‘Hass' Avocado Fruit Nutrient Removal as Affected by Production Conditions

This research was conducted during 2007 and 2008 to improve nutrition practices in 'Hass' avocado orchards in Michoacan, Mexico. The objective was to assess the influence of climate (semiwarm semihumid, semiwarm humid, and temperate subhumid), irrigation (irrigated vs.rainfed), and period of bloom and fruit set: crazy (Aug-Sept), normal (Dec-Feb), and marceña (Feb-Mar) on the amount of nutrients removed by ‘Hass’ avocado fruit. A total of 864 fruit samples were analyzed, obtained from six orchards and six trees per orchard, considering three flowering periods, four fruit parts (skin, pulp, seed coat, and cotyledons) and two replicates per tree. Dry matter content of N, P, K, Ca, Mg, S, Na, Cl ¯, Fe, Cu, Mn, B and Zn was determined. Nutrient removal was calculated based on the sum of the contents of each nutrient in the different fruit parts, considering their fresh and dry weight. Only N, Ca and Cl¯ removal was affected by the climate in the fruit-producing area. With exception of Cu, the amount of nutrients removed showed no differences between irrigated and rainfed orchards. For most of the analyzed nutrients (N, K, Ca, Mg, S, Na, Fe, Cu, and Mn), fruit set during the “marceña” bloom (harvested in January) had the greatest removal, compared to that of the “crazy” (harvested in July) and “normal” blooms (harvested in October).