大白菜(B.rassica Pekinensis Rupr.以下简称白菜)适宜播种期的确定是获得高产、稳产和优质的关键措施之一。各地每年都根据历年的丰欠情况,病虫害发生的可能性和当年秋季天气的预测预报来确定适宜的播种期。北京近郊地区秋季白菜的适宜播种期,五十年代曾提出过“立秋前一(天) The determination of suitable sowing date of Chinese cabbage (B. rassica Pekinensis Rupr.) Is one of the key measures to obtain high yield, stable yield and high quality. Every year, the appropriate sowing date is determined on the basis of abundant arbories over the years, the possibility of occurrence of pests and diseases, and forecast and forecast of autumnal weather of that year. In the suburbs of Beijing, the suitable sowing dates of autumn cabbage were put forward in the 1950s.