Control Methods and Technical Key Points for Mango Shoot Blight and Gummosis

Mango shoot blight and gummosis mainly damages branches and the main trunk, causing dieback, but it can also harm seedlings and fruit. When seedlings are affected, dark brown necrotic spots usually appear from the bud graft point or wounds, rapidly spreading upward and downward, causing the scion to die. When the main trunk or branches are affected, the cortex necroses and shows canker symptoms, and from the diseased part oozes gum that is initially white and later brown; the branches above the diseased part wither, with small black dots forming on them, the leaves on the dead branches turn brown, curl upward, and drop easily, and the fruit also shrivels, generally without falling off. Sometimes new branches emerge below the diseased part, but they grow poorly and their leaves are discolored.

When pedicels are affected, longitudinal cracks appear, and if the lesion extends to young fruit, it can cause the young fruit to drop. When mature fruit is affected, symptoms appear during the softening stage, initially as watery soft spots at the fruit stalk, later expanding into large grayish-brown spots and exuding sticky juice, with the inner fruit becoming brown and soft-rotted.

Control methods: 1. During cultivation, prevent mechanical injury and longhorn beetle damage. 2. Take budwood from healthy mother trees, sterilize grafting knives with 75% alcohol, plant bud-grafted seedlings in dry, well-ventilated places, especially keeping the graft union dry, and ensure ventilation after the bud graft takes and the tie is removed. 3. In combination with shaping and pruning, cut off diseased branches. When cutting, cut 20-30 cm below the diseased part; for lesions on the main trunk, use a sharp knife to excise the diseased part down to healthy tissue, then apply Bordeaux paste to the wound, or 70% thiophanate-methyl wettable powder 200-fold solution mixed with cow dung. 4. During the flowering period, spray 3% copper oxychloride suspension. When young fruit is about 1 cm in diameter, spray 0.6% equal-amount Bordeaux mixture, 70% thiophanate-methyl wettable powder 800-1000-fold solution, or 50% carbendazim wettable powder 500-fold solution. Generally once every 10-15 days, for a total of 3 sprays.