Effect of weed-control practice and irrigation levels on weeds and yield of wheat (Triticum aestivum)

A field experiment was conducted to study the effect of different weed-control practices and irrigation levels on weeds and yield of wheat (Triticum aestivum L. emend. Fiori & Paol.) in winter 2002–03 and 2003–04 in Pakistan. The experiment comprised four weed-control practices, viz. weedy check, pre-emergence application of pendimethalin, post-emergence application of isoproturon + carfentrazone ethyl and manual weed control (two hoeings), and four irrigation levels, viz. 0.50, 0.75, 1.00 and 1.25 irrigation water (IW): cumulative pan evaporation (CPE). The manual hoeing resulted in minimum weed density and dry weight of weeds, and gave maximum grain yield of 62.46 and 61.45 q/ha due to more spike-bearing tillers, 1,000-grain weight and number of grains/spike, but was statistically similar to post-emergence application of isoproturon + carfentrazone ethyl. The effect of irrigation levels on weed density and dry weight of weeds was non-signifcant in 2002–03 but was significant in 2003–04. The maximum grain yield was obtained at 1.25 IW:CPE.