How to Treat Pepper Anthracnose? Latest Prevention and Control Techniques and Methods Tutorial
Anthracnose is a relatively common disease on hot (sweet) peppers, distributed worldwide. It can cause pepper leaf drop, fruit rot, and seedling death. Damage is generally not severe, but in rainy years the disease can be serious. According to its symptoms, it can be divided into 3 types: black anthracnose, black spot anthracnose and red anthracnose.
Black anthracnose occurs in Northeast China, North China, East China, South China, Southwest China and other regions. The general diseased fruit rate is about 5%, and in severe cases the diseased fruit rate reaches 20%-30%, which has a certain impact on pepper quality and yield. Black spot anthracnose occurs only in Zhejiang, Jiangsu, Guizhou and other places. Red anthracnose occurs less often.
Besides harming peppers, this disease also infects eggplants and tomatoes. It mainly harms the fruit, especially fruit nearing maturity, and also infects leaves and fruit stalks. When fruit is affected, the initial lesion is water-soaked, brown, oblong or irregular; after expansion the lesion becomes sunken, and raised irregular ring patterns form on the surface of the spot, densely covered with small black or orange-red granules (acervuli). When humid, there is a moist discoloration ring around the lesion; when dry, the lesion often shrinks and cracks very easily. When leaves are affected, initially chlorotic water-soaked spots appear, which after expansion turn brown, round, with a grayish-white center, and later small black dots arranged in rings form on the lesion. Stems and fruit stalks are sometimes affected, forming brown sunken spots, irregular in shape, which tend to crack when dry. In the field there is also a kind of diseased fruit whose symptoms are similar to the above, but the black granules produced on the spot surface are larger and darker in color; it is often called black spot anthracnose.
Prevention and Control Measures for Pepper Anthracnose
1. Select disease-resistant varieties: Disease-resistant varieties can be selected according to specific local conditions. Generally, varieties with a strong spicy taste are more resistant, such as Hangzhou Chicken Claw Pepper; among sweet pepper varieties, Changfeng, Qiejiao No. 1, Tiepiqing and others are more resistant.
2. Use disease-free seeds and disinfect seeds: Establish disease-free seed production fields or save seeds from disease-free fruit. If seeds carry the pathogen, before sowing soak them in 55°C warm water for 10 min or in 50°C warm water for 30 min for disinfection. After removal, cool in cold water and sow after sprouting. Alternatively, soak seeds in cold water for 10-12 h, then soak in 1% copper sulfate solution for 5 min, remove and neutralize the acidity with a small amount of plant ash or quicklime, and then sow.
3. Crop rotation and strengthened cultivation management: Severely affected plots should practice crop rotation with Solanaceae and Legume vegetables for more than 2-3 years. On the basis of applying sufficient organic fertilizer, apply nitrogen, phosphorus and potassium fertilizers; avoid overly dense planting and planting in low-lying land; raise seedlings in nutrient pots and cultivate strong seedlings of the right age; prevent fruit sunscald; remove diseased plant residues in the field to reduce sources of pathogen infection.
4. Chemical control: Spray at the early stage of disease or when fruit begins to color. Effective agents are: 50% Shibaogong, 80% Daconil m-45, 75% Dakening, 65% zineb, 80% Punuo, 60% Tuofu, 70% thiophanate-methyl, 80% anthracnose Fumei, Bordeaux mixture (0.5:1:100), 50% carbendazim, etc., once every 7-10 d, spraying 2-3 times in succession.