Abstract
A description is provided for Penicillium digitatum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On decaying citrus fruit. DISEASE: Green mould of citrus fruit. Growth is rapid atter infection, the fruit surface becoming covered in a white mould which quickly becomes olive due to the production of the conidia. The fruit then softens and begins to shrink and if exposed to the air becomes a hollow mummified shell. Distinct from Penicillium italicum (see CMI Descript. 99) which is blue-green and finally reduces the fruit to a slimy mass. GEOGRAPHICAL DISTRIBUTION: Common in all citrus producing areas, but widespread as a storage rot of citrus fruit. TRANSMISSION: Common in soil of citrus producing areas and enters the fruit as a wound parasite but will not penetrate undamaged fruit. Said to occur more frequently than P. italicum on fallen fruit on light soil in Israel (31: 603). Spores also particularly abundant in air of citrus packing houses and fruit conditioning rooms (40: 400; 41: 89).