Effect of Application Timing on Winter Wheat Response to Metribuzin

Abstract

Metribuzin will control many problematic weed species in winter wheat in the mid-Atlantic states, including herbicide-resistant biotypes, but it has not been recommended due to crop safety concerns. In a three-year trial, metribuzin was applied at 105 or 210 g ai ha−1to wheat at the PRE, 2-leaf (Feekes stage 1 to 2), early spring (Feekes stage 3 to 4), and late spring (Feekes stage 4 to 6) growth stages using wheat cultivars sensitive to metribuzin. Early spring applications had the least amount of injury, and injury at this timing was transient and yield was not reduced. Yield loss was observed with the other application timings in at least one out of three years. Rainfall shortly after application appears to increase the risk of wheat injury.