 1 2 3 Response3
Early -- --(%)-- ---------

Crimson Sweet 12.4 11.3 11.8 NS
Jack of Hearts 12.5 12.0 12.6 NS
Mickylee 12 0 12.5 12.2 NS
Royal Jubilee NH NH NH NS
Sangria 11.6 11.6 11.6 NS

Total
Crimson Sweet 11.7 11.4 11.5 NS
Jack of Hearts 11.9 11.9 12.4 NS
Mickylee 11.8 11.8 11.8 NS
Royal Jubilee 11.2 11.4 11.8 NS
Sangria 11.7 11.7 11.6 NS


'Harvested 22 and 28 May.
2Not harvested.
3NS = not significant.







The Gulf Coast Research and Education Center


The Gulf Coast Research and Education Center is
a unit of the Institute of Food and Agricultural Sci-
ences, University of Florida. The Research Center
originated in the fall of 1925 as the Tomato
Disease Laboratory with the primary objective of
developing control procedures for an epidemic out-
break of nailhead spot of tomato. Research was ex-
panded in subsequent years to include study of sev-
eral other tomato diseases.

In 1937, new research facilities were established
in the town of Manatee, and the Center scope was
enlarged to include horticultural, entomological, and
soil science studies of several vegetable crops. The
ornamental program was a natural addition to the
Center's responsibilities because of the emerging in-
dustry in the area in the early 1940's.

The Center's current location was established in
1965 where a comprehensive research and extension
program on vegetable crops and ornamental plants is
conducted. Three state extension specialists posi-
tions, 16 state research scientists, and two grant
supported scientists from various disciplines of
training participate in all phases of vegetable and
ornamental horticultural programs. This interdisci-
plinary team approach, combining several research
disciplines and a wide range of industry and faculty
contacts, often is more productive than could be ac-
complished with limited investments in independent
programs.


The Center's primary mission is to develop new
and expand existing knowledge and technology, and
to disseminate new scientific knowledge in Florida, so
that agriculture remains efficient and economically
sound.

The secondary mission of the Center is to assist
the Cooperative Extension Service, IFAS campus
departments, in which Center faculty hold appropri-
ate liaison appointments, and other research centers
in extension, educational training, and cooperative
research programs for the benefit of Florida's pro-
ducers, students, and citizens.

Program areas of emphasis include: (1) genetics,
breeding, and variety development and evaluation;
(2) biological, chemical, and mechanical pest manage-
ment in entomology, plant pathology, nematology,
bacteriology, virology, and weed science; (3) produc-
tion efficiency, culture, management, and counteract-
ing environmental stress; (4) water management and
natural resource protection; (5) post-harvest physiol-
ogy, harvesting, handling and food quality of horti-
cultural crops; (6) technical support and assistance to
the Florida Cooperative Extension Service; and (7)
advancement offundamental knowledge ofdisciplines
represented by faculty and (8) directing graduate
student training and teaching special undergraduate
classes.


Location of
GCREC Bradenton


IFAS IS:
" The Institute of Food and Agricultural Sciences,
University of Florida.
" A statewide organization dedicated to teaching,
research and extension.
Q Faculty located in Gainesville and at 13 research
and education centers, 67 county extension
offices and four demonstration units throughout
the state.
" A partnership in food and agriculture, and natural
and renewable resource research and education,
funded by state, federal and local government,
and by gifts and grants from individuals, founda-
tions, government and industry.
C) An organization whose mission is:
Educating students in the food, agricultural,
and related sciences and natural resources.
Strengthening Florida's diverse food and
agricultural industry and its environment
through research.
Enhancing for all Floridians, the application
of research and knowledge to improve the
quality of life statewide through IFAS exten-
sion programs.




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