Inflorescence Analysis as Alternative to Leaf Analysis to Evaluate the Nutritional Status of Olive Trees

The objective of this study was to explore the possibility of using inflorescences instead of leaves as tree organ to assess the nutritional status in olive orchards. Leaves and inflorescences of olive trees (cv. Arbequina), planted under a high density planting system in two different sites (SE of Tunisia and NE of Spain), were used. The experiment was carried out in two consecutive years, 2006 and 2007. Leaf samples were taken at five different developmental stages: inflorescence emergence, fruit set, pit hardening, fruit development and fruit maturity. Inflorescences were sampled at the stage of white button, when the corolla changes from green to white colour. No significant correlations were found between inflorescence and leaf concentrations of N, P, K, Ca and Mg for each site in both years. However, some significant correlations were obtained between leaf and inflorescence mineral contents in both years when analyzing the full set of data for both locations, although correlations were different in each year. At the pit hardening stage, which coincides with the standard date for leaf sampling, significant correlations between leaves and inflorescence concentrations were obtained only for N (r=-0.827**) in 2006, and for N (r=-0.604*), K (r=-0.527*), P (r=0.760**) and Ca (r=-0.824**) in 2007.