穗肥调控时期对大穗型水稻品种结实率及产量的影响

摘要

In order to further improve setting rate,the effects of different head dressing regulation on two rice varieties with large panicles were studied,the effects of application periods on rice heading and fruiting were analyzed to enhance the regulation effects.Results:after applying panicle fertilizer at inverse 3rd leaf,the degradation ratio of primary branches per-panicle reduced by 0.64 and 2.33 percentages and the secondary branches per-panicle reduced by 5.27 and 1.78 percentages;the degradation ratio of spikelet decreased by 7.88 and 5.84 percentages;the final seed-setting ratio reached 85.62% and 83.41%. Therefore,as for large-spike rice it was no need to take measures to promote the spikelet number,but adding nitrogen before the stage of pollen mother cell meiosis could ensure the adequate nutrition during meiosis and prevent the degradation of rachis-branches and spikelet.%为探明大穗型水稻品种的穗肥适宜施用时期，促进水稻结实率与产量的提高，对2个大穗型品种（Y两优5845和金优785）进行不同时期穗肥调控研究，分析穗肥施用时期对水稻结实率及产量的影响。结果表明：倒三叶施用穗肥后Y两优5845和金优785一次枝梗退化率比倒五叶施穗肥的降低0．64百分点和2．33百分点，二次枝梗降低5．27百分点和1．78百分点，颖花退化率降低7．88百分点和5．84百分点，结实率达85．62％和83．41％；倒三叶施用穗肥的处理产量显著高于倒五叶施肥的处理，Y两优5854和金优785分别达960．3 kg/667m2和873．21 kg/667m2。结论：大穗型水稻品种适宜的穗肥施用时期为倒三叶期，此期施用穗肥能够保证减数分裂期有充足的营养供应，防止枝梗及颖花退化，增加结实率，从而提高产量。