穗肥运筹对膜下滴灌水稻产量和产量构成因素的影响

Effects of nitrogen fertilizer applied at heading stage on keng rice yield and its components in under-plastic-mulching drip irrigation

以‘武运粳27号'为试验材料,设置2种施氮总量(370.5 kg/hm^2和445.5 kg/hm^2)和2种穗肥运筹比例(促花肥和保花肥的施用比例6:4和5:5),研究不同穗肥运筹对南通地区膜下滴灌水稻单位面积产量和产量构成因素的影响。结果表明,膜下滴灌水稻促花肥:保花肥为6:4处理的单位面积产量、总颖花量、穗数和每穗粒数显著或极显著高于5:5处理,但结实率极显著低于5:5处理;单位面积颖花量、穗数、每穗粒数的增加与增产关系密切,且各因子中每穗粒数的作用最大;各处理成穗率不超过50%。本试验条件下,膜下滴灌水稻要获得较高产量,必须在确保一定穗数的基础上,以攻取大穗作为高产目标。

Field experiments with keng rice cultivar ＇ Wuyunjing 27＇ were carried out at 2 nitrogen fertilizer rates（370.5 kg/hm^2 and 445.5 kg/hm^2） and 2 quantitative ratios of flower forcing fertilizer to flower protection fertilizer（6：4 and 5：5） so as to study the effects of nitrogen fertilizer applied at heading stage on keng rice yield and its components in under-plastic-mulching drip irrigation in Nantong area.The results showed that the ratio of6：4 could make the per unit area grain yield,total spikelets,panicles and grains per panicle significantly or very significantly higher than the ratio of 5：5 though the seed-setting rate under the 6：4 treatment was very significantly lower than that under the 5：5 treatment.The grain yield increment was closely correlated to the increments of per unit area total spikelets,panicles and grains per panicle,and the grains per panicle had the greatest effect.The percentage of productive tillers in all the ferlizer treatments was not over 50%.In order to reach high yield of keng rice in this experimental conditions,it was necessary to gain large panicles on the basis of a certain number of panicles.