Glyphosate as Harvest Aid for Corn (Zea mays)

Abstract

Glyphosate was evaluated as a preharvest treatment for enhancing corn kernel dry down and quackgrass control. Glyphosate at 0.4, 0.8, 1.3, and 1.7 kg ae/ha was applied to corn before physiological maturity (kernel moisture 44 to 47%) and at physiological maturity (kernel moisture 35 to 39%). Three weeks after treatment, grain moisture of plants treated at physiological maturity was 2.3 to 6.9% less than that of plants treated before physiological maturity which was 2.2 to 5.5% less than that of untreated plants. Glyphosate did not increase corn kernel drying effectively under high humidity conditions. Glyphosate applied to pre-physiologically-mature corn controlled quackgrass 49 to 64% in the fall of 1984 and 69 to 91% in the fall of 1985. None of the glyphosate treatments reduced corn yield. Glyphosate applied preharvest above the corn canopy may increase the rate of corn kernel drying and may control fall quackgrass in the northern corn belt.