Occasionally, wheat leaves and spikes are invaded by the bacterium, Xanthomonas campestris pv. translucens. When leaf tissue is affected, the resulting disease is known as bacterial streak. When the bacterium invades the head, the disease is called black chaff. While this disease has primarily been a problem in the lower mid-South, it is often found in Kentucky in fields that have been impacted by strong winds with blowing soil or following a damaging freeze.