Haemophilosis

Haemophilosis in plants refers to a group of bacterial infections caused by microorganisms within the genus Haemophilus. These pathogens are gram-negative bacteria that primarily target the vascular system of host plants. By colonizing the xylem and phloem, these bacteria interfere with the translocation of nutrients and water, which eventually leads to the collapse of the plant's physiological integrity.

A wide variety of agricultural crops, particularly vegetables and certain ornamental species, are susceptible to infection by these bacteria. The susceptibility often increases in crops that are stressed by environmental factors or mechanical injury. Plants grown in greenhouse conditions with high humidity are at a heightened risk, as the environment facilitates the rapid multiplication of the pathogen.

The symptoms of haemophilosis typically manifest as irregular necrotic spots on leaves and stems. As the infection progresses, affected parts show clear signs of chlorosis, followed by wilting and tissue necrosis. In severe cases, the vascular tissue shows visible browning or blackening when cut, which is a hallmark sign of systemic bacterial invasion disrupting the plant's hydraulic conductivity.

The spread of the disease is heavily dependent on specific climatic conditions, particularly high humidity levels and ambient temperatures ranging from 20°C to 28°C. The pathogen persists in soil, plant debris, and infected seeds. Mechanical transmission via gardening tools or insect vectors plays a significant role in moving the bacteria from diseased plants to healthy areas of the field or greenhouse.

Effective management requires an integrated approach to avoid total crop loss. Key strategies include practicing crop rotation to break the disease cycle, sanitizing all tools after working with diseased plants, and ensuring proper spacing to improve air circulation. While chemical control using copper-based bactericides may provide suppression, early detection and the elimination of primary infection sources are the most reliable methods to control haemophilosis.