Herbicide reduction in metribuzin-based weed control programs in corn

The relative effectiveness of 13 metribuzin-based weed control programs in field corn was investigated in a 3-yr study. Reduction in herbicide rates was made by modifying some commonly used metribuzin-based herbicide programs for weed control in corn. Satisfactory weed control, corn yield and economic return were obtained under each herbicide treatment, suggesting that reduction in herbicide use to reduce environmental hazard and enhance the economical benefit is achievable. Among the various herbicide programs, banded herbicide application at reduced rates plus one cultivation was observed to be the most economic weed management practice. Herbicides applied early (2–3 leaves) showed better results than those applied later (6–7 leaves) in the development stage of corn, although both times of application are within the critical period of weed control for corn. Key words: Corn (Zea mays), economic return, herbicides, weed control