播期和密度对麦茬中粳稻皖稻68生育期和产量形成的影响

研究不同播期和移栽密度试条件下皖稻68的生育期和产量形成的变化情况，结果表明，皖稻68生育期天数随播期的推迟而递减，但推迟到6月14日播种仍可正常成熟；移栽密度对生育期无明显影响。不同播期同期栽插的，随播期推迟产量下降，但因秧龄长短的原因，穗数随播期推迟而增加，每穗粒数、结实率和千粒重递减；增加移栽密度有利于增加穗数而增产。本试验条件下皖稻68作为沿淮麦茬稻栽培，育秧移栽的以5月5日和15日播种，移栽密度为30.0万/hm2和40.0万/hm2产量最高，机插秧以5月25日左右播种为宜，直播稻以6月4日至14日为播种适期。

The effect of Sowing date and density of rice stubble in WanDao 68 reproductive period and yield formation

Areas along the Huai River in Anhui Province-using field test method-in order to give rice stubble' s light-simple Cultivation to provide technical support such as machine planting and live, and reseach the con-ditions of the different sowing date and transplanting density in the WanDao 68 growing period and yield chang-es. The results show that the growth period of WanDao 68 is reduced with the delayed sowing time, but deferred to the June 14 seeding still may be normal ripe; transplanting density on the growth period had no significant ef-fect. Different sowing dates of planting in the same period, production is declined with the sowing date post-poned, but the reasons for the length of seedling age, spike is increased with the sowing date postponed, each kernel number, seed setting rate and grain weight is decreased; With the increased spike, Increasing transplant-ing density of late sowing can increase the number of output. Under the experimental conditions-WanDao 68 as rice stubble cultivation-the period of the highest yield is transplanting seedlings is the May 5 and 15 day plant-ing, transplanting density of 300 000/hm2 and 400 000/hm2 Machine-planting' s appropriate planting date is May 25, direct seeding rice is 4-14 June period for the planting appropriate.