Studies On Strategy Foradjusting Sowing Date Of Winter Wheat (Triticum Aestivum L.) Under Global Warming Conditions

The studies were carried out in the Scientific & Education Park of Henan Agricultural University and Agricultural Center of Xiayi County, and semi-winter wheat cultivar Zhoumai 18, Zhengmai 004, weak spring cultivar Zhengmai 9023 and Yunong 949 were applied to study the changes in growth and development, yield and quality of winter wheat in different sowing dates. The major results were as followed:(1) Characteristics of the changes in main meteorological factors of the Central and Eastern Henan Plains in the recent 30 years were studied: changes in meteorological factors in wheat growing season during years of 2001~2009 were more significant than those of 1971~1980, the average pentad temperature of sowing season (in October) on the Central and Eastern Henan Plains increased by 1.3℃, the ten-day-period rain precipitation of sowing season(in October) in Zhengzhou decreased by 4.94 mm and that in Xiayi County decreased by 1.4 mm. The average ten-day-period sunshine duration during the years of 1971~1980 in Zhengzhou decreased by 14.51h, while that in Xiayi County decreased by 12.82h.(2) Responses from growth and development, yield and quality of winter wheat in Central and Eastern Henan Plains to different sowing dates were studied. With the delay of sowing dates, the dates of entering jointing stage and flag leaf stage delayed, time duration of yielding stage shortened, maturity stages of all cultivars were less affected by the changes in sowing dates. The total stem number of each winter wheat plant during the whole growth period, the number of secondary roots of each plant and dry weight of root system were all relatively large. In Central and Eastern Henan Plains, when the semi-winter wheat cultivar Zhoumai 18 and Zhengmai 004 were sowed during the days of October 12~ October 17, the three elements of grain yield components were coordinated; as a result, yields were higher. Weak spring cultivar Zhengmai 9023 and Yunong 949 were able to achieve higher yields when sowed during the days of October 17~October 22. In Eastern Henan Plain, wheat grain yields decreased with the delay of sowing date. In Xiayi County, semi-winter wheat cultivar Zhoumai 18 and Zhengmai 004 achieved the highest yielding output when sowed during the days of October 10~October 14, weak spring cultivar Zhengmai 9023 and Yunong949 achieved high yields when sowed during the days of October 14~October 18. In Central and Eastern Henan Plains, Zhoumai 18 and Zhengmai004 yielded grains of better nutritional quality and food quality. Zhengmai9023 and Yunong 949 yielded grains of better quality when sowed during the days of October 17~October 22.(3)The sowing date of winter wheat under global warming conditions in Center and Eastern Henan Plains were observed. According to the climate change, and growth and yield, and formation rules of quality, in Center Henan plain, suitable sowing dates of semi-winter wheat should be adjusted to October 12~16 and those of the weak spring wheat should be adjusted to the October 17~21; in Eastern Henan Plain, suitable sowing dates of semi-winter wheat should be adjusted to October 10~14 and those of weak spring wheat should be adjusted to October 14~18. Reasonable adjustments in sowing dates were conducive to cultivate winter wheat of high yield, quality and efficiency under global warming conditions in the Center and Eastern Henan Plains.