整精米率是影响优质长粒籼稻发展的重要因素之一。为明确长江中下游稻区优质长粒籼稻适宜的播期、收获期和储存期,以3个长粒优质常规籼稻为材料,探讨了不同播期（5月10日、5月20日、5月25日、5月30日）、收获期（90%谷粒成熟、完全成熟、完全成熟后6 d）、储存期（10 d、40 d、60 d）对水稻整精米率的影响。结果表明,随着播期推迟,灌浆成熟期气温降低,全生育期明显缩短,整精米率、垩白粒率、垩白度总体上呈下降趋势,且日均温与整精米率、垩白度、垩白粒率呈极显著正相关关系;优质长粒籼稻在完全成熟收获,且储存40 d以后加工整精米率较高。

Head rice rate is one of the important factors affecting the development of high-quality long-grain indica rice. In order to explore the suitable sowing date, harvest period and storage period of high-quality long-grain indica rice in the middle and lower reaches of the Yangtze river, three high-quality long-grain conventional indica rice were used as materials. The results showed that, with the delay of sowing date, the temperature decreased during the grain filling stage, which resulted in the significant shortening of the whole growth period, and the head rice rate, chalky grain rate, chalkiness ratio showed an overall downward trend. The daily average temperature was significantly positive correlated with the head rice rate, chalky grain rate and chalkiness ratio. High-quality long- grain indica rice was harvested at full maturity stage and stored for 40 d before processing, would have higher head rice rate.