Spray inoculum on upper surface of one cotyledon with a painter's air brush at 5-10 psi air pressure. Spread the droplet gently and uniformly over the cotyledon using a fingertip. Resistant and susceptible checks are sown in row 6. The flats are placed on a heated germination bench. Vermiculite temperatures of 32 C insure rapid and uniform germination.
Newspaper is removed when seeds germinate.
Plants are rated as susceptible, intermediate or resistant 6-8 days after inoculation. Lesions on susceptible plants are brown with chlorotic halos. Lesions enlarge and coalesce. Lesions on resistant plants are tan, surrounding tissue remains green. Lesions remain small and localized.