不同机栽方式下杂交稻产量及其形成特征比较

摘要

为寻求能够更好发挥杂交水稻产量潜力的机栽方式，解决好现有机插杂交水稻秧苗素质弱、盘根难、大田移栽漏穴率高等难题，以甬优2640、Y两优1号为材料，设置钵苗、毯状大苗、常规毯苗3种机栽方式，在高产栽培条件下系统比较研究了其产量差异及其形成。结果表明，钵苗和毯状大苗产量极显著高于常规毯苗（P<0.01），甬优2640和Y两优1号钵苗实际产量分别高20.70%和20.81%，毯状大苗分别高12.26%和12.94%。钵苗机插由于采用壮秧带土移栽，几无缓苗期，群体茎蘖消长平稳，群体高峰苗数分别为最终穗数的1.2和1.3倍，最终成穗率80%左右，生育中、后期光合系统配置优，群体生长率和净同化率高，抽穗至成熟期物质积累量和积累比例高，单茎物质输出与转运协调性好，最终实际产量最高。毯状大苗机插方式可培育35 d左右秧龄壮秧，带大蘖移栽，但秧苗返青活棵后，由于低位无效分蘖少，高峰苗数显著少于常规毯苗机插（P<0.05），为最终穗数的1.4倍左右，最终成穗率70%左右，生育中后期光合系统配置优于常规毯苗机插稻，群体生长率和净同化率等群体指标虽不及钵苗但明显优于常规毯苗，最终毯状大苗实产极显著高于常规毯苗（P<0.01）。该文为发展机插杂交稻提供了参考。%Planting mechanization is a main tendency of the whole-course mechanization development in rice production in China; and the rice mechanized transplanting ratio was more than 38% across the country in 2014. Mechanical transplanting rice can enhance the working efficiency and increase planting income. However, the current varieties of mechanical transplanted rice are mostly conventional rice, and the hybrid rice varieties are less used, due to some problems that cause hybrid rice cultivar can’t be applied to mechanical transplanting. In order to explore the better technology of mechanical transplanting for exerting the high yield of hybrid rice, and to solve the problems such as the weak seedlings, packing difficulty and high drain hole in field of mechanical transplanting hybrid rice, a field experiment was conducted using hybrid rice cultivars which respectively were Yongyou 2640 (japonica hybrid rice) and Y Liangyou 1 (indicia hybrid rice) in the demonstration base of Huaiyin District and Xuyi County in Jiangsu Province. Three different mechanical transplanting methods were adopted, which included mechanical transplanting of pot seedling (PS), mechanical transplanting of old blanket seedling (OS) and mechanical transplanting of conventional blanket seedling (CS). in The climate conditions in 2014 were representative and consistent with those of recent 3 years in precipitation, sunshine and temperature. The seedling rate in each bowl seedling tray was 40 gram and 35 gram with japonica hybrid rice and indicia hybrid rice respectively for the mechanical transplanting of PS, 60 and 50 gram respectively for the mechanical transplanting of OS, and 80 and 60 gram respectively for the CS. The 3 different ages for mechanical transplanting seedling were 30, 35 and 22 d, and seedlings with different mechanical transplanting were transplanted in the plot of 90 m2 (15 m × 6 m) seperately. The nitrogen fertilizer amounts of japonica hybrid rice and indicia hybrid rice were 300 and 225 kg/hm2, respectively. The other management measures were uniform with high-yield cultivation. In this experiment, we investigated the yield and its components, the number of culms and tillers, the leaf area index, the composition of leaf area, photosynthetic potential(pp), dry matter production and accumulation, crop growth rate (CGR) and net assimilation rate (NAR) and matter transport in culm and sheath in the high-yield cultivation. Results showed that, the population spikelets of PS and OS were significantly (P<0.05) or very significantly (P<0.01) higher than CS, the filled-grain percentage and 1000-grain weight were slightly higher than CS, and the actual yields of PS and OS were significantly higher (P<0.01) than that of CS, which increased by 20.70%-20.81% and 12.26%-12.94% respectively. The high yield of PS was attributed to seedlings transplanted with soil, shorter rejuvenation period, steady dynamic of tillers, appropriate peak tillers, higher percentage of productive tiller (80%), higher PP, CGR and NAR, greater dry matter accumulation in the middle and late growth stage, and coordinating matter output and transport. The reason of high yield of OS was that its seedling age could extend to 35 d and was transplanted to field with strong tillers, and that the peak tillers were fewer, the percentage of productive tiller was higher (70%), the indices of population were significantly better than CS. Based on the above system analysis, the paper was also suitable for production verification and scientific evaluation on the mechanical planting approach of high-yielding hybrid rice. This article provides an important reference to the development of mechanical transplanting hybrid rice.