University of Illinois

No. 15/July 3, 1997

Concern about Exceed Carryover

Exceed (primisulfuron + prosulfuron) has persisted and injured a follow crop of soybeans. The circumstances usually involved are high soil pH, overlaps (especially along headlands), and droughty conditions the year of application.

The 1997 Exceed label contains changes regarding minimizing carryover injury to soybeans, such as:

  1. If Exceed is applied after June 30 or if severe droughty conditions develop within 6 months following Exceed application, only soybean varieties with enhanced tolerance to sulfonlyurea herbicides (STS soybeans) may be planted the following season.

  2. High soil pH (7.8 or higher): Only corn, sorghum, or small grains may be planted the following season. Do not plant even STS soybeans.

Marshal McGlamery and Aaron Hager, Department of Crop Sciences, (217)333-4424