EFFECT OF DIQUAT, PARAQUAT AND GLYPHOSATE ON PREHARVEST DRYING OF WHEAT

Abstract

Three chemicals, each applied at two rates, were evaluated for use as preharvest desiccants in Neepawa wheat (Triticum aestivum L.) over 3 yr. Diquat and paraquat were tested at rates of 0.2 and 0.4 kg/ha, while glyphosate was applied at 0.5 and 1.0 kg/ha. The rates of drying of the grain and straw in desiccant-treated plots were compared with those of untreated standing and windrowed controls. Precipitation differed during the sampling period in each year, but did not influence the effectiveness of the desiccants. Rate of drying of both grain and straw was highest in the windrowed treatment. None of the chemical desiccants, applied when grain moisture content was 43% or less, reduced grain or straw moisture faster than the untreated standing control in any of the 3 yr.