نویسندگان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
To study the effect of sowing date on grain yield and yield components of bread wheat, a field experiment was conducted in Gorgan Agricultural Research Station in two cropping seasons (2005-2006 and 2006-2007). Experimental design was Split-plot arrangements in randomized complete block design with three replications. Main plots were assigned to 4 levels of sowing date: 01 December, 21 December, 10 January and 30 January. Two bread wheat cultivars Moghan 3 and Arta were randomized in sub-plots. The average soil temperature at these sowing dates were 14 º C, 11 º C, 6 º C and 4 º C respectively. Results showed that there were significant differences between two years for biological yield, number of spike per m2, days to heading, days to maturity and GDD to heading. All traits except number of grains per spike were significantly affected by sowing date (different GDD). The highest biological yield (14415 Kg ha-1) was obtained in sowing date 01 December (with 14 º C soil temperature and GDD = 2247 º Cd). The highest grain yield (4480 kgha-1) was also produced in 1st sowing date (01 December). In the late sowing date, grain yield decreased, because of heat stress at the end of season and low soil temperature average at planting date. There were also significant differences between wheat cultivars for grain yield and biological yield. Moghan 3 had higher grain yield (average of 4324 kg/ha) and significantly differed from Arta. In conclusion, suitable sowing date was 01 December with 14 º C soil temperature and GDD = 2247 º Cd.
کلیدواژهها [English]
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