矮化苗发生症状幼苗矮小,叶片小,色泽浅而无光,节间过密,茎秆硬化且细,根系发育不良,色黄褐。主要原因(1)苗床土质不好;(2)水分不足甚至是缺水;(3)温度低;(4)缺肥。防治方法(1)育苗床或幼苗床的土质,一定要选肥沃、透水透风、物理性质好的壤土或轻壤土,不可不加选择地用任何土 Dwarf seedling symptoms of seedling short, small leaves, light color and light, internodes dense, stems harden and fine, root system dysplasia, yellowish brown. The main reason (1) poor soil bed quality; (2) lack of water or even water shortages; (3) low temperature; (4) lack of fat. Control methods (1) nursery bed or seedbed soil, must choose fertile, water and air permeability, good physical properties of loam or light loam, indiscriminate use of any soil