Benefits - Drawbacks of Various Winter Cover Crops in Vegetable Pest Management

Benefits - Drawbacks of Various Winter Cover Crops in Vegetable Pest Management

Summary

This project will study interactions between cover crops and selected beneficial and pest insects and arthropods. Targeted pests are tarnished plant bug and potato leafhopper, which are known to move from cover crops to main season crops, and the wireworm complex, which may be managed using cover crops. Additionally, the project will incorporate studies the interactions between cover crops and soil-dwelling bacteria, both in terms of plant health and managing wireworms.

Objectives
1. Measure the density of selected insect pests and generalist arthropod predators over time in seven winter cover crops in the field. Determine what effects cover crop management might have on their survival and on movement out of the cover crop.

2. Evaluate the growth and survival of wireworms on roots of cover crops in the laboratory, and determine the effect of cover crop residues incorporate into field soil on their growth and survival.

3. Examine the effect of winter cover crops on diversity of plant-growth-promoting bacteria and deleterious bacteria in the rhizosphere of the cover crop and on the subsequent crops.

4. Isolate bacteria associated with wireworm mortality and examine their effects on plant root health.

Project description
Winter cover crops improve the sustainability of vegetable farms in the Northeast on their beneficial effects on soil quality and nutrient management. They may also assist in pest management, through favorable effects on natural enemies of pests, negative effects on the pest species, or direct effects on the health of the soil and plant. However, there are also examples of interactions in which a cover crop may increase insect pest or pathogen populations, causing damage on the subsequent crop. Research on these interactions is needed, so that more specific information can be available to growers.
We plan to examine a range of winter cover crops available in the Northeast, and their interactions with selected beneficial and pest organisms. We will grow seven cover crops in the field and survey arthropods through the fall, winter and spring. In these surveys, we will focus on generalist arthropod predators, and on two insect pests known to move from cover crops onto main season crops: the tarnished plant bug and the potato leafhopper. We will also study the wireworm complex, a group of below-ground insect pests with a multi-year life cycle that may be managed using cover crops.
At the same time, we will assay soil samples for the presence of plant-growth-promoting bacteria and deleterious bacteria. We will examine the possible role of plant-growth-promoting Pseudomonas species in controlling wireworms.

Approved March 2000.

Collaborators: