- Agronomic: canola
- Vegetables: broccoli, cabbages, cauliflower, brussel sprouts
- Crop Production: cover crops, intercropping
- Education and Training: demonstration, display, extension, farmer to farmer, focus group, on-farm/ranch research, participatory research
- Farm Business Management: budgets/cost and returns, feasibility study, whole farm planning
- Natural Resources/Environment: biodiversity
- Pest Management: allelopathy, biological control, biorational pesticides, botanical pesticides, field monitoring/scouting, flame, integrated pest management, mulches - killed, mulches - living, prevention, trap crops, traps
- Soil Management: green manures
- Sustainable Communities: sustainability measures
Brassica crops are a major component of mixed vegetable farms in the Pacific Northwest. Crucifer flea beetles, Phyllotreta cruciferae, threaten production of these crops. Feeding by flea beetles kills small plants, sometimes leading to total crop loss, and scars the foliage of plants that survive. The beetles move into fields from surrounding habitats, complicating in-field control efforts. Current control options include using row covers, which are expensive and unwieldy because they block access to the crop, and insecticides, which must be applied frequently as flea beetles continuously move into the crop, which heightens expense and harms the environment. We propose to take advantage of the discovery of allyl isothiocyanate (AITC), which is the specific chemical that CFB uses to find host plants, to draw beetles to trap crops known to produce high levels of AITC. We will also test lures baited with a recently identified CFB aggregation pheromone, flaying the trap crop to heighten release of AITC from foliage and the application of wetted mustard meal that releases AITC to further heighten the attractiveness of the trap crop strips. Flea beetles attracted to the trap crop will then be killed by flaming or tilling under the trap crop or by applying an insect-specific pathogen as a biopesticide. The trap crop and the mustard seed meals will be produced on-farm, replacing chemical and mechanical controls that must be purchased with controls that growers can produce themselves.
Our objectives include the following: identify particularly effective trap crop plants using AITC production from the foliage as our guide; develop effective lures to enhance flea beetles aggregation in the trap crop; look for synergies between specific trap crops and lures; field test and compare strategies to deploy these controls; evaluate the economics of our new flea beetle control strategies and transmit what we learn to growers through an innovative extension program including farm visits hosted by growers. Our farm visits will focus on hands-on learning. In addition to tours of the on-farm research plots guided by grower-cooperators, participants will practice sampling flea beetles; harvest, process, and apply mustard seed meal; and examine results of an economic analysis of our new control techniques. A grower advisory panel is guiding the project, and all of our research will be conducted on the farms of our cooperators. Additional outreach efforts will include development of a project website that includes a worksheet to calculate the costs and benefits of our new controls, extension talks, scientific papers, and other traditional means to reach stakeholders.
Our short-term outcome will be the establishment of new flea beetle control schemes on cooperating farms. These demonstration projects will be used to educate other growers, fostering our medium-range outcome of adoption of some new control approaches on 50% of mixed-vegetable farms in the region. Because nearly all of our local mixed-vegetable growers struggle with flea beetle control, with few or no good control options, this is a reasonable adoption goal. Evaluation of our project will be assessed by our grower advisory panel and through grower questionnaires and interviews. Our proposal addresses Western SARE Goal 1 by fostering profitable sustainable farming while maintaining environmental quality; Goal 2 by allowing growers to switch to on-farm products for pest control, lowering costs and thus increasing income; Goal 3 by reducing the use of toxic materials, optimizing on-farm resources and integrating biological controls; Goal 4 by increasing crop diversification through the addition of trap crops and by restoring growers’ ability to include crucifer crops in their rotations; and Goal 5 by examining the economic impacts of the sustainable pest control options we will examine.
Project objectives from proposal:
Our project will have six central objectives:
1. Determine the varieties of mustard (B. juncea) that produce the highest levels of AITC, the plant chemical that CFB use to locate their host plants, and the size and shape of trap crop plantings most efficient for attracting CFB.
2. Determine whether flaying the trap crop to damage plants and cause release of AITC, or adding mustard seed meals that produce abundant AITC, enhance attraction of CFB.
3. Determine whether releasing CFB aggregation pheromone within the trap crop enhances attraction of CFB to the trap crop.
4. Compare applications of the insect pathogen B. bassiana, flaming and tilling under the crop to kill CFB once they are drawn into the trap crop.
5. Participant interviews will be used to determine economic costs and benefits of traditional versus these new control options. Detailed budgets will be available online in a spreadsheet form that will allow growers to compare among new versus traditional controls.
6. Transmit what we learn to growers through an extension program including farm visits that use hands-on learning as the key training tool; also, transmit information to growers through a wide variety of more traditional outreach strategies to maximize coverage.