冬小麦推迟春季首次灌水后不同品种的产量及水分利用效率

Effects on Yield and Water Use Efficiency in Winter Wheat Varieties When Postponing the First Irrigation in Spring

１９９１～１９９３年研究表明，即使两年度均为小麦生育期降水较少年份，且冬、春降水很少，在相同灌水量条件下，首次灌水推迟至拔节期或稍后１０日左右，小麦仍可获得高产，并提高了水分利用效率；在减少供水７５ｍｍ情况下，仍可维持高产而水分利用效率进一步提高。总的来看，随着首次灌水推迟，水分利用总量降低，而水分利用效率却因产量和水分利用而协调变化。品种对首次灌水推迟的反应不同：高产中早熟和前期对水分胁迫适应性强的品种更适于高产节水栽培，可将春季首次灌水推迟至拔节后挑旗前；晚熟大穗大粒型品种不宜推迟春季首次灌水，以免减产。

The effect of first irrigation delay in spring for winter wheat on yield and water use efficiency was analysed during 1991 - 1993. The rat fall in both years was less than normal during wheat growing season,in particular in winter and spring. The results showed that, when the first irrigation was delayed to stem elongation or about 10 days later, the high water use efficiency and high yield of wheat could be reached, if the same amount of water was given for the whole growing season. The water use efficiency could be improved further and high yield could be maintained, when water input reduced by about 75mm. In general, total water consumption reduced with the postponement of first irrigation; however, the response of different varieties differed. Varieties with high yield,early-middle maturity and adaptation to early water stress are more suitable for cultivation for high yield and water saving by delaying the first irrigation to the period of post-stem-elongation and pre-booting. In order to avoid yield reduction, varieties with late maturity,large spike,and large grain size are not suitable for delaying the first irrigation in spring.