Development and Evaluation of IPM Systems Components for Insect Pests and Pathogens of Cucurbit Crops in the Southeastern U.S.

View the project final report

Commodities

• Vegetables: cucurbits

Practices

• Crop Production: pollination
• Pest Management: biological control, chemical control, integrated pest management, mulches - general, precision herbicide use

Managing insects in cucurbit crops is a longstanding challenge due to conflicting needs of intense pest management and strong pollination services. The cucurbit pest complex is notoriously problematic because it includes insects that inflict considerable feeding damage and are also vectors of pathogens that threaten total crop loss. Intense broad-spectrum pesticide use can harm predatory insects and pollinators that are critical for profitable yields. Stronger cultural tools and more selective insecticides are needed to limit pest pressure and conserve ecosystem services by beneficial insects. Colored and reflective mulches are commonly employed to promote plant growth and repel herbivores, but their effects on predator and pollinator attraction are unclear. Likewise, living mulches planted between plastic-mulched rows may buffer the effects of insecticide applications on beneficial insects by providing refuge habitat. However, ecosystem services and potential disservices associated with living mulches in conventionally-managed systems are not well-documented, and for that reason, they are rarely incorporated in conventional vegetable production. To that end, we propose a research project and a series of experiments manipulating colored mulches, living mulches, and applications of broad spectrum and selective insecticides across three Southeastern states. We will develop novel cultural tools that better harmonize chemical and biological control, and evaluate their utility in an economic framework that balances risks, costs and benefits in each system. We will also demonstrate and deploy these tools by engaging with growers in workshops, field days, and grower conferences across the Southeast.

Objective 1. Quantify mulch-mediated impacts on:

1a) flower production patterns, fruit set, fruit weight, and yields. (VA team-Kuhar and Alford, VA Grower- Hill)

1b) the incidence and timing of common cucurbit pests/arthropod vectored disease, abundance and diversity of natural enemies, and pollinators. (VA team-Kuhar and Alford, VA Grower- Hill)

Objective 2. Harmonize chemical and biological control by integrating plasticulture with living mulches and threshold-based pesticide applications (VA team-Kuhar and Alford, NC team-Walgenbach, SC team-Blubaugh, VA Grower- Hill, NC Grower- Davis)

Objective 3. Assess the impact of:

3a) colored, reflective, and living mulches, (VA team-Kuhar and Alford, NC team-Walgenbach, SC team-Blubaugh, VA Grower- Hill, NC Grower- Davis)

3b) conventional and reduced risk pesticide exposure, (VA team-Kuhar and Alford, NC team-Walgenbach, SC team-Blubaugh, VA Grower- Hill)

3c) augmentative releases (VA team-Kuhar and Alford, NC team-Walgenbach, SC team-Blubaugh, SC grower- Sermons, NC Grower- Davis)

on the parasitizing ability of Gryon pennsylvanicum on squash bug egg masses.

Objective 4. Estimate the economics of different plastic mulch colors, living mulches between beds, and reduced risk pesticides (VA team-Alford)