Abstract
A description is provided for Alternaria zinniae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Ageratum, Aster, Bidens, Calendula, Callistephus, Chrysanthemum, Coreopsis, Cosmos, Dahlia, Gaillardia, Galinsoga, Gerbera, Helianthus, Notonia, Parthenium, Sphaeranthus indicus, Tagetes, Tithonia, Volutarella, Xanthium, Zinnia. Also recorded are a number of non-compositae hosts such as bean (50, 3295), rape (43, 1212b), Clarkia, Hibiscus esculentus (66. 4729), pawpaws (66. 4729) and seeds of tobacco (64, 1748) but these reports should be regarded with some doubt. Simmons (1982) also reports other hosts like Gentiana, Papaver and Reseda. DISEASE: Leaf spot of Zinnia. The fungus attacks the leaves, stems of its host and can cause damping-off of seedlings where both the root and the stems of the plant may be affected. In older plants the fungus attacks the older leaves and then spreads to the younger leaves, and when the attack is severe the spots may become confluent. GEOGRAPHICAL DISTRIBUTION: Africa: Egypt, Ethiopia, Ghana, Kenya, Libya, Malawi, Mauritius, Sierra Leone, South Africa, Sudan, Tanzania, Uganda, Zambia, Zimbabwe. Asia: Brunei, China (Liaoning). India, Indonesia (Borneo), Korea, Nepal, Pakistan. Australasia & Oceania: Australia. Europe: Cyprus. Denmark, France, Germany, Hungary, Italy, Norway, Poland, Portugal, Romania, The Netherlands. Central & North America: Bermuda, Canada, Jamaica, USA (Hawaii, Illinois, South Dakota). TRANSMISSION: On seeds by wind dispersal of airborne conidia.
