By Katie Bohn
Different cover crops may affect how plants can defend themselves against pests — including attracting more insects that eat harmful caterpillars, according to a new study led by researchers at Penn State’s College of Agricultural Sciences.
The research, published in the journal Basic and Applied Ecology, analyzed the effects and resulting trade-offs of different cover crops, which are plants grown between growing seasons to help protect and enrich the soil.
For example, the team found that plants grown in soil previously used by pea cover crops emitted more of the chemical indole, which primes neighboring plants to defend themselves against insects by enhancing the production of stress hormones and defensive chemicals. However, these plants also had lower levels of benzoxazinoid — a natural toxin present in some plants that can act as a pesticide, antifungal and feeding deterrent.
The researchers also found that predator insects preferred to eat caterpillars from corn grown in soil previously occupied by pea cover crops.
Jared Ali, associate professor of entomology, director of the Center for Chemical Ecology and corresponding author on the paper, said the findings offer practical solutions for growers using techniques they’re already familiar with.
Source : psu.edu