Pendimethalin and Corn Gluten Meal Combinations to Control Turf Weeds

Abstract

Concerns over ground water contamination and other environmental issues have prompted research to reduce synthetic herbicide use. Corn ( Zea mays L.) gluten meal, a by‐product of wet milling, inhibits germination and the establishment of many annual and perennial weed species. Our objective in the field was to investigate crabgrass control ( Digitaria spp.) in Kentucky Bluegrass ( Poa pratensis L.) turf established on a Nicollet soil (fine‐loamy, mixed, mesic Aquic Hapludoll). In the greenhouse, we investigated the control of large crabgrass [ Digitaria sanguinalis (L.) Scop.] on the same soil with no turfgrass cover. Experiments were conducted with corn gluten meal at 0, 49, 98, and 147 g m −2 combined in a factorial arrangement with pendimethalin [ N ‐(1‐ethylpropyl)‐3,4‐dimethyl‐2,6‐dinitrobenzenamine] at 0, 29, 59, 88, and 117 mg ai m −2 . The minimum label rate for pendimethalin is 176 mg ai m −2 . Field crabgrass control was improved by application of a sublethal rate of pendimethalin in addition to corn gluten meal. As the application rate of corn gluten meal increased from 49 to 147 g m −2 , the level of pendimethalin required to provide 75 to 85% control for 15 wk decreased from 88 to 29 mg ai m −2 . There was no increase in crabgrass control in plots that received amounts of corn gluten meal and pendimethalin exceeding these combined rates.