不同断水及收获期对南方优质晚粳稻产量和品质的影响

Effects of Water Irrigation Cut-off and Harvest Date on the Grain Yield and Quality of High-quality Japonica Rice during the Late-rice Cropping Season in Southern China

为探究南方稻区优质晚粳稻适宜的断水及收获时期,2014~2015年以常规粳稻镇稻11号及籼粳杂交稻甬优2640为材料,探讨了不同断水时间(抽穗后28、35、42、49 d)、不同收获时期(抽穗后35、40、45、50、55 d)对晚粳稻籽粒充实度、产量及品质的影响。结果表明:在本试验条件下,每延迟1 d断水,镇稻11号及甬优2640产量分别增加21~23 kg/hm^2及31~35 kg/hm^2;每延迟1 d收获,两个品种产量分别增加63~66 kg/hm^2及102~104kg/hm^2。断水(或收获)时期延迟,晚粳稻出糙率、精米率及整精米率增加,垩白粒率及垩白度降低,胶稠度及直链淀粉含量增加。抽穗后42~49 d断水或抽穗后50~55 d收获,晚粳稻产量及千粒重差异均不显著,稻米品质也差异不显著。可见,在江西中部稻区,晚粳稻抽穗后42~49 d断水及抽穗后50~55 d收获较适宜。

In order to explore the suitable water irrigation cut-off and harvest date of high-quality japonica rice during the late-rice cropping season in Southern China,the varieties of conventional japonica Zhendao 11 and indica-japonica hybrid rice Yongyou 2640 were used as the experimental materials in 2014-2015.The water treatment was set to stop irrigation at 28,35,42 and 49 d after heading respectively,and the different harvest date treatments was set to harvest at 35,40,45,50 and 55 d after heading respectively.All the treatments were harvested at 55 d after heading.The effects of water irrigation cut-off and harvest date on the grain filled grade,yield and quality of late japonica rice were studied.The results showed that:the yields of Zhendao 11 and Yongyou 2640 increased 21~23 kg/hm^2 and 31-35 kg/hm^2 as delaying water irrigation cut-off 1 d,and their yields increased 63-66 kg/hm^2 and 102-104 kg/hm^2 respectively for every each day of delayed harvest.As the delay of water cut-off or harvest date,the brown rice rate,milled rice rate,whole milled rice rate,gel consistency and amylase content of late japonica rice were increased,and the chalkiness rate,chalkiness degree of late japonica rice were decreased.The yield and 1000-grain weight of late japonica rice showed no significant differences when cutting off water irrigation between 42-49 d after heading(or harvest between 50-55 d after heading),and there was no significant difference in rice quality.So water was cut off at 42-49 d after late japonica rice heading and harvest at 50-55 d after heading were more suitable for the late japonica rice in the rice region of central Jiangxi.