Weed Suppression, White Mold Incidence, and Snap Bean Yield in Fall and Spring-planted Cover Crop Residue Systems: Part 1 (1994)

Report to the Oregon Processed Vegetable Commission

Ed Peachey, Ray Williams, and John Luna
OSU Dept. of Horticulture


Limited herbicide options and the tentative state of registration for Ronilan fungicide in snap bean production require development of additional management strategies for suppression of weeds and white mold (Sclerotinia sclerotiorum) in snap bean production. One possibility employs cereal residues derived from cover crops. Cereal cover crop residues left on the soil effectively suppress many small-seeded, annual weeds through allelopathy and mulch barriers. In addition, several compounds have been isolated from cereals that have antiftmgal properties. These compounds, coupled with other influences of the cereal residue, may reduce the effect of disease organisms in vegetable production systems. In 1993, minimum tillage and cover crop residues significantly reduced white mold incidence with little or no effect on crop yield. The objectives of this research were to evaluate weed suppression, white mold incidence, and snap bean yield in reduced tillage systems with two cereal residue management options.