Alternaria macrospora. [Descriptions of Fungi and Bacteria].
Abstract A description is provided for Alternaria macrospora. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On cotton (Gossypium spp.) and possibly on other hosts. DISEASE: Leaf spot of cotton. On leaves a small, necrotic spot, with a purplish halo, expands to about 1 cm diam., the centre becoming grey and cracked; the zonation is more clearly defined on the upper surface. Defoliation can be severe, especially where the peduncle becomes infected (28: 65). Stem lesions begin as a small sunken spot which develops into a canker, the tissue splitting and cracking to cause a break. The glandular areas on the receptacle are also attacked and this can result in failure of the boll to develop. Flowers and bolls may be shed; the latter become mummified and the fibre attacked (20: 461; 30: 37). Boll rots can also be caused by A. gossypina (Thum.) Hopkins (17: 674; 26: 14). GEOGRAPHICAL DISTRIBUTION: Australia, Brazil, Central African Republic, Ceylon, China, Congo, Egypt, Ethiopia, Formosa, France, French Sudan, Ghana, Guadeloupe, India, Italy, Jamaica, Japan, Kenya, Malawi, Morocco, Nicaragua, Nigeria, Pakistan, Rhodesia, Rumania, Senegal, Sierra Leone, South Africa, Somalia, Sudan, Tanzania, Togo, Trinidad, Uganda, Venezuela, Zambia. TRANSMISSION: No observations appear to have been reported; seed transmission is possible.