BIOCHAR, FYM AND NITROGEN INCREASES WEED INFESTATION IN WHEAT

Weeds being serious concern to crop production are directly affected by nutrient sources and amount of available nutrients in the soil. the aim of the present study was to investigate the effect of biochar (bc), farmyard manure (fym) and nitrogen levels on the weed infestation in wheat crop. the experiment with three replications and 12 treatments combinations was conducted during winter 2012-13 at new developmental farm of the university of agriculture, peshawar. a control treatment was included in the experiment. biochar at the rate of 0, 25 and 50 tons ha-1 was applied to the field a year ago. two levels of nitrogen (60 and 120 kg ha^-1) and two levels of fym (5 and 10 tons ha^-1) were applied to the wheat during the experimental year. fym significantly affected weed density 35 and 70 days after sowing (das), weed fresh and dry biomass were higher at higher level of fym as compared to low level of fym. nitrogen and biochar application significantly affected weeds fresh and dry biomass and were higher in plots treated with 120 kg n ha^-1 and 50 tons bc ha^-1 as compared to 60 kg n ha^-1 and no biochar treated plots, respectively. it is concluded from the above findings that fertilized plots resulted in higher weed density and fresh and dry biomass due to availability of nutrients throughout the growing season.