Resumo

TORRADO-JAIME, Mayary  e  CASTANO-ZAPATA, Jairo. Incidence and severity of black (Mycosphaerella fijiensis Morelet) and yellow (Mycosphaerella musicola Leach et Mulder) sigatokas of plantain according to the phenological stages. Agron. colomb. [online]. 2008, vol.26, n.3, pp.435-442. ISSN 0120-9965.

In Colombia, black and yellow sigatokas, caused by Mycosphaerella fijiensis and M. musicola, respectively, are two of the major diseases that affect plantain cultivation. Although there is information about their presence, their appearance according to plant development and environmental conditions is unknown. This research was conducted at the experimental station of Montelindo (University of Caldas), located at 1,050 m a.s.l., annual mean temperature 22.8 ºC, rainfall 2,200 mm and relative humidity 76%. Rhizomes of Dominico Hartón, Africa, FHIA-20 and FHIA-21 were sown following a random block design with four repetitions and 10 plants per repetition. Disease incidence and severity, fungi spores counting and climatic elements data was recorded from planting through harvesting stages. Five development stages were defined for the crop: emergency, seedling, pre-bloom, bloom, and physiologic maturity. The sigatokas appeared from seedling stage and remained during the entire cultivation cycle, with the black Sigatoka being more aggressive in the study area. The highest conidia population in D. Hartón and Africa was recorded in pre-bloom and filled bunch stages; the hybrids FHIA-20 and FHIA-21 coincided with the bloom stage. Gradual increases of temperature, intense precipitation followed by dry periods and high foliar humidity, favored disease incidence and severity.

Palavras-chave : Musa spp.; hybrids; cultivars; Caldas; diseases.

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