Abstract
A description is provided for Wojnowicia hirta. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Cereals and grasses (Agropyron, Avena, Bromus, Calamagrostis, Calamovilfa, Dacrylis, Distichlis, Elymus, Festuca, Hordeum, Koeleria, Phleum, Poa, Secale, Sorghastrum, Sorghum, Spartina, Stipa, Triticum). DISEASE: Secondary foot rot or root rot of cereals and grasses. Also referred to as rot of mature straw. Rot of cereals and grasses is very common (5, 223; 6, 272; 7, 370; 11, 503; 12, 685; 16, 242; 48, 120; 1602) and considered to be of definite economic importance (Sprague, 1950). In France infected wheat plants have been reported to become etiolated and progressively shrivelled without producing lesions (4, 662). As the disease progresses, cells at the base of the culms were claimed to collapse resulting in the breaking of the stems and general lodging of plants in infected areas (5, 223; 12, 685). Subsequently pycnidia were reported appearing on lower leaf-sheaths above and below the soil line (1, 288). Sometimes affected wheat plants have been found to show discolouration of culm bases and roots (5, 223), or dark brown to black spots and streaks on the stem which are partly superficial (7, 370, Sprague, 1935). GEOGRAPHICAL DISTRIBUTION: Africa (Morocco, South Africa, Tunisia); Asia (Turkey); Australasia and Oceania (Australia, New South Wales, South Australia, Victoria, Western Australia); Europe (Belgium, Bulgaria, Czechoslovakia, Finland, France, Germany, Irish Republic, Italy, Netherlands, Poland, Rumania, Spain, Switzerland, UK, USSR); North America (Canada, Alberta, Saskatchewan; USA, Arkansas, California, Colorado, Dakota, Idaho, Kansas, Montana, Oregon, Washington, Wyoming). TRANSMISSION: Infected soil has been found to be the chief mode of transmission where stubble has been ploughed under (3, 191). It has also been reported that W. hirta occurs on culms overwintered in the field usually at the 2nd node (9, 639-641).