春季低温霜冻对玉米生育及产量的影响

Effect of Spring Low Temperature and Frost Damage to the Growth and Yield of Maize

利用临夏州6个气象站1992—2012年4—5月逐日气温、地温资料，结合临夏地区4—5月出现低温、晚霜冻等灾害性天气的前期气候特点和变化规律，分析研究临夏州春季日平均气温稳定通过10℃TX-5-10cm地温稳定在8-10℃时段的变化。通过2011—2012年的试验数据分析，4月5日_5月5日播种的各个期次，日平均气温在13．0～17．4℃，株高、茎秆和叶面积增加明显，玉米整体生长状况良好。结果确定了临夏州玉米最适宜播种期，能更好地避开低温、晚霜冻对玉米苗期及后期产量的影响，为当地玉米稳产高产提供充分的科学依据。

On the basis of the daily air temperature and earth temperature data of the months 4 ＆ 5 during the years 1992 to 2012 from 6 meteorological sta- tions in State Linxia, combining the characters and variation patterns of the climate during the prophase of the occur- rence of disastrous weather conditions such as low temperature, late frost, etc. in State Linxia in the months 4 ＆ 5, the variation of time interval during which the daily average air temperature passed through 10~C steadily and in which the 5 cm-to-10 em-deep earth temperature remained in the range 8-10~C in State Linxia during spring were analyzed and researched. By analyzing the experimen- tal data of the years 2011 ＆ 2012, for each batch sowed from April 5th to May 5th, while the daily average air tempera- ture in the range 13.0-17.4~C, the plant height, stem diameter and leaf area aug- mented manifestly, and the integral growth state of the maize was good, Our conclusion confirmed the optimal sow- ing time of maize in Linxia, to avoid the disastrous effects on the emergence time of maize and the post phase yield from the low temperature and late frost more efficiently, and provided sufficient and scientific foundations to the stable and high yield of maize in the location.