Chemical and Cultural Methods for Downy Brome Control and Yield of Winter Wheat1

Abstract

AbstractDowny brome (Bromus tectorum L.) is difficult to control with stubble mulch fallow. Herbicides effectively control this weeds so combinations of herbicides and stubble mulch fallowing were evaluated. Winter wheat (Triticum aestivum L.) yields from chemical, stubble mulch, and chemical plus stubble mulch fallow systems were obtained from 1960 to 1966 at nitrogen levels of 45, 90, and 134 kg/ha.In the summer fallow year, vegetation was controlled in the chemical plots with a winter treatment of atrazine [(2‐chloro ‐4‐(ethylamino‐)‐6‐(isopropylamino)‐s‐triazine] plus amitrole (3‐amino‐s‐triazole), and the use 2,4‐D [(2,4‐dichlorophenoxy)acetic acid] in the summer. Wheat was seeded directly into nontilled soil. Conventional stubble‐mulch tillage was used for tilled plots. Tillage was initiated in early June in the chemical + stubble mulch plots.Effect of nitrogen rate and fallowing method on wheat yield was inconsistent over the study period. Chemical + stubble mulch fallow was the most consistent treatment. Yields from this treatment were significantly higher than from chemical alone 3 of the 5 years, indicating that tillage often is beneficial in this soil type even when weeds are not a factor.