) TRIRICAM AESTIVUM L.( بر عملكرد و اجزاء عملكرد گندم )AVENA LUDOVICIANA( بررسي تاثير شوري آب آبياري و تراكم هاي يولاف وحشي

Effects of salinity and wild oat (Avena ludoviciana) densities on yield and yield components of wheat (Triticum aestivum L.)

Salinity is one of the main constrains for wheat production in south of Khorasan province. In this region, wild oat (Avena ludoviciana) is one of the noxious weeds which compete with wheat crop.In order to study on the effects of salinity and wild oat density on yield and yield components of wheat (Var. Roushan) a field experiment was conducted during the 2000 and 2001 growing season in the Agricultural Research Station of Birjand University. Experimental design was split plot with three replications. Treatments were: Salinity of irrigation water with four levels (1.5, 4.2, 5.5, and 10.5 dS/m in the first year and 1.5, 5.5, 7.5 and 10.5 dS/m in the second year) and five wild oat density (0, 20, 40, 80 and 160 plants/m`). "Roushan" variety was used in this expriment.Results showed that grain weight, grain yield and relative grain yield decreased significantly by salinity. However, number of spike/m2, number of grain in spike and harvest index were not significantly affected by salinity. Grain weight in the second year, grain yield and relative grain yield decreased significantly by wild oat density. Nevertheless, number of spike/m2, number of grain /spike, grain weight in the first year and harvest index were not affected significantly by wild oat density.Generally, results of this experiment showed that ability of wild oat competition can reduce under high salinity condition.