Occurrence regularity and Control techniques of Sweet (Hot) Pepper virus Disease

Virus disease is the main disease in the production of sweet (spicy) pepper. The early onset affects the normal growth of the plant, forming the shape of "little old man"; the late onset of the disease forms flowers, leaves, flowers, faces and fruits, which affects photosynthesis and its commerciality, often resulting in greater economic losses.

In order to help farmers solve this problem, Tunliu County has preliminarily explored some effective comprehensive prevention and control measures after three years of research and experimental demonstration. The details are as follows:

First, symptoms:

The main symptoms are mosaic, deformity and cluster, stripe necrosis and so on. Mosaic: diseased leaves appear dark green and light green mottled, leaves wrinkled, easy to crack, or brown necrotic spots. Leaf deformities and clusters in the initial heart leaf veins fade green, gradually form a thick and light mottled, leaf wrinkle thickening, and produce a large area of yellowish brown necrotic spots. The leaf margin is curled, the young leaves are narrow as linear, the diseased plants are obviously dwarfed, and the upper leaves are clustered. Fruit infected, flower face-like thick and light, the formation of brown necrotic spots, the disease spread along the petiole to branches, main stems and growth points, the emergence of systematic necrotic stripes, plant obvious dwarfing, resulting in fallen leaves, flowers and fruits.

1. Pathogen:

The main pathogens of sweet (spicy) pepper virus disease are cucumber mosaic virus (CMA) and tobacco mosaic virus (TMV). Cucumber mosaic virus causes systemic mosaic, deformities, clusters, fern leaves, necrotic spots and stripes in leaves. Tobacco mosaic virus is mainly damaged in the early stage, which often causes acute necrotic spots, vein necrosis and apical necrosis.

Third, occurrence characteristics:

Virus diseases are mainly transmitted by insects and by contact. Insect vectors include aphids, thrips, planthoppers and so on. The virus transmitted by insects is cucumber mosaic virus. Poisonous insects suck poisonous juices from surrounding weeds and carry them on sweet (spicy) peppers. The virus infected by contact is tobacco mosaic virus, which is spread by contact and friction through seedling division, pruning, management and other agricultural activities. Continuous cropping, low-lying terrain, lack of fertilizer, lack of water, weak crop growth and high temperature are all conducive to the occurrence of virus diseases.

4. prevention and control measures:

1. Select disease-resistant varieties, such as Beijing Zhongjiao 4, Xiangyan 16, Super Lvba 16, Hefeng 207, Nongyan 16-2, etc., all of which are resistant and resistant.

2. Agricultural management measures: (1) crop rotation. It can effectively reduce the chance of infection. (2) intercropping with tall stalk crops. For example, intercropping corn can shade and cool down, reduce the incidence of virus disease, blight, sunburn and so on. (3) cleaning the countryside and ploughing deep in autumn. Diseased fruit and diseased leaves should not be discarded casually, but should be taken out of the field, burned or buried. The depth of autumn ploughing is more than 15 cm, and the diseased body will be turned into the soil.

3. To cultivate strong seedlings: ① drying seeds. After drying the seeds in the sun for 2 to 3 days, the germs on the seed epidermis were removed, and the seeds were soaked with ②. Put the sun-dried seeds in a container, add 25 ℃ of hot water and soak for 3 to 4 hours. Soak the seeds in ③ warm soup. Put the soaked seeds in a container, first put in cold water, then add 25 ℃ of hot water, raise the temperature to 55 ℃ for half an hour, and then cool down naturally. ④ treatment. Soak the seeds with 10% trisodium phosphate for 10 minutes, then rinse with clean water; sprout with ⑤. Dry seed sowing, more than 20 days before emergence, 7-8 days after accelerating germination; ⑥ seedbed soil treatment. Before sowing, mix 9 grams of carbendazim per square meter into 5 kilograms of soil on the seedbed. When the poisonous soil is covered with a cover, the temperature of the seedbed should be controlled at 25 ℃ ~ 30 ℃. Attention should be paid to covering the soil: if it is too thick, the seedling will be weak; if it is too thin, it will be unearthed with a cap. To master the thickness of 1 centimeter. After being unearthed, the temperature of the seedling bed was controlled at 25 ℃ ~ 28 ℃. When the two branches and leaves came out, the growing point began to grow. This period was called the heart-breaking period, and it was also the most fragile time. It was easy to get the disease of stunting, and Purek or Kelu was sprayed for 1 time or 2 times.

4. determine the planting period: green pepper is not only a temperature-loving crop, but also afraid of high heat, so it should be planted in time, and old seedlings are easy to appear early; if it is too late, it is easy to seal the ridge, resulting in high soil temperature, damage to the root system, lack of moisture, and easy to get sick. After planting, to slow down and start early, need to spray a growth regulator, spray or not spray, the difference in growth period is about 10 days.

5, reasonable watering: green pepper likes water and is afraid of water, more water is irrigated, and the root system is stagnant and weak, so small water should be watered frequently, the ground should be leveled, and the canal system should be matched.

6. Rational fertilization: balanced fertilization is advocated. The proportion of fertilizer required for green pepper is N ∶ P ∶ Kraft 1 ∶ 0.5 ∶ 1.2-1.4. In the later stage, potash fertilizer must be increased to improve plant stress resistance.

7. Physical control: the use of anti-insect nets to prevent viral vectors such as aphids and planthoppers can greatly reduce the incidence of viral diseases.

8. Chemical control: the agents used are: ① Moulin Hydrochloride, trade name: virus A, du Kexing, virus Xianfeng, virus Suke; ② mushroom proteoglycans, trade name: Shiduning, Kangfeng, Kangdufeng, Kangfeng No. 1, virus Black Killer; ③ phytopathogen. In the case of mild disease, you can choose one to spray; if it is serious, accounting for 20% to 30%, three kinds of drugs must be mixed and sprayed at the same time to achieve "leaching", once every three days, three times in a row.