Abstract:

【Objective】To investigate the effects of different mechanical direct seeding patterns on lodging resistance and yield of high quality late indica rice in South China, and provide the reference for high yield and lodging resistance cultivation of high quality late indica rice in South China,【Method】 the indica inbred rice variety Huanghuazhan and the indica hybrid rice variety Taiyou 398 were used as materials and three direct seeding patterns, including dry direct seeding, wet direct seeding and flooded direct seeding were designed to determine the yield and yield components, emergence rate, dry matter accumulation, leaf area index, stem morphology and mechanical properties of high quality late indica rice. 【Result】 Compared with wet direct seeding or flooded direct seeding, dry direct seeding significantly increased seedling emergence rate of late rice varieties by 6.10% to 22.96%, and the dry matter accumulation and leaf area index also increased. At the same time, dry direct seeding pattern was conducive to increasing the yield of late rice varieties by 6.99% to 27.77%, and Taiyou 398 had higher yield increasing rate than Huanghuazhan. In terms of yield components, the increasing of yield of late rice varieties under mechanical direct seeding was mainly attributed to the increase in the number of effective panicles. In addition, the plant height of dry direct seeded rice was relatively low, and basal internodes were relatively short, but the stem was stronger and the stem wall was thicker than the two treatments, which was conducive to improving the break force and culm phenotype index of the plant, and reducing the bending moment and lodging index. The correlation analysis showed that the stem diameter, wall thickness and culm phenotype index were positively correlated with the break force, but negatively correlated with the lodging index. The plant height, panicle length and bending moment were negatively correlated with the break force, and positively correlated with the lodging index.【Conclusion】 Mechanical dry direct seeding practice could not only contribute to yield increase of high-quality late indica rice in South China, but also significantly increase the stem strength, and improve the lodging resistance of plants and reduce the risk of direct seeded rice production.

Key words: mechanical direct seeding, late indica rice, grain yield, lodging resistance

摘要：

【目的】研究不同机直播方式对南方优质晚籼稻茎秆抗倒伏能力及产量的影响,为南方优质晚籼稻高产抗倒栽培提供参考。【方法】以籼型常规稻品种黄华占和籼型杂交稻品种泰优398为材料,设置旱直播、湿直播和淹水直播3个处理,分别测定优质晚籼稻的产量及产量构成、出苗率、干物质生产、叶面积指数和茎秆形态与力学特性。【结果】与湿直播方式或淹水直播方式相比,旱直播方式可显著提高供试晚稻品种的出苗率,增幅为6.10% ~ 22.96%,且干物质生产和叶面积指数均增加。同时,旱直播方式有利于提高供试晚稻品种产量,两品种增产幅度为6.99%~27.77%,其中泰优398产量增幅高于黄华占,从产量构成因素来看,机械旱直播方式下供试晚稻品种产量的提高主要得益于有效穗数增加。此外,旱直播方式下供试水稻株高相对较矮,基部各节间较短,但茎秆粗壮,茎壁较厚,有利于提高植株茎秆抗折力和秆型指数,降低弯曲力矩与倒伏指数。相关分析表明,茎粗、壁厚和秆型指数与抗折力显著正相关,而与倒伏指数显著负相关;株高、穗长、弯曲力矩与抗折力显著负相关,与倒伏指数显著正相关。【结论】采用机械旱直播方式不仅有利于增加南方优质晚籼稻产量,还能显著增加茎秆强度,提高植株抗倒伏能力,降低直播生产的风险。

关键词: 机直播, 优质晚籼稻, 产量, 倒伏特性