淮北地区优质食味粳稻温光适应性和最佳播种期

【目的】 探明淮北地区不同温光条件对优质食味粳稻产量的影响。 【方法】 以优质食味中熟中粳南粳2728和南粳505,迟熟中粳南粳9108和福粳1606为试验材料,设置5月10日（S1）、5月17日（S2）、5月24日（S3）、5月31日（S4）、6月7日（S5）、6月14日（S6）、6月21日（S7）7个播期处理。研究不同播期处理下水稻产量、生育期、日均温度、积温和日均辐射量的差异,水稻产量与日均温度、积温、日均辐射量的相互关系。 【结果】 （1）随播种期的推迟,水稻产量显著下降。播种期每推迟7 d,中熟中粳和迟熟中粳产量分别降低0.49 t·hm ^-2、0.63 t·hm ^-2。（2）随播种期的推迟,播种至拔节期、拔节至抽穗期和全生育期天数呈下降趋势。抽穗至成熟期生育天数呈增加趋势,迟熟中粳S5—S7处理不能正常成熟,抽穗至成熟期生育天数缩短,2种类型水稻产量与全生育期天数极显著正相关。（3）随着播种期的推迟,播种至拔节期日均温度显著升高,拔节至抽穗期、抽穗至成熟期和全生育期日均温度显著下降。2种类型水稻产量与播种至拔节期日均温度极显著负相关,与拔节至抽穗期、抽穗至成熟期和全生育期日均温度极显著正相关。（4）2种类型水稻播种至拔节期、拔节至抽穗期、抽穗至成熟期和全生育期积温随播期推迟均呈下降趋势。播种期每推迟7 d,中熟中粳和迟熟中粳全生育期积温分别降低106.6℃、123.1℃。2种类型水稻产量与各生育阶段积温极显著正相关。（5）随播种期推迟,全生育期日均辐射量显著下降,中熟中粳产量与拔节至抽穗期和全生育期日均辐射量极显著正相关,与播种至拔节期和抽穗至成熟期日均辐射量呈正相关关系。迟熟中粳产量与播种至拔节期日均辐射量显著正相关,与全生育期产量极显著正相关,与拔节至抽穗期和抽穗至成熟期日均辐射量正相关。【结论】在稻麦两熟的淮北地区,与光照相比,产量对温度的响应更为敏感。在播期范围内,各生育阶段积温越高,水稻产量越高。为了保证2种类型优质粳稻能够安全成熟,中熟中粳和迟熟中粳应分别于6月14日和5月31日之前播种。当2种生育类型水稻播种期在5月10日至5月24日,水稻能获得较高的产量。

Temperature and Light Adaptability of High-Quality Japonica Rice and Optimum Seeding Date in Huaibei Region

【Objective】The objective of the study was to elucidate the effects of different temperatures and light on the yield of high-quality japonica rice in Huaibei region.【Method】Taking medium-maturing medium japonica rice (MMMJ) Nanjing2728 and Nanjing505, late-maturing medium japonica rice (LMMJ) Nanjing9108 and Fujing1606 as experimental materials, seven seeding treatments were set on May 10 (S1), May 17 (S2), May 24 (S3), May 31 (S4), June 7 (S5), June 14 (S6) and June 21 (S7). The effects of rice yield, growth period, mean daily temperature, accumulated temperature and mean daily radiation under different seeding dates, as well as the correlation between yield and mean daily temperature, accumulated temperature and mean daily radiation were studied.【Result】(1) The yield of rice decreased significantly with the delay of seeding time, the seeding date was postponed every seven days, and the yield of MMMJ and LMMJ was reduced by 0.49 t·hm ^-2 and 0.63 t·hm ^-2, respectively. (2) With the delay of seeding time, the number of days from seeding date (SD) to stem elongation (SE), stem elongation (SE) to heading (HE) and the whole growth period showed a decreasing trend. The number days from heading (HE) to maturity (MA) showed an increasing trend, LMMJ S5-S7 could not ripen normally, and the number of days from HE to MA decreased. There was a significant positive correlation between the yield of two types of rice and the days of the whole growth period. (3) With the delay of seeding time, the mean daily temperature increased significantly from SD to SE, and decreased significantly from SE to HE, HE to MA and the whole growth period. (4) The yield of the two types of rice was negatively correlated with the mean daily temperature from SD to SE, and positively correlated with the mean daily temperature from SE to HE, HE to MA and the whole growth period. The accumulated temperature of each growth stage of two types of rice decreased with the delay of seeding time. The seeding date was postponed every seven days, the accumulated temperature in the whole growth period of MMMJ and LMMJ was reduced by 106.6℃ and 123.1℃, respectively. There was a significant positive correlation between the yield of the two types of rice and the accumulated temperature at each growth stage. (5) The mean daily radiation in the whole growth period decreased significantly. There was a significant positive correlation between the yield of MMMJ and the mean daily radiation from SE to HE and the whole growth period, and a positive correlation between the mean daily radiation from SD to SE and from HE to MA. There was a significant positive correlation between the yield of LMMJ and the mean daily radiation from SD to SE, and a very significant positive correlation between it and the yield of the whole growth stage, and a positive correlation between it and the mean daily radiation amount from SE to HE and from HE to MA.【Conclusion】In Huaibei region, the rice yield was more sensitive to temperature than light. The higher the accumulated temperature at each growth stage was, the higher rice yield achieved. In order to ensure the safety and maturity of the two types of high-quality japonica rice, MMMJ and LMMJ should be sown before June 14 and May 31, respectively. When the seeding date was from May 10 to May 24, the two types of high-quality japonica rice yield could be higher.