an evaluation of yield and yield components of bread wheat (triticum aestivum l.) cultivars when in competition with rye (secale cereale l.)

secale cereale is a nosious, problematic weed of wheat fields in iran. for evaluation of the yield and yield components of bread wheat (triticum aestivum l.) cultivars in the presence of rye an experiment was established in a randomized compelet block design with factorial arrangment of treatments in meshkindasht and varamin during 2002-2003 growin season. experimental factors were wheat cultivars (azadi, mahdavi, roshan, tabasi, pishtaz, shiraz, karaj2 and nicknejad) and rye platation (0,120 plants/m2). results showed that rye plantation resulted in reduced yield and yield components of bread wheat. grain yield loss varied from 7.32 to 44.82% and biological yield loss from 9.62 to 37.15% among cultivars at the two different locations.