Actinobacteriosis

Actinobacteriosis is a plant disease caused by various members of the Actinobacteria phylum. While many actinobacteria are beneficial soil microorganisms, specific species, most notably Streptomyces scabies, act as pathogens that damage root crops and tubers, negatively affecting crop yield and quality.

The primary hosts for these pathogens are potatoes, sugar beets, carrots, and radishes. These bacteria infiltrate the plant through lenticels, wounds, or natural openings in the skin of underground organs, subsequently colonizing the tissue and creating lesions that compromise the plant's health and marketability.

Symptoms of the infection typically include the formation of scabs, deep pits, or irregular necrotic lesions on the surface of the produce. These lesions may become rough or corky, often serving as entry points for opportunistic fungi or bacteria, which accelerates tissue decay during storage and transportation.

The development of the disease is heavily influenced by environmental factors. High soil pH (alkaline conditions) and low soil moisture during the tuberization period are major triggers. Furthermore, the pathogen thrives in loose, well-aerated sandy soils where it can persist for years even in the absence of a host plant.

Preventive measures are essential for management since chemical options are often ineffective. Recommended strategies include:

• practicing long-term crop rotation to reduce pathogen population;
• adjusting soil acidity using physiological acid fertilizers;
• ensuring adequate irrigation during the sensitive stages of plant growth;
• selecting resistant cultivars and certified disease-free planting material.