Evaluation of non-labeled herbicides in cotton production in Mississippi

Weed resistance has decreased the number of herbicides that provide effective weed control in cotton. Studies were conducted to determine weed control efficacy and crop safety in cotton with herbicides not currently labeled for use in the crop. Herbicides were applied at two different timings near Starkville and Brooksville, MS. Cotton injury following application of ametryn, bentazon, florpyrauxifen-benzyl, topramezone and tolpyralate at the 3-5 or the 8-10 node growth stage ranged from 24 to 43% and 15 to 51%, respectively, up to 56 days after application. Except for bentazon, applying non-labeled herbicides to cotton at the 3-5 or 8-10 node growth stage decreased seedcotton yield 25 to 44%. Application of bentazon had no effect on yield when applied to cotton at both growth stages and may need to be further evaluated for use in cotton