Submitted to: Leopold Center for Sustainable Agriculture Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: August 20, 1997
Publication Date: N/A
Technical Abstract: Weed management decisions are affected by several factors, including economic and environmental concerns. Spring-seeded smother plants may provide an alternative to current weed management practices through the use of managed competition. Experiments were conducted in corn and soybeans in 1995 and 1996 at Sioux Center and Ames, IA. Five plant species were selected as potential smother plants: Caliph medic, Santiago medic, Sava medic, Berseem clover, and short-cycle brassica. Our primary focus was to understand interspecies competition by evaluating spring-seeded smother plants in corn and soybean. The primary crop/smother plant combinations were planted at early and late dates based on local conditions. The smother plants were seeded and incorporated by hand in a 25 cm wide band over the crop row. Among the observations taken of the smother plants, primary crop, and weeds were density, height, weed shoot biomass, and weed suppression. Weed suppression as percent control compared to weedy checks ranged from 19-90% among the smother plant species. The effect of smother plants on grain yield was variable. These results imply the need for more research focused on the positive interactions in order to gain more insight on biological management and competitive interactions among weeds, smother plants, and the primary crop.