LSU AgCenter weed scientists will not include new herbicide technologies in the AgCenter’s 2018 weed control guide.

Cotton and soybean varieties tolerant to the herbicides dicamba and 2,4-D became available to farmers last year.

The LSU AgCenter is evaluating the yield potential of both Xtend cotton and soybean lines and Enlist cotton lines in official variety trials and core block on-farm demonstrations. AgCenter researchers said several varieties expressing these herbicide-resistant traits have performed very well in trials and on farms. The researchers included that information in publications on cotton and soybean variety performance. 

AgCenter weed scientist Daniel Stephenson said other standard herbicide programs, including glyphosate, can still be used on these new herbicide-resistant corn and cotton technologies, but the AgCenter currently is not recommending the statewide use of weed management programs containing dicamba in Xtend cotton and soybean varieties or 2,4-D in Enlist cotton varieties.

Stephenson said the AgCenter weed science program requires a minimum of two consecutive years of product or system evaluation before a decision is rendered as to the utility of that product or system.

“Although we have two years of data for some formulations, we do not have sufficient data concerning the dicamba formulations, XtendiMax with VaporGrip or FeXapan,” he said, adding, “Programs containing either dicamba in Xtend cotton or soybean or 2,4-D in Enlist cotton, regardless of the herbicide formulation, will not be listed in the LSU AgCenter’s 2018 Louisiana Suggested Chemical Weed Management Guide.”

Related:10 things to know about dicamba

Stephenson said he hopes to have sufficient data to allow a decision concerning their utility in the future.

“Regardless of the herbicide-tolerant technology used, LSU AgCenter weed scientists will assist Louisiana crop producers, agricultural consultants and industry personnel with determining a best-fit weed management program that does not contain either dicamba or 2,4-D,” he said.

Stephenson emphasized that anyone planning to use these herbicides on the cotton or soybean technology must be trained in an educational program approved by the Louisiana Department of Agriculture and Forestry. They also must strictly follow the product label and tank clean-out procedures to prevent tank contamination.

While AgCenter weed scientists are not suggesting the statewide use of weed management programs containing dicamba or 2,4-D, Stephenson said he recognizes there may be situations where a dicamba application in Xtend crops or a 2,4-D application in Enlist cotton is needed to alleviate a severe issue.

Related:5 tips to limit off-site dicamba movement

“We reserve the right to use our preliminary data to assist a Louisiana producer in potentially rectifying any severe problems with weed escapes or in those situations where weed resistance dictates alternative control measures,” he said.

Anyone with concerns or questions can contact Stephenson at (318) 308-7225 or weed scientist Donnie Miller at (318) 614-4044.