一、春后早发,才能搭好丰产架子立春以后,上海地区的油菜便渡过了越冬阶段,进入春发阶段。这期间,随着气温的逐渐上升,土壤中迟效肥料加速分解,释放大量速效养分,油菜生长很快。据我们调查,早熟品种春发阶段(二月上旬至三月上旬抽苔前)的生长量比播种至二月上旬的生长量要大几倍.叶片数增加一倍,叶面积增加三到四倍,每株干重增加二到三倍,根系吸 First, the early spring after the hair, to take a good yield shelves After the beginning of spring, the rape in Shanghai will have spent the winter stage, into the spring stage. During this period, with the gradual rise in temperature, soil accelerated decomposition of fertilizer, releasing a lot of available nutrients, rape quickly grows. According to our survey, the amount of growth of early-maturing varieties in spring (before early February to early March bolting) is several times higher than that of sowing till early February, the leaf number doubled and the leaf area increased by three to four Times, dry weight per plant increased two to three times, root suction