播期对机插晚稻甬优2640生长特性的影响

以籼粳杂交晚稻品种甬优2640为研究对象,于2012、2013年在金华市进行分播期机插晚稻试验,并结合气象资料,分析播期对晚稻生长特性及产量的影响,探讨该品种在机插栽培方式下在研究区的最迟适宜播期.结果表明：（1）随着播期推迟晚稻全生育期呈先缩短后延长的变化趋势,播种-齐穗天数在秋季冷空气影响早的年份表现为先缩短后延长,冷空气影响晚则表现为全生育期缩短；（2）甬优2640表现出杂种优势,最大产量达9964.5kg/hm2,最大群体颖花量达44512.5×104/hm2；（3）晚稻产量随着播期的推迟而降低,播期对结实率影响最大,结实率为产量变化的主要影响因素,播期对群体颖花量影响较小,对千粒重基本无影响；（4）晚稻孕穗抽穗期遇低温其育性降低,但具有一定的低温耐受能力,齐穗前25d内23℃负积温是结实率最敏感的低温因子,齐穗前23℃负积温≤16.6℃·d能够保障晚稻稳产；（5）以80％保证率下的23℃负积温≤16.6℃·d的终日日期作为安全齐穗期,机插晚稻甬优2640最迟适宜播种期为6月29日-7月2日.

Effects of Different Sowing Date on Growth Characteristics of Yongyou 2640 as Mechanical Transplanting Late Rice

Taking japonica-indica hybrid late rice variety of Yongyou 2640 as material, field experiments of mechanical transplanting late rice were conducted under different sowing date in Jinhua, Zhejiang province in 2012 and 2013. Based on experiment and meteorological data, the effects of sowing date on growth characteristics and grain yield of late rice were analyzed. The latest suitable sowing date of the late rice variety was studied under mechanical transplanting method in the research area. The results showed that, with the delay of sowing date, whole growing days of late rice were initially decreased and then increased, sowing-full heading days were initially decreased and then increased in the year of cold air activity early in fall, and they were decreased when cold air activity late. Yongyou 2640 showed heterosis, with maximum grain yield 9964.5kg/ha and maximum population spikelets 44512. 5 x 104 No./ha. Grain yield of late rice was decreased with the delay of sowing date, seed setting rate was influenced obviously by sowing date, so it was the key influence factor of grain yield variation. Population of spikelet was less influenced by sowing date, and 1000-grain weight was less influenced. The fertility of late rice was reduced if it met low temperature during booting to heading stage, but it had certain tolerance ability to low temperature, negative accumulated temperature of 23℃ in 25 days before full heading date was the most sensitive accumulated temperature of 23℃ was not greater than 16. 6℃ low temperature factor, the condition · d could ensure stable yield of late rice. of negative accumulated temperature of 23℃ less than 16.6℃· d under the 80% assurance rate was that negative The final date regard as safe full heading date, so the latest suitable sowing date of Yongyou 2640 was from June 29 to July 2 as mechanicaltransplanting late rice.