Abstract

NUNEZ-RIOS, Tania; LEYVA-MIR, Santos Gerardo; RODRIGUEZ-PEREZ, Juan Enrique  and  MARISCAL-AMARO, Luis Antonio. Etiology and control of flower necrosis and fruit rot in cucumber in Morelos, Mexico. Rev. Chapingo Ser.Hortic [online]. 2013, vol.19, n.2, pp.255-255. ISSN 2007-4034.  https://doi.org/10.5154/r.rchsh.2012.10.059.

During field surveys conducted in 2010, severe symptoms of leaf blight, flower necrosis and fruit rot were observed in cucumber fields in Totolapan, Morelos, Mexico. Disease incidence ranged between 40 and 50 %. Fungal colonies were isolated from symptomatic cucumber leaves, flowers and fruits collected from different fields. Morphological characteristics of the colonies, conidia, and sclerotia of these fungal isolates were similar to Botrytis cinerea. A representative isolate of B. cinerea was selected for molecular analysis by amplification of the ITS region. Pathogenicity of the representative isolate was tested by inoculation of a conidial suspension on 10 cucumber seedlings and 10 fruits. Five seedlings and fruits inoculated with sterile distilled water served as controls. Control seedlings and fruits remained healthy, but grey lesions on inoculated leaves and fruits were observed five days after inoculation. B. cinerea was consistently re-isolated from leaves and fruits with lesions. On the basis of the isolation, morphological and molecular identification, and pathogenicity tests, B. cinerea was determined to be the causal agent of leaf blight, flower necrosis and fruit rot in cucumber in Totolapan, Morelos, Mexico. Additionally, the efficacy of four fungicides and the bio-control agent T. harzianum against B. cinerea in cucumber plants was evaluated in a greenhouse test. The fungicides chlorothalonil and thiabendazole showed the highest percent control, but the chemical treatments and the strain of T. harzianum did not significantly reduce the symptoms caused by B. cinerea.

Keywords : Cucumis sativus; Botrytis cinerea; Botryotinia fuckeliana; Trichoderma harzianum; fungicides.

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