Biochar and integrated phosphorus management suppress weed density in maize crop

Weeds pose a significant threat to successful crop production. To meet the increasing future food demand, sustainable and efficient weed control remains a cornerstone practice. Usage of high doses of herbicides for killing weeds has created several ecological and environmental problems which cannot be overlooked. Therefore, other weed control practices and techniques should be adopted to minimize weed-crop competition and increase the growth and productivity of crop, instead of chemicals. An experiment was established at Agronomy Research Farm, the University of Agriculture Peshawar to evaluate the effects of biochar and organic-inorganic P sources on density, fresh and dry weight of weeds in maize during 2016. Experiment was executed using randomized complete block design and treatments included biochar (0 and 10 tonnes ha-1) and three sources of P; FYM, PM and one DAP. Phosphorus at the rate of 100 kg ha-1 was applied in such a way that each plot received 50, 75 and 100% P from PM or FYM and the rest from DAP. Biochar and P sources significantly affected density, fresh and dry weight of weeds at 25 and 50 days after sowing of crop. 10 tonnes ha-1 biochar reduced weed density and fresh and dry weight of weeds at both intervals i.e. 25 and 50 days after sowing. Similarly, lower weed density, weed fresh and dry weight with addition of PM or FYM and DAP in 50:50 ratios. Sole FYM and PM resulted in higher weed density and weeds fresh and dry biomass. It is concluded that 10 tons ha-1 biochar and P application 50% from FYM or PM and 50% from DAP improved maize growth and reduced weed competition.