اثر تاریخ کاشت بر عملکرد و برخی خصوصیات فنولوژیک ارقام و ژنوتیپ‌های گندم نان

In order to study on response of wheat lines/cultivars with different growth habit and vernalization to planting date, an experiment was carried out in Split Plot design based on randomized complete block design with three replications in three cropping seasons (2005-2008) in Agricultural Research Station of Jolgeh-Rokh . Sowing dates (12 Oct., 1Nov. and 21 Nov.) and genotypes considered as main and sub plots, respectively. Results of combined analysis showed that effect of year, planting date, cultivar, year × planting date, year × cultivar, planting date × cultivar, and year × planting date × cultivar was significant on cold tolerance, days to emergence, days to heading, days to physiological ripening, number of spikes per square meter, number of grains per spike, thousand kernels weight and grain yield. The maximum and minimum of grain yields obtained from the first planting date (7118 kg/ha) and third planting date (4122 kg/ha), respectively. The higher grain yield of first planting date was mainly related to more number of spikes per square meter (due to better emergence and establishment and more tillering) and in some extent to higher number of grain per spike and TKW. The maximum and minimum of grain yields obtained from Sissons cultivar (6797 kg/ha) and M-81-13 cultivar (4291 kg/ha), respectively. The higher grain yield of Sissons was related to more number of spike per square meter and adoptability to delayed planting dates. The maximum (8269 kg/ha) and minimum (3637 kg/ha) of grain yield obtained from first planting date and Sissons cultivar, and third planting date and M-81-13 cultivar, respectively. The low grain yield of treatment of third planting date × M-81-13 cultivar was related to unfavorable emergence, sucsebility of cold and less number of spike per square meter.