Competitive ability of wild oats (Avena ludoviciana Dur.) and broad leaf weeds with wheat in relation to crop density and nitrogen levels.

Field experiments were conducted at the experimental area of Punjab Agricultural University, Ludhiana during rabi seasons of 1998–99 and 1999–2000 in order to study the competitive behaviour of wild oats and broad leaf weeds with wheat raised on loamy sand soil. Two seed rates (100 and 150 kg ha−1) and three nitrogen levels (120, 150 and 180 kg ha−1) were kept in main plots and four weed competition treatments i. e. competition with wild oats alone, with broad leaf weeds alone, with both and no coinpetition (weed-free) in sub-plots. The differences in grain yield of wheat with seed rates were non-significant during both the years. Among weed competition treatments, association of wild oats alone or both types of weeds with wheat resulted in significantly more reduction in grain yield than alone broad leaf weeds. On an average, 17.0, 36.6 and 45.1% reduction in grain yield of wheat was observed with competition of only broad leaf weeds, only wild oats and both, respectively.