Bacterial wilt of pea

The pathogen Xanthomonas pisi is a gram-negative bacterium responsible for vascular wilt in pea crops. It colonizes the xylem of the host plant, producing extracellular polysaccharides that physically obstruct the transport of water and nutrients, eventually leading to plant wilting.

The primary host of this disease is the field pea (Pisum sativum). While it primarily affects pea crops, the pathogen can also exist in association with other legume species, serving as a reservoir for infection that persists within the agricultural landscape.

Symptoms often begin as small chlorotic lesions on leaves, which subsequently evolve into water-soaked patches and dark necrosis. As the disease progresses, systemic symptoms include leaf yellowing, stunting, and the characteristic wilting of the plant tops, revealing dark, discolored vascular bundles upon cross-sectioning.

The spread of Xanthomonas pisi is favored by warm, humid weather conditions, which promote the multiplication of the bacteria. The infection is frequently disseminated through contaminated seeds, infected plant debris left in the soil, and via mechanical spread caused by farm machinery or insect vectors during cultivation.

The economic impact of this disease is significant, as it leads to reduced yields, lower seed quality, and poor crop vigor. Management requires an integrated approach focusing on exclusion, sanitation, and the use of resistant germplasm to minimize the prevalence of the pathogen in high-risk areas.

• Use of disease-free, certified pea seeds.
• Implementing a minimum three-year crop rotation cycle.
• Deep plowing to accelerate the decomposition of infected crop residues.
• Effective integrated pest management (IPM) to reduce mechanical injuries to plants.
• Monitoring fields for early detection to isolate affected areas and prevent further spread.