以杂交稻和常规稻为试验材料,在苏南常熟、苏中兴化和苏北东海3个试验点同时开展播期试验,探讨迟播迟栽条件下机插稻稳产、增产问题。结果表明,随着播期的推迟,各试验点水稻生物产量、经济产量、经济系数、单位面积穗数、每穗粒数、群体颖花量和结实率不断下降,生育期延迟且全生育期缩短。分析发现,每穗粒数受播期影响最大,其余依次为结实率、穗数、千粒重。甬优2638依其大穗优势具有更高的产量潜力,但随着播期的推迟,其产量优势减小。甬优2638在各稻区均表现出抽穗较早、群体库容大、生物产量高等优势,具有在迟播迟栽生产条件下获取稳产、高产的潜质。迟播迟栽对不同类型水稻品种产量及生育期具有较大影响。据此,从安全生育性及稳产角度考虑,对不同类型品种在不同稻区生产的最晚播期进行了初步拟定,以为大面积生产提供参考。 With hybrid rice and conventional rice as test materials, sowing dates were conducted in three experimental sites of Changshu in Jiangsu Province, Zhongxing in Jiangsu Province and East China Sea in Jiangsu Province to discuss the problem of stable yield and yield increase of latently sown rice. The results showed that with the delay of sowing date, the biological yield, economic yield, economic coefficient, spike number per unit area, grain number per spike, spikelet population and seed setting rate of rice in all experimental sites decreased continuously, the growth period was delayed and the whole growth period shorten. Analysis found that grain number per spike was the most affected by the sowing date, followed by the rate of seed set, spikes, grain weight. Yongyou 2638 had higher yield potential according to its big spike advantage, but with the sowing date delayed, its yield advantage decreased. Yongyou 2638 showed the advantages of earlier ear emergence, larger population capacity and higher biological yield in all rice areas, with the potential of obtaining stable yield and high yield under late sowing and late sowing production conditions. Late sowing delayed planting has a greater impact on yield and growth period of different types of rice varieties. Accordingly, from the perspective of safe fertility and stable production, the latest sowing date of different types of rice varieties in different rice production areas has been tentatively formulated to provide a reference for large-scale production.