From ISTA 7-001 method:
After 6 days of growth in an appropriate chamber, look for conidiophores that are simple or slightly branched, arising singly or in small groups from the surface of the seed or on aerial mycelium. Conidia are usually solitary, obclavate, up to 450 μm long (including beak), pale, olivaceous brown at first, becoming brown with age, with a long beak up to 3 times the length of the body (Ellis, 1971). Groups of sunken conidia are sometimes visible by the emerging clusters of their bright long beaks.
