Efficacy of Ignite and Flexstar Tank Mixtures on Giant Ragweed and Common Lambsquarters

Abstract

Control of giant ragweed and common lambsquarters, two commonly found broadleaf weeds in the Eastern corn-belt, is erratic with glyphosate. Field experiments were conducted to determine the effects of Ignite and five rates of Flexstar alone or in combination on 8- to 12-inch-tall giant ragweed and 5- to 8inch-tall common lambsquarters. At 21 days after treatment, an increase in the rate of Flexstar alone from 4 to 21 fl oz/acre increased the suppression of giant ragweed and common lambsquarters from 33 to 84% and 0 to 16%, respectively. Height reduction from applications of Ignite at 24 fl oz/acre alone or in tank mixtures with all rates of Flexstar was greater than 92% for giant ragweed, but only 70 to 87% for common lambsquarters. Ignite alone or tank mixed with Flexstar can be an effective management tool for control of glyphosate-resistant giant ragweed in Liberty-Link soybean, but not common lambsquarters. A preemergence residual herbicide should be included to improve control of common lambsquarters.