The spore suspension was shaken for 15 s using a Deluxe
Mixer, Model S8220 (Lab-Line Instruments, Melrose Park,
IL, USA) to break any conidial chains and then filtered
through four layers of cheesecloth to remove mycelial
fragments. Spore concentrations were determined using
a haemocytometer and adjusted with sterile water to
ca 5 · 105 spores ml)1, and kept on ice until used.