The tamarillo, or tree tomato, produced in Colombia, has great potential for commercialization in the global market for tropical exotic fruits, but suffers quality losses during the postharvest phase due to the use of inappropriate technologies. In order to extend the postharvest life of these fruits, the effect of calcium chloride (CaCl2) and different storage temperatures was evaluated. A completely randomized design was used, where the block criterion was the temperature with three treatments (control and calcium chloride doses of 570 and 862 mM) and three blocks (6, 9°C and ambient temperature [20°C]), for a total of nine experimental treatments monitored every five days for 20 days. The CaCl2treatments delayed softening over time, as compared to the control but did not affect the other quality attributes. Generally, the fruits stored at low temperatures lost less fresh weight and had a lower respiration rate as compared with the fruits stored at the ambient temperature. During the postharvest, it was observed that the fruits had a pH between 3.84 and 4.36, total acidity between 0.57 and 1.6% and 9.79°Brix on average. The physicochemical properties of the tamarillo were more affected by the ambient temperature than by the application of CaCl2. The temperature of 9°C is recommended for maintaining the quality of this fruit for 20 days.

Plantulas de tomate.Foto: Álvarez-Herrera.Efecto de diferentes láminas de riego sobre la producción y calidad de fresa (Fragaria sp.)Effect of different irrigation water levels on the production and quality of the strawberry (Fragaria sp.) Fresa variedad Ventana en fructificación.Foto: Y.A. Deaquiz RESUMENLa fresa es un cultivo de gran importancia económica para muchos agricultores de Colombia, principalmente para los de clima de frío de Boyacá y Cundinamarca; sin embargo, en estas zonas el bajo nivel de tecnificación del sistema de producción y el desconocimiento del manejo adecuado del riego en el cultivo de fresa conlleva al uso ineficiente del recurso hídrico. Por lo anterior, el objetivo de esta investigación fue evaluar el efecto de diferentes láminas de riego sobre la producción y calidad poscosecha de los frutos de fresa var. Ventana. Se utilizó un diseño experimental completamente al azar con cinco tratamientos y cuatro repeticiones. Los tratamientos correspondieron a cinco láminas de riego determinadas por cinco coeficientes multiplicadores de la evaporación (0,8; 1,0; 1,2; 1,4 o 1,6 de la evaporación medida dentro del invernadero). Para la siembra se utilizó turba rubia como sustrato, las aplicaciones se realizaron mediante sistema de riego por goteo. La lámina de riego de 1,6 presentó los mejores resultados de masa fresca de hojas, masa seca de hojas, corona y peciolos, área foliar y sólidos solubles totales de frutos; mientras que la lámina de riego de 1,4 obtuvo los mejores resultados de masa fresca de corona y peciolos, raíz, masa seca de raíz, frutos y relación de madurez. El coeficiente de riego de 1,4 presentó los mejores rendimientos y mantuvo una alta eficiencia en el uso del agua. El manejo de diferentes láminas de riego afecta las características organolépticas de los frutos de fresa.Palabras clave adicionales: uso eficiente del agua, estrés hídrico, evaporación, productividad, poscosecha.

Soil is a dynamic system, with physical, chemical and biological properties that have high spatial variability, making necessary to use innovative methodologies to study this variability. The aim of this study was to determine the spatial variability of moisture and compaction in soils with different plant covers. The study was conducted in the department of Boyaca (Co lombia), municipality of Sogamoso, Ombachita District. A total of 95 sampling points were measured as a rigid network in an area of 34.18 ha, which were georeferenced and taken as representative for the plant cover in the sampling area. The values of penetration resistance (PR) found in the soil ranged from 0.717 to 1.385 MPa, so that, as the depth increased, the PR increased, while the volumetric moisture presented an inversely proportional behavior for depth. The cover that prevailed in the study area was a mosaic of pastures and crops (MPC), at 30.1%. The moisture values were lower in the area planted with eucalyptus. The PR showed greater spatial dependence at a greater depth, while the moisture presented a moderate dependence at different depths.