Abstract
A description is provided for Alternaria panax. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Araliaceae: Aralia, Brassaia, Dizygotheca, Fatsia, Mertya, Nothopanax, Polyscias, Pseudopanax, Schefflera, Tupidanthus. DISEASE: Occurs on leaves, petioles and stems, causing necrosis and abscission of leaflets and leaves. In severe epidemics it causes defoliation of the plants. GEOGRAPHICAL DISTRIBUTION: Asia: Korea, Japan, People's Republic of China (Guang-xi, Yunnan), USSR. Australasia & Oceania: Australia (Queensland), New Zealand, USA (Hawaii). Europe: Spain, U.K. North America: USA (Florida, Ohio, Indiana, Wisconsin). South America: Venezuela. TRANSMISSION: The fungus overwinters as mycelium in moribund vegetation, or as conidia in the soil. In favourable conditions the following year, sporulation will occur, the spores being dispersed to fresh vegetation by wind or other means. Alternaria panax thrives in warm, moist conditions, with an optimum temperature of 24-27°C.