Crinipellis perniciosa . [Descriptions of Fungi and Bacteria

Abstract

Abstract A description is provided for Crinipellis perniciosa . Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Restricted to Theobroma spp. and Herrania spp. Recorded on: T. bicolor, T. cacao, T. calodesmis, T. glauca, T. grandiflora, T. microcarpa, T. obovata and T. subincana (37: 151); H. albiflora, H. nitida and H. purpurea (39: 684). DISEASE: Witches' broom disease of cacao. Infection of the breaking vegetative buds, flower cushions and young fruit leads to hypertrophy, reduction in leaf size, abnormal proliferation of axillary buds, growth of vegetative shoots from cushions and distortion of the fruit. These pathogenic effects may be due to the production of enzymes which inactivate the host auxins (48, 9g, 2864). The pathogen is generally confined to the hypertrophied areas which eventually become necrotic and later develop sporophores. At the epidemic level (reached in Ecuador, Surinam, Trinidad and Tobago) nearly all the vegetative growing points are infected and killed, up to 75% of the crop being directly destroyed. GEOGRAPHICAL DISTRIBUTION: Confined to parts of lowland tropical South America, Trinidad, Tobago and Grenada (CMI Map 37 ed. 2, 1965). Endemic on wild species of Theobroma in the Amazon and Orinoco river systems (17: 801; 23: 56; 42: 78). TRANSMISSION: Air dispersed basidiospores, released mostly between 1800 hr and 0600 hr, probably do not survive the day following the night on which they are shed. No conidial state is known.