PLACEMENT OF DI-ALLATE AND TRI-ALLATE FOR CONTROL OF WILD OATS IN WHEAT

Abstract

Two years of field trials at a number of sites in Western Canada showed that selective control of wild oats in wheat with di-allate or tri-allate was feasible if the seed was planted 3 in. deep and the chemicals incorporated shallowly after seeding. The most reliable and practical means of achieving this placement of the chemical was by harrowing immediately after application. Harrowing twice resulted in slightly better wild oat control than harrowing once, but this did not increase crop yields. At one site, in 1962, under conditions of excessive moisture and late seeding, there was severe injury to wheat. However, even here the injury was less with the post-seeding than with the pre-seeding method. There was some evidence that wheat was more tolerant to tri-allate than di-allate. Pre-seeding incorporation with the disk gave slightly better weed control than post-seeding incorporation with a double harrow, but again differences were not great enough to affect yield.