Abstract: In order to explore effects of dry direct seeded on stem lodging ability and yield of upland rice in southern China. Hanyou 73 and Huyou 2 were used as experimental materials, with three treatments of dry direct seeded (DDS), wet direct seeded (WDS) and flooded direct seeded (FDS) to compare the effects on seedling emergence rate, yield composition and lodging resistance of upland rice. The results showed that compared with WDS and FDS, the seedling emergence rate of DDS increased by 6.57%-23.29%, and the differences among the treatments were significant (P<0.05). In addition, DDS was conducive to improve grain yield of upland rice varieties and the grain yield increase of the two varieties was 7.89%-22.21% and the yield of Huyou 2 was 3.87% higher than that of Hanyou 73. Through the analysis of yield components, the increase in grain yield was mainly due to the increase of effective panicles per unit area. In addition, DDS was beneficial to improvement of the bending resistance and culm shape index of the tested varieties, reduce of bending moment and lodging index, and the shorter plant height and base internodes were beneficial to strengthening the stalk growth and increasing stem wall thickness. Stem thickness, wall thickness and culm type index were significant or extremely significant positive correlation with bending resistance, and extremely significant negative correlation with lodging index. Plant height and bending moment had extremely significant negative correlation with break force, but had extremely significant positive correlation with lodging index. In conclusion, DDS was not only to improve the grain yield of direct seeded upland rice, but also to enhance plant lodging resistance, decrease lodging risk, which could be popularized in production. This study provides a theoretical basis for achieving high and stable yield cultivation of upland rice varieties in South China.

Key words: dry direct seeded, upland rice variety, yield formation, lodging

摘要： 为探究南方稻区旱直播对旱稻茎秆倒伏能力及产量的影响,本试验以旱稻品种旱优73和沪优2号为材料,进行不同直播方式大田晚稻试验,共设置3个处理:旱直播(DDS)、湿直播(WDS)和淹水直播(FDS),系统比较3种直播方式下旱稻的产量、产量构成及抗倒伏特性。结果表明,与WDS和FDS相比,DDS可提高旱稻供试品种的出苗率,增幅为6.57%~23.29%,且处理间差异达显著水平(P<0.05)。同时,DDS有利于提高供试品种旱稻产量,两品种增产幅度为7.89%~22.21%,其中沪优2号产量较旱优73增加3.87%。从产量构成因素分析,产量的提高主要得益于单位面积有效穗数的提高。此外,DDS有利于提高供试品种茎秆抗折力和秆型指数,降低弯曲力矩与倒伏指数,株高与基部节间较短,有利于茎秆粗壮和增加茎壁厚度。茎粗、壁厚和秆型指数与抗折力呈显著或极显著正相关,与倒伏指数呈极显著负相关。株高和弯曲力矩与抗折力呈极显著负相关,与倒伏指数呈极显著正相关。上述结果表明,采用DDS种植方式不仅有利于提高旱稻产量,而且可明显提高植株抗倒伏能力,降低倒伏风险,可在生产中推广使用。本研究结果为南方稻区旱稻品种直播高产稳产栽培提供了理论依据。

关键词: 旱直播, 旱稻品种, 产量形成, 倒伏