Effect of cultivar selection on metribuzin efficacy in field pea (Pisum sativum)
Field studies were conducted at Morden, Manitoba from 1993 to 1995 to investigate the effect of cultivar selection on the effectiveness of metribuzin {4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one} for wild mustard control in field pea. In check plots, Titan, a cultivar with long vines, suppressed wild mustard growth more than Trump, a cultivar with short vines Wild mustard control with metribuzin was more consistent in Titan than in Trump. Metribuzin at 140 g ha−1 (half the full label rate) reduced wild mustard dry weight by 75 to 99% in plots seeded to Titan and by 38 to 88% in plots seeded to Trump. Results suggest that less herbicide is required for weed management in more competitive field pea cultivars. Key words: Cultivars, competitiveness, metribuzin, wild mustard, Sinapis arvensis, yield