Spring-seeded smother plants for weed control in corn and soybean

ABSTRACT:

Considerable interest exists in the development of alternate weed management options. Spring-seeded smother plants may provide an alternative to current weed management practices through management of interplant competition and surface residues. Experiments were conducted in corn and soybeans in 1995 and 1996 at Sioux Center and Ames, IA. Caliph medic, Santiago medic, Sava medic, Berseem clover, and yellow mustard were evaluated as potential smother plants. The smother plants were seeded and incorporated in a 25-cm-wide band over the crop row immediately after crop planting. Weed suppression ranged from 19 to 90% among the smother plant species. The effect of smother plants on corn and soybean yields varied among locations, years, smother plant species, and weed pressure. In some instances, yields with smother plants were equal to weed-free crop;, while at other times yields were as low as the weedy crop. These results imply that smother plants have potential for weed control. However, more research is needed to reduce variability and to gain more insight on biological, management, and competitive interactions among weeds, smother plants, and the harvested crop.