Why Pepper Anthracnose Occurs Frequently and How to Prevent and Treat It with Fungicides
In China, peppers are mainly distributed in Sichuan, Guizhou, Hunan, Yunnan, Shaanxi, Henan (Xichuan County), Jize County in Hebei Province and Togtoh County in Inner Mongolia. They are a common vegetable and can also be used as a side dish. In the process of growing peppers, disease prevention and control is especially important. The common anthracnose is one of the diseases that affects the yield and quality of peppers, so what causes pepper anthracnose? What are the symptoms? How to prevent and control it? What fungicide should be used?
I. Causes of pepper anthracnose
Pepper anthracnose, also called pepper continuous cropping disease, is a major disease of peppers, widely distributed and seriously damaging. Under high temperature and high humidity conditions, it spreads quickly, damages for a long time, causes severe damage and large losses.
1. Poor varieties
Linear peppers are less resistant to disease than sweet peppers. In recent years, mixed and degraded varieties have also been an important cause of disease epidemics.
2. Continuous cropping
With continuous planting year after year, pathogens accumulate quickly and the base number is high. Once conditions are suitable, the disease will rapidly expand and spread.
If diseased leaves, diseased fruits and plant residues are not thoroughly removed, the pathogens will continuously spread outward through wind and rain. Even on new cropping land, as long as the pathogens exist and conditions are suitable, the disease can break out and become epidemic.
3. Unscientific seedbed management
That is, no chemical disinfection treatment of seeds and no soil disinfection are carried out. Under high temperature and high humidity conditions, the seedbed becomes infected, and after transplanting into the field, it can continue to cause damage.
The pathogen invades through wounds. After the disease occurs, it spreads and causes damage through wind and rain, airflow, and piercing-sucking pests such as aphids and leafhoppers.
The pathogen develops at a temperature of 12-32°C, with an optimum temperature of 27°C and a relative humidity of about 95%. An early rainy season with suitable temperature and humidity is also an important cause of disease occurrence and spread.
II. Symptoms of pepper anthracnose
Pepper anthracnose mainly damages pepper fruits, and can also damage leaves, fruit stalks and stems. When fruits are affected, the lesions are brown, water-soaked, long-round or irregular, sunken, with slightly raised concentric ring markings, on which there are a large number of small black dots. The edges of the lesions have a moist discolored ring. When the lesions dry, they often shrink, become thin-paper-like and easily rupture. When leaves are infected, water-soaked spots first appear, gradually turning brown. The lesions are round with grayish-white centers, on which black dots are arranged in rings, and the diseased leaves fall off easily. When fruit stalks and stems are infected, the lesions are brown, slightly sunken and irregular in shape, and tend to crack when dry.
III. How to prevent and control pepper anthracnose? What fungicide should be used?
1. Select seeds and promote disease-resistant varieties.
2. Reasonable crop rotation: carry out a 2-3 year rotation with wheat and corn, and avoid continuous cropping with cucurbits and vegetables.
3. Strengthen cultivation management. According to variety characteristics, water and fertilizer conditions, plant at a reasonable density; greenhouses should be ventilated in time to remove moisture and avoid high temperature and high humidity; drain water in time after rain; remove diseased leaves, diseased fruits and residual plants in time; increase the application of phosphorus and potassium fertilizers to improve the plant's disease resistance and immunity.
4. Chemical control: when raising pepper seedlings, Aote can be mixed into the soil. Before transplanting, 2-5 kg of Aote can be used per mu (the amount depends on the severity of continuous cropping), or Aote can be applied by flushing at regular intervals during the growing period. This can effectively prevent and control continuous cropping diseases, dead plants and dead seedlings, make plants robust, enhance crop disease resistance, and reduce disease.
Before disease onset, spray a pepper-specific product once every about 15 days, using 20 ml mixed with 15 kg of water, to prevent the occurrence of pepper diseases. In the early stage of disease, spray an anthracnose-specific product once every 10-15 days, using 20 ml mixed with one container of water (15 kg), for 3-4 consecutive sprays.
When the disease is severe, 20 ml of pepper-specific product and 20 ml of anthracnose-specific product can be mixed together with 15 kg of water, or 30 ml of anthracnose-specific product can be mixed with 15 kg of water and evenly sprayed over the whole pepper plant.