Symptoms, Identification and Control Methods of Damping-off in Green Peppers

Green pepper, also known as chili pepper, cayenne pepper, sea pepper, pepper eggplant, sweet pepper, is a crop of the Solanaceae family, genus Capsicum, an annual or perennial herbaceous plant, cultivated throughout the country, and is a traditional main vegetable in our country. It is rich in nutrients, containing protein, organic acids, vitamins, pigments, capsaicin and minerals needed by the human body such as calcium, phosphorus and iron. It helps promote appetite and digestion, and its vitamin C content is very high. Both the young and mature fruits of green pepper can be eaten fresh; the flesh of green pepper is thick and crisp-tender, and rich in vitamin C. The green fruit contains about 93.9% water, about 3.8% carbohydrates, and vitamin C; the red ripe fruit contains vitamin C up to 460 mg. It can be served cold, stir-fried, boiled, used as filling, pickled, and processed into cans and candied fruit.

Characteristics of green pepper

1. Peppers can be divided by fruit shape into five categories: cherry pepper, cone pepper, clustered pepper, bullhorn pepper and bell pepper.

2. The main root of green pepper is not well developed, with few roots; the root mass is mostly distributed in the 10--15 cm topsoil layer, and its root system is neither drought-tolerant nor waterlogging-resistant. Its root regeneration ability is weaker than that of tomato and eggplant. It is not tolerant of concentrated fertilizer.

3. Flower drop, fruit drop and leaf drop of pepper (commonly known as the “three drops”) also tend to occur easily; this is an important problem in pepper production and has a great impact on yield.

The causes of the “three drops” are relatively complex. Flower drop in early spring is mainly caused by low temperature affecting pollination and pollen tube elongation; drought in soil and air is also a cause of flower drop; excessive or insufficient nitrogen fertilizer, excessive vegetative growth of branches and leaves, insufficient light and other factors directly affect the balance between vegetative growth and reproductive growth and lead to flower drop; high temperature and drought leading to the occurrence of viral disease, or high temperature and waterlogging weakening the root absorption capacity, physiological disorders of the plant, and pests and diseases (anthracnose, ring spot disease, cotton bollworm, noctuid moths), etc., cause a large number of “three drops”.

Symptoms and control methods of damping-off in green pepper

Symptoms of damping-off in green pepper:

The diseased part at the base of the young stem shows water-soaked lesions, the diseased part turns yellow-brown, then constricts into a thread-like shape, causing the seedlings to damp off or die. Because the disease develops very quickly, the seedlings quickly fall over while the cotyledons have not yet wilted and are still green, that is, damping-off. In the seedbed, seedlings damp off and die in patches. Under low temperature and high humidity, white flocculent mycelium grows on the diseased seedlings or on the soil surface near the diseased seedlings.

Control methods for damping-off in green pepper:

Select disease-resistant varieties; apply Chongzhidao soil-matching formula plus as base fertilizer; ventilate to control humidity; at the early stage of disease, carry out seedling separation and thinning early, and spray Jiumiao seaweed acid iodine to cultivate strong seedlings; soak seeds with 50% amobam 500 times solution for direct sowing or wash and then germinate; spray with thiophanate-methyl wettable powder 800-1000 times solution mixed with Huaguo Yisheng Guoneng calcium.