Corn lodging, during rapid vegetative growth just before pollination, is not a welcome site. No surprise, it generally follows a storm front that has moved through the area. Shallow roots (e.g., compaction), soggy soils coupled with high winds, rootworm feeding, etc, can solely, or be combined, cause significant damage. To properly assess, go to a damaged area, dig up roots with a shovel, clean off the soil, and evaluate. Rootworm feeding scars are noticeable by the brown discoloration anywhere on the root system. This damage alone is not likely to reduce the root’s anchoring ability. Root pruning, especially whole nodes missing, would likely implicate rootworm for the lodging. This video will contrast two root systems with rootworm damage, representing significant and minor feeding.
Another give-away, is the density of rootworm beetles flying about as you enter the field. If you are finding bunches of western corn rootworm beetles in lodged fields, and Bt-RW corn was planted, please contact your seed company personnel. Plants should be tested for the presence of the appropriate Bt protein. If testing positive for the protein, we would be quite interested to collect beetles for Bt-trait resistance testing. Please contact us at 765-494-563.