FIELD VALIDATION OF AMMONIUM SULPHATE AS AN ACTIVATOR ADJUVANT ON BROMOXYNIL + MCPA + METRIBUZIN EFFICACY AGAINST MAIZE WEEDS

The use of herbicides is very important for controlling weeds in maize. The efficacy of herbicides can be enhanced with the use of adjuvants. A field experiment was conducted at Agronomic Research Area, University of Agriculture, Faisalabad during autumn 2012 to study the efficacy of bromoxynil + MCPA + metribuzin (Valent-470EW a premixed formulation) with ammonium sulphate as an adjuvant. The experiment comprised of seven treatments namely weedy check, bromoxynil + MCPA + metribuzin @ 1250 mLha^-1 (commercial product dose), 937.5 mL ha^-1 @ 1250 mL ha^-1 + 2% ammonium sulphate, @ 937.5 mLha^-1 + 2% ammonium sulphate @ 1250 mL ha^-1 + 4% ammonium sulphate and @ 937.5 mL ha^-1 + 4% ammonium sulphate. The bromoxynil + MCPA + metribuzin @ 1250 mL ha^-1 + 2% ammonium sulphate gave maximum weed control and minimum dry weight of all weeds. Weed control efficacy was 59-89, 59-100 and 88-100 % for sedges, narrow leaved and broad leaved weeds, respectively. All the yield components, except plant population and number of cobs per plant, were affected significantly and maximum increase in grain yield (66.67%) was achieved by bromoxynil + MCPA + metribuzin @ 1250 mL ha^-1 + 2 % ammonium sulphate.