华北地区播种量不同时旱稻产量的形成

为探明旱稻新品种旱稻297在华北地区的产量形成并确定适宜的种植密度,在2003年120 kg/hm2播种量基础上,2004年增设更为节约的60和90 kg/hm22个播种量,研究不同种植密度下的产量构成。结果显示:2004年60、90和120 kg/hm2播种量的产量分别为3.8、3.5和3.4 t/hm2;成熟期3个播量地上部生物量(单位面积内旱稻植株茎、叶、穗的总干重)在1 005.0~1 283.4 g/m2范围内无显著差异;收获指数分别为0.36、0.34和0.26,随播种量增大而依次降低,且120 kg/hm2播种量显著低于其他2个播种量。从产量构成因子来看,颖花数少是本试验旱稻产量低的主要原因;结实率对产量的作用受环境影响,年际间差异较大。总之,2004年60 kg/hm2播种量表现出较好的群体结构,在单株最高分蘖数、分蘖成穗率、穗粒数和结实率上都优于其他2个播种量;而90 kg/hm2播种量在相同条件下单位面积的颖花数最高。因此,60~90 kg/hm2播种量的旱稻群体在生产中具有进一步提高产量水平的潜力,是比较适宜的播种量。

Yield of aerobic rice at different seeding rates in North China

To study the yield of an aerobic rice variety,HanDao297(HD297),and determine a reasonable planting density,a field experiment was carried out in 2003 and 2004.The seeding rate was 120 kg/hm~2 in 2003 and three seeding rates60,90 and 120 kg/hm~2-were used in 2004.The grain yields(t/hm~2) at the three seeding rates were 3.8,3.5,and 3.4 respectively.The aboveground biomass at maturity varied from(1?005.0?g/m~2) to(1?283.4?g/m~2) and the differences among the three seeding rates were not significant.The harvest index(HI) was 0.36 for 60?kg/hm~2,0.34 for 90?kg/hm~2,and 0.26 for 120?kg/hm~2 and the HI at 120?kg/hm~2 was significantly lower than the other two rates.Generally,the small glume number led to the low yields of aerobic rice.Percentage of filled spikelets affected yields as did the variation in growth environment but grain weight had little effects on yields.For Han Dao 297,the best population density for maximum number of total and productive tillers,spikelet number per panicle,and percentage of filled spikelets was for 60?kg/hm~2.However,the number of glumes per unit area was highest at 90?kg/hm~2.Therefore,the seeding rate of 60-90?kg/hm~2 is recommended for high grain yield.