Performance of wheat (Triticum aestivum) in relation to small canary grass (Phalaris minor) under different levels of irrigation, nitrogen and weed population

A 3-year field experiment was conducted during the winter season of 1986-87 to evaluate the performance of wheat (Triticum aestivum L. emend . Fiori & Paol.) under different levels of irrigation, nitrogen und weed population. It was laid out on a deep, well-drained, sandy-loam soil of Ludhiana, with 18 combination comprising 2 irrigation regimes based on Irrigation water: cumulative pan evaporation (IW:PAN-E) ratio of 0.4 and 0, 8, 3 levels of N (80, 120 and 160 kg N/ha) and 3 weed population intensities (0, 40 and 80 plants/m 2 ) of small canary grass (Phalaris minor Retz.). Weed-population Intensity of 40 and 80 plants/m 2 decreased the grain yield of wheat by 21 and 23% respectively. the nitrogen x weed population interaction was not significant. Irrigation regime had no significant effect on the grain yield of wheat. There was high depletion of soil moisture from the soil profile in the presence of weeds and higher levels of N.