Leaf spot disease on winter jujube leaves initially appears as small, brownish-brown circular spots that gradually grow to about 1–1.5 mm in diameter. As the infection progresses, these lesions may merge, causing the leaves to yellow and fall prematurely. This early defoliation can negatively affect fruit set and lead to premature dropping of young fruits. In severe cases, the tree's overall health is compromised, reducing yield and quality. The disease is caused by one or three different types of pathogenic bacteria. To prevent it, garden hygiene is crucial—clearing and burning fallen leaves during winter helps eliminate pathogens. Before bud break, apply a 5° lime sulfur solution in the affected areas. From May to July, spray with carbendazim at a dilution of 800 times, repeating 2–3 times for effective control.
When Jiaoye (a type of leaf blight) infects jujube trees, the first signs are gray spots on the leaves that later turn brown. These spots may merge, causing the leaf tips and edges to curl inward and appear scorched. Affected leaves often fall early, and young fruits become thin and drop prematurely. Severe infections can occur twice in mid-September and late September, with new growth becoming re-infected. This repeated cycle significantly weakens the tree and reduces fruit production. To manage the disease, prune and remove dead branches after bud break, and burn all infected material. During the active periods in June, July, and August, spray the leaves with either 500-times diluted net dry leaves or 500-times diluted antibiotics to suppress the spread.
In the early stages of black spot disease, small black spots appear on the leaves, which gradually expand into round or irregular dark lesions ranging from 0.4 to 6.0 mm in size. As the disease worsens, the spots may coalesce, turning the leaves black. Under a microscope, you can observe conidiophores and conidia of the pathogenic fungi. Control measures include removing and disposing of fallen leaves to reduce the infection source. At the onset of symptoms, apply a 800-times diluted spray to the leaves for effective suppression. Regular monitoring and timely intervention are essential to prevent widespread damage and maintain tree health.
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