Chemical weed management in wheat at higher altitudes.

To evaluate the effect of different herbicides for controlling weeds in wheat (variety Fakhr-i-Sarhad),at higher attitude, an experiment was conducted at Agriculture Research Station, Chitral during Rabi season 2003-04, using Randomized Complete Block Design, keeping four replications. The experiment, sown in November comprised of eight treatments, viz; seven herbicides and a weedy check. Each treatment consisted of 5 rows each 30 cm apart and 5 m long thus giving a total size of 5 m x 1.5 m. The herbicides used included; terbutryn + triasulfuron at 0.16 kg, 2,4-D at 0.7 kg, fenoxaprop-P-ethyl at 0.93 kg, clodinafop at 0.05 kg, bromoxynil + MCPA at 0.49 kg, carfentrazon-ethyl at 0.02 kg and isoproturon at 1.0 kg a.i ha(-1). The data were recorded on weed kill efficiency (%), fresh weed biomass (kg ha(-1)), plant height (cm), spike length (cm), number of tillers m(-2), number of grains spike(-1), thousand grains weight (g), biological yield (kg ha(-1)), grain yield (kg ha(-1)) and harvest index (%). The data recorded on weed kill efficiency, weed biomass (kg ha1), grains yield (kg ha(-1)) and harvest index (%) were significantly affected by the different herbicidal treatments. Statistically isoproturon treatment exhibited the best performance, with maximum weed kill efficiency (48.26%) and minimum fresh weed biomass (433.3 kg ha(-1)) as compared to weedy check (6 %) and (1102 kg ha(-1)), respectively. Similarly, the spike length (8.34 cm), number of tillers (427 m(-2)), number of grains spike(-1) (38.0), thousand grains weight (39.85 g), biological yield (8475 kg ha(-1)), grain yield (2530 kg ha(-1)) and harvest index (31.3%) were the highest in isoproturon treatments as compared to weedy check having (7.64 cm), (356 m(-2)), (34.1), (37.12 g), (6858 kg), (1913 kg ha(-1)) and (27%), respectively.