不同播种量对直播杂交稻产量及干物质生产的影响

Effects of Different Seeding Rates on Grain Yield and Dry Matter Production of Direct-seeding Hybrid Rice

为了探明直播杂交稻在不同播种量下的生长与产量表现,以杂交稻隆两优1212、隆两优华占、晶两优华占为材料,采用人工撒播栽培方式进行不同播种量(11.25,22.50,33.75 kg/hm^2)大田试验。结果表明,随着播种量的增加,3个品种的产量和成熟期干物重表现为增加趋势;不同播种量主要通过调节有效穗、每穗总粒数来影响产量。与中播种量处理相比,高播种量处理产量增加幅度较小,而用种量大幅增加,综合产量和种子成本,杂交稻直播栽培的播种量以22.5 kg/hm^2为宜。

In order to clarify the effects of different seeding rates on the growth and grain yield of direct-seeding hybrid rice, a field experiment with three hybrid rice Jingliangyou Huazhan） was conducted at Changsha in varieties （Longliangyou 1212, Longliangyou Huazhan and 2016. The seeding rate treatments were established as the low rate （ 11.25 kg/hm^2 ）, medium rate （22.50 kg/hm^2 ） and high rate （33.75 kg/hm^2 ） by artificial broadcasting. The results showed that the grain yield and the dry matter accumulation at maturity stage showed an increased tendency with increased direct-seeding rates. The grain yield of different seeding rate treatments was mainly affected by the number of effective panicles and the number of spikelets per panicle. Compared with the medium seeding rate, the high seeding rate increased grain yield a little but needed much more seeds. It follows that the medium seeding rate （22.5 kg/hm^2 ） can be seen as the suitable seeding rate of direct-seeding hybrid rice in consideration of both grain yield and seed cost.