All reports and records of Verticillium albo-atrum from Australia have been examined. The only ones authenticated by specimens and cultures are on potato from South Australia, Tasmania and Victoria. In some cases, reports on other hosts can be shown to refer to V. dahliae; in others, the identity of the causal fungus cannot now be determined. Confusion about the host range and geographic distribution of V. albo-atrum in Australia has arisen from (i) failure of much of the earlier literature to distinguish between V. albo-atrum and V. dahliae; (ii) assuming that diseases reported only as Verticillium wilt were caused by V. albo-atrum and (iii) failure of many workers to retain specimens and cultures which would allow the identity of reported hosts and fungi to be checked at a later date. Thus, Verticillium albo-atrum must be regarded as a pathogen of major quarantine significance for Australia and stringent measures taken to exclude it. Strains attacking hops and lucerne in some other countries are of especial quarantine importance.

In recent years, sclerotia of the ergot C/aviceps purpuree (Fr.) Tul. have been found mixed with cereal grain harvested in Australia. This has caused some concern to growers and exporters of grain. In most cases, the sclerotia have originated from ergot-infected rye grasses (Lolium spp.) growing in crops, but in a few cases infection of wheat has also been seen. Infection of wheat by C/aviceps purpurea has been reported from most wheat-growing countries. In Australia, it has been known on wheat since last century, when McAlpine (3) listed it in Victoria. In 1915, Darnell-Smith & Mackinnon (2) described and figured infected wheat heads from N,S.W. and there are some more recent records from this state (specimens in DAR). There are also records of C. purpurea on wheat from South Australia (specimen DAR 25106 in Biology Branch Herbarium), and Tasmania (1). Waterhouse (8) reported infection in sterile F1 hybrids of wheat and rye inoculated with conidia of C. purpurea, and in the same inoculated plots both Triticum aegilopoides Bal. and T. monococcum L. were also infected. In Australia, whilst individual wheat heads have been heavily infected, the level of infection in crops generally has been low. Moreover, some of the Australian records have come from material in plant breeders' plots. Overseas work has indicated that susceptibility to ergot infection in wheat is related partly to the length of the flowering period (5,6). In fertile wheat and barley, which are largely self-pollinated, the level of infection in nature is generally very low; however, in some male sterile and hybrid wheats, where the flowering period is longer, the possibility of ergot infection is increased greatly (5).

tile perithecia in association with stromatic structures within 7 to 10 days of inoculation, Perithecia varied in shape from globose to flaskshaped and attained a diameter of 100 to 250 um. Mature, clavate to cylindrical asci ranged in size from 41 to 88 /-1m x 9.5 to 15,um (mean 64.5 x 11,5/-1m) and contained eight 1-celled, hyaline, allantoid ascospores. The ascospores varied in size from 12.5 to 22/-1m x 4,5 to 6/lm (mean 17,5 x 5/-1m ). The perithecia, asci and ascospores produced by the fungus are typical of Glomerella cingulata as described by von Schrenck and Spaulding (3),

The identity of the fungus on all field specimens was confirmed by Mr. J. Walker, N.S.W. Department of Agriculture. The hosts were identified by the staff of the National Herbarium of N.S.W., Royal Botanic Gardens, Sydney. I thank Dr. L.W. Burgess, Department of Plant Pathology and Agricultural Entomology, University of Sydney for his support and encouragement, and I acknowledge financial support from the R.C.D.F. and more recently, from a Thomas Lawrence Pawlett Scholarship awarded by the University of Sydney.

Effect of Soil Moisture on Decline of Pinus radiata

Examination of the type and other specimens of Gaeumannomyces graminis (Sacc.) Arx & Olivier and of Ophiobolus oryzinus Sacc. has shown that they are identical, and should be known under the name G. graminis var. graminis . This fungus produces on its hosts a mycelium with abundant lobed brown hyphopodia. The fungus causing take-all of wheat differs from G. graminis var. graminis in having simple unlobed hyphopodia and is named G. graminis var. tritici var. nov. The oat take-all fungus, G. graminis var. avenae (E. M. Turner) Dennis, also has simple unlobed hyphopodia, with larger ascospores than the other two varieties. A group of Gaeumannomyces species with hyphopodiate mycelia on Carex spp. is recognized. The significance of these results on identification of cereal take-all fungi and on their host ranges is discussed. Type specimens of several species described earlier than G. graminis were also examined. The names Sphaeria cariceti Berk. & Br. and S. eucrypta Berk. & Br. cannot be applied to the cereal take-all group of fungi. S. helicospora Berk. & Br. is transferred to Acanthophiobolus and S. chaetophora Crouan is reduced to synonymy under this name. Several other species are considered.