Managing Quackgrass Infestations as Cover Crops in Herbicide-Resistant Corn 1999
Project Leaders: N. Gift, R.R. Hahn, and J. Mt. Pleasant, Department of Soil, Crop, and Atmospheric Sciences, Cornell University, Ithaca, NY
Quackgrass (Elytrigia repens (L.) Nevski) is an invasive weed — not normally considered to be a desirable cover crop. However, its high nutritional value makes this weed more tolerable in alfalfa (Medicago sativa L.) than in corn (Zea mays L.). Growers typically attempt to eradicate quackgrass from corn fields, but manage this weed less aggressively in alfalfa, where it contributes to hay quality and yield. The objective of this study was to evaluate herbicides for use in herbicide-resistant corn which could: 1) suppress quackgrass to minimize its effect on corn silage yield, 2) leave adequate quackgrass residue to control erosion (act as a good cover crop), and 3) leave quackgrass as a grass companion crop for alfalfa. In this first year of the study, the weather was unusually dry, and the presence of quackgrass hurt corn yields in all treatments. Quackgrass did, however, provide sufficient ground cover in many of the treatments.