Leaf spot disease on winter jujube leaves initially appears as small, brownish-brown circular spots, typically 1 to 1.5 mm in diameter. As the disease progresses, these spots may merge and cause the leaves to turn yellow and fall prematurely. Severe infections can lead to reduced fruit set and early fruit drop, significantly affecting yield. The lesions often appear as brown spots with yellowing surrounding tissue, leading to early leaf loss. There are two or three types of pathogenic bacteria involved in winter jujube leaf spot. To manage the disease, it is recommended to clear the garden in winter and burn fallen leaves to eliminate pathogens. Before bud break, apply a 5-degree lime sulfur solution. During May to July, spray carbendazim at a dilution of 800 times, repeating 2–3 times for effective control.
When Jiaoye disease infects jujube trees, the first symptoms appear as gray spots on the leaves, which later turn brown. These spots may merge, causing the leaf edges to become scorched and curl inward. Affected leaves turn yellow and fall early, while young fruits become thin and drop prematurely. In severe cases, the disease can occur twice—once in mid-September and again later in the season. New leaves that emerge after the initial infection can be re-infected, weakening the tree and reducing overall productivity. Prevention involves pruning and burning dead branches during winter, removing infected shoots, and cutting back diseased twigs after bud break to reduce the infection source. During June, July, and August, spray 500 times diluted net dry leaves or antibiotics to control the spread.
In the early stages of black spot disease, small black spots appear on the leaves. These spots gradually expand into round or irregular dark lesions, ranging from 0.4 to 6.0 mm in diameter. When the disease becomes severe, the lesions may merge and darken further, forming large, blackened areas. Under a microscope, you can observe conidiophores and conidia of the causal fungi. To control the disease, remove fallen leaves and debris to minimize the infection source. At the first sign of infection, spray the leaves with a 800 times diluted solution of the fungicide for effective management.
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