Place cotyledons in a beaker of distilled water and rub cotyledons with the fingers to dislodge the sporangia. 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 on top of the flat prevents cooling by evaporation.
Newspaper is removed when seeds germinate.
Plants are rated as susceptible or resistant 7-8 days after inoculation. Susceptible plants have strong chlorosis, while resistant plants have no chlorosis or very faint localized chlorosis.