灌水时期和灌水量对甘肃河西玉米制种产量和水分利用的影响

Effects of irrigation stage and amount on hybrid seed yield of maize and water use of maize in Hexi Corridor of Gansu

以玉米杂交种吉祥1号为材料，在甘肃武威凉州区连续两年研究了灌水时期和灌水量对制种产量和水分利用的影响。结果表明：在2012年和2013年玉米生育期降水128．2 mm和98．1 mm条件下，灌水量由480 mm下降到210 mm减少56．2％，两年平均种子产量降低41．6％，每增加1 mm灌水种子产量增加14．05 kg·hm-2，同480 mm高水分处理相比，360、330 mm的中等水分处理减产0．47％～8．26％、8．66％～24．90％。不同时期的灌水效应差异很大，母本吐丝期、大喇叭口期、灌浆中后期少灌水的减产效应大小为：三个时期减少灌水＞两个时期减少灌水＞一个时期减少灌水，一次60 mm灌水在母本吐丝期要比大喇叭口期、灌浆中期减产6．5％、7．2％，一次30 mm灌水相应减产11．2％、8．5％。无论试验年份如何，玉米水分利用效率（WUE）随灌水量、耗水量增加而提高，但较高WUE并未在高水分产量最高的处理，而在中等水分处理。不同灌水量和灌水时期 WUE和灌水效率（IWUE）变化与产量变化相一致，灌水减少若发生在母本吐丝期均降低了 WUE和IWUE，发生在灌浆中期、大喇叭口期却相反。综合考虑产量和水分效率，生育期灌水量减少25％～30％并不降低制种玉米种子产量，母本吐丝期对灌水最敏感，节水应在母本吐丝以前或灌浆中后期进行，以达到节水增产目标。

A two-year field experiment with hybrid maize variety No .1 Jixiang was conducted to examine the effects of irrigation amount and stage on seed yield and water use efficiency（WUE）at Liangzhou,Wuwei,Gansu,China .Re-sults indicated that,with rainfall of 128 .2 mm in 2012 and 98 .1 mm in 2013 during growing season of maize,avarage seed yield decreased by 41 .6%as irrigantion amount reduced by 56 .2% ranged from 480 mm to 210 mm,and seed yield increased 14 .05 kg·hm-2 when 1 mm additional irrigation water was supplied .Compared with high irrigation treat-ment of 480 mm,the yield decreased by 0 .47%~8 .26%and 8 .66%~24 .90%in moderate irrigation treatments of 360 mm and 330 mm .There were great differences in effects of irrigation applied at maternal silking and tasselling and middle filling stages,and for yield reduced effects due to irrigation amount decrease were followed by three stages decrease of irrigation at the same time 〉two stages alternating irrigation decrease 〉a stage decrease of irrigation .Seed yield re-duction was 6 .5%and 7 .2%with 60 mm irrigation at silking stage in contrasting to taselling and middle grain filling stages,and 1 1 .2%and 8 .5%with 30 mm irrigation at the same stage,respectively .No matter how the year,water use efficiency （WUE）increased with the increase of irrigation amount and evaportranspiration （ET）,and high WUE value was obtained at moderate irrigation treatment but not at high irrigation treatment with high yield .Changes of WUE and I-WUE （irrigation water use efficiency ）values were same to seed yield changes,and the decreased amount of irrigation at maternal silking stage resulted in WUE and IWUE reduction,but did not at tasselling and middle grain filling stages .It concluded that considering of hybrid seed yield and water use changes,reduction of 25%~30%in irrigation amount did not decrease seed yield,and maternal silking stage of maize was most sensitive to irrigation,suggesting reasonable irriga-tion would be at pre-silking and middle-late grain filling stages to achieving water-saving and yield-increasing .