Chemical control of downy brome, littleseed canarygrass and green foxtail in rapeseed in southern ıran

Abstract

In order to investigate the effect of herbicide and choice of adjuvant on three grass weed species; downy brome (Bromus tectorum), littleseed canarygrass (Phalaris minor) and green foxtail (Setaria viridis); a greenhouse study was conducted in a factorial experiment laid out in randomized complete block design. Treatments included herbicide at five levels (propaquizafop, fluazifop-p-butyl, cycloxydim, sethoxydim and quizalofop-p-ethyl) each applied at two concentrations and either with/without adjuvant (volck or citoweet). The performance of herbicides and adjuvants was evaluated by rating the effect of treatment on an ordinal scale in each experimental unit at 10 and 20 days after planting (DAP). The results showed that herbicide efficiency rating distributions were significantly different between two times (10 and 20 DPA). Application of quizalofop-p-ethyl and propaquizafop were recorded as the best herbicide treatments in controlling the weeds used in this study 10DAP, however the difference between herbicides faded at 20 DAP. Also, no significant effect was found for concentration of herbicides and type of adjuvant. In addition, 30 days after herbicide application, maximum dry weight and leaf area of canola was recorded for cycloxydim, propaquizafop and quizalofop-pethyl, respectively whereas minimum dry weight and leaf area of canola was observed in pots sprayed with sethoxydim and fluazifop-p-butyl respectively.