![]() The annual economic losses associated with late blight, in potato alone, are estimated at $3-5 billion. Late blight disease causes low potato and tomato yields. Generally, changes that increase humidity, such as excess rainfall, cold nights, and fog, trigger the outbreak of the late blight disease. The pathogen survives at an optimum temperatures of 18⁰ – 22⁰,and humidity of <90%. Phytophthora infestans grows and thrives in cool and wet weather conditions. Schwartz, Colorado State University, Optimum conditions for late blight development Late blight in potato (Phytophthora infestans) An infection starts at lenticels, tuber eyes, or cracks, resulting in purple, brown, or reddish tubers. ![]() On the other hand, infection of potato tubers occurs when the spores fall from leaves/stems into the soil. Wilting leaves is a common symptom of highly infected plants. If left untreated, the disease spreads to all parts of the potato plant, causing a significant plant damage. The sporophores develop into white spores that are noticed at the edges of the lower surface of leaves. In moist conditions, phytophthora infestans produces sporophores enclosed in sporangium on the exterior side of affected parts. As the disease progresses, the lesions turn either brown or black and spread to leaves and stem tips, where moisture is higher. The initial sign of infection is green or gray spots that develop on the old lower leaves of a potato plant. Signs and symptoms of late blight infection in potato In potatoes, the disease affects the leaves, stems and tubers. The causative pathogen for late blight disease is fungus-like oomycete (water mold), scientifically named P hytophthora infestans. Late blight is a destructive disease that primarily infects potatoes and tomatoes, but also other members of the Solanaceae family.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |