Head and kernel infections may occur if weather conditions are favorable. The fungus is often introduced into fields on infested seed and survives between grass crops as spores or mycelium in the soil or in crop debris. Since seedborne inoculum is so important for the spread of spot blotch, use a good, clean, fungicide-treated seed. Rotating small grains, including barley, with non-grass crops and destroying crop residue may help reduce disease damage. Anson is the only available barley variety that has good spot blotch resistance.
Net blotch is named for the net-like pattern found on barley leaves and leaf sheaths.
Lesions usually appear as small brown spots or streaks which expand to brown oval are oblong streaks. A yellow margin or halo is usually found around individual leaf lesions. Development of numerous lesions on a leaf results in the net-like pattern. The fungus survives between growing seasons on infested crop debris or seed. Disease development is favored by cool, wet weather in the fall and spring.