The impact of planting date and various cultivars on various characteristics, grains and yield, in Ardestan district

In order to determine the effects of date of planting, phenotype and genotype growth parameters on grain yield formation, and also assess the characteristics of autumn wheat ideal cultivars, a research was performed in the experimental farm of Ardestan Azad University during the 2004 growing season. The experimental design was a split plot with three replicates. The sowing dates were 5th and 20th of November and 5th of December, and the ten cultivars of wheat used were Ghods, Pishtaz, Hirmand, Hamun M-73-18, Roshan, Shiraz, Falat, Chamran and Dez. The date of sowing and cultivars were the main plots and sub-plots, respectively. The sowing date had a significant effect on the length of spike, the length of peduncle, the number of grains per spike, and also on grain yield in such a way that on the 5th of November (first planting date) different cultivars had taller spikes, more grains per spike as well as a maximum cultivar grain yield. The results showed a highly significant impact on all the characteristics, except plant height, in the same way as for individual characteristics, like the spike length, peduncle height, number of grains per unit area, biological yield, grain yield, straw yield, and thousand grain weight. Roshan cultivar was recognized as one of the index cultivars. Regarding the point that Pishtaz cultivar recorded the highest harvest index and the lowest straw yield compared to other cultivars, it is possible to use Roshan as one with two purposes in the production of grass and grain. It is also possible to introduce Pishtaz as a cultivar being adapted to the conditions of Ardestan. The results of the grain yield measurements correlate significantly with those obtained from other characteristics. Therefore, it was concluded that the measurement of grain yield is not only the best measurement method for the evaluation of the effects of sowing date and the most appropriate wheat cultivars but also that there is no need to do any other complementary measurement once this type of measurement is performed.