ANNUAL WEED CONTROL WITH PARAQUAT IN COMBINATION WITH OTHER HERBICIDES
Paraquat at 0.28 kg/ha effectively controlled barley (Hordeum vulgare L. ’Galt’), wheat (Triticum aestivum L. ’Neepawa’) and oat (Avena sativa L. ’Random’) in field trials conducted during 1982 and 1983. Grass control was excellent with paraquat and its activity was unaffected when it was applied in combination with either clopyralid, picloram, metribuzin, linuron, or chlorsulfuron. Slight reductions in paraquat phytotoxicity occurred in some instances when paraquat was applied in combination with commercially formulated mixtured of clopyralid plus 2,4-D, clopyralid plus MCPA or picloram plus 2,4-D, but grass control was still acceptable (90% or greater). However, a commercially formulated mixture of cyanazine plus MCPA consistently reduced the phytotoxicity of paraquat and rendered grass control unacceptable. Control of rapeseed (Brassica campestris L. ’Candle’) with paraquat and most paraquat mixtures was excellent in 1982 but was poor and variable in 1983.Key words: Wheat, barley, oat, rapeseed, zero tillage, chemical summerfallow