Although the weather this summer feels like we are moving from summer back into summer, the first frosts of fall are approaching, and production for many vegetable fields has run its course. Producers are wrapping up their field season, and that needs to begin with destruction of any crop residues left in fields. Crop residue that remains in the field after harvest provides food for many of the insect pests we have been combating during the summer months. This provides them with needed nutrition and helps them reach critical stages needed to survive winter.
Prompt sanitation of crop residue is a helpful tactic to interrupt the lifecycle of pests. Most insect pests need to reach a specific stage and build energy reserves in preparation for winter; sanitation reduces or eliminates their food, which interferes with their process of getting to these stages. Methods to eliminate crop residue include shredding, disking, and tilling. Examples of insect pests that can be reduced through sanitation include some of our more difficult to manage vegetable pests, such as cabbageworms, squash vine borer, squash bug, stink bugs, Colorado potato beetle, corn earworm, and squash beetle. Timely sanitation can be a very effective pest management tool and can work well with cover cropping in the off-season.
Producers that have planted Bt sweet corn are required to destroy crop residues within 30 days of the end of harvest. This is done to manage corn earworm resistance to the Bt traits in the corn. But this same tactic used to disrupt corn earworm can be used with many other crops to disrupt other pest lifecycles.
By Ric Bessin, Extension Entomologist