Part 2, Section 1: Pest Management

Table of Contents

Pest Management

Weed Management

Definition of a weed

A weed is a plant out of place not intentionally sown, whose undesirable qualities outweigh its good points. Some crop plants even can become weeds when they grow where they are not wanted. In contrast, a number of plants usually thought of as weeds may actually be helpful in controlling erosion or serving as food for wild animals and birds.

Weeds are troublesome in many ways. They reduce crop yield by robbing water, light, space, and soil nutrients. Weeds can produce allelopathic substances that are toxic to crop plants. Weeds often serve as hosts for crop diseases; they also may provide shelter for insects and diseases to overwinter. Some weeds, such as wild garlic or eastern black nightshade, detract from the quality of a crop. To plan an effective weed management program, a producer must be able to identify weeds present and understand how weed biology affects where weeds are found and their relative competitiveness.