白菜型冬油菜在北方不同生态区的生育期变化及复种潜力分析

Analysis of growth period variation and potential in multi-cropping of winter rapeseed in different ecological and environmental areas of northern China

研究北方不同生态区白菜型冬油菜的生育期差异,可为合理安排后茬作物、提高复种指数、优化种植制度提供依据。本研究以18份不同抗寒性白菜型冬油菜为材料,分析17个不同生态区冬油菜5年的生育期变化。结果表明：白菜型冬油菜在北方地区种植,总体表现为生育期在品种间、年份间差异较小,相差1~5 d左右;不同抗寒性的品种生育时期存在差异,抗寒性强的品种表现出越冬期延长（枯叶期提前,返青期推迟）,营养生长向生殖生长的过渡期相对缩短,花期缩短,但籽粒灌浆期、成熟期延长。而不同生态地区间生育期差异较大,突出地表现为华北等气温较高的地区,播期较迟,收获期高温逼热促早熟,生育期较短,为240~270 d;而最冷月平均气温较低的甘肃河西地区、极端低温较低的新疆地区及高海拔的鄂尔多斯高原地区,生育期较长,为270~300 d。影响北方冬油菜生育期的环境因素主要是温度,其次为纬度、海拔等,随着纬度、海拔的升高,温度降低,冬油菜生育期延长。冬油菜5月下旬到6月中上旬收获,收获后可复种向日葵、糜子、谷子、荞麦、早熟马铃薯等,可实现一年二茬,提高复种指数,具有较大复种潜力。

Investigations on difference in the growth period of winter rapeseed（ Brassica campestris L.） in different ecological and environmental areas of northern China may allow rationalization of crop rotation and improvement of multiple cropping indexes,which eventually advances cropping systems. Field experiments were carried out using 18 winter rapeseed varieties with different levels of resistance to cold during 2008—2013 at 17 different ecological and environmental regions in northern China and their growth period variations were determined thereby. The results showed that the growth period of winter rapeseed planted in north China had no obvious difference between different varieties and years,ranging from 1 d to 5 d. However,the growth stage of winter rapeseed differed between different varieties with different levels of cold resistance. The winter rapeseed with strong cold resistance had its wilt leaf stage extended（ the wilt leaf date was shifted early,the regreening date was postponed）. The transition stage from vegetative growth to reproductive growth was shortened greatly,and postulation period became relatively prolonged. However,the difference was extremely significant between different ecological and environmental areas. It was apparent thatthe growth period was relatively shorter（ 240 ~ 270 d） in northern China where the temperature was higher,which was because of late sowing and high temperature at prematurity. However,the growth period was delayed to about270 ~ 300 d at high altitude areas including ordos plateau,Xinjiang province（ low extreme temperature） and the west of Gansu province（ average low temperature）,which was because of low temperature and early sowing. The causes for the difference of the growing period in different areas were primarily temperature,and also latitude and altitude.In conclusion,decreased temperature but increased latitude and altitude could result in the extended growth period for winter rapeseed in north China. In addition,after harvesting winter rapeseed,multi-cropping could be implemented using sunflower,millet,buckwheat,potato,which would not only allow two harvests annually but also improve multiple cropping indexes and possess large potential in multiple cropping.