Interseeded Winter Annual Rye in Dry Bean Cropping Systems

Abstract

Public concern over herbicide contamination of water, surfactant effects on amphibians, and herbicide-resistant weeds has led to increased interest in alternative weed-control systems. In addition, direct-cut harvest-associated yield losses of dry bean (Phaseolus vulgaris L.) are of concern to some growers. Often there is difficulty operating combine mechanisms near soil surfaces to reach the lowermost bean pods. The objectives of this study were to evaluate the utility of an interseeded spring-planted rye (Secale cereale L.) cover for: (a) weed suppression and (b) elongation of dry bean stems to raise lower pod heights and facilitate direct-cut harvest. We hypothesized that a rye cover would suppress weeds and shade dry bean plants, resulting in a stem elongation response. Overall, interseeded rye cover reduced dry bean yields, above-ground biomass, and plant heights. Rye cover also suppressed above-ground weed biomass in several instances. However, despite overall reductions in dry bean-plant vigor, treatments including rye cover resulted in significantly greater heights of lowermost dry bean-pod attachment, indicating the presence of a stem elongation effect.