Bacterial spot of millet is caused by the bacterium Pseudomonas syringae. Little is known about how the bacterium infects millet, disseminates within and among fields, or survives between susceptible crops. The disease is probably similar to other diseases caused by pseudomonads, where the pathogen establishes large populations on leaves before infecting the plant through natural openings or wounds. The pathogen is likely disseminated between fields by irrigation water, aerosol movement, and contaminated workers and equipment. Related pathogens are known to survive on leaves of numerous crops and weeds, volunteer crop plants, and in crop debris.
Bacterial spot symptoms and damage are not well known, but the disease appears as water-soaked spots. Lesions are oval to elongated, and eventually turn tan or necrotic with a thin dark brown margin. The disease is of little concern during most years in the High Plains region.
No biological control strategies have been developed for bacterial spot.
No cultural control strategies have been developed, but management practices for other diseases caused by P. syringae include a two-year or longer rotation to non-hosts, sanitation of weeds, volunteer crop plants, and crop debris, use of pathogen-free irrigation water sources, and avoiding working in fields when foliage is wet.
No chemical controls are available for bacterial spot
Categories: Millet, Disease, Bacterial Spot
Date: 03/22/05