Interseeded Winter Annual Rye in Dry Bean Cropping Systems

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 lower-most 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.