Sea Shrimp Series,Pink Shrimp,Headless Pink Shrimp,Headless Ramboo Prawn GOLD STAR FISHERY ZHOUSHAN CO.,LTD. , https://www.goldstar-aquatic.com
Pest control program of late winter jujube
Late winter jujube is prone to several major diseases, including black spot disease, date rust disease, and jujube fruit shrivel. In terms of pests, the main threats are hawthorn leafhoppers, green leafhoppers, and other types of leafhoppers. These pests and diseases can significantly affect the health of the trees, reduce yield, and compromise fruit quality.
Date rust, commonly referred to as jujube rust, primarily affects the leaves. Initially, small yellowish spots appear on the upper surface of the leaves, which later develop into irregular, raised lesions. As the disease progresses, these spots become dry and release a yellow powder. On the underside of the leaves, chlorotic spots form, eventually turning tan before the leaves fall prematurely. Severe infections lead to early defoliation, which can cause the fruits to shrink, lose sugar content, and weaken the tree’s overall vigor. The disease typically peaks in August and September, with outbreaks more severe in hot, rainy summers and less common in dry years. Trees located in low-lying areas with dense canopies or damaged foliage are more susceptible. To manage this, timely drainage during the rainy season is essential to avoid excessive humidity. In early July, spraying a mixture of 25% Guanxin (Gibberellin) at 5000–6000 times dilution combined with soft water at 4000 times is recommended, applied two to three times. If rain persists in August, another round of spraying with the same mixture should be done to control the spread effectively.
Jujube fruit shrivel disease mainly impacts the fruit. Symptoms include halo formation, water-soaked spots, discoloration, shriveling, and premature dropping. Affected fruits show yellowish, watery patches on the sides, with clear edges and gradual darkening. Some fruits may display light brown stripes from the stem, while the flesh becomes pale, spongy, and necrotic. The disease is still not fully understood, with some researchers attributing it to fungal causes, others to bacterial infection, and many believing it results from a combination of both. It is also thought that the disease often arises due to pest damage or environmental stress such as high temperatures and drought, which can cause mechanical injuries like sunburn. Prevention involves careful pesticide use, selecting broad-spectrum fungicides that target both fungi and bacteria. Spraying 72% agricultural streptomycin at 2000–3000 times dilution combined with nano-nano WP at 1000 times every 10–15 days after fruit set is effective. Adding soft water at 4000 times enhances coverage. Recently, new bactericides like 80% JinNai seawater dispersible granules have emerged, offering cost-effective solutions when used at 800–1000 times dilution. Regular pruning, proper fruit thinning, and applying calcium lactate or amino acid mixtures during flowering also contribute to better disease management.
Black spot disease primarily affects the fruit, appearing during the fruit expansion stage. Infected fruits develop irregular yellow spots on the shoulders or base, which gradually turn reddish-brown and dark brown. The flesh beneath the spots becomes yellowish, and in severe cases, turns brown, then gray-black or black. The affected tissue becomes spongy and bitter. In humid conditions, small black spots may appear on the surface. To prevent this, maintaining tree health is crucial. Weak trees or those suffering from iron deficiency are more prone to the disease. Applying imported green fertilizer at 6000 times dilution, along with optional injections of Sterpool trace element fertilizer at 6000 times, and regular foliar sprays of amino acid mixtures at 200–300 times can help restore tree vitality. During the fruit expansion period, spraying 65% Pud-Kin wettable powder at 600–800 times dilution with soft water at 4000 times is effective. At the first sign of disease, applying 50% Dove-Have suspending agent at 800–1000 times, or 70% Nano-Sweet WP at 1000 times, or 70% Jian Li-Tong WP mixed with Roushui-Tong at 4000 times can help control the spread.