单本密植机插对杂交稻生长和产量的影响

Effect of Mechanized Transplanting with High Hill Density and Single Seedling per Hill on Growth and Grain Yield in Hybrid Rice

为了研究单本密植机插和常规机插对杂交稻分蘖动态、干物质积累、辐射利用率和产量及产量构成的影响,在湖南省浏阳市以杂交稻泰优390、五优308为材料和在广东省肇庆市以五优308为材料,进行印刷播种和常规播种的秧苗素质比较以及单本密植机插和常规机插的大田栽培试验。结果表明,两试验点印刷播种的叶龄、白根数、总根数、茎基宽、地上部干重和地下部干重均明显高于常规播种。单本密植机插的最高分蘖数和有效分蘖数显著低于常规机插,但单本密植机插的每穗粒数、总颖花数、结实率和千粒重高于常规机插,增产10.28%~13.96%,达到显著水平。从穗部性状来看,单本密植机插的一次枝梗数、二次枝梗数、穗长、着粒密度和单穗重均显著高于常规机插。在生长前期,单本密植机插的干物质积累和叶面积指数低于常规机插,而成熟期干物质量比常规机插高0.61%~9.45%,且收获指数显著高于常规机插。此外,单本密植机插的截获辐射量和截获率低于常规机插,而辐射利用率显著高于常规机插。由此可见,杂交稻单本密植机插不仅可以降低用种量、提高秧苗素质,还能增加每穗粒数、总颖花数、千粒重及提高结实率、收获指数和辐射利用率,从而获得高产。

The high sowing rate and poor transplanting performance hinder a large-scale mechanized transplanting of hybrid rice in China. In order to study the effects of mechanized transplanting with high hill density and single seedling per hill（MTHS） and conventional mechanized transplanting（CMT） on tillering, dry matter accumulation, radiation use efficiency, grain yield and its components, comparisons of seedling quality between printing sowing and conventional sowing, and field experiments between MTHS and CMT were conducted using hybrid rice cultivars Taiyou 390 and Wuyou 308 at Liuyang, Hunan province and using Wuyou 308 at Zhaoqing, Guangdong province. The results showed that leaf age, white root number, total root number, basal width of shoot, dry weight of shoot and dry weight of root of the printing sowing were more than those of the conventional sowing at two locations. The MTHS had significantly less maximum tiller number and effective tiller number than CMT, but had more spikelets per panicle and spikelets per m^2, higher grain setting rate and 1000-grain weight, as well as significantly increased grain yield by 10.28-13.96%. On the other hand, The MTHS had more primary branch number and secondary branch number, longer panicle length, higher grain density and panicle weight than CMT, with significant differences. Although the MTHS had less dry matter accumulation and lower LAI than CMT before the heading stage, produced more dry matter at physiology maturity and had significantly higher harvest index and radiation use efficiency. Therefore, the MTHS could produce high grain yield for hybrid rice due to not only reducing sowing rate and improving seedling quality, but also increasing spikelets per panicle, spikelets per m2 and 1000-grain weight and improving grain setting rate, harvest index and radiation use efficiency.