CORESTA Meeting, Agronomy/Phytopathology, 2019, Victoria Falls, AP 21

Evaluations of rimsulfuron application timing and rate in flue-cured tobacco

North Carolina State University, Department of Crop & Soil Sciences, Raleigh, NC, U.S.A.

Field studies were conducted from 2016 through 2018 to evaluate flue-cured tobacco response to rimsulfuron application timing and rate (17 and 34 g a.i. ha-1). Additionally, weed control was evaluated in combination with current recommended herbicide programs for flue-cured tobacco production. Depending on rate, visual injury ranged from 6 to 33 % across environments when rimsulfuron was applied postemergence over-the-top (POT) three weeks after transplanting (WAT). By six WAT no visual injury was observed and there were no differences in yield, quality, or value of cured-leaf when compared to tobacco receiving only clomazone plus sulfentrazone pre-transplant (PRE-T). No injury was observed for any PRE-T or post-directed (PD) at lay-by application containing rimsulfuron. When applied PD, rimsulfuron performed similar to pendimethlain and napropamide for Palmer amaranth (Amaranthus palmerii) and grass control (Digitaria sanguinalis, Eleusine indica, and Echinochloa crus-galli), while providing slightly greater control of yellow nutsedge (Cyperus esculentus). These results indicate rimsulfuron did not adversely affect yield components of flue-cured tobacco. However, due to potential early season injury, POT applications of rimsulfuron will not be recommended. The addition of rimsufluron, PRE-T and PD, would provide flue-cured tobacco growers with additional options for weed control.