Evaluating the Effect of Biological Control and Planting Mixed Varieties to Manage Whitefly and Aphid Pests in Organic Squash

View the project final report

Commodities

• Vegetables: cucurbits

Practices

• Crop Production: intercropping
• Education and Training: on-farm/ranch research
• Natural Resources/Environment: habitat enhancement
• Pest Management: biological control, integrated pest management
• Production Systems: organic agriculture

Zucchini squash, Cucurbita pepo L., is a high value vegetable crop in Florida. Damage from aphid and whitefly pests are major problems for many growers around the state. Information on organic pest management, particularly the efficacy of products and strategies available, is very limited and sometimes unavailable for many growers. The purpose of this study was to evaluate the biological control agent Amblyseius swirskii in a diversified planting system to determine their effectiveness in managing aphids and whiteflies in organic squash. The specific objectives were to 1) evaluate the effect of planting multiple varieties of squash on arthropod pests and disease incidence compared with pure stands of a single squash variety, and 2) determine the effect of intercropping sweet alyssum with squash on arthropod pests and natural enemy populations. The experiment was conducted on a certified organic farm. The experimental design was 2×2 factorial plot design with four replicates evaluating 1) single squash variety planting vs. mixed squash variety planting, and 2) the effect of sweet alyssum on pest and natural enemy populations. Amblyseius swirskii was released into the experimental plots, and experimental treatments were compared to a grower’s standard control of mixed squash variety planting with no biological control or companion plant. Whitefly pressure was observed to be greatest in single variety plantings of squash, and there were fewer immature whiteflies observed on squash plants intercropped with sweet alyssum in both single variety and mixed variety plantings. Physiological disorders were also higher in the single variety plantings. Orius and A. swirskii populations were greater on squash in the single variety plantings. Mixed variety plantings and intercropping with sweet alyssum could be effective at reducing pest populations and pest symptoms on squash plants.

The overall purpose of this study was to evaluate the biological control agent Amblyseius swirskii in a diversified planting system to determine their effectiveness in managing aphids and whiteflies in organic squash.
The specific objectives were to 1) evaluate the effect of planting multiple varieties of squash on arthropod pests and disease incidence compared with pure stands of a single squash variety, and 2) determine the effect of intercropping sweet alyssum with squash on arthropod pests and natural enemy populations. This project will aid in identifying reduced-risk tools that are compatible with beneficial insects and contribute to developing a comprehensive IPM program for controlling economic pests of organic squash.