Control of Downy Brome (Bromus tectorum) and Volunteer Wheat (Triticum aestivum) in Fallow with Tillage and Pronamide

Abstract

Field studies were conducted in 1986-87 and 1988-89 to compare chiseling, disking, and skewtreading to no-till and to compare 0.3 and 0.4 kg ai ha−1pronamide applied before or after fall tillages for weed control in fallow. Chiseling or disking in October 1986 when weeds were emerged reduced the dry weight of volunteer wheat about 90% the following spring; however, only disking reduced the dry weight of downy brome 90%. Disking or skewtreading in October 1988 before weeds germinated reduced the dry weight of volunteer wheat about 95% 6 mo later, but none of the three tillages reduced the dry weight of downy brome. Pronamide applied at 0.3 and 0.4 kg ha−1to emerged downy brome and volunteer wheat with either chiseling or disking before or after herbicide application reduced the dry weight of both species 90% or more 6 mo later compared with tillage alone. If weeds did not emerge until early November, then only pronamide at 0.4 kg ha−1applied in no-till or after fall tillage controlled both species at least 90%.