EFFECT OF WILD MUSTARD (BRASSICA KABER) COMPETITION ON YIELD AND QUALITY OF TRIAZINE-TOLERANT AND TRIAZINE-SUSCEPTIBLE CANOLA (BRASSICA-NAPUS AND BRASSICA-RAPA)

Research was conducted at two sites near Brandon, Manitoba, in 1990 an d 1991 to determine the influence of time of removal of wild mustard f rom triazine-tolerant (TT) or triazine-susceptible (TS) canola and the effects of wild mustard seed contamination on canola seed yield and o il characteristics. Wild mustard was removed by either cyanazine or et hametsulfuron at the two-to-four-leaf or the four-to-eight-leaf stage of wild mustard in each of six canola cultivars. Wild mustard decrease d harvested seed yield of canola, and the presence of wild mustard see d in harvested canola seeds increased meal glucosinolate content compa red with that of the weed-free check. Canola yield was greater than th at of the untreated check when wild mustard was removed at either the two-to-four-leaf or the four-to-eight-leaf stage. Canola seed yield wa s reduced compared with that of the weed-free check when wild mustard was allowed to compete with canola until the four-to-eight-leaf stage. Meal protein content was decreased by either wild mustard competition or the presence of wild mustard seed in the samples in 1991 but not i n 1990. Canola seed samples contaminated with wild mustard seed had re duced oil and oleic acid content at both sites. Wild mustard competiti on reduced canola oil and oleic acid content of the two TT cultivars m ore than it did those of TS cultivars. The presence of wild mustard se ed (but not interference from wild mustard) increased the linolenic an d erucic acid content of the extracted oil.