Halo Blight of Mungbean in Australia

Abstract

Halo blight, one of the major diseases of mungbean, is caused by the bacterium Pseudomonas savastanoi pv. phaseolicola. The pathogen infects the foliar parts of the plant, causing water-soaked spots that eventually develop surrounding yellow margins. The disease is particularly destructive under moderate temperature and high humidity, especially when it occurs during late vegetative through to early reproductive stage. In such conditions, severely infected crops could experience a yield loss up to 70%. Halo blight can be widespread on mungbeans grown in Southern Queensland and Northern New South Wales. However, due to its seedborne and cryptic nature of transmission, the disease is likely to be under-reported. This report addresses major aspects of halo blight symptomology, pathology and epidemiology.