以武运粳31号为试验材料，探讨了机插密度（机插规格或抓苗量）对其茎蘖成穗率及产量的影响，以明确分蘖力中等、穗型中等水稻品种高产群体的适宜机插密度。结果表明，武运粳31号机插，在行株距为29.7 cm×12.5 cm、抓苗量为4株左右时，茎蘖成穗率、有效穗数、结实率和产量均较高，是适宜的机插密度。

In order to determine the mechanical planting density of medium tillers and medium panicle type rice varieties, discuss the effects of mechanical planting density on the yield and spike rate, an experiment was conducted using Wuyungeng 31 as material. The results showed that the yield was the highest when the plant spacing of Wuyungeng 31 is 29.7 cm×12.5 cm and 4 seedlings per hill, it had high spike rate, effective panicles and seed setting rate. It was the appropriate density of Wuyungeng 31 in production.