Isolates of Blumeriella jaapii, Gnomonia erythrostoma, Nectria galligena, P
hytophthora cactorum, phytophthora fragaria rubi and Venturia inaequalis we
re grown in Petri dishes on specific media. The fungal hyphae complexed str
ongly with externally added oligomeric proanthocyanidins but also with mono
meric catechin. This was evidenced histochemically by staining with the sel
ective flavanol reagent p-dimethylaminocinnamaldehyde (DMACA).