mulch treatment methods for whitefly control in tomato … · in effort to resurrect the tomato...
TRANSCRIPT
RESEARCH POSTER PRESENTATION DESIGN © 2015
www.PosterPresentations.com
The Lower Rio Grande Valley in Texas was once a very productive
area for winter tomatoes. At it’s peak, the LRGV maintained over
40,000 acres of tomato production. Over the past several decades,
an invasion of devastating diseases most notably the Tomato
Yellow Leaf Curl Virus (TYLCV) has almost wiped out the tomato
industry and is still a limiting factor for farmers interested in this
high-value crop. The challenges of organic or transitioning farms
are even more formidable since these farmers lack the tool that can
defend against the virus (and its main vector the silver leaf whitefly
(Bemesia tabaci)).
In effort to resurrect the tomato industry in south Texas and assist
local farmers looking to capture the momentum of local organic
agriculture, we selected the tomato variety, Tycoon F1, which has
some resistance to TYLCV, to experiment with. In an effort to
deter the whitefly using UV light, we compared the use of silver
mulch and standard hay as mulch in terms of total marketable
yields and number of whiteflies.
Introduction
Research Questions
All research was conducted at UTRGV Agrecology Research
Garden that is certified organic by USDA. The tomatoes were
started in a greenhouse on Aug. 6th and transplanted on Aug. 29th,
2015 into a 36” wide raised bed with 2 ft staggered spacing and a 4
ft buffer between each mulch treatment. Each treatment block was
repeated three times.
Nine sticky traps were collected each week for four weeks and
counted for number of whiteflies. A total of four harvests were
collected and measured for average fruit weight and total
marketable fruit.
Methods
A one-way ANOVA showed a significant difference in the average
marketable fruit weight between the silver plastic mulch and hay,
however the silver plastic compared bare soil was not significant.
Whiteflies traps followed a similar trend as marketable fruit. Silver
plastic had the best overall performance but the difference was not
statistically significant.
Preliminary Results Discussion
Overall the reflective plastic had less whiteflies, produced fruit
earlier, and more consistently compared to tomatoes grown over
hay or bare soil. The low statistical values may be due to sample
size. To test this a larger experiment will be conducted at Terra
Preta farm, Edinburg, Tx.
Incorporating integrated pest management (IPM) would be
valuable in the South Texas tomato growing industry. In
September, massive amounts of whiteflies migrate due to the
harvest of cotton fields. Later transplanting dates may promote
better harvests for winter tomatoes. This combined with reflective
mulch should be relatively effective in deterring the whitefly. A 4’
x 2400’ roll of silver reflective plastic mulch costs around $224. To
reduce the cost of man-hours, using a plastic mulch layer
attachment is highly reccomended and would cost between $1900-
$4000. A plastic mulch planter costs roughly $115. One draw back
to this method of pest management is that the plastic is discarded
after a single use. In regions where this plastic is common, such as
in the California strawberry industry, recycling centers are
available for thes types of materials.
Refrences
1. Cznosnek H (ed) The Tomato yellow leaf curl virus disease:management
molecular biology and breeding for resistance. Springer, Dordrecht,
Neththerlands
2. C. Summers, J. Mitchell, J. Stapleton 59(2):90-94, Mulches reduce
aphid-borne viruses and whiteflies in cantaloupe, California, 2005.
ACKNOWLEGEMENTS
Special thanks to Subtropical Organic Agricultural Research
(SOAR) Partnership from USDA- NIFA-ORG award # 2013-
51106-20970, where funding this project was provided, the
Agroecology lab at UTRGV, and the advisement of Dr. Alexis
Racelis.
1) Will there be a difference in planting strategies/mulching in
terms of whitefly infestations?
2) Will there be a difference in marketable tomato yields among
the two mulching strategies?
Department of Biology, University of Texas- Rio Grande Valley
Lindsey Richards, Alexis Racelis
Mulch Treatment Methods for Whitefly Control in Tomato Plants
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Sept. 8-15 Sept. 22-29 Sept. 29-Oct. 6Num
ber
of
whit
efl
ies
on s
ticky
traps
Week
Weekly Comparison of Whitefly Population on Sticky Traps
Reflective Bare Hay
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Reflective Bare Hay
Avg.
num
ber
of
whit
efl
ies
Average Number of Whiteflies per Treatment
Week 1: Sept. 8th – 15th (6 weeks old)
Bare (Control) Hay Silver Reflective Plastic
Week 2: Sept. 22nd – 29th (8 weeks old)
Week 3: Sept. 29th – Oct. 6th ( 9 weeks old)
Week 4: Oct. 6th – 13th (10 weeks old)
Dec. 1st Harvest
90
95
100
105
110
115
Silver Plastic Hay Bare
Wei
ght
(g)
Average Fruit Weight
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Silver Plastic Hay Bare
Wei
ght
(g)
Total Marketable Fruit Weight