Potato phytoplasmosis

Potato phytoplasmosis, commonly referred to as Stolbur, is a devastating plant disease caused by specialized bacteria known as phytoplasmas. These pathogens lack a cell wall and thrive exclusively within the plant's phloem, which severely disrupts the translocation of sugars and nutrients from the leaves to the tubers.

The disease affects a wide range of host plants within the Solanaceae family, including potatoes, tomatoes, and peppers, as well as various perennial weeds. These weeds act as vital reservoirs for the pathogen, sustaining the infection cycle throughout the growing season and ensuring its survival over winter.

Symptomatology typically involves the yellowing and upward rolling of the upper leaflets, often accompanied by purple or reddish discoloration. As the disease progresses, the plant exhibits stunted growth, shortened internodes, and the development of aerial tubers or thin, weak sprouts from the daughter tubers.

The spread of potato phytoplasmosis is mediated solely by insect vectors, most notably leafhoppers. The pathogen is transmitted in a persistent manner: once a leafhopper acquires the phytoplasma from an infected host, it remains a carrier for its entire lifespan, effectively inoculating healthy potato plants during feeding.

Effective management and prevention strategies are crucial for maintaining yield quality:

• Elimination of weed reservoirs, particularly bindweed and other Solanaceous weeds.
• Implementation of rigorous insect pest control programs targeting leafhoppers.
• Use of high-quality, certified disease-free seed tubers.
• Maintaining adequate spatial isolation between potato fields and other susceptible vegetable crops.
• Early detection and removal of symptomatic plants to reduce the inoculum source within the field.