千方百计保护叶片。叶片是进行光合作用、制造有机养料的器官,甜菜产量及含糖量的高低与块根成熟期的叶面积系数大小有直接关系。甜菜比一般作物叶片多,叶面积大,每株可长50～70片叶子,最多的可达100多片。但危害甜菜叶片的病虫较多,为害时间也长。甜菜褐斑病从7月上旬到9月上、中旬都能发生,如防治不及时,会使叶片大量损失;8～9月份二代和三代甘蓝 Do everything possible to protect the leaves. Leaf is the photosynthesis of organic nutrients manufacturing organs, sugar beet production and sugar content and the level of leaf area at maturity is directly related to the size of the coefficient. Beet leaf more than the average crop, leaf area, each plant can grow 50 to 70 leaves, up to more than 100 pieces. But more harm to the pests of beet leaves, damage time is also long. Brown sugar beet disease from early July to September, mid-can occur, such as control is not timely, will make a lot of leaf loss; 8 to September second and third generation cabbage