Uso de programas de manejo basados en productos biológicos para el control de enfermedades en el cultivo del cerezo
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Date
2023
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Publisher
Universidad de Concepción
Abstract
El cáncer bacterial y las pudriciones causadas por hongos de pre y post cosecha son enfermedades que afectan al cerezo mundialmente. El uso de productos biológicos es una alternativa de control adecuada para reducir el uso de agroquímicos. Sin embargo, existe poca información sobre la interacción entre estos productos y su efecto sobre las dinámicas poblacionales de los fitopatógenos cuando se incorporan dentro de un programa de manejo integrados de enfermedades. Este trabajo evaluó el impacto fitosanitario de programas basados en productos biológicos, en el manejo de estas enfermedades del cerezo y desarrolló un sistema de qPCR para evaluar presencia de Pseudomonas syringae pv. syringae (Pss) en tejidos de cerezo. Se establecieron unidades de media hectárea bajo dos tratamientos basados en bioproductos, otra unidad basada sólo en control químico y una unidad bajo el manejo del productor, dentro de un huerto de cerezos ‘Sweetheart’ ubicado en Chillán, Chile. Se realizaron conteos poblacionales y medidas de incidencia y severidad en estados fenológicos específicos del cultivo. Los resultados indican que los tratamientos basados en bioproductos a base de Pseudomonas protegens, Bacillus spp. y Trichoderma spp. disminuyeron las poblaciones de Pseudomonas syringae pv. syringae; Botrytis cinerea y Alternaria spp. durante estados fenológicos específicos, sin ser diferentes respecto a los demás tratamientos. No existieron diferencias significativas en la incidencia y severidad de cancros bacterianos entre los tratamientos, pero si hubo disminuciones en la incidencia de un 87% en pudrición por Alternaria spp., y de un 60% en pudrición por Botrytis cinerea en fruto maduro en el programa químico con respecto a los basados en productos biológicos, durante la primera y segunda temporada, respectivamente. Estos resultados permiten promover la inclusión de bioproductos en programas comerciales de manejo de enfermedades en cerezo. Se realizaron curvas estándar por qPCR para la cuantificación de Pss en tres estados fenológicos susceptibles, comparando los resultados con los obtenidos por método de conteo en placas Petri. Los resultados indican que el método qPCR es altamente sensitivo, rápido, y efectivo en el monitoreo de la carga de Pss, con límites de detección entre 104 y 105 UFC mL-1, indicando que es una buena herramienta para la toma de decisiones relacionadas al control del cáncer bacterial.
Bacterial canker and pre- and postharvest rots are diseases affecting sweet cherry worldwide. The use of biological products is a suitable alternative to reduce agrochemical applications. However, there is a lack of information on the interaction between these products and their effect on the population dynamics of these pathogens when incorporated into integrated disease management programs. This study evaluated the phytosanitary impact of biological based management programs on sweet cherry disease control. Half hectare units were established under two biological-based programs, one based only on chemical control and the other under the local grower program, in a ´Sweetheart´ sweet cherry orchard in Chillán, Chile. Population counts and incidence and severity measurements were made on cherry at specific phenological stages. Results showed that biological-based programs, which included Pseudomonas protegens, Bacillus spp. and Trichoderma spp., reduced populations of Pseudomonas syringae pv. syringae; Botrytis cinerea and Alternaria spp. at specific phenological stages, with no differences regarding chemical and grower programs. There were no significant differences in the incidence and severity of bacterial cankers among all management programs, but there were decreases of 87% for Alternaria spp. rot incidence and 60% for Botrytis cinerea rot incidence in ripe fruit in the chemical program compared to the biological product-based programs during the first and second seasons, respectively. These results support the inclusion of bioproducts in commercial cherry disease management programs. qPCR standard curves were generated for Pss quantification in three susceptible phenological stages of sweet cherry and the results were compared to those obtained using the bacterial drop count method. The obtained results showed that qPCR is a highly sensitive, fast, and effective method for Pss load monitoring, with detection limits ranging from 104 to 105 CFU mL-1, indicating that it is a good tool for decision-making related to bacterial canker control.
Bacterial canker and pre- and postharvest rots are diseases affecting sweet cherry worldwide. The use of biological products is a suitable alternative to reduce agrochemical applications. However, there is a lack of information on the interaction between these products and their effect on the population dynamics of these pathogens when incorporated into integrated disease management programs. This study evaluated the phytosanitary impact of biological based management programs on sweet cherry disease control. Half hectare units were established under two biological-based programs, one based only on chemical control and the other under the local grower program, in a ´Sweetheart´ sweet cherry orchard in Chillán, Chile. Population counts and incidence and severity measurements were made on cherry at specific phenological stages. Results showed that biological-based programs, which included Pseudomonas protegens, Bacillus spp. and Trichoderma spp., reduced populations of Pseudomonas syringae pv. syringae; Botrytis cinerea and Alternaria spp. at specific phenological stages, with no differences regarding chemical and grower programs. There were no significant differences in the incidence and severity of bacterial cankers among all management programs, but there were decreases of 87% for Alternaria spp. rot incidence and 60% for Botrytis cinerea rot incidence in ripe fruit in the chemical program compared to the biological product-based programs during the first and second seasons, respectively. These results support the inclusion of bioproducts in commercial cherry disease management programs. qPCR standard curves were generated for Pss quantification in three susceptible phenological stages of sweet cherry and the results were compared to those obtained using the bacterial drop count method. The obtained results showed that qPCR is a highly sensitive, fast, and effective method for Pss load monitoring, with detection limits ranging from 104 to 105 CFU mL-1, indicating that it is a good tool for decision-making related to bacterial canker control.
Description
Tesis presentada para optar al grado de Magister en Ciencias Agronómicas
Keywords
Control biológico de plagas agrícolas, Cerezo - Enfermedades y plagas