IMPACT OF SORGHUM EXTRACT TYPE, CONCENTRATION AND APPLICATION TIME ON WEEDS DENSITY AND WHEAT YIELD

Traditional weed control methods are laborious, tedious and weather dependent. Weedicides causes contamination of environment, health threats and weed resistant development. Alternative weed management methods are needed to minimized environmental contamination. Therefore, the impact of sorghum water extract on weeds dynamics and wheat yield was evaluated at Agronomy Research Farm, University of Agriculture Peshawar, Pakistan during 2014-15. The experiment was composed of two sorghum extract types (stem and leaf extracts), three extract concentrations (1:3, 1:4 and 1:5 kg L-1) and three application time (emergence, tillering and 50 % at emergence + 50 % at tillering). Herbicides treated, hand weeding and unweeded plots were included for comparison. Herbicides treated plots resulted in fewer weeds (39.0 m-2), more leaf area tiller-1 (114.7 cm2), taller plants (90.2 cm), longer spikes (10.57 cm) and more grain yield (3916.7 kg ha-1) compared to sorghum water extract (SWE) sprayed plots. Among concentrations SWE applied with 1:3 concentration produced minimum weeds (84.4 m-2), more leaf area tiller-1(104.6 cm2), taller plants (89.4 cm), longer spikes (9.95 cm) and more grain yield (3547.2 kg ha-1). Among application time SWE applied at tillering gave lower weeds density (87.7 m-2), higher leaf area tiller-1 (102.3 cm2), taller plants (87.8 cm), longer spikes (9.85 cm) and higher grain yield (3308.9 kg ha-1). Leaf water extract gave fewer weeds (91.4 m-2), higher leaf area tiller-1 (101.9 cm2), taller plants (87.6 cm), longer spikes (9.85 cm) and more grain yield (3263 kg ha-1) compared to stem water extracts. It is concluded that leaf water extract sprayed at tillering with 1:3 concentration reduced weeds density and increased grain yield of wheat and is recommended for reducing weeds density and increasing grain yield of wheat in agro- climatic conditions of Peshawar, Pakistan.