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Louisiana Rice: New Herbicides on the Horizon

Ernst Undesser
By Bruce Schultz, LSU AgCenter February 26, 2016

Farmers and crop consultants heard about several new chemicals to control weeds in rice fields at a learning session held by the LSU AgCenter on Friday (Feb. 26).

LSU AgCenter weed scientist Eric Webster said the products won’t be available for the upcoming season. “We’re probably a couple of years away from having most of these.”

The herbicide-resistant rice technology Provisia will help farmers control herbicide-resistant red rice and outcrosses that cannot be controlled with herbicides currently available to farmers, he said. The system will complement Clearfield rice and extend its viability.

 

Currently, Webster said, the only way a farmer can successfully rid a field of weedy rice is to grow three successive years of soybeans, but Provisia will provide an alternative rotation crop for the second year.

LSU AgCenter rice breeder Steve Linscombe traveled Thursday to Puerto Rico to work on a 7-acre seed increase of Provisia rice that will be harvested within the next two weeks, Webster said.

Farmers will be taking a chance when they mix other herbicides with the Provisia system’s herbicide, quizalofop, because tank mixes occasionally interfere with the chemical’s effectiveness, he said.

Graduate student Sam Rustom said testing has shown that the effectiveness of quizalofop is affected most when it is mixed with a wide range of other herbicides, including Grasp, Grasp Xtra, Regiment, RiceBeaux and propanil.

Webster said another product for the future is benzobicyclon, which is effective against sprangletop, aquatic weeds and red rice.

It will cause injury to a rice crop, he said, and this year’s research will focus on how much benzobicyclon rice can tolerate. The chemical has been used for years in Japan on short-grain rice, which seems to be more tolerant.

Graduate student Ben McKnight said the chemical is highly effective against ducksalad, and it also works well on cattails and yellow nutsedge. He said it has to be applied when a rice field is flooded.

The herbicide Rinskor shows promise for controlling grasses, sedges and aquatic weeds, and it has a new mode of action, McKnight said. It could be available next year with the product name of Loyant.

AgCenter weed scientist Daniel Stephenson said farmers can take a number of steps to prevent the problem of herbicide-resistant weeds, including rotating herbicides and crops and ensuring herbicides are applied at the correct time at the recommended rate.

Resistance has developed in weeds because farmers relied too much on one herbicide for years, he said.

Ernst Undesser
By Bruce Schultz, LSU AgCenter February 26, 2016