Effect of agricultural inputs and essential oils on the soil of vegetables in Colombia's Caribbean region

Abstract

The contribution of vegetables to food security and economic development in Colombia, as well as to environmental problems worldwide, justifies the interest to design sustainable production strategies for the agro-chain. This study was developed to evaluate the effect of the application of essential oils and agricultural inputs in chili peppers, beans and eggplants in Codazzi, Cesar, Colombia. The methodology included the compatibility analysis between pesticides used in these vegetables, and Lippia alba and Cymbopogon citratus oils in relation to their biocidal effect in vitro on native strains of Macrophomina phaseolina, Phytophthora capsici and Colletotrichum gloeosporioides. Applications of thiabendazole in an individual basis and combined with oils were carried out in the field. Physicochemical and microbiological indicators of soil, pests and diseases incidence and crop yield were measured. Oils controlled up to 97% of plant pathogens in vitro and exhibited compatibility with carbendazim and thiabendazole. In the field, up to 67 % of disease control was observed with C. citratus + thiabendazole compared to the control (p = 0.00), yields were close to the regional average, and better microbiological and physicochemical soil conditions were observed. In conclusion, there are differences in the edaphic effect between treatments, as the agrochemical and the oil combinations were more favorable than the individual effect of each product on the variables evaluated. The above exhorts to continue soil evaluations with oils to elucidate the duration of the described effects.

El aporte de las hortalizas a la seguridad alimentaria y desarrollo económico de Colombia y la problemática ambiental mundial, justifica el interés de diseñar estrategias productivas sostenibles para la agrocadena. Se desarrolló un estudio para evaluar el efecto de la aplicación de aceites esenciales y agroinsumos en cultivos de ají, fríjol y berenjena en Codazzi, Cesar. La metodología comprendió el análisis de compatibilidad entre pesticidas utilizados en estas hortalizas, aceites de Lippia alba y Cymbopogon citratus, respecto al efecto biocida in vitro sobre cepas nativas de Macrophomina phaseolina, Phytophthora capsici y Colletotrichum gloeosporioides. En campo, se aplicó tiabendazol individual y combinado con los aceites. Se midieron indicadores fisicoquímicos y microbiológicos de suelo, incidencia de plagas y enfermedades y rendimiento de cultivos. Los aceites controlaron in vitro hasta el 97 % de fitopatógenos y exhibieron compatibilidad con carbendazim y tiabendazol. En campo, se observó control de enfermedades hasta del 67 % con C. citratus + tiabendazol respecto al testigo (P=0,00), rendimientos cercanos al promedio regional, mejores condiciones microbiológicas y fisicoquímicas del suelo. En conclusión, existen diferencias en el efecto edáfico entre tratamientos, fue más favorable la combinación de aceites y el agroquímico respecto al efecto individual de cada producto sobre las variables evaluadas. Lo anterior exhorta a continuar evaluaciones en campo con aceites para elucidar la duración de los efectos descritos.