Abstract: Taking three spring wheat cultivars as test materials, a field experiment was conducted to study the effects of different irrigation treatments on the stomatal conductance of the cultivars during their growth period, with the relationships between the stomatal conductance and the environmental factors analyzed. On the basis of winter irrigation with 1800  m³·hm^-2of water, three irrigation treatments, i.e., irrigating three times (T₁), two times (T₂
), and once (T₃) during spring wheat growth period, were installed, with 1050 m³·hm^-2of irrigation water each time. All irrigation treatments had greater effects on the stomatal conductance, which was decreased with the decreasing times of irrigation, and varied with the cultivars. From jointing stage to florescence, the stomatal conductance in all treatments had the same variation trend, i.e., decreased after an initial increase, and reached the peak at heading stage. After florescence, difference occurred among the treatments. In treatment T₁, the stomatal conductance of all test cultivars increased after an initial decrease; in treatment T₂, the variation patterns of stomatal conductance differed with cultivars; while in treatment T₃, the conductance of all cultivars decreased all along. Among the environmental factors, relative atmospheric humidity had the greatest effects on the stomatal conductance, and their correlation coefficient in treatments T₂ and T₃ reached significant (0.82^*)and very significant (0.92^**). respectively. The stomatal regulation mechanism of spring wheat adapting to water deficit in Hexi corridor was of feedback manner.

Key words: spring wheat, irrigation, stomatal conductance, environmental factor, soil moisture and salinity, spatial distribution, influence factors, Manas river catchment.