Timing Kerb Applications in Lettuce

Abstract

Kerb (Pronamide) is often ineffective when it is leached below germinating weed seeds with sprinkler irrigation. Efficacy can be improved by making delayed aerial applications after the sprinklers have been started and before weeds have become established. Tests were conducted to determine the optimal time of application. Optimal times varied with the season and ranged from two to three days after the sprinklers had started during the early season (Sept.) to five to six days during the late season (January).