大白菜播种期与产量形成关系的研究

Studies on the Relationship between the Seeding Date and Yield Formation of Chinese Cabbage

对北京地区多年（１９５２～１９９１年）生产调查资料及田间试验分析，结果表明，大白菜播种期与产量间存在二次多项式关系，在适宜播种期前或后产量均下降；气象因子对产量的影响后期大于前期，特别是气温、日较差、降水量和日照时数；播种期的早晚对大白菜结球生长期的长短影响较大。在当前的栽培条件下，北京地区的适宜播种期应为８月３日至９日。此期有利于大白菜高产、稳产和提高抵抗病害的能力，又可减缓后期不利气象因子的影响。

Based on the production investigation and field .tests in 1952￣1991, in terms of statistic analyses, the optimum seeding time of Chinese cabbage and the relationship between yield of it and meteorological conditions in Beijing area were studied. The results indicated that there are quadratic polynomials rating curve between the seeding time and yield of Chinese cabbage in various regions. The yield decreases before and after the optimum seeding time; the influence of meteorological conditions, especially precipitation and sunshine hours in the later season is heavier than that in the early season. The seeding time has a very important influence on the length of heading stage of Chinese cabbage. The optimum seeding time should be August 3～9 in Beijing area. Making this decision might be helpful not only for high and stable yields and disease control, but also for reducing the influence of harmful meteorological conditions in later stage.