The presence of a fungus on grains of perennial rye-grass which failed to germinate was recorded in New Zealand by Hyde in 1932. In 1938 the same fungus was associated by Hyde with exceptionally low germination in Italian rye-grass and, later that year (Hyde, 1938 a), the poor germinating capacity was ascribed to infection by Pullularia. Seed of the Scottish harvest of 1938 showed the signs of infection by Pullularia described in Hyde's papers (Noble, 1939), and cultures obtained from mycelium within infected seed, sterilised on the surface, were identified as Pullularia pullulans (De Bary) Berk.

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SUMMARY The presence in soil from Scotland and England of Phoma exigua f. sp. exigua and P. exigua f.sp. foveata, which cause gangrene, is confirmed by isolation, and it is established that infection of tubers occurs before lifting, and after lifting from soil adhering to tubers. The distribution of the disease is related to soil moisture, gangrene being most prevalent in tubers from the north‐eastern counties of Scotland where the moisture content of arable soils remains high throughout the growing season. The incidence of the disease may be affected by the haulm, either as a source of infection—though not an important source—or by its effect on the maturity of the tubers. The incidence of gangrene is less where haulm destruction is rapid. The incidence of gangrene in a crop is not related to its incidence in the seed tubers planted and, unless infection is severe, the effect on yield is not serious. Symptoms of skin necrosis were associated with tubers from acid soils, infected with P. exigua f.sp. foveata and stored at low temperature.