“…Development of resistance to organomercurial fungicides in vivo has been demonstrated in a number of fungal genera including Aspergillus (Gibson, 1953), Chrysosporium (Williams & Pugh, 1975), Leptosphaeria (Harrower, 1976), Pyrenophora (Noble et al, 1966), Cladosporium, Syncephalastrum (Greenaway, 1972a), Ulocladium (Greenaway, 1973 b) and Penicillium (Kiessling, 1961 ;Greenaway, Cripps & Ward, 1974).…”