Abstract

Wilt of bananas (Musa spp.), caused by Fusarium oxysporum Schlect. f. sp. cubense(E. F. Smith) Snyd. &Hans. (FOC), has a long history in subtropical Queensland, where it has destroyed many plantations of cv. Lady finger. Cavendish (AAA) clones are now being attacked in subtropical Queensland. Vegetative compatibility was used to subdivide Australian populations of FOC. One hundred and fortyeight isolates were placed in six vegetative compatibility groups (VCGs). VCG was correlated with virulence on specific cultivars in the field. All putative race 1 isolates belonged to VCGs 0124 and 0125 and with one exception, isolates in this group were recovered only from cultivars susceptible to race 1. Evidence is presented which suggests that wilt in Cavendish cultivars in Queensland is due to the previous widespread distribution of Cavendish competent strains (VCGS 0120,0129) in plantings of Lady finger, which is the major Australian race 1 susceptible cultivar.