Citrus Common Pests and Diseases and Detailed Control Methods
Citrus, also known as red tangerine and by other names, has a cultivation history of more than 4000 years. Through long-term cultivation and selection, citrus has become a precious fruit for humans, and it is grown extremely widely in our country. However, during cultivation, tangerines are plagued by many pests and diseases, seriously affecting yield and quality, thus causing the tangerines' appearance and taste to be poor. So let me introduce the common pests and diseases of citrus and their control methods:
1. Citrus canker
Citrus canker occurs more severely in rainy areas. When it develops, small brown spots appear on the leaves and fruit. As the disease progresses, the fruit and leaves become densely covered with spots. In mild cases, a large number of disease scars appear on the fruit surface, which not only affects the appearance and price but also makes the fruit not keep well and prone to rotting. In severe cases, it causes fruit drop and serious losses.
Control methods: When planting, choose seedlings that are strong-growing and free from disease damage, strengthen fertilizer and water management to increase the plants' disease resistance, and spray pesticides regularly for prevention and control. When the disease occurs, promptly remove diseased leaves to prevent the spread of the disease, then spray a 300-fold dilution of high-fat film for control.
2. Anthracnose
Anthracnose is one of the most common and most harmful diseases of many fruits. It mainly harms the fruit and also harms the leaves. In the later stages of the disease, it causes branches and leaves to wither and drop and the fruit to rot, and in severe cases causes the plant to die. When the leaves are affected, dark green disease spots appear. As the disease progresses, the spots turn brown, and the leaves begin to curl, wilt, and finally drop. When the fruit is affected, dark green oil-soaked spots appear on the surface. The spots rapidly expand to cover the entire fruit. During the rainy season or when air humidity is high, a white mold layer appears on the spots, causing the fruit to rot.
Control methods: In winter, prune off the diseased leaves and branches of the plants, clear away the debris in the orchard, and burn or deeply bury it in a centralized manner to reduce the pathogen. Apply more phosphorus and potassium fertilizers to increase the plants' disease resistance, strengthen management, and drain water promptly during the rainy season. When the disease occurs, remove the affected parts and then spray pesticides for control.
3. Green mold
Green mold, also called blue mold, mainly harms the fruit. When the disease occurs, the pathogen invades through the fruit stem and wounds, causing water-soaked spots to appear on the fruit, and the skin easily ruptures. As the disease progresses, a white mold layer appears at the spots. Over time, this mold layer gradually turns blue or green, causing the fruit to rot.
Control methods: Harvest the fruit only when it is ripe, and be careful not to cause wounds during harvesting. It is best to harvest in clear weather, not in cloudy and rainy weather. After harvesting, leave the fruit in a cool, ventilated place for about a week before storing it in the warehouse. The storage place must be dry and clean, not damp. When the disease occurs, spraying a 400-600-fold dilution of thiabendazole suspension concentrate can control it.
4. Pests
Tangerines have many pests, mainly red spider mites, scale insects, and whiteflies. They mainly harm the fruit and leaves and often gather in groups on the undersides of leaves to suck sap, causing the leaves to wither and drop, resulting in poor plant growth and affecting yield and quality.
Control methods: During overwintering, clear the orchard debris and burn or deeply bury it in a centralized manner, then scrape off the insect eggs on the plants to reduce the source of pests. When damage occurs, natural enemies can be used for control, or chemical pesticides can be sprayed for control.
Summary: The above is the relevant introduction to the common pests and diseases of citrus and their control methods. I hope it is helpful to friends who need it!