为了克服蔬菜淡季,延长供应时间,提高单位面积产量,南昌市蔬菜所从1987年起,半年内在一块地上,由原来种一次大白菜改为种两次成功。选择的品种是早茬用83—2或早热5号早熟大白菜品种。7月下旬至8月初播种,生长期55～60天,单 In order to overcome the vegetable off-season, to extend the supply time and improve the yield per unit area, Nanchang Vegetable Institute from 1987 onwards, within six months in a piece of land, from the original plan to change a Chinese cabbage twice success. Selected varieties are early crop with 83-2 or early heat No. 5 precocious cabbage varieties. Late July to early August sowing, the growing period of 55 to 60 days, single