Authors:O. Bilgin, A. Y. Bilgin, T. Gençtan, and I. BAŞER
Received: 14 February, 2000; accepted: 29 August, 2000 In this research, three bread wheat varieties were sown at six different plant densities in the experimental field of Tekirda đ Agricultural Faculty according to a split-plot randomised block design. A range of characters such as number of tillers per plant, number of spikes per plant, grain weight of tillers per plant, plant height, harvest index, plant yield and grain yield per hectare were investigated. The results of variance analysis showed that the effects of sowing rate and variety and their interaction on number of tillers per plant, plant height and grain yield per hectare were all significant. In addition, the effect of plant density on grain weight per tillers, grain yield per plant and number of spikes per plant was significant, whereas the effect of variety was only significant on harvest index. It was found that the number of fertile tillers per plant was the most suitable character as a selection criterion for improving grain yield in the Thrace Region. According to path analysis the direct and indirect effects of the measured characters on grain yield per plant and grain yield per hectare showed that the number of spikes per plant, harvest index, grain weight of tillers per plant and plant height had a direct positive effect on grain yield per plant. However, the number of spikes per plant and the number of tillers per plant had a negative effect on grain yield per hectare, while the harvest index and grain yield per plant had a positive direct effect.