农艺措施对成都平原两熟区机插超级稻长龄秧苗生长的影响

以超级稻II优602为材料，研究了播种量、播期和育秧盘类型等农艺措施对成都平原稻麦(油)两熟区机插稻长龄秧苗生长的影响。结果表明: (1)正常播期下超级稻长龄秧在播种后30~42 d，发根力虽有降低，但群体数量减少缓慢，根冠比、茎基宽度、单位苗高干重等指标均有所增加; 而播种后42~54 d，群体数量急剧减少，根冠比和单位苗高干重下降，发根力进一步降低。(2)推迟播期有利于提高苗床秧苗数量，但根冠比、单位苗高干重以及发根力等指标并无明显的提高甚至有所降低。(3)播种量为431.03~554.19 g m^-2时有利于兼顾长龄秧群体数量和个体素质。(4)当秧龄超过一定时期(播种后40 d左右)后穴盘育秧的效果更佳，无论进一步延长秧龄还是适当增加播种密度，均减缓秧苗素质和群体数量的下降。以上结果表明，在成都平原旱育方式下机插稻长龄秧的培育播期选择在4月15日左右，播种量选择431.03~554.19 g m^-2，秧龄在42 d左右，秧盘选择塑料硬穴盘为宜。

Effects of Agronomic Measures on Mechanical Transplanting Long-Age Seedlings of Super Rice in Rapeseed(Wheat)-Rice Planting Area of Chengdu Basin

The effects of agronomic measures including sowing norm,date and types of seedling tray on rice long-age seedlings,were studied by using super rice,II-you 602,in wheat(rapeseed)-rice planting area in Chengdu basin.The results indicated that in normal sowing time,though rooting ability of long-age seedlings decreased from 30 to 42 days after sowing,the population size of seedlings declined slowly,root-shoot ratio,width of stem base and dry weight per unit seedling height increased.However,between 42 and 54 days after sowing,the population size of seedlings decreased sharply,root-shoot ratio and dry weight per unit seedling height began to decline,and rooting ability of long-age seedlings continued to fall.With postponement of sowing time,the population size of seedlings increased,but root-shoot ratio,rooting ability and dry weight per unit seedling height not improved dramatically and even declined.The sowing norm of 431.03 to 554.19 g m-2 was beneficial to population size and individual quality.The effects of plastic cell-tray were better when seedling age over a certain phase(about 40 days after sowing),the descending of seedling quality and population size was slower,whether further seedling age was prolonged or sowing norm properly increased.The above results showed that sowing date of around April 15,sowing norm of 431.03 to 554.19 g m-2,using hard plastic cell-tray and seedling age of about 42 days were good for raising mechanical transplanting long-age seedlings by the dry raising method of rice seedlings in Chengdu basin.