In this work, the efficiency of chitosan as a biocontrol agent against Fusarium solani on tomato plants was determined and the antifungal activity and the induction of defence enzymes were evaluated. Treatments were carried out with different concentrations of chitosan (1, 2 and 3 g L⁻¹) combined with a synthetic fungicide (carbendazim). The results showed that all chitosan treatments significantly inhibited the mycelial growth and biomass of F. solani, with the most effective results obtained with the 3 g L⁻¹ treatment. Scanning electron microscopy revealed that chitosan causes severe structural damage to F. solani, including cell lysis and the deformation of mycelium and spores. In addition, plants treated with chitosan showed significant improvements in height, stem diameter, root dry biomass and root length compared to those treated with synthetic fungicide and the control (no chitosan application). Enzyme assays showed that chitosan significantly increased superoxide dismutase, catalase, peroxidase and phenylalanine ammonia-lyase activity, indicating an increased defensive response. These results suggest that chitosan is a viable and less toxic alternative for the management of disease caused by F. solani in tomato plants, promoting both plant health and growth.

Este artículo presenta una revisión sistemática de las prácticas de conservación y manejo sostenible del suelo en la agricultura, destacando la integración de métodos tradicionales y modernos. El objetivo es evaluar cómo estas prácticas influyen en la salud del suelo y la producción agrícola sostenible. Se realizó una búsqueda exhaustiva en bases de datos científicas, seleccionando estudios relevantes publicados entre 2012 y 2023. Los resultados indican que técnicas como la labranza cero, rotación de cultivos, y uso de abonos orgánicos mejoran significativamente la estructura del suelo, retención de nutrientes, y biodiversidad. Estas prácticas también contribuyen a la mitigación del cambio climático. Se concluye que un enfoque integral que combine prácticas tradicionales y modernas es esencial para una agricultura sostenible, y se resalta la necesidad de más investigaciones en diferentes contextos edafoclimáticos para optimizar estas estrategias de conservación del suelo.

Synthetic fungicides have experienced a significant increase in recent years, necessitating the search for more sustainable and environmentally friendly alternatives. In this regard, chitosan has emerged as an option to reduce reliance on these products. This study evaluated the effect of chitosan as a biocontrol agent against Fusarium oxysporum in tomato fruits. A fully randomized experimental design incorporating 6 treatments was employed, consisting of four chitosan treatments (0.5, 1, 2, and 3 g L^-1), a negative control involving the application of a synthetic fungicide, and a positive control inoculated with F. oxysporum. Samples were taken from infected tomato fruits. The F4 isolate of Fusarium sp. was identified as F. oxysporum, and demonstrated the highest level of virulence. Among the four chitosan treatments, the 3 g L^-1 treatment showed the highest a percentage of mycelial growth inhibition (PMGI) at 79.92% and the greatest reduction in biomass at 0.65 g, which did not differ significantly from the synthetic fungicide. Regarding disease severity and incidence, there were significant variations among each of the chitosan treatments, with the highest results obtained with the 2 and 3 g L^-1 treatments. All chitosan treatments reduced disease severity in tomato fruits. Applying chitosan on fruits of the tomato plant presents an alternative for diminishing reliance on synthetic fungicides.

El Zea mays (maíz) es un cultivo esencial para la economía mundial y la seguridad alimentaria. El uso excesivo de pesticidas en este cultivo plantea riesgos ambientales y para la salud. El objetivo es promover prácticas agrícolas sostenibles. Esta revisión examina críticamente la investigación sobre los efectos del uso de pesticidas en el cultivo de maíz. Se realizó una revisión exhaustiva de la literatura utilizando bases de datos académicas como Google Scholar, Scielo y Redalyc. Se analizaron estudios publicados entre 2005-2023 sobre el impacto de insecticidas, fungicidas y herbicidas en el maíz. Los estudios revelan efectos perjudiciales del uso excesivo de pesticidas como contaminación del suelo y agua, resistencia de plagas, reducción de la biodiversidad y daños fisiológicos en las plantas. Se encontraron residuos de insecticidas en suelos agrícolas, representando riesgos adicionales. Las alternativas como biopesticidas, extractos botánicos y control biológico emergen como opciones viables y sostenibles. Esta revisión subraya los riesgos del uso excesivo de pesticidas en el maíz y la necesidad de adoptar estrategias integrales, incluyendo prácticas responsables, manejo integrado de plagas y variedades resistentes. Es imperativo implementar soluciones basadas en evidencia científica para garantizar la productividad y sostenibilidad de este cultivo vital.

Cocoa represents a crucial source of income in coastal regions of Ecuador, where the product is exported for the production of high-value chocolates. However, elevated levels of cadmium (Cd) in cocoa beans, attributable to volcanic soils, have the potential to impede international trade, particularly in accordance with European Union regulations. The main objective of this study was to reduce Cd concentrations in cocoa beans of two genotypes, Nacional and CCN-51, by applying different doses of pectin trans-eliminase (PTE) enzyme during the fermentation process in conjunction with mucilage washing techniques, pre-drying resting periods, and various drying methods. To this end, a Taguchi orthogonal design (L9) was employed to evaluate nine treatments per genotype, complemented with two controls. The most efficacious treatment for Nacional was identified as T7, involving a 0.30 mL·kg⁻¹ PTE dose, the absence of mucilage washing, a 48 h resting period, and drying in a marquee. This treatment resulted in a 68.6% reduction in Cd concentration (from 0.28 to 0.09 mg·kg⁻¹). For CCN-51, T3 (0.10 mL·kg⁻¹ PTE, complete washing, 48 h resting, and splint drying) yielded a 26.4% reduction in Cd (from 0.42 to 0.31 mg·kg⁻¹). It is noteworthy that none of the treatments exceeded the EU regulatory threshold of 0.8 mg·kg⁻¹. A physico-chemical analysis was conducted, which revealed significant treatment effects on pH (ranging from 5.63 to 6.85) and acidity (0.02% to 0.03%). Sensory evaluation indicated enhancements in cocoa and nutty flavors, along with a reduction in undesirable astringency and bitterness, particularly in Nacional samples. The findings of this study demonstrate that the combination of enzyme-assisted fermentation and optimized postharvest techniques represents a pragmatic approach to the mitigation of cadmium in cocoa, while simultaneously preserving or enhancing product quality.

The use of Trichoderma spp. represents a sustainable alternative to improve the propagation of Theobroma cacao L. seedlings. This study evaluated the effect of selected Trichoderma spp. strains on the germination and initial growth of Nacional cacao under different substrates in nursery conditions. Four strains (T. harzianum strains 1 and 2, T. reesei, and T. viride), as well as a control, were applied to three substrate mixtures: forest soil + organic compost, forest soil + perlite, and forest soil + peat. Seed germination was high (100%) in all treatments. However, seedling survival significantly improved with the use of peat (>90%) compared to forest soil + compost (52.5%). In terms of growth, T. viride in perlite promoted greater fresh root weight (12.18 g) and dry root weight (6.91 g), as well as greater seedling height (38.31 cm). Similarly, T. viride in peat generated the highest shoot fresh biomass (16.05 g) and dry biomass (9.19 g). The results confirm that inoculation with Trichoderma spp., in combination with suitable substrates, enhances the initial growth of cacao seedlings, increasing their vigor and productive potential in sustainable agroecological systems. The appropriate selection of strain and substrate is key to improving efficiency and sustainability in cacao nurseries, contributing to high-performance agriculture with lower dependence on chemical inputs