By Marcelo Dimase and Janice Degni et.al
What was observed
Severe corn rootworm damage is being observed in multiple continuous corn fields in Central New York in 2026. Unexpected root node injury and goosenecking were observed across 22 fields in Onondaga, Cortland, Cayuga, and Madison Counties. Mean node injury scores at the town level ranged from 1.65 to 2.33 based on the Iowa State 0–3 scale (Oleson et al. 2005). A score of 1.0 represents one root node destroyed. A score of 2.0 represents two root nodes destroyed. A score of 3.0 represents three root nodes destroyed. Injury to each root node may correspond to approximately 15% yield loss.
Bt traits confirmed include AMXT, Qrome, Vorceed, and Duracade Viptera technology in the scored fields, which also reported medium-to-high rates of neonicotinoid seed treatment. These observations document injury but, by themselves, do not determine resistance or establish the cause of reduced control. Growers with continuous corn should document root injury, lodging, scout for adults, and establish a plan to manage rootworm pressure in 2027.
Management context
The common thread across many affected fields is repeated corn production, which increases the risk of corn rootworm pressure. These 2026 observations support renewed attention to scouting, rotation, resistance stewardship, and diversified management. Additional scientific testing is needed before attributing injury in any field to resistance.
The following inputs were reported by growers for the scored fields. This information is included for completeness of the record and does not characterize product performance.
Source : cornell.edu