What is LAI? Leaf area index (LAI) is the ratio of leaf area to land area. Soybean requires LAI values of at least 3.5 to 4.0 by early to mid-reproductive developmental stages to achieve maximum yield for that year and environment. A soybean crop that does not achieve adequate LAI could be at risk to yield loss from insect leaf-feeders, whereas, fields with high (4+) LAI can sustain significant insect feeding with little to no effect on yield. This publication will aid producers in evaluating soybean fields at risk to yield reduction from leaf-feeding insects.

Slugs cause significant economic injury to corn and soybean crops in Virginia every year. Symptoms of slug feeding will vary depending on the size or the growth stage of the crop, and the size of the slug. In corn, slug damage is typically limited to defoliation of emerging leaves.