常优一号杂粳机插高产形成规律及调控关键技术研究

High-yielding Formation Law and Key Regulatory Technologies of Machine-transplanted Japonica Hybrid Rice Changyou No.1

以杂粳"常优一号"为试验材料,通过丰产示范与专题试验,分析探讨其高产形成规律及其调控关键技术。结果表明,每穗粒数与产量的关系,最为密切,呈极显著正相关,各产量构成要素对产量贡献作用,以每穗粒数的作用最大,其次为有效穗,再次为结实率与千粒重。其直接通径量,每穗粒数高达1.958,分别为有效穗、结实率、千粒重的1.88、3.12和5.35倍。在适度足穗的前提下,主攻大穗、增加粒数,对于夺取高产,乃至超高产,尤其重要。试验结果还表明,不同施N水平与穴栽苗数对产量及构成要素均有积极的调控效应。合理施N有显著的增穗和增粒作用,但并非越多越好。增苗虽有增穗的积极作用,但减粒的负效则更大。由此提出,常优一号在机插栽培条件下,其适宜指标为270.0万穗/hm2,每穗165粒,结实率>85%,千粒重≥27 g,施N量270 kg/hm2,穴栽≤2苗。

The hybrid japonica rice ＂Changyou No.1＂ was used to study the high-yielding formation law and its key regulatory technologies by the high-yielding demonstrations and special tests.The results showed that the grains per spike and yield were mostly related,and they were significantly positively correlated.Grains per spike had the greatest contribution to yield,followed by the effective spikes,seed setting rate and 1000-grain weight.The direct path coefficient of grains per spike was 1.958,which was 1.88 times of effective spikes,3.12 times of seed setting rate,and 5.35 times of 1000-grain weight.Therefore,big spikes and adding grains per spike were important to high yield under the condition of the moderate enough effective spikes.The results also indicated that different nitrogen application levels and seedlings per hole had positive control effect to the yield and its components.Reasonably applying nitrogen fertilizer could increase the spikes and the grains,but not the more the better.Adding the seedlings was benefit for adding the spikes,but it had great negative effect to the grains.Therefore,under the condition of machine-transplanting,Changyou No.1＇s suitable spike number was 2700000/hm^2,suitable number of grain per spike was 165,seed setting rate was more than 85%,1000-grain weight ≥27 g,nitrogen application rate was 270.0 kg/hm^2,and the number of seedlings per hole ≤2.