1997年延边地区的异常气温对水稻生育及产量的影响

Effect of Abnormal Temperature in Yanbian Area of 1997 on Rice Development and Yield

延边地区１９９７年因５月中旬至６月上旬的异常低气温，造成水稻出叶速度非常缓慢，叶色浅，出蘖速度减慢，前期有效分蘖数量不足．此后高温天气，出叶速度加快，叶色迅速变深，分蘖数急速增加，８月上旬安全抽穗．气温异常变化造成有效分蘖终止期和最高分蘖期延迟１０天左右，叶龄指数分别增加约１５，有效分蘖率提高，保证了穗数．７、８月份气温高于历年，但９月１５日下轻霜，此后粒重不再增加，结实期积温不足，结实率有所下降．在这种异常气温条件下最佳经济效益的氮、磷、钾肥配比为２．８∶１∶１．９．

Abnormal low temperature from the middle ten-days of may to the first ten day period of June in 1997,it caused slow leafing speed, light leaf colour, slow tillering speed, lack of prophase effective tillering number. After that high temperature caused fast leafing speed, dark leaf colour, increase tillering number, and start ear sprouting at the first ten day period of August.Temperature of July and August were higher than fast years ,fall first frost at 15th September. After that grain weight didn't increase ,setting percentage drop. The first proportion of N、P and K was 2.8∶1∶1.9 under the condition of abnormal temperature.