Efficacy evaluation of some dual purpose herbicides to control weeds in maize (Zea mays L.)

Field experiments were conducted in 2005 at 4 locations in Iran, to evaluate maize yield response and control of weeds with nicosulfuron at 40, 60, and 80 g ai/ha, foramsulfuron at 337.5, 450, and 562.5 g ai/ha, rimsulfuron at 5, 7.5, and 10 g ai/ha as dual purpose herbicides, and 2,4-D plus MCPA as reference standard. All herbicides were applied at three- to six-leaf stage of maize. Results indicated that nicosulfuron and foramsulfuron at the highest dose provided satisfactory control of broadleaved and grass weeds in maize. Application of nicosulfuron at 80 g ai/ha resulted in the highest maize yield after the weed-free check. However, 2,4-D plus MCPA plots had the lowest grain yield among all treatments. This could be attributed to the spectrum of weed control with this herbicide, since the grass weeds escaped control where maize was sprayed with 2,4-D plus MCPA.