Weed suppressing ability of different bread wheat genotypes in drylands of Western Iran.

A genetic option for increasing wheat production is to reduce menace of weeds through developing or screening weed tolerant wheat genotypes. To screen bread wheat genotypes tolerant to weeds in dryland conditions, twenty six genotypes and two checks were evaluated in weed-free and weedinfested plots using a strip-plot experiment in 2002–03 at Dryland Agricultural Research Institute Srarood-Kermanshah, Iran. Labeling the genotypes as G1,…,G28, the top five genotypes for grain yield in presence of weeds were G15, G8, G26, G2 and G13. Genotypes G13, G26, G2 and G4 were found most tolerant to weed-interference. However, using the competition index, the genotypes within top 5 for yield under weed-interference were G13 and G2. The clustering of the genotypes using the tolerance and competition indices resulted into three clusters each giving a different level of tolerance and yield. Considering the tolerance, competition and high yield, genotypes G13, G26 and G8 were found most suitable for introduction in breeding program.