بررسي اثرات تغيير اقليم بر خصوصيات رشدي و عملكرد دانه گندم زمستاني در شرايط ديم و فارياب تبريز با استفاده از شبيه سازي

Evaluating the Effect of Climate Change on Growth and Yield of Rain-fed and Well-watered Winter Wheat in Tabriz, Using Simulation

The present study was initiated to evaluate the effect of climate change on phenology, growth and development of drought-stressed and non-stressed winter wheat. At first, the monthly mean temperature, radiation and precipitation was estimated for increased CO2 concentration, using two General Circulation Models (GISS and GFDL). Then the CICER model was subjected to some modifications and re-coded in TURBO C. According to prediction of GISS and GFDL models, increased CO2 concentration will increase the mean temperature in autumn by 4.79 and 4.52, and in February and spring by 4.68 and 4.32 degrees centigrade, respectively. The mean precipitation in autumn and winter will be increased by 36 and 41%, respectively. The change in radiation will be lower, as compared to temperature and precipitation. The time of flowering and maturity will be shortened. Therefore, the possibility of double cropping will be increased. The biological yield will increase by 50 to 67% for rain-fed wheat, and by 29 to 39% for well-watered wheat. Under non-stressed conditions, although total intercepted radiation will be diminished during the growth period, the grain yield will be increased due to higher radiation use efficiency, fraction intercepted radiation and harvest index. Under rain-fed conditions, although the harvest index will be higher, the increase in grain yield will mainly be due to higher transpiration efficiency. The percentage of increase in water use efficiency will be higher in rain-fed condition than other condition. The need for irrigation will be lower due to diminished evapotranspiration.