20年左右的老桑,如忽视肥培管理或受桑虫危害,造成树势衰败,萌发的桑条细瘦,叶形小,产叶量低,可采取截干更新的办法,能使桑树复壮。在冬季或春季桑树发芽前,将衰败的桑树离地10～15厘米锯除,并覆盖1厘米左右的细土,可减少桑树水分的蒸发和树液的流失量,4月中、下旬,被锯除桑树基部的潜伏芽,一般能抽出新梢3～4 20 years old mulberry, such as ignoring the management of fertilizer or by mulberry worm harm, resulting in the decline of the tree, the mulberry thin germination, leaf shape is small, leaf yield is low, can take truncated stems and updates of the way to make mulberry rejuvenation . In winter or spring before the mulberry germination, mulberry decay from 10 to 15 centimeters saw the ground, and covered about 1 cm of fine soil, can reduce the evaporation of mulberry water and tree liquid loss, in April, late, was Saw except mulberry base latent buds, usually can shoot out shoot 3 ~ 4