通过播期试验，对三江平原5个主栽水稻品种的品质性状进行分析。结果表明，播期对整精米率、垩白米率、垩白度、直链淀粉含量、蛋白质含量、食味值均有影响，对糙米率、精米率影响较小。随着播期的推迟，整精米率明显降低，外观品质变劣，且二者呈极显著负相关；直链淀粉含量呈升高趋势，蛋白质含量则呈降低趋势；食味值变化因品种而异。对品质各性状的变异系数进行聚类分析，结果表明，垩白粒率、垩白度受播期影响最大，属于敏感性状；糙米率、精米率、食味值、直链淀粉含量和蛋白质含量受播期影响较小，属于迟钝性状；整精米率受播期影响变异幅度在二者之间。综合而言，早播对5个水稻品种整体品质提升具有正向作用；但从食味值角度出发，早熟品种龙粳31和龙粳46适当晚播可能更有利于口感的改善。

Through sowing date test, the rice quality characters of five main cultivars in Sanjiang Plain were analyzed. The results showed that, the sowing date had effect on head milled rice rate, chalky rice rate, chalkiness degree, amylose content, protein content and taste value, but had little effect on brown rice rate and milled rice rate. With the delay of sowing date, the head rice rate decreased and the appearance quality deteriorated, and there was a significant negative correlation between them; the amylose content increased, while the protein content decreased; the change of taste value varied with varieties. Cluster analysis of coefficients of variation of quality traits showed that chalky rice rate and chalkiness degree were most affected by sowing date and belonged to sensitive traits; brown rice rate, milled rice rate, taste value, amylose content and protein content were less affected by sowing date and belonged to slow traits; and head rice rate was affected by sowing date was between the two. Generally speaking, early sowing had a positive effect on the overall quality improvement of the five rice varieties, but from the point of taste value, late sowing of early-maturing varieties Longgeng 31 and Longgeng 46 might be more beneficial to the improvement of taste.