Peach trees have black spots.
Black spots in peach trees may be peach scab, also known as scab, which is one of the common diseases of peach trees. When the peach trees were onset, black spots or even cracks appeared on the surface of the diseased fruits, which seriously affected the value of the products.
1. Injury symptoms: mainly damage the fruit, followed by damage shoots and leaves. The fruit began to appear brown round spot, and later gradually expanded to 2 ~ 3 mm black spots, lesions for a long time together into a film. Because the pathogen is only the epidermis of the diseased fruit, the growth of the peel is stopped and the wood is plugged, and the growth of the flesh is not affected. Therefore, fruit cracking often occurs when the disease is severe. Onset of shoots, brown round lesions in the early stages, uplift of the late lesions, deepening of the color, and sometimes flow plastic phenomenon. The pathogen only affects the surface of the diseased branches. When the sap flows in the second year, it will produce small black spots, which are the conidia of pathogens and become the main primary infestation source of peach scab.
2. Causes of the disease: The pathogen of Peach Scab is Melphathers. The pathogenic bacteria mainly overwintered with mycelium on shoots. Warm and humid conditions in the greenhouse are conducive to disease occurrence. The earlier the fruit matures, the lighter the incidence. Because the nectarine is glabrous and the pathogens are easy to invade, the incidence is heavier.
Shenzhen Jie Zhong Lian Investment Co., Ltd. , https://www.szmeizonscares.com