Field experiments were conducted in 1994 and 1995 in Van in order to study the relationships between grain yield and yield componets, and the interrelationships among these yield components and other characteristics in Tir wheat. In this research, heading duration, the number of spikes per m 2 , grain filling period, the number of grain per spike, grain weight, and grain yield were studied. Direct and indirect effects of the yield components (the number of spikes per m 2 , the number of grain per spike, and grain weight) on grain yield were found by Path coefficient analysis. Direct and indirect effects of other characteristics on these components were also determined. The direct effects, obtained in the Path coefficient analysis, indicated that grain yield depended mainly upon spike number per m 2 and secondly upon the grain number per spike. Grain weight showed less influence. On the other hand, duration had a highly negative influence on the grain filling period. At the end of the research, it has been found possible to increase grain yield when spike number per m 2 used as a selection criterion in Tir wheat.

Field experiments were conducted in 1994 and 1995 in Van in order to study the relationships between grain yield and yield componets, and the interrelationships among these yield components and other characteristics in Tir wheat. In this research, heading duration, the number of spikes per m 2 , grain filling period, the number of grain per spike, grain weight, and grain yield were studied. Direct and indirect effects of the yield components (the number of spikes per m 2 , the number of grain per spike, and grain weight) on grain yield were found by Path coefficient analysis. Direct and indirect effects of other characteristics on these components were also determined. The direct effects, obtained in the Path coefficient analysis, indicated that grain yield depended mainly upon spike number per m 2 and secondly upon the grain number per spike. Grain weight showed less influence. On the other hand, duration had a highly negative influence on the grain filling period. At the end of the research, it has been found possible to increase grain yield when spike number per m 2 used as a selection criterion in Tir wheat.