Control of Leaf Spot Diseases on Ecotypes of Faba Bean (<i>Vicia faba</i> L.) Produced in the Andean Region of Bolivia
- 1 Departamento de Fitotecnia y Producción Vegetal, Facultad de Ciencias Agrícolas, Pecuarias, Forestales y Veterinarias Dr. “Martín Cárdenas”, Universidad Mayor de San Simón (UMSS), Cochabamba, Bolivia; 2Instituto Nacional de Investigación Agrícola y Forestal (INIAF), La Paz, Bolivia
- 2 Departamento de Fitotecnia y Producción Vegetal, Facultad de Ciencias Agrícolas, Pecuarias, Forestales y Veterinarias Dr. “Martín Cárdenas”, Universidad Mayor de San Simón (UMSS), Cochabamba, Bolivia; 2Instituto Nacional de Investigación Agrícola y Forestal (INIAF), La Paz, Bolivia
Abstract
The basin of Lake Titicaca is a faba bean-producing microregion of Bolivia where the crop is destined for export. The most commonly cultivated ecotypes “Gigante de Copacabana” and “Usnayo” are affected by diseases that can cause production losses. The aims of the present work were to identify the causal agents of leaf spot affecting these ecotypes, to record disease intensity levels, and to estimate their effect on production. In 2004 and 2005, leaflet, stem and pod samples were taken from faba bean plants with leaf spot growing in the Lake Titicaca area, and from plants in an experimental plot established to determine the effect of five different treatments on production and disease intensity: T1 = Control; T2 = seed treatment with Trichoderma sp. + alternate foliar spraying with benomyl and mancozeb; T3 = seed treatment with fludioxanil/metalaxyl M + alternate foliar spraying with benomyl and mancozeb; T4 = foliar spraying with Trichoderma sp.; T5 = alternate foliar spraying with cymoxanyl and mancozeb-chlorothalonil. Microscopic analysis of the samples revealed the presence of new fungal pathogens for faba beans in Bolivia ( Cladosporium sp., and Lepthosphaerulina sp.) as well as emerging fungal pathogens ( Botrytis cinerea , B. fabae , Ascochyta fabae , Alternaria sp. and Cercospora sp.). None of the treatments affected the disease progression curve (DPC) for incidence, although effects were seen with respect to disease severity. The seed + foliar treatments (T2 and T3) were more effective at controlling disease than leaf treatments on their own (T4 and T5). Modelling analysis showed faba bean leaf spot disease to be moderately destructive. Compared to chemical treatments, biocontrol with Trichoderma spp. preliminary was found to provide good control of the disease. Losses due to leaf spot disease of 36% were recorded, and a strong correlation detected between yield and disease severity.
- F. Balderrama, V. Iriarte, O. Barea, G. Iporre and E. Carrasco, “Cadena Agroalimentaria del Haba de Altura para Exportación (estudio preliminar),” Fundación Proinpa, Cochabamba, 2001.
- G. Heredia, “Ensayos Regionales de Rendimiento de Haba de Altura,” In: Informe Anual 1995-1996, Programa Nacional de Leguminosas de grano, Altiplano Norte, Instituto Boliviano de Tecnología Agropecuaria, La Paz, Bolivia, 1996, pp. 11-17.
- V. Otazu, W. M. Brown and M. de Quiton, “Enfermedades de las plantas en Bolivia,” Ministerio de Asuntos Campesinos y Agropecuarios/Instituto Boliviano de Tecnología Agropecuaria/Consorcio Internacional para el Desarrollo, Cochabamba, 1982.
- M. De Quitón, “Enfermedades de Haba.” In: H. Waaijenberg and M. Caro, Eds., Programa Nacional de Leguminosas de Grano: Resultados de Investigaciones, 1991-1998, Cochabamba, 2000, pp. 59-88.
- M. Coca-Morante, “Programa tubérculos y cultivos andinos,” Informe técnico Estación Experimental Belén, Facultad de Agronomía, Universidad Mayor de San Andrés, La Paz, 2002.
- V. D. Damsteegt, “New and Emerging Plant Viruses,” 1999. http://www.apsnet.org/feature/newviruses/top.html
- Y. Elad, “Biological Control of Foliar Pathogens by Means of Trichoderma Harzianum and Potential Modes of Action,” Crop Protection, Vol. 19, No. 8, 2000, pp. 709-714. doi:10.1016/S0261-2194(00)00094-6
- P. A. G. Elmer and T. Reglinski, “Review: Biosupression of Botrytis Cinerea in Grapes,” Plant Pathology, Vol. 55, No. 2, 2006, pp. 155-177. doi:10.1111/j.1365-3059.2006.01348.x
- A. Perelló, C. Mónaco, M. R. Simón, M. Sisterna and G. Dal Bello, “Biocontrol Efficacy of Trichoderma Isolates for Tan Spot of Wheat in Argentina,” Crop Protection, Vol. 22, No. 9, 2003, pp. 1099-1106. doi:10.1016/S0261-2194(03)00143-1
- B. Williamson, B. Tudzynski, P. Tudzynski and J. A. Van Kan, “Botrytis Cinerea: The Cause of Grey Mould Disease,” Molecular Plant Pathology, Vol. 8, No. 5, 2007, pp. 561-580. doi:10.1111/j.1364-3703.2007.00417.x
- D. Shtienberg, “Modelling: The Basis for Rational Disease Management,” Crop Protection, Vol. 19, No. 8-10, 2000, pp. 747-752. doi:10.1016/S0261-2194(00)00099-5
- M. J. Jeger, “Analysis of Disease Progress as a Basis for Evaluating Disease Management Practices,” Annual Review of Phytopathology, Vol. 42, 2004, pp. 61-82. doi:10.1146/annurev.phyto.42.040803.140427
- “Servicio Nacional de Hidrología y Meteorología,” Resumen Climatológico del Altiplano de La Paz, 2005.