Cheat (Bromus secalinus) control with herbicides applied to mature seeds.
Several herbicides were evaluated as seed-applied treatments to determine the feasibility of controlling cheat (B. secalinus) by applying herbicide directly onto the cheat seeds during the wheat harvesting process and returning the treated seeds to the field (Oklahoma, USA, in 1995 and 1996). Seed-applied trifluralin reduced cheat emergence 80% in exploratory evaluations. In herbicide-seed mixing time and spray volume experiments, short mixing times were adequate, and spray volumes from 113 to 227 ml/kg seeds did not affect results. Herbicides applied with a sprayer-equipped auger reduced cheat emergence > 90% and were as effective as herbicides applied with a rotary drum seed-treater. Increasing spray volume increased the efficacy of auger-applied treatments. Adjuvants did not improve the efficacy of seed-applied trifluralin.