Pepper plants are commonly grown in gardens all across the United States. There are varieties for hot peppers, sweet peppers and salad peppers, and these are susceptible to diseases. Good maintenance practices are the best defense against most diseases that affect pepper plants.
Types of Diseases
Peppers are susceptible to a variety of disease. The most common types are viruses. Common strains are the cucumber virus, the tobacco mosaic virus, tomato spotted wilt virus, potato virus Y and pepper mottle virus. Fungus is another cause of disease, including phytophthora blight, anthracnose, damping-off and sclerotinia stem rot. A few diseases are bacterial in nature, such as bacterial spot and bacterial soft rot.
Many of the diseases are spread through contact with water, such as bacterial leaf spot and phytophthora blight. Rainwater comes in contact with the disease and through wind or touch is transmitted to the next plant, where the water deposits the bacteria or fungus on the stems, fruit or foliage. Infection usually takes a few days. Where strong winds are involved, the disease can be spread through an entire crop quickly. Warm temperatures and humid conditions also foster growth of disease in peppers. Most fungus diseases are transmitted through contaminated soil, where in some cases the fungus can live for years.
Each disease has its own set of symptoms, but some more common ones can be spotted easily. An overall wilting or yellowing of an otherwise healthy and watered plant can be a sign of trouble. Spots of gray, tan or black or lesions on the stems should be addressed. Raised bumps or warts on the fruit as well as soft spots are indicators of disease problems.
In most cases, if disease is left untreated, the pepper plant will die. In plants that survive, fruit production will be diminished as the plants health deteriorates. In worst-case situations, the disease will spread to other pepper plants and perhaps other plants such tomatoes and cucumbers, depending on the specific disease. Treatment after the disease is present is not always effective and varies with the type of disease, its severity when treated and other environmental conditions.
Disease prevention is the best option. Beginning with disease-resistant varieties of peppers gives your plants the best start. Plants should be watered early in the day, so excess water has time to evaporate and plants should not be handled or disturbed while wet. Pepper plants can benefit from an application of fungicide designed for peppers and applied according to the manufacturer's directions. Disease is less likely to get a stronghold and go unnoticed if the bed is kept weed-free and mulched.