Potato virus X

Pathogen and disease type. The pathogen is Potato virus X (PVX), the type species of the Potexvirus genus. It is a widespread systemic plant virus that colonizes all parts of the host plant, including tubers, and remains viable within them throughout the growing season and during storage.

Host plants. While the primary host is the potato plant, the virus has a broad host range within the Solanaceae family. This includes important agricultural crops such as tomatoes and tobacco, as well as various wild weeds that serve as reservoirs for the pathogen.

Symptoms and signs. PVX infection is frequently latent, meaning plants may appear healthy despite being infected. When symptoms do appear, they commonly manifest as mosaic patterns, leaf mottling, mild chlorosis, or leaf curling. In severe cases, particularly in susceptible cultivars, necrotic symptoms on foliage may occur.

Development and transmission. The virus is primarily transmitted through mechanical contact. Unlike many other plant viruses, it does not rely on insect vectors; instead, it spreads through plant-to-plant contact, contaminated machinery, pruning tools, and even human activity during routine field operations.

Economic impact and control. PVX causes significant yield losses and leads to the progressive degeneration of potato stocks. Control strategies focus on prevention: using certified virus-free seed tubers, maintaining strict sanitation protocols for farm equipment, removing volunteer potato plants, and practicing effective crop rotation and field isolation.