不同播期及秧龄对机械栽插晚稻产量形成的影响

Effects of sowing date and seedling age on the yield of late rice with mechanical transplanting

采用大田试验,设计15d(Y1)和20d(Y2)2个秧龄以及6月25日(播期一,B1)、6月30日(播期二,B2)、7月5日(播期三,B3)3个播期处理,以探讨机械插秧下秧龄和播期对晚稻产量的影响。结果表明:播期二和播期一的产量间无显著差异,但分别高于播期三产量8.7%、3.5%,随着播期延后,播期三各产量构成因子除千粒重外,呈下降趋势。H优518最高产量相比最低产量降低速度显著高于鄂粳403,分别达45.0%、13.5%,花后干物质积累H优518也显著大于鄂粳403。综合分析可知,晚籼稻比晚粳稻对低温反应更敏感,前者高产需提早播种,推迟播期不利于结实灌浆,后者高产也需在较早播种基础上保证足够苗数,两者秧龄都不宜超过20d。播期和秧龄可能导致生理上的变化,还需要进一步研究。

Two seedling age （Y1 ,15 d and Y2,20 d） and three sowing date （B1 25th June,B2： 30th June and B3： 5th July） were used to study the effects of sowing date and seedling age on grain yield of late rice with mechanical transplanting.The results showed that the yield of B2 and B1 were no significantly different, but 8.7% and 3.5% higher than that of B3.The yield components except 1 000-grain weight decreased with delaying the sowing date.The yield of Hyou 518 and EJ 403 decreased from the highest yield to lowest yield were 45% and 13.5% , respectively.The post-heading biomass accumulation of the former was significantly lower than that of the latter.The yield of Y1 of B2 and B3 was 0.2 t/hm^2 higher than that of Y2 except B1 , because the booting stage of B1 through high temperature led to a significant decrease of spikelet.The late indica rice under low temperature was more sensitive than the late japonica rice.The former must be sown early for high yield , because the delayed sowing date may be against the grain filling.The latter one for high yield should be sown early to have enough seeds.The seeding age of both should be less than 20 d. Further studies are needed to investigate the physiological changes caused by sowing date and seeding age.