Abstract

KIEHR, M; DELHEY, R  and  AZPILICUETA, A. Smudge and other diseases of onion caused by Colletotrichum circinans, in southern Argentina. Phyton (B. Aires) [online]. 2012, vol.81, n.2, pp.161-164. ISSN 1851-5657.

While studying the etiology of onion diseases in southern Argentina, a coelomycetous fungus was found associated with diverse disease expressions. They included the typical smudge symptoms in white onion bulbs in local markets as well as field infections on yellow- and red-coloured cultivars, with severe infections on transplants in the seed-bed. The fungus was isolated and identified as Colletotrichum circinans on the basis of its morphological, morphometric, biological and pathological characteristics. Two isolates, obtained from white bulbs and from transplants, were inoculated on bulbs of white and yellow-coloured cultivars and produced the typical smudge symptoms on the outer scales. Koch´s postulates were fulfilled by re-isolating the inoculated fungus. This is the first record of C. circinans in southern Argentina and the first observation of the disease in the feld in this country.

Keywords : Colletotrichum circinans; Onion; Smudge; Southern Argentina.

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