If you’re relatively new to growing soybeans, you’re likely checking on the crop more often than others. That’s good, of course, as scouting is rarely a waste of time. What you may be seeing at this time of year is leaf damage — insect feeding on leaf margins or in a “shot” hole pattern. What’s causing it and is there anything you can do about it?
To answer that question, Lyndsey Smith, editor of RealAgriculture.com, headed to the field with Terry Buss, with Manitoba Agriculture, Food and Rural Initiatives, to take a look at plant defoliation and insect pest pressure.
In this episode of the Soybean School West, Buss names the three biggest leaf feeders of soybean, how to identify which insect is causing damage by their feeding pattern and how to judge whether or not an insecticide application is warranted. Buss stresses that farmers need to scout thoroughly by pulling plants and assessing the full plant for feeding, as often insect feeding is worst in the upper canopy where it is most visible (and most distressing!). Click this link for a soybean leaflet defoliation scale from Iowa State.