秧龄对超稀播旱育秧模式杂交中稻的产量效应

【目的】研究杂交中稻超稀播旱育秧模式的产量效应。【方法】选用“冈优725”和“Ⅱ优838”2个杂交中稻品种为试验材料，每个品种设置2种育秧模式（常规密播旱育秧(对照)和超稀播旱育秧）和6种秧龄（45，51，57，63，69和75 d），分析育秧模式和移栽秧龄对杂交中稻生育进程、田间茎蘖数、经济性状和产量的影响。【结果】1）与常规密播旱育秧模式相比，超稀播旱育秧模式下，当秧龄超过51 d时，随秧龄的增加，杂交中稻全生育期显著延长，有效穗数、单穗着粒数、单穗实粒数、结实率、成穗率和单穗质量下降；当秧龄超过60 d时，水稻产量随秧龄延长而显著降低。2）当秧龄大于57 d时，超稀播旱育秧模式的最高茎蘖数较常规密播旱育秧模式显著（P<0.05）提高，且其提高程度随秧龄的增加而显著（P<0.05）增加。3）在超稀播旱育秧模式下，63和69 d秧龄的稻谷产量分别为9 047和8 247 kg/hm²，与常规密播旱育秧模式下45 d秧龄的稻谷产量（8 918 kg/hm²）相当。【结论】在川西北丘陵旱区，超稀播旱育秧模式有利于培育大龄壮秧，其秧龄可以延长至63～69 d，能有效缓解因旱迟栽带来的不利影响。

Yield effect of super-sparse and dry seedling method for hybrid rice

【Objective】 The study investigated the yield effect of super-sparse and dry seedling method for hybrid rice.【Method】 In this study,"Gangyou 725" and "Ⅱ You 838" were used as experimental materials,two seedling methods and six seedling ages were set as following:1) Two seedling methods included super-sparse and dry seedling method(SSD) and normal-density and dry seedling method(NDD);2) For each seedling method,we also set six seedling age(45,51,57,63,69 and 75 d).Number of stem and tillers,economic traits and grain yield of SSD were analyzed respectively,compared with that of NDD.【Result】 1) Compared with NDD,when seedling age was more than 51 d,full growth period was prolonged,effective panicles reduced,full grains per panicle decreased,grain number per panicle reduced,and grain weight per panicle of SSD decreased with the increase of seedling age.When seedling age was more than 60 d,rice yield reduced significantly with the increase of seedling age.2) When the seedling age was more than 57 d,the maximum number of stem and tiller of SSD increased significantly(P<0.05) compared with that of NND,and its amount increased with the seedling age.3) For SSD,rice yield was 9 047 and 8 247 kg/hm2 when seedling age reached 63 d and 69 d respectively;which is similar to NND(8 918 kg/hm2) when seedling age reached 45 d.【Conclusion】 In the hilly and northwest regions of Sichuan Province,NND method was better to breed older and stronger seedlings,its seedling age can be prolonged to 63-69 d in drought summer days,which effectively relieved negative impacts of seasonal drought on rice production.