Phosphorus (P) is a limiting nutrient for coffee seedlings. To meet this requirement, coffee growers usually apply di-ammonium phosphate (DAP), which is highly sensitive to local price fluctuations. The use of arbuscular mycorrhizal fungi (AMF) and phosphate-solubilizing fungi (PSF) has been recommended, but the results derived from their application are inconsistent and uncertain, depending on soil fertility status. The response of AMF and PSF application in the plant growth of coffee seedlings during the nursery stage was evaluated in four non-sterile soils, which represent the most abundant type of soils in the coffee regions of Colombia: Eutropept, Dystropept, Fulvudand, and Ultisol. The treatments included a commercial AMF inoculum, PSF-Phlebia subserialis-CH4, and a consortium of AMF+PSF, at four P levels (0, 0.5, 1, and 2 g.plant^-1 P₂O₅) using DAP fertilizer. Shoot dry weight (SDW) was affected by P applications in Fulvudand. In the other soils, a P-response occurred with 0.5 g.plant^-1 , whereas 1 and 2 g.plant^-1 of P₂O₅ caused a significant reduction in SDW. AMF increased SDW by 40% in Eutropept. The negative effect of higher P amounts was mitigated (> 70%) through PSF and AMF+PSF in Ultisol and Eutropept, respectively. In plants in which microorganisms increased SDW, the P concentration was 0.17 to 0.22%. The plant growth promotion of coffee seedlings during the nursery stage with AMF and/or PSF applications varied according to soil type and P amounts applied.

This paper reports the results of a study conducted to determine the influence of coarse aggregate type on the workability, compressive strength, and flexural strength of normal and high strength concretes with target 28-day compressive strengths of 30 and 60 MPa and two water/cement ratios of 0.44 and 0.27. The concretes were prepared using four types of natural coarse aggregates, namely diabase, calcareous, river gravel, and basalt, with maximum particle sizes of 12.7 and 19.1 millimeters. Silica fume was added to the high-strength concretes at a replacement ratio to Portland cement of 10% by mass. The results showed that among all aggregates, basaltic aggregate with a maximum particle size of 12.7 millimeters produced concrete with the highest compressive and flexural strength, followed by limestone and river aggregate, indicating that particle size, surface texture, structure and mineralogical composition play a dominant role in the behavior of concretes, especially high strength concretes. Normal strength concretes showed similar compressive strengths, while the concrete containing limestone gave slightly higher strength. These results show that for a given water/cementitious material ratio, the influence of the type of coarse aggregate on the compressive strength of the concrete is more important for high strength concrete than for normal strength concrete.

Este Avance Técnico presenta algunas de las principales características de un insecticida de reciente desarrollo mundial, registrado en Colombia como Incipio® ante el ICA y su evaluación para el control de la broca del café, formulado en una suspensión concentrada (SC) con su ingrediente activo isocycloseram, que corresponde a las isoxazolinas, una molécula que pertenece al grupo 30 de IRAC.

La broca del café, Hypothenemus hampei Ferrari (Coleoptera: Curculionidae: Scolytinae), es la plaga más limitante de la economía cafetera colombiana. Esta plaga produce caída de frutos, pérdida de peso y calidad del grano cosechado, con lo cual, al vender el grano, hay disminución de ingresos. En Colombia, se ha desarrollado una estrategia de Manejo Integrado de Broca “MIB”, que involucra diferentes componentes, entre ellos la aplicación de insecticidas, esta estrategia es ampliamente utilizada cuando las otras herramientas son insuficientes. Ethiprole es el ingrediente activo del insecticida Curbix® SC 200; con registro ICA para el control de la broca del café. Es utilizado para controlar insectos masticadores y chupadores en diversos cultivos.

This paper reports the results of a study conducted to determine the influence of coarse aggregate type on the workability, compressive strength, and flexural strength of normal and high strength concretes with target 28-day compressive strengths of 30 and 60 MPa and two water/cement ratios of 0.44 and 0.27. The concretes were prepared using four types of natural coarse aggregates, namely diabase, calcareous, river gravel, and basalt, with maximum particle sizes of 12.7 and 19.1 millimeters. Silica fume was added to the high-strength concretes at a replacement ratio to Portland cement of 10% by mass. The results showed that among all aggregates, basaltic aggregate with a maximum particle size of 12.7 millimeters produced concrete with the highest compressive and flexural strength, followed by limestone and river aggregate, indicating that particle size, surface texture, structure and mineralogical composition play a dominant role in the behavior of concretes, especially high strength concretes. Normal strength concretes showed similar compressive strengths, while the concrete containing limestone gave slightly higher strength. These results show that for a given water/cementitious material ratio, the influence of the type of coarse aggregate on the compressive strength of the concrete is more important for high strength concrete than for normal strength concrete.

Cenicafé ha identificado siete prácticas clave para optimizar el proceso de beneficio húmedo y seco del café, con el propósito de mejorar los factores de conversión y rendimiento, así como preservar la calidad del grano. Sin embargo, hasta ahora no se había cuantificado el impacto económico de no implementar estas recomendaciones técnicas en las fincas cafeteras. Este estudio evaluó las prácticas que generan mayores pérdidas físicas y económicas durante el beneficio, enfocándose en dos aspectos: 1) el efecto de la clasificación del café sobre la calidad física y las pérdidas en el proceso de beneficio, y 2) el efecto del mantenimiento, limpieza y calibración de la despulpadora. Así mismo, se comparó el proceso realizado por caficultores con el modelo estandarizado de las siete prácticas clave (7P®) recomendadas por Cenicafé, analizando su impacto sobre la cantidad y calidad física del café pergamino seco y su valor comercial según los precios de la Cooperativa de Caficultores. Los resultados revelan que un proceso técnico estandarizado reduce la cantidad de café pergamino necesaria para obtener un saco de 70 kg de café excelso, y que la recuperación de pasillas puede aumentar los ingresos hasta en un 8,8%. Por otro lado, la falta de calibración de equipos puede ocasionar pérdidas de hasta un 73,86% de la producción. Estos hallazgos destacan la importancia de adoptar prácticas técnicas adecuadas para mejorar el rendimiento y la rentabilidad económica para los caficultores.