Abstract
A description is provided for Alternaria cucumerina. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Citrullus lanatus, Cucumis melo, C. sativus, Cucurbita spp. DISEASE: Leaf spot of cucumber and melon (watermelon, musk melon, cantaloupe). Symptoms begin as yellow-brown flecks, 0.5 mm diam., on the upper surface of usually the crown leaves. They have a light green halo and gradually enlarge, becoming coalescent, with concentric ringing more commonly on the upper surface. Death of the leaves can be followed by lesions, several cm diam., forming on ripe fruit. These become covered with a dark, olive-green, conidial mass; they may be sunken and also show the concentric zonation. Infection of fruit in the field may be aggravated by exposure to sunlight (10: 431). Infection of stems or petioles does not occur. The pathogen can also cause decay in transit and storage, especially of melons and squash. GEOGRAPHICAL DISTRIBUTION: Arabia, Australia, Canada, Chile, Cuba, Cyprus, England, France, Japan, Kenya, Libya, Mozambique, New Zealand, Nigeria, Rhodesia, Rumania, Sierra Leone, South Africa, Sudan, Thailand, Trinidad, U.S.A., Venezuela, Zambia. TRANSMISSION: Seed may become contaminated with conidia. Survival from season to season is probably through mycelium in host debris. No air dispersal studies have been reported.
Understanding Magma Rise and Storage Using Major Element Diffusion in Olivine; Pupuke Maar, Auckland Field, New Zealand
