播期对寒地水稻生长发育及产量和品质的影响

通过探讨播期对寒地水稻生长发育和产质的影响及确立最佳的播期范围，对指导今后寒地水稻生产实践具有重要意义。试验在大田条件下，以‘空育131’为试验材料，设置7个播期处理，分析播期对寒地水稻茎蘖动态、干物质积累及产量形成的影响。结果表明：不同播期处理对水稻茎蘖数、成穗率、干物质积累、产量及其构成的影响均存在显著差异，其中B2、B3、B4处理显著提高了水稻产量，增加了水稻每平方米有效穗数、结实率、每穗实粒数和粒重，实际产量较B1增幅分别为18.12%，17.70%和14.92%，较 B7增幅分别为41.38%，40.89%和37.56%，以B2处理作用效果最佳，其次是B3处理。与其它处理相比，B2、B3、B4处理叶面积指数高，干物质积累多，能够形成高质量群体；具有高的茎蘖成穗率、结实率和穗粒数，产量构成因子间互补作用强，最终实现籽粒产量和碾磨品质的提高。相比之下，播期过早或过晚均会导致水稻干物质积累、成穗率、结实率以及产量的显著或极显著降低，且不利于碾磨品质的提高，其中晚播能够显著或极显著降低垩白粒率和垩白度。综合分析表明，寒地水稻4月10—20日之间播种更适合在目前寒地稻区水稻高产、高效栽培中应用。

Sowing Date Affects Growth,Development, Yield and Quality of Rice in Cold Region

To discuss the effects of sowing date on the growth, development and yield and quality of rice and to establish the optimum sowing date range are of certain significance for guiding rice production practice in cold regions. The experiment is carried out in filed, and‘Kongyu131’was used as the experimental material. Seven kinds of sowing dates were set up. The effects of sowing date on tillering dynamics, dry matter accumulation and yield formation of rice were analyzed. The results showed that there were significant differences in tiller number, panicle rate, dry matter accumulation, yield and its composition with different sowing dates. B2, B3 and B4 treatments significantly increased yield, effective panicles per square meter, seed setting rate, grain number per panicle and grain weight; the actual yield increased by 18.12%, 17.70% and 14.92% compared with B1, increased by 41.38%, 40.89% and 37.56% compared with B7, respectively. The effect of B2 treatment was the best, followed by that of B3. Compared with other treatments, B2, B3 and B4 treatments had higher leaf area index, more dry matter accumulation, and could form high quality population. They had higher spike rate, seed setting rate and grain number per spike, and had strong complementary effect among yield components, and ultimately improved grain yield and milling quality. In contrast, sowing too early or too late could lead to significant or extremely significant decrease in dry matter accumulation, panicle formation rate, seed setting rate and yield, and it was not conducive to the improvement of milling quality. Late sowing could significantly or extremely and significantly reduce chalky grain rate and chalkiness. The comprehensive analysis shows that the sowing date between April 10 and 20 is more suitable for high yield and high efficiency rice cultivation in cold region.