江汉平原杂交早稻安全播种育秧气温指标试验

Air Temperature Index for Safety Seedling Raising of Early Hybrid Rice of the Double-Cropping System in Jianghan Plain

利用荆州农业气象试验站2009、2011、2012年杂交早稻分期播种和2012年盆栽低温控制试验数据,验证杂交早稻安全播种育秧平均气温、平均最低气温界限指标,并分析日平均气温稳定通过10℃初日变化。结果表明,杂交早稻适宜播种期平均气温指标为10.7～16.5℃,平均最低气温指标为6.8～11.7℃。播种后8～10℃低温处理持续3、4、5 d,与对照相比出苗率分别降低10、17、31个百分点,处理1～2 d对出苗率影响不大,但播种至出苗间隔日数延长。江汉平原稳定通过10℃初日历年平均日期为3月24日,达80%保证率初日为3月30日,从下一茬双季杂交晚稻安全齐穗考虑,其现行中熟偏迟杂交籼型早稻播种期宜安排在3月下旬中后期,根据天气预报在冷头泡种,冷中催芽,冷尾暖头抢晴播种薄膜秧。

Abstract： The field experiments about different sowing dates in 2009, 2011, 2012 and the pot culture control experiment with low air temperature in 2012 were conducted to verify the average air temperature and mean minimum temperature index- es for safety seedling raising of early hybrid rice of the double-cropping system in Jianghan plain. In addition, the variation of beginning date steadily passing 10 ℃ was analyzed. The results indicated that the threshold and the suitable mean air tem- perature index for early hybrid rice was 10.7-16.5 ℃ and the average minimum air temperature index was 6.8-11.7 ℃. The e- mergence rates of early hybrid rice treated with 8-10 ℃ air temperature for 3, 4, and 5 days decreased by 10, 17, and 31 percentage points respectively. Although it did not reduced when treated for 1 or 2 days, but the duration days from sowing to seedling emergence prolonged. Based on the average date and 80% guaranteed rate of beginning date of steadily pass 10~ was March 24 and March 30, suitable sowing date of indica-type early hybrid rice should be scheduled from March 25 to 31, which should be seed soaking and accelerating germination when cold air intrusion, and sowing at the end of low tem- perature in order to safety full head for late hybrid rice, in accordance with weather forecast.