研究了播期对山旱地甘蓝型冬油菜生长发育、越冬率及产量构成因素的影响。结果表明，叶片数、叶鲜重、叶干重、主根长、主根颈直径、根鲜重、根干重、株高、单株角果数、千粒重、单株产量等随着播期推迟而减小，越冬率和折合产量随播期推迟呈先增加后减少趋势。陇东南山旱地甘蓝型冬油菜适宜播期8月28日，折合产量最高，为5 245.03 kg/hm2，其苗期叶片数6.6片、主根长16.78 cm、主根颈直径0.58 cm、叶干重3.63 g/株、根干重0.82 g/株。成株期单株分枝数8.83个、单株角果数228.75个，越冬率86.7%，综合性状最优。

The effects of sowing dates on the growth， overwintering rate and yield components of Brassica napus were studied. The results showed that the number of leaves， the fresh weight of leaves， the dry weight of leaves， the length of main root，the diameter of root neck， the fresh weight of roots， the dry weight of roots， the plant height， the number of pods per plant， 1000-seed weight and the yield per plant decreased with the delay of sowing date， the overwintering rate and equivalent yield increased first and then decreased with the delay of sowing date. Suitable planting date of Brassica napus in Nanshan dryland of Longdong on August 28. The equivalent yield of winter rape was the highest， 5 245.03 kg/hm2， the number of leaves was 6.6， the length of main root was 16.78 cm， the diameter of main root was 0.58 cm， the dry weight of leaf was 3.63 g， the dry weight of root was 0.82 g， the number of branches per plant was 8.83， the total number of pods per plant was 228.75， the overwintering rate was 86.7%， and the comprehensive character is optimal.

S565.4

甘肃省重大专项项目(17ZD2NA016-4)；甘肃省特色作物产业技术体系(GARS-TSZ-4)。