Supporting Natural Enemies of the Cabbage Aphid with Hedgerow Plantings

View the project final report

Commodities

• Vegetables: greens (leafy), kale

Practices

• Education and Training: demonstration
• Natural Resources/Environment: hedgerows
• Pest Management: biological control

Our project seeks to expand the adoption of Conservation Biological Control practices for aphid
management on vegetable farms in northern Utah and the Intermountain West. Most farmers in
the region are faced with significant hurdles in learning and upfront costs required to implement
such practices. Aphid control is a fruitful “introduction” to Conservation Biological Control as
aphids have many natural enemies, and are a persistent problem for vegetable growers. Cabbage
aphid problems in particular have increased in recent years, as more farmers in the region grow
kale and other brassica crops year-round to meet customer demand.
Our project will establish aphid-control hedgerows at six farms, three of which will be used as
demonstration sites. Hedgerows will be evaluated for their potential to attract
natural enemies of cabbage aphid and to reduce aphid damage to cole crops, using associated
control plots (at varying distances from hedgerows) for comparison.
Education and outreach components of the project focus on building knowledge and visibility of
Conservation Biological Control practices at the grassroots level, and on making connections
among urban vegetable growers and the ways they implement Conservation Biological Control strategies in our region. We will extend Conservation Biological Control education and the results of this study to growers throughout
the Intermountain region with USU Extension or other publications, with an emphasis on the cost-benefit analysis of incorporating long-term Conservation Biological Control strategies such as hedgerows for pest control.
Our project attempts to lower the barriers to adoption of Conservation Biological Control
practices by emphasizing 1) that Conservation Biological Control is just formalizing and expanding on practices many farmers are already implementing, 2) Conservation Biological Control plants can be chosen for their direct profit potential (culinary or medicinal herbs, seeds, or bouquets for sale), and 3) the multiple resource conservation benefits of hedgerows specifically (e.g., reducing soil erosion, filtering runoff, preventing weed encroachment).

Objective 1. Evaluate whether hedgerows attract natural enemies of cabbage aphid

Objective 2. Evaluate whether fewer cole crops reach economic loss thresholds with
hedgerows

Objective 3. Use established hedgerows and outcomes of this study (Objectives 1 and 2) to
support broader education goals with Conservation Biological Control through
presentations to urban and small-acreage vegetable farmers.

Objective 4. Encourage grower-to-grower information exchange regarding Conservation
Biological Control with workshops or farm tours at demonstration farm sites.