摘要： 三年试验结果表明，影响夏播小麦生育性状和产量的生态因素，是小麦灌浆期和全生育期内日平均气温。不同海拔产量差异显著性测定结果表明，海拔在1200米以上是张家口坝下丘陵山区夏播小麦种植的适宜海拔范围，亦即全生育期日均温为14.7-19.8℃，灌浆期日均温为13.6-19.2℃。不同海拔与日均温、产量和生育性状回归关系表明，海拔由80O-1800米每升降100米，日均温减增0.9-O.8℃，亩产量增减141公斤，千粒重增减0.54克，植株高度增减3.7厘米。根据不同海拔梯度上不同品种、不同播期与产量的双因方差分析结果表明，在北纬39º50´的 蔚县，适宜品种以涿城1号为主，搭配公17和中7606；适宜播种期，在海拔1200米处为6月中下旬，1400米处为6月中旬，1600米处为6月上中旬，1800米处为6月上旬。而在北纬40º58´的崇礼县，适宜品种以公17为主，搭配涿城1号和中7606；适宜播种期，在海拔1200米处为5月中下旬，1400至1600米处皆为5月下中旬，1800米处为5月下旬。由于崇礼县比蔚县纬度北移1度，其播种期相应提早20天左右。小麦成熟期分别在当地早霜期之前的9月份陆续到达。不同海拔不同纬度的播种期，是由当地的温度条件决定的。

关键词: 小麦, 夏播, 日平均温度

Abstract: The result of path analysis shows that the ecological factors affecting characters and the yield of summer wheat are daily mean temperatures during the filling period and the whole growing season.The test of the sigrificance of yield difference at different eltitudes indicates:The optimum area for Summer-sown wheat is on Zhang Jiakou Baxia hilly region,its altitude is 1200 M above sea level.In this area,the daily mean temperature is 14.7-19.8℃ during the growing season and 13-6-19.2℃ in the filling period.The relationship of regression coefficient between the altitude and daily mean temperature;the yield and its growth charaters shows:when the elevation goes up by 100 M in the range of 800-1800 M,the daily temperature lowers 0.9-0.8 ℃,the yield per mu,the weight of 1000 seeds and the plant height in-crease 14.1 kg,0.54 g and 3.7 CM respectively.A two-factor analysis of variance between the cultivars sowing time and yield at different altitudes indicates that in Yu county which is located at 39°50’north latitude the most suitable cultivar is Zhuocheng 1,then Cong 17 and Zhong 7606;the optimal sowing time is the later half of June at 1200 M altitude,arounde middle of June at 1400 M,the early half of June at 1600 M and in the first ten-day period of June at 1800 M.In Chong Li county of 40°58’north latitude,the most suitable cultivars are Cong 17,then Zhuocheng 1 and Zhong 7606;the optimal sowing time is in the later half of May at 1200 M,around the middle of May at 1400-1600 M,and in the last ten-day period of May at 1800M.Compared to Yu county,Chong Li county is one degree to the north,so the sowing time should be 20 days earlier.The mature period of wheat is in September.But,the sowing time at different latitudes and altitudes depends on the local temperature.

Key words: Wheat, Summer-sown, Daily mean-temperature