大白菜(结球白菜)大白菜为华北地区冬春主要蔬菜,除收获时能供应市场外,部分品种尚可经过贮藏陆续销售。主要的优良品种有下列五个:1.北京大青口:由本所自北京农家引种选育而得,为晚熟种,在北京栽培面积较大,每亩产量为15,000—20,000斤(为荒菜重, Chinese cabbage (cabbage cabbage) Chinese cabbage is the main winter and spring vegetables in North China, except when harvested to supply the market, some varieties can still be sold through storage. The main fine varieties have the following five: 1. Beijing Daqingkou: Beijing by the Institute of the introduction and breeding of farmers derived from late-maturing species in Beijing cultivation area larger per acre yield of 15,000-20,000 kg weight,