PYTHIUM SPP. ASSOCIATED WITH CAVITY SPOT OF CARROTS IN WESTERN-AUSTRALIA

Cavity spot lesions on mature carrots from growers' properties, and ma ture and maturing carrots from a disease nursery, were sampled for Pyt hium spp. Over 98% of the isolates were P. sulcatum; other species iso lated were P. irregulare and Pythium 'D'. P. coloratum was not found. In vitro pathogenicity tests on carrots showed that isolates of P. sul catum caused lesions while P. irregulare and Pythium 'D' did not. We c onclude that P. sulcatum is the most common and most important species associated with cavity spot of carrots in Western Australia.