早稻的播期与热量利用效率

为防止盲目拓展播期,通过大田分期播种试验、热量分布及利弊分析,结合发育期及生物要素研究。结果表明,尽管早播早稻一度获得最高分蘖倍率,但收获时以适期播种最终得到最高的有效茎倍数。早播的获得最大总生物量,适期播种获得理想的产量。早播早稻无效分蘖较多;适期播种在产量结构方面表现出优势;晚播早稻在成穗数、单穗结实粒数上不理想;早播早稻管理成本高,遭遇苗期低温、花期暴雨概率大。晚播早稻抽穗灌浆期遭遇高温热害情况多,对叶绿素、光合、稻米品质有不利影响。拓展播期需综合考虑气候变化与反复性带来的风险,以及热量分布对生物总量与产量的不同影响。

Early Rice: Relationship Between Sowing Date and Heat Utilization Efficiency

To prevent the blind extension of sowing date, the research was conducted through field sowing test at different stages and the analysis of heat distribution, combined with the study on the developmental period and the biological factors. The results showed that: although the early sowing early rice once reached the highest tillering rate, suitable sowing early rice still achieved the highest effective stem multiple at the harvest time; the total maximum biomass was obtained by early sowing, and the ideal yield was obtained by suitable sowing; early sowing early rice had more non-effective tillers; the suitable sowing hold an advantage in yield structure; late sowing early rice did not perform well on the number of panicles and single-earned panicles; early sowing early rice had high management cost and showed a high probability of suffering low temperature at seedling stage and heavy rain during the flowering period; late sowing early rice was easy to suffer from extreme heat at heading and filling stage, which had adverse effects on chlorophyll, photosynthesis and rice quality. To extend the sowing date, the risk caused by climate change and its repetitiveness, and the different effects of heat distribution on the biomass and yield should be considered comprehensively.