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 st
rongly with externally added oligomeric proanthocyanidins but also with mon
omeric catechin. This was evidenced histochemically by staining with the se
lective flavanol reagent p-dimethylaminocinnamaldehyde (DMACA).