Weed Control Options In Conventional Rice

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The 2018 Mississippi rice season was tough, but we ended up with decent yields in most fields. Delays in application timing and levee preparation along with herbicide resistance and hot, dry conditions in May challenged weed control programs. Early planted rice was the easiest to manage. We got good stands, and the herbicides performed well in the wetter, cooler environment.

Fall and winter rains resulted in ruts in many late-harvested fields and delayed fieldwork, which will have to be done this spring. Because they now have larger equipment, growers still should be able to get their rice crop in the ground during April and most of May — our typical planting window. We have been meeting with our farmers to help them make decisions about rice varieties, pesticides and fertilization and monitoring winter weed populations to determine if burndown herbicide applications are needed.

Strategies To Eliminate Troublesome Weeds
Major grass weeds include barnyardgrass, broadleaf signal grass and sprangletop. We also have problems with herbicide-resistant annual flat sedge and yellow nut sedge. Broadleaf weeds include coffeebean, joint vetch, morningglory, eclipta and pigweed. Our weed control efforts begin with either tillage or a herbicide application at planting to start weed-free. Pre-emerge options include a tankmix of Roundup for burndown and Command. We often add Sharpen herbicide to help with burndown and provide residual control of broadleaves and sedges.

If weeds are present in a conventional field when the rice crop emerges, we apply Clincher SF, Facet or Bolero herbicide tankmixed with Prowl, depending on the weed spectrum. This regimen is followed by preflood fertilizer and herbicide applications at the four-leaf rice stage. In conventional rice, tankmix choices include Regiment and Facet, RiceStar and Facet, propanil and Facet or Bolero, or RebelEX — a premix of Grasp SC and Clincher SF. For best results, we get the flood on as soon as we can.

In addition to providing other services, we check fields weekly or biweekly to monitor pest populations and make pesticide recommendations at economic threshold. As independent crop consultants, we try to make unbiased product recommendations to improve our growers’ bottom line. We attend meetings in the off-season to learn about research efforts and talk to other consultants about what is working for them. With improved genetics, technology, pest management, fertility efforts, equipment and irrigation, the upward movement of yields should continue.

In my opinion, the short-term challenges we face today are typically short-lived. My hope is the tariff wars will soon be over, and world trade can thrive.

Recap

  1. 1. Early planted rice was the easiest to manage in 2018. We got good stands, and the herbicides performed well in the wetter, cooler environment.
  2. Weed control efforts typically begin with either tillage or a herbicide application at planting. Pre-emerge options include a tankmix of Roundup for burndown and Command. We often add Sharpen herbicide to help with burndown and provide residual control of broadleaves and sedges.
  3. If weeds are present in a conventional field when the rice crop emerges, we apply Clincher SF, Facet or Bolero herbicide tankmixed with Prowl, depending on the weed spectrum.
  4. This regimen is followed by a preflood application at the four-leaf rice stage. In conventional rice, tankmix choices include Regiment and Facet, RiceStar and Facet, propanil and Facet or Bolero, or RebelEX — a premix of Grasp SC and Clincher SF. For best results, we get the flood on as soon as we can.

Winston Earnheart, Ph. D.
Earnheart Agricultural Consultant Service
Tunica, Mississippi

About the Author

  • B.S., agronomy, Mississippi State University; M.S. and Ph.D., biology, University of Mississippi
  • Has consulted independently for 46 years on rice, cotton, corn, soybeans, peanuts, pecans and wheat. Farmed for 25 years
  • Past president of the Mississippi Agricultural Consultants Association (MACA)
  • Taught at Tunica Academy in the off-season for 10 years. College professor of natural sciences at Crichton College for two years, followed by two years at Victory University
  • First Baptist Church of Tunica choir director for 35 years
  • Married to Pat. Six grown children and three grandchildren
  • Enjoys church life, family life, hunting, fishing and playing guitar

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