This project is presented as an innovative and clean alternative that optimizes the use of small areas for strawberry (Fragaria ananassa Duch) production in the department of Nariño. This research was conducted at the Centro Internacional de Producción Limpia Lope -SENA- Regional Nariño, with the aim of evaluating physical and chemical variables of organic substrates such as coconut fiber, rice husk, and their mixtures for strawberry (Fragaria ananassa Duch) variety Albión production in a hydroponic system. Six treatments and four repetitions were performed; the treatments were 100% rice husk, 70% rice husk and 30% coconut fiber mixture, 50% of each of the substrates used, a mixture of 70% coconut fiber and 30% rice husk, 100% coconut fiber, and a control in soil with plastic cover. A comparative analysis was made between the average values obtained in the initial stage and the final stage of the experiment, evaluating physical and chemical properties such as bulk density, real density, gravimetric moisture, granulometry, pH, and electrical conductivity. The experiment showed that taking initial and final measurements of the substrates allows adequate monitoring for optimal crop development since a substrate with a high percentage of particles in the sieve <0.25, electrical conductivities greater than 2000 µS.cm-1, and an increase in bulk density can produce salinization and compaction, negatively impacting the crop.

0000-0001-9222-4674 3 municipios de La Florida y Buesaco, ubicados en el departamento de Nariño, se establecieron dos ensayos, bajo un diseño de Bloques Completos al Azar, con tres repeticiones. La interacción genotipo por ambiente fue signifi cativa para el peso de fruto (PF), diámetro ecuatorial, sólidos solubles totales, contenido de jugo y rendimiento (RTO). En La Florida, B1, B2, B3, B4xB5 y B2XLaSelva fueron los de mejor comportamiento en cuanto a RTO, con promedios entre 6,64 a 9,35t.ha -1 y PF, con 143 a 167g, en su orden. En Buesaco, se destacaron B1 y B2xB8 con RTOs de 7,72 y 9,43t.ha -1 y PF, entre 92,03 y 112,97g, promedios que están por encima del promedio regional y son la base para mejorar estas características.Palabras clave: Solanum quitoense; rendimiento; peso de fruto; índice de selección; interacción genotipo ambiente.Lagos-Santander, L.K.; Lagos-Burbano, T.C.; Duarte-Alvarado, D.E.; Criollo-Escobar, H.; Angulo-Ramos, N.F.: Evaluación de germoplasma de lulo ABSTRACT Solanum quitoense is a plant of great relevance to undertake productive projects for export as an exotic fruit or for industry. Its importance lies in the possibility of contributing to the development of producers in the Andean region, because the lulo is demanded in the market for its flavor, aroma, nutritional and organoleptic properties. Despite its importance, this species has technological deficiencies, among which, the lack of improved cultivars that guarantee greater yields and fruit quality and establish its agronomic efficiency through different environments is highlighted. The objective of this work was to evaluate the performance of the yield and traits related to the fruit in populations of lulo de Castilla. Eight parents and 10 hybrids were used. In the municipalities of La Florida and Buesaco located in the department of Nariño, two trials were established under a Randomized Complete Blocks design with three repetitions. Genotype interaction by environment was significant for fruit weight (FP), equatorial diameter, total soluble solids, juice content and yield (RTO). In La Florida, B1, B2, B3, B4xB5 and B2XLaSelva were the best performers in terms of RTO with averages between 6.64 to 9.35t.ha-1 and PF with 143 to 167g, in order. In Buesaco, B1 and B2xB8 stood out with RTOs of 7.72 and 9.43t.ha-1, PF between 92.03 and 112.97g, averages that are above the regional average and are the basis for improving these characteristics.

Lulo (Solanum quitoense) is a promising Andean fruit tree that is highly valued in international markets because of its nutritional characteristics, flavor, aroma, and high content of vitamins A and C with antioxidant properties. However, certain sanitary problems, such as Fusarium oxysporum and soil nematodes, pose challenges to the competitiveness of lulo crops. Cultivating lulo plants grafted onto resistant patterns, such as S. hirtum, is a plausible solution to these sanitary issues; so, determining the behavior of grafted plants is relevant. In this study, the phenology and growth dynamics of grafted lulo plants were evaluated with functional analyses based on thermal time (degree days-DD). Completion of the vegetative phase of the lulo required 561 DD from planting to the onset of flower bud sprouting, 715 DD to reach anthesis, 801 DD for fruit set, and a cumulative total of 2,464 DD to reach fruit ripening. The functional analyses showed that Richards’s model fit the dynamics of the growth variables (height, leaf area index, crop growth index, total dry weight, leaf dry weight, and stem dry weight). Of the total plant dry biomass, 39.7% corresponded to the stems, 33.8% was from the fruits, 15.54% was from the leaves, 10.56% was from the roots, and 0.4% was from the flowers. The yield was not affected by the grafting process of lulo S. quitoense onto S. hirtum stocks; on the contrary, the crop population and productivity were maintained for a longer time.

RESUMENEl tomate de árbol es una especie frutal que se caracteriza por ser una alternativa productiva, de buena aceptación y alta demanda. Sin embargo, su producción se ha visto afectada la "gota o tizón tardío" enfermedad causada por el oomycete Phytophthora infestans sensu lato. Uno de los métodos ampliamente utilizados para el control del patógeno en campo es de tipo químico, no obstante existen alternativas eficientes y sostenibles para disminuir el impacto de la enfermedad como la resistencia genética. El objetivo de esta investigación fue evaluar 29 genotipos de tomate de árbol procedentes de los departamentos de Nariño y Putumayo (Colombia) frente al ataque de dos cepas de P. infestans sensu lato, mediante pruebas de patogenicidad empleando la técni-ca in leaf analizando las variables: área bajo la curva de progreso de la enfermedad (AUDPC), eficiencia de infección, tamaño de lesión, tasa de esporulación y período de incubación. Al analizar los resultados obtenidos, se encontraron diferencias en el comportamiento de los genotipos evaluados frente al ataque del patógeno. Se destacó el genotipo G1 por presentar los valores más bajos para las variables AUDPC (15,554), eficiencia de infección (39%) y tamaño de lesión (6,38 cm 2 ), lo cual se explica por la de una interacción genotipo-cepa y permite clasificarlo como potencial de uso para mejoramiento genético.Palabras clave adicionales: in leaf, Oomycete, patogenicidad, tolerancia. (Cav.) Sendt.], es un frutal representativo y originario de los Andes americanos de buena aceptación y alta demanda por su contenido de vitaminas, agradable sabor, color y con posibilidades de consumo fresco y potencial agroindustrial (Lobo, 2006;Lagos et al, 2012). Es un frutal de climas templados y fríos, se desarrolla bien en temperaturas entre 13 y 24°C, siendo la óptima entre 16 y 19°C. Esta planta se desarrolla en altitudes que varían de 1.000 a 3.000 msnm (Lagos et al., 2012). En Colombia, la superficie cultivada de tomate de ár-bol alcanza aproximadamente las 8.107 ha y un rendimiento promedio de 13 t ha -1 (Agronet, 2014), siendo los departamentos de Antioquia, Huila, Nariño y Boyacá los principales productores.En Nariño se reporta una área sembrada de 487 ha con una producción de 2.844 t y un rendimiento de 10 t ha -1 con una diferencia de 3 t ha -1 con respecto al promedio nacional (Agronet, 2014). Sin embargo, este incremento se ha visto afectado por la escasa oferta de híbridos o variedades mejoradas que suplan las necesidades del productor y ayuden a resolver los problemas fitosanitarios causados por patógenos de importancia como Phytophthora infestans sensu lato, Colletotrichum acutatum, virus, entre otras, los cuales afectan el rendimiento y la calidad del producto, reduciendo significativamente los ingresos del agricultor (Arturo et al., 2003).Dentro de las enfermedades más limitantes para el cultivo de las Solanaceas se encuentra la gota o tizón tardío causado por el oomycete Phytophthora infestans sensu lato. Este patógeno es de una gran agresividad no solo en...

The cultivation of lulo de Castilla (Solanum quitoense Lam.) in Colombia is subject to a series of sanitary problems, which has forced many producers to abandon the crop as a result of the total loss of plantations or to transfer the crop to new areas. It is necessary to implement breeding programs in order to produce varieties that are tolerant to the limiting problems. Since these programs require broad genetic variability in the progenitors, the present study aimed to evaluate the possibility of inducing in vitro variability in explants subjected to different doses of gamma radiation using a Co60 source. The evaluated radiation doses were 0 Gy, 15 Gy, 30 Gy, 45 Gy, and 60 Gy in calluses induced with cotyledonary leaves and in seedlings from in vitro cultures of lulo with and without thorns. The survival and regeneration potential were also evaluated. The calluses were the explants that showed the highest survival, and the lulo seedlings without thorns were the most radiosensitive with a mortality of 100% at a dose of 30 Gy. The lulo seedlings with thorns had 100% mortality at a dose of 45 Gy. The irradiated lulo seedlings with thorns had a greater regeneration capacity than the lulo without thorns, with 1.52 seedling per explant and 1.12 seedling per explant, respectively, and the RAM markers showed genetic variability in all the irradiation treatments.