Relay cropping system for enhanced biological pest control in dry bean production

Overview

This solution addresses the growing need for sustainable food production by introducing a relay cropping system in which a summer crop (dry bean) is planted into an established winter crop (winter wheat). By growing two crops on the same land in a single season, the approach increases land-use efficiency while creating habitat conditions that favor natural biological control of crop pests. The research specifically targets pests such as the western bean cutworm, which are typically managed through foliar insecticide sprays in dry bean production. By enhancing populations of beneficial predators, the system aims to reduce reliance on chemical controls, supporting integrated pest management (IPM) strategies and more sustainable agronomic practices.

Technical specifications

Research approach and methodology:

• A randomized complete block design (RCBD) study compares four treatments: winter wheat, dry bean, cover crop, and a winter wheat-dry bean relay crop, with four replicates per treatment.
• Weekly vacuum sampling is conducted from the center of each plot to monitor aphid and predator populations.
• Future validation will incorporate vacuum, sweep, and pitfall sampling methods to comprehensively assess predator abundance and diversity across treatments.
• Sentinel prey will be deployed to measure the functional impact of predators on biological control of target pests.

Key findings to date:

• Aphid populations were significantly higher in the relay cropping treatment compared with conventional dry bean monoculture (P<0.05).
• Predator numbers tended to be higher in the relay treatment, though the difference was not statistically significant in initial trials.
• These preliminary results align with published literature suggesting that increased habitat complexity supports natural enemy communities.

Benefits for agricultural stakeholders:

• Reduced dependence on foliar insecticide applications, lowering input costs and supporting resistance management.
• Improved land-use efficiency through dual-cropping in a single growing season.
• Enhanced biological control supporting IPM and sustainable agriculture goals.
• Potential applicability to other cropping systems facing similar pest management challenges.

Technology readiness level

The relay cropping system is currently at an early research and validation stage. Initial proof-of-concept field trials have demonstrated promising trends in predator and aphid population dynamics. A one-year follow-up study is planned to rigorously validate the benefits of relay cropping for biological control using expanded sampling protocols and sentinel prey assessments. Funding is sought to support personnel and equipment needs for this validation phase. The research is positioned to generate publishable findings and practical recommendations for growers within a relatively short timeline, with potential for broader adoption pending successful validation results.