播期对浙东南地区直播晚粳稻产量、生育期及温光利用的影响

为筛选适宜在浙东南地区作受灾补播的直播晚粳稻品种,选用3个籼粳杂交稻(甬优1540、甬优7850、嘉优中科3号)和2个常规粳稻(秀水519、秀水417),开展大田分期直播试验,研究不同播期对水稻产量及产量构成因素、生育期和温光资源利用的影响。结果表明,水稻产量表现为籼粳杂交稻>常规粳稻,具体为甬优1540>甬优7850>嘉优中科3号>秀水519>秀水417,随着播期的推迟,产量均呈下降趋势,下降幅度为籼粳杂交稻>常规粳稻,播期每推迟5 d,籼粳杂交稻平均产量下降0.71 t·hm^-2,常规粳稻下降0.30 t·hm^-2,主要与每穗粒数和结实率显著降低有关;水稻生育时期随播期推迟而相应顺延,且播种-齐穗期、齐穗-成熟期等生育阶段缩短,籼粳杂交稻全生育期缩短幅度大于常规粳稻;水稻全生育期的有效积温、日照时数及其利用率和有效积温生产效率随播期推迟基本呈下降趋势,同一播期内,籼粳杂交稻有效积温生产效率高于常规粳稻。产量与齐穗-成熟期的温光资源呈显著或极显著正相关。救灾品种若在7月15日前补播,籼粳杂交稻首选甬优1540,其次为甬优7850,而常规粳稻宜选用秀水519,且播期可推迟至7月20日。本研究结果可为浙东南地区受灾后,采用直播技术选择适宜救灾补播品种提供实践指导与科学依据。

Effects of Seeding Dates on Grain Yield,Growth Period and Utilization of Temperature and Sunshine of Late Japonica Rice Under the Direct Seeding in Southeastern Zhejiang Province

To screen the suitable late japonica rice cultivars for disaster relief and reseeding in the southeast area of Zhejiang province, we directly seeded three indica-japonica hybrid rice cultivars (Yongyou 1540, Yongyou 7850 and Jiayouzhongke 3) and two inbred japonica rice cultivars (Xiushui 519 and Xiushui 417) by staged in the field, and analyzed the effects of different seeding dates on the grain yield and yield components, growth period and utilization of temperature and sunshine resources. The results showed that the grain yield of indica-japonica hybrid rice was higher than that of inbred japonica rice, specifically Yongyou 1540 > Yongyou 7850 > Jiayouzhongke 3 > Xiushui 519 > Xiushui 417. With the delay of seeding date, the grain yield showed a downward trend, which the decreasing range was indica-japonica hybrid rice > inbred japonica rice. For each delay of seeding date for 5 d, the average grain yield of indica-japonica hybrid rice decreased by 0.71 t·hm^-2, and that of inbred japonica rice decreased by 0.30 t·hm^-2, which was mainly due to the significant reduction of grain number per panicle and seed setting rate. The growth stages of rice were postponed correspondingly with the delay of sowing date, and the growth stages of seeding-full heading and full heading-maturity were shortened. The whole growth periods of indica-japonica hybrid rice were shorter than those of inbred japonica rice. During the whole growth period of rice, the effective accumulated temperature, sunshine hours, and their utilization efficiency, and production efficiency of effective accumulated temperature of all the cultivars basically decreased with the delay of seeding date. The production efficiency of effective accumulated temperature of indica-japonica hybrid rice was higher than that of inbred japonica rice at the same seeding date. The grain yield was significantly positive correlated with the resources of temperature and sunshine from the heading to maturity. Yongyou 1540 was the first choice for indica-japonica hybrid rice cultivars suitable for disaster relief before July 15, followed by Yongyou 7850. Xiushui 519 was the first choice for inbred japonica rice cultivars, and the seeding date could be delayed until July 20. The results of this study could provide practical guidance and scientific basis for selecting suitable cultivars by direct seeding technology after disaster in the southeastern Zhejiang province.