Watermelons in Texas

Crop Brief on Production, Pests, & Pesticideswatermelon

Crop Briefs were prepared by Dr. Dudley Smith, Texas Agricultural Experiment Station and Dr. Juan Anciso, Texas AgriLife Extension Service Service
Watermelon Production
  • Texas ranks 3rd in U.S. production.
  • Cash receipts exceed $50 million. Statewide economic impacts exceed $160 million.
  • Watermelons are the state’s largest annual horticultural crop. Over 42,000 acres are grown throughout Texas in over 100 counties.
  • Grower/shippers coordinate sales into large metro areas and out-of-state shipments. Roadside market melons come from smaller acreage and part-time farmers.
  • Sequential harvests start in April in the Lower Rio Grande Valley, in June and July in the Winter Garden and East Texas areas, and progresses to August in the Rolling Plains area, with late summer and early fall harvests in the Cross Timbers/DeLeon and southern High Plains.
  • Cultivar selection is an important management decision in combating pests and meeting market windows. Populations vary from 2,000 to 3,000 plants per acre, and can be grown under a wide array of irrigation practices or dryland.
Insect Pests
  • Annually occurring insects include whiteflies, aphids, mites, lepidopteran worms, leafminers, squash bugs, and thrips. Aphids and whiteflies also transmit serious viruses. Early planting helps reduce losses due to late-season insects.
  • Beneficial parasitoids and predators are available but are not widely used due to low reliability.
  • Diazinon, methomyl (Lannate), and dimethoate (Cygon) are three FQPA targeted products that if withdrawn could reduce yield by 10%. There are no current replacements for diazinon. An alternative for dimethoate could be imidacloprid (Admire, Provado), which is labeled as a Section 3. An alternative for methomyl could be tebufenozide (Confirm).
  • Some varieties resist several pathogens such as Fusarium, wilt and powdery mildew. Planting seed is tested for bacterial fruit blotch pathogen.
  • Rotation reduces the risk of Fusarium wilt and bacterial blotch.
  • Chlorothalonil (Bravo) and dithiocarbamates (Maneb and others) are the products targeted by FQPA. Withdrawal could reduce yields by 50% since these two products control a broad spectrum of fungal diseases. There are no commercial replacements for these products. Azoxystrobin (Quadris) and myclobutanil (Nova) (Emergency Use/Section 18) are only effective against only a few pathogens and are not broad spectrum. Other commercial fungicides are used primarily for downy mildew control.
  • Annual broadleaf weeds reduce production and hamper harvest. Pigweed, purslane, sunflower, and other weeds rob the crop of water and shade the foliage. Texas panicum and perennials such as johnsongrass and yellow nutsedge reduce yields.
  • Cultivation is practiced while the plants are young. But vines over one foot long can not be tilled. Fields are rotated annually to reduce weeds and diseases.
  • Bensulide (Prefar) is a FQPA targeted product that, if withdrawn, could reduce yields by 20%. Trifluralin (Treflan) and naptalam (Alanap) can cause phytotoxicity. Halosulfuron (Permit) is being evaluated for over the top application.
  • Watermelons are commercially produced in over 40% of the counties and rural areas in Texas. In east Texas substantial family income is generated from small plot/roadside sales.
  • Insecticides, fungicides, and herbicides help sustain production.
  • For latest information regarding these issues and status of risk assessments visit ipmwww.ncsu.edu/opmppiap and www.epa.gov/pesticides.
Crop Briefsis an information series developed by Texas A&M AgriLife of the Texas A&M University System on critical pest problems and pesticide needs for Texas agriculture. This effort is supported by the Texas Vegetable Association, and other commodity groups. Dr. Dudley Smith, Texas Agricultural Experiment Station and Dr. Juan Anciso, Texas AgriLife Extension Service prepared these reports August 2000 using information from numerous sources. Departmental Report SCS-2000-01.The information given herein is for educational programs only. Reference to commercial products or trade names is made with the understanding no discrimination is intended and no endorsement by the Texas AgriLife Extension Service and the Texas Agricultural Experiment Station is implied.

Educational programs conducted by Texas A&M AgriLife, Texas A&M University, Texas Agricultural Experiment Station, and the Texas AgriLife Extension Service serve people of all ages regardless of socioeconomic level race, color, sex, religion, handicap or national origin.

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