Mycobacteriosis

Plant mycobacteriosis is an infectious disease caused by bacteria from the Mycobacteriaceae family. These actinobacteria are characterized by complex cellular structures, allowing them to persist in various environmental conditions. While less common than typical soft rot bacteria, they present a significant challenge due to their ability to colonize vascular tissues and cause chronic systemic infection.

The disease is triggered by various species within the Mycobacterium genus. These pathogens primarily enter the host plant through wounds, stomata, or root systems. Transmission occurs via infested soil, contaminated agricultural tools, infected seeds, or insect vectors. Because of their hardy nature, these bacteria can survive for long periods in plant debris, making long-term field hygiene essential.

Symptoms often manifest as systemic wilting, chlorosis, and the development of localized necrotic lesions on leaves and stems. As the bacteria multiply within the vascular bundles, they impede the transport of water and nutrients, leading to progressive stunting and death of the plant. In some crop species, the disease also induces the formation of hyperplastic galls or ulcers on stems and roots.

The development of the disease is heavily influenced by environmental factors, particularly high humidity and moderate to warm temperatures. Plants weakened by environmental stress, poor nutrition, or existing pest infestations are significantly more susceptible to infection. Optimal humidity levels in greenhouses often facilitate the rapid spread of mycobacteriosis if sanitary measures are neglected.

Protecting crops against mycobacteriosis requires a multi-faceted approach. Key prevention strategies include

• the use of certified disease-free planting material,
• the implementation of strict crop rotation cycles,
• regular disinfection of agricultural equipment,
• effective control of insect vectors,
• the removal and destruction of infected plant debris to minimize inoculum levels in the soil.