Two experiments were carried out on strawberry plants which are very susceptible to Armillaria infection and show symptoms of infection more quickly (Raziq and Fox, 2004) than woody plants. For that reason, the experiments were conducted in the strawberry/ A. gallica pathosystem. The strawberry cultivar Elsanta was used because, in preliminary trials, it was found to be very susceptible to A. gallica (100% infection rate following artificial inoculation; data not shown). Each plant was grown in a 2-L pot containing neutral peat (BVB Substrates, The Netherlands). Pots were kept in a
greenhouse under controlled conditions at 22 ± 4 C and relative humidity (RH) of 60 ± 20%. These plants were irrigated regularly and treated with sulfur (Thiovit 80; Syngenta AG, Basel,Switzerland) to control powdery mildew. Each experiment was performed using a mixture of bark from different tree species because this mixture was found to be the best substrate for T. atroviride SC1 survival in the experiments described above