Abstract:
The field experiment was carried out to study the effect of different weed control treatments namely; manual hoeing, wheat straw mulching at 6 t ha-1, acetachlor at 125 g a.i. ha-1 and pendimethalin+prometryne at 875 g a.i. ha-1 along with a weedy check under ridge and flat sowing, on weed growth and yield of cotton during the year 2007 and 2008. The density of the weeds under study was decreased significantly with all weed control treatments compared with weedy check and weed control efficiency varied from 32.27 to 73.55%, 54.61 to 7.28%, 16.38 to 72.88% and 28.21 to 59.60% for Cyperus rotundus, Trianthema portulacastrum, Convolvulus. arvensis and Cynodon dactylon at early growth stages. The number of monopodial and sympodial branches and mature bolls per plant, seed weight and seed cotton yield was also increased with
all weed control practices over weedy check. Pendimethalin+prometryne @ 875 g a.i. ha-1 resulted in significantly the maximum seed cotton yield of 2249.18 kg ha-1. Among sowing methods, ridge sowing was the better method in terms of controlling weeds, reducing dry weight of weeds, increasing monopodial and sympodial branches per plant, total number of bolls per plant, number of mature bolls per plant, seed cotton weight and seed cotton yield. To obtain maximum seed cotton yield and net returns in cotton, pendimethalin + prometryne @ 875 g ha-1 applied to control weeds and cotton should be sown on ridges under agro ecological conditions of Faisalabad, Pakistan.
