Weed scientist studies Provisia, Loyant technologies

Research focusing on the Provisia technology was a major part of the work by LSU AgCenter weed scientist Eric Webster in 2020.

Provisia offers hope for farmers dealing with bad red rice and outcrossing problems with weedy rice, Webster said, but the technology needs to be managed properly.

He said the improved yield of PVL02 over PVL01 will probably persuade farmers to consider the new option.

“In 2021, I expect to see a lot more Provisia planted, but you can’t get careless with it,” he said. “You have to address problems immediately.”

He said escapes have to be removed as soon as they appear, and farmers should avoid back-to-back years of planting Provisia just like the advisory for Clearfield stressed rotating other varieties and crops.

Webster said he recommends a third application of the Provisia herbicide to control late-season problems. Provisia is limited to 31 ounces per season, so that amounts to three applications of 10 ounces per acre, he said.

He said his work also involves controlling late and early weed problems with Provisia.

Webster is also studying weed control methods with the row rice system at the AgCenter H. Rouse Caffey Rice Research Station and at the St. Joseph Research Station. Webster said the lack of standing water brings new weed problems found in a dryland setting, but most rice herbicides were developed for a flood. More goosegrass, johnsongrass and pigweeds are likely with rice grown in an upland system, he said.

Webster’s research also included more work on the Loyant herbicide, and that included applying the herbicide on urea fertilizer. Although that technique is not as effective as applying the chemical in a spray, it does prevent drift problems.

Webster said more growers are returning to conventional varieties because of lower seed costs and because Clearfield has reduced effectiveness, and they are using water seeding for the weed control.

He said fimbristylis, a sedgelike weed, became more widespread in rice fields in 2020, and controlling that weed is best achieved with herbicides such as propanil and Basagran.

“It tends to be more of an early season problem,” he said.

Weed research photoJPG

Eric Webster, second from right, and his crew place rings in test plots used to study the herbicide Loyant on aquatic weeds. Shown in the water are, left to right, students Connor Webster and David Walker, Webster and student Sam Rustom. Near the trailer, left to right, are John Sonnier, student Bradley Greer and Meera Patel.

11/24/2020 10:20:13 PM
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