- Agronomic: mustard
- Vegetables: brassica group
- Pest Management: integrated pest management, trap crops
- Production Systems: organic agriculture
The proposed project explores the use of an existing concept on 'Banker Plants' in greenhouse IPM, to expand our knowledge and ability to manage the harlequin bug, an important field pest that attacks collard, kale, cabbage, broccoli and other crucifers in the Southeastern U.S. causing severe reduction in market value or death of the plants. The economic impact of this pest can be far-reaching especially among small growers who produce most of the collard and kale found in many U.S. market outlets. Collard, kale and cabbage, like other Brassicaceae, are attacked by an insect pest complex from seedling throughout crop growth. This results in extensive damage that warrants frequent and predictable application of insecticides to keep the pest below economically damaging levels, sometimes resulting in over $1 billion in management costs and crop loss. Cases of resistance by some crucifer pests to all classes of insecticides have been reported in the U.S. and elsewhere. Heightened public concern regarding excess pesticides use on vegetables and the documented negative effects have provided the impetus for increased research to find viable alternatives to pesticide dependence. The proposed research will build on and improve the efficiency of current deployment of mustard trap crops for HB control in the field, as well as provide a footprint for their use in other cropping systems using the banker plant concept -- a greenhouse pest management approach. This will be accomplished by manipulating either the fixed intra-row or movable inter-row establishment of a banker trap crop (pest sink) positioned at different distances within or between main row crops. We will examine the effect of banker trap plants on overall HB attraction to, and retention on, the trap crop by assessing egg number and parasitization, nymphal and adult distribution between trap plants and main crop plants, damage to main crop, and leaf biomass at harvest. The density ratio will be modeled to enable adjustment for use with other pests in this or another agroecosystem thus giving the findings wider pest management application. This approach will reduce the area occupied by the trap crop, especially important in the case of a sacrificial trap crop which has no other value, and also provide the grower the flexibility of having the trap plants always available at the most attractive stage (if the mobile BTraP is adopted). The long-term goal is to reduce insecticide use in vegetable production, increase farm profits while enhancing food and environmental safety as well as well being in farm communities. It will also conserve natural enemies and pollinators. This project models existing knowledge from one area of science (greenhouse biological control) to accomplish a different pest management goal. Its success would hopefully foster enough interest and research on trap crop use to attract increased funding. The project targets small vegetable growers working in different agroecosystems but can be scaled to medium-sized farms. On-farm demonstrations will be established in conjunction with collaborating growers in North Carolina and Virginia.
Project objectives from proposal:
- Using variable plant ratios to conduct laboratory bioassays and greenhouse cage studies to evaluate efficiency of "Banker trap Plants (BTraPs) established at variable fixed simulated intra-row densities using four different mustard varieties to obtain different trap crop:main crop ratios.
- Carry out field evaluation to a) validate the optimal ratios of the lab experiment and then b) determine the effect of the optimal fixed-BTraP ratios from Objective 1 and 2a, compared with movable BTraPs variants on harlequin bug attraction and retention on two recommended mustard trap crops.
- Conduct on-farm validation and the economic sustainability of the two best BTraP deployment systems determined from Objective 2.
- Perform an economic assessment of the various trap crop models in Objective 2 and their deployment in Objective 3 to determine benefit/cost optimization, overall system profitability and which model choice will be the best.