Abstract The objective of this work was to determine the effect of planting densities on the yield and quality of 'Hass' avocado (Persea americana) in the department of Antioquia, Colombia. The experimental design was randomized complete blocks with three replicates. The treatments were six plant densities (204, 278, 333, 400, 625, and 816 trees per hectare) with five harvest seasons, and each experimental unit consisted of six nine-year-old trees. The highest fruit yield is obtained at 333 and 400 trees per hectare. The main harvest represents 70% (18 Mg ha-1) of the annual production, whereas the secondary (mitaca) harvest represents 30% (5.25 Mg ha-1). Yield per tree and number of avocado fruits per tree are negatively affected by the increase in planting densities. In addition, fruit quality parameters show better results at intermediate planting densities of 333 and 400 trees per hectare, with the highest ratios of mesocarp and the lowest of seed, both in fresh and dry weight.

Resumo O objetivo deste trabalho foi determinar o efeito de densidades de plantio na produção e na qualidade do abacateiro 'Hass' (Persea americana) no departamento de Antioquia, Colômbia. O delineamento experimental foi de blocos ao acaso, com três repetições. Os tratamentos foram seis densidades de plantio (204, 278, 333, 400, 625 e 816 árvores por hectare) com cinco colheitas, e cada unidade experimental consistiu em seis árvores com nove anos de idade. O maior rendimento é obtido às densidades de 333 e 400 árvores por hectare. A colheita principal representa 70% (18 Mg ha-1) da produção anual, enquanto a colheita secundária (mitaca) representa 30% (5.25 Mg ha-1). A produção por árvore e o número de frutos de abacate por árvore é afetado negativamente pelo aumento das densidades de plantio. Além disso, os parâmetros de qualidade dos frutos apresentam melhores resultados nas densidades de plantio intermediárias de 333 e 400 árvores por hectare, com as maiores proporções de mesocarpo e a menor de sementes, tanto em massa fresca quanto em seca.

RESUMEN La cantidad de hojarasca producida por árboles de aguacate cv. Hass constituyen una importante fuente potencial de recursos minerales, por lo que la cuantificación de su producción y naturaleza son cruciales para comprender el ciclaje de nutrientes. El objetivo principal de este estudio fue cuantificar la producción de hojarasca, flores y frutos pequeños caídos, en huertos de aguacate, en ocho localidades y en tres zonas productoras del departamento de Antioquia (Oriente, Suroeste y Norte). La mayor producción de hojarasca se presentó en el Suroeste antioqueño, siendo superior en Jardín (7,6 t ha-1 año-1); las localidades del oriente presentaron caída de hojas similares (4,03- 3,4 t ha-1 año-1). La materia seca producida en el norte fue muy similar en ambas localidades. La materia seca obtenida fue de 2,8 t ha-1 año-1 Los mayores aportes de hojarasca en todas las localidades se presentaron durante las épocas más secas. Se encontró que aproximadamente el 80% de los frutos caídos corresponden a diámetros menores a 1 cm. Las mayores producciones y caída de flores se presentaron en las localidades del suroeste Antioqueño, seguido de la región del norte.

ABSTRACT The amount of leaf litter produced by avocado trees cv. Hass is an important potential source of mineral resources, and quantifying its production and nature is crucial to understanding the cycling of nutrients. The main objective of this study was to quantify the production of leaf litter and fallen flowers and small fruits in avocado orchards at eight locations in three producing areas in the Department of Antioquia (west, southwest, and north). The highest leaf litter production occurred in southwest Antioquia, at Jardin (7.6 t ha-1 year-1); the east locations had similar leaf fall (4.03-3.4 t ha-1 year-1). The dry matter produced in the north was very similar in both locations. The dry matter was 2.8 t ha-1 year-1. Higher leaf litter was recorded in all locations during the driest periods. Approximately 80% of the fallen fruits had diameters less than 1 cm. The highest flower production and fall occurred in southwest Antioquia, followed by the northern region.

RESUMEN La investigación se realizó en 2015 en cinco localidades productoras de frijol en Colombia. El objetivo fue evaluar el efecto de diferentes tratamientos de fertilización química y biológica sobre el rendimiento de frijoles volubles y arbustivos. De acuerdo con los resultados obtenidos, en Antioquia, es posible reemplazar la fertilización química por fertilización biológica en el frijol voluble Corpoica LAS-106 y el arbustivo Citará. En Cundinamarca, similar situación se presentó con el frijol "Cargamanto Rojo". En Santander, se encontró que la combinación de micorrizas (AMF) y Rhizobium mejora el rendimiento de los fríjoles arbustivos ICA-Rovirense (2839,5 t ha-1) e ICA- Radical-J1J1 (1955,7 t ha-1), con respecto al rendimiento promedio nacional (1,2 t ha-1). El uso de biofertilizantes (hongos formadores de micorriza y Rhizobium) mejoró los rendimientos en el cultivo del frijol, con los materiales utilizados (volubles y arbustivos) y en las localidades estudiadas. Existe un efecto aditivo en las aplicaciones de los biofertilizantes evaluados, ya que se observó un mayor rendimiento en el cultivo de frijol cuando estos se aplicaron combinados que individualmente.

ABSTRACT The research was carried out in 2015 in five bean producing locations in Colombia. The objective was to evaluate the effect of different treatments of chemical and biological fertilization on the yield of climbing and bush beans. According to the results obtained, in Antioquia, it is possible to replace the chemical fertilization by biological fertilization in the climbing bean Corpoica LAS-106 and the bush bean Citará. In Cundinamarca, similar situation was presented with "Cargamanto Rojo". In Santander, it was found that the combination of mycorrhizae (AMF) and Rhizobium improves the performance of the bush bean ICA-Rovirense (2839.5 t ha-1) and ICA-Radical-J1J1 (1955.7 t ha-1), with respect to national average yield (1.2 t ha-1). The use of biofertilizers (mycorrhizal fungi and Rhizobium) improved the yields in the bean crop, with the materials used (climbing and bush) and in the localities studied. There is an additive effect in the applications of the biofertilizers evaluated, since it is a higher yield in the bean crop when these were applied individually combined.