EVALUATION OF HERBICIDES FOR WEED MANAGEMENT IN MAIZE AND THEIR IMPACT ON MAIZE GRAIN YIELD

Different herbicides were evaluated against the hand weeding and weedy check, for weed competition and grain yield of maize. The experiment was carried out at the Agricultural Research Institute (Tarnab) Peshawar, during the maize growing season 2009. The experiment was laid out in randomized complete block design with three replications using the maize variety “Azam” with a seed rate of28 kgha-1 . Seven different herbicides were applied at their recommended rates. The treatments applied were atrazine + s-metolachlor (Primextra Gold 720SC as standard), atrazine (Atarazine 38 SC as standard), s- metolachlor (Dual gold 960 EC as stand.), atrazine + propisochlor (Weed out 720SC as candidate), butachlor (Client 90% EC as cand.), acetochlor (Appeal 99% EC as cand.), acetochlor (Acetor 50% EC as cand.), a hand weeding and a weedy check treatment. Data was collected on weed density m-2, mortality percentage, fresh weed biomass, maize grain yield and grain yield. All the treatments significantly affected the checked parameters. The hand weeding treatment has been mostly successful in all parameters however it was overtaken by Primextra gold 720 SC in the cost benefit ratio. Like the hand weeding treatment, all the herbicides considerably affected weeds density and reduced their population to a significant level as compared to the weedy check treatments. Luckily, no crop injury was observed in any of the herbicide treatments. The mortality percentage of weeds ranged between 74.94 – 81.84%, whereas hand weeding showed 97.2%. Acetor 50% EC and Primextra gold 720SC showed the best performance in weeds mortality percentage. Similarly, the weed biomass in the herbicide treatments ranged between 1032 – 1416 kg ha-1. However, lowest weed biomass was found in hand weeding and highest in weedy check treatments. Highest grain yield of maize was achieved in hand weeding and in contrary lowest grain yield in weedy control plots. The overall increase in yield by the herbicides over weedy control was found from 13.94 to 22.08%. Herbicides thus by reducing the weed density and biomass increased the grain yield of maize. Hand weeded treatments fetched highest gross income and added income followed by Acetor 50EC and Primextra gold 720 SC treatments. However, maximum CBR was calculated for Primextra gold 720SC followed by Acetor 50EC and Atrazine 38 SC treatments. The CBR calculated in the hand weeded treatments was though the lowest. Primextra gold 720 SC and Acetor 50 EC are therefore recommended for effective weed control as pre emergence and post emergence herbicide respectively for maize economic yield in Peshawar valley.