Effects of Hairy Vetch (Vicia villosa) Cover Crop and Banded Herbicides on Weeds, Grain Yield, and Economic Returns in Corn (Zea mays)

Abstract

ABSTRACT A two-year field study was conducted during 2002-2003 on a Dundee silt loam soil, Stoneville, MS, to examine the effects of hairy vetch cover crop (HV-D, hairy vetch desiccated at corn planting; HV-B, hairy vetch desiccated in a 38-cm band over crop row at corn planting; and no hairy vetch) and preemergence (PRE) plus postemergence (POST) herbicides applied broadcast and banded on weed control, yield, and economic return in corn. Atrazine plus metolachlor were applied PRE and POST. Bentazon in 2002 and carfentrazone in 2003 were applied in mixture with atrazine plus metolachlor POST. More hairy vetch dry biomass was present in the HV-B system (2,941 kg/ha) than in the HV-D (1,397 kg/ha) and no hairy vetch (0 kg/ha) systems at 7 wk after planting corn (WAP). Live and desiccated hairy vetch in HV-B and HV-D systems suppressed pitted morning glory compared with no hairy vetch at 7 WAP. Densities of barnyardgrass, carpetweed, smooth pigweed, or yellow nutsedge were not reduced in HV-D and HV-B systems compared with no hairy vetch. Hairy vetch cover crop residue in HV-D and HV-B systems had no effect on total weed dry biomass at 7 WAP compared with no hairy vetch. Corn yields were higher in the HV-D system, regardless of herbicide treatment, and the HV-B with broadcast-applied PRE plus POST herbicide treatment compared with no hairy vetch treatments in 2003. Corn yields were similar with band- and broadcast-applied PRE plus POST herbicides when no hairy vetch or all hairy vetch was desiccated at planting (HV-D). Higher costs associated with hairy vetch were offset by higher corn yields in the HV-D system compared with no hairy vetch in 2003, as net returns were similar in both systems. Applying PRE plus POST herbicides in a band resulted in similar net returns as broadcast herbicide application in the no hairy vetch and HV-D systems. These findings indicate that hairy vetch cover crop had little effect on reducing densities of weed species studied, higher costs associated with cover crops can be negated with higher corn yields, and herbicide inputs can be reduced by applying herbicides in a band vs. broadcast without reducing corn yields or economic returns.