Dry hot weather stops disease development. Initial infections normally occur during seedling emergence with secondary disease outbreaks often following windy rainstorms or crop cultivation while the foliage is wet. Bacterial blight is primarily a leaf disease, although stems, petioles, and pods may be affected. Spots are surrounded by a water-soaked margin bordered by a yellow halo. Spots often run together to form irregular brown areas, portions of which may drop out, resulting in a ragged appearance.
Management involves planting resistant cultivars and planting pathogen free seed.
Cultivation of fields when foliage is wet should be avoided to prevent spreading the pathogen. Bacterial Pustule, although common in most soybean production areas, is of minor importance because of the high level Of resistance to the pathogen in many commercially available cultivars. The bacterium overwinters in infected crop residue, in seeds and on the roots of wheat and some weeds. Consequently, new infections occur whenever wet conditions prevail. Later in the center of the spots a small, raised pustule develops which is most noticeable on the lower leaf surface.