COMPETITIVE INDICES OF Echinochloa crusgalli AND MAIZE UNDER AGRO-ECOLOGICAL CONDITIONS OF DERA ISMAIL KHAN, PAKISTAN

To investigate the competitive indices and yield losses due to Echinochloa crusgalli in maize, an experiment was carried out during summer 2013 at Agriculture Research Institute (ARI) Dera Ismail Khan, Pakistan. The trial was conducted in RCB design replicated thrice, comprising eight treatments viz, maize + E. crusgalli 0 plants, maize + E. crusgalli 75 plants, maize + E. crusgalli 150 plants, maize + E. crusgalli 225 plants, maize + E. crusgalli 300 plants, maize + E. crusgalli 375 plants, maize + E. crusgalli 450 plants and E. crusgalli pure stand (600 plants). The data recorded in different plots were compared with control plot. Plant height (cm), stem girth (cm), number of grains cob^-1, 1000-grain weight (g), biological yield (t ha^-1) and grain yield (t ha^-1) of maize significantly (P≤0.01) differed. The highest grain yield and biological yield was observed in control (no competition) whereas minimum in the plot having 450 E. crusgalli plants. Similarly other parameters also decreased significantly with increased densities of E. crusgalli.