Soft rot (Pectobacterium aroidearum)

The causative agent, Pectobacterium aroidearum, is a pectinolytic bacterium known for inducing soft rot in a wide range of horticultural and agronomic crops. It belongs to a group of bacteria that produce powerful extracellular enzymes capable of degrading plant cell walls, leading to the collapse of tissue structure.

This pathogen demonstrates a broad host range, impacting plants such as potatoes, tomatoes, various brassicas, and many ornamental species. The bacteria can persist in crop residues, irrigation water, and even within the latent state in plant tissues, waiting for favorable conditions to proliferate.

Symptoms typically manifest as rapid tissue softening and discoloration. Infected areas become water-soaked and mushy, often emitting a pungent odor due to the activity of various saprophytic organisms that invade the softened tissue. In many cases, the entire stem or storage organ can disintegrate within a few days.

Development is heavily favored by high moisture levels, poor drainage, and high humidity, combined with moderate to warm temperatures. Spread usually occurs through contaminated farm tools, water splashes, insect vectors, or contact between healthy and infected produce during harvesting and transport.

Management of Pectobacterium aroidearum requires an integrated approach. Prevention is significantly more effective than treatment. Key strategies include maintaining optimal soil drainage, implementing rigorous sanitation programs for equipment, practicing crop rotation with non-host species, and ensuring produce is kept dry and well-ventilated during storage to inhibit bacterial growth.