Submitted to: North Central Weed Science Society US Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: December 12, 1996
Publication Date: N/A
Technical Abstract: Weed management decisions are affected by several factors, such as 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 a corn/soybean rotation 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. Weed-free and weedy control plots were established as a standard of comparison. 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. Density, height, weed shoot biomass, and weed suppression were some of the observations taken of the smother plants, primary crop, and weeds. 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. Most of the smother plant treatments have not yielded as high as the weed-free check, with many not differing from the weedy check. These results imply the need for future research focused on the positive aspects in order to gain more valuable input on biological management and competitive interaction among weeds, smother plants, and the primary crop.