S13 - Session P3 - Seasonal variation of leaf Ca, Fe, and Mn concentration in six olive cultivars

Authors: Ioanna Manolikaki, Nektaria Digalaki, Georgios Psarras, Konstantinos Tzerakis, Chrysi Sergentani, Anastasia Papamanolioudaki, Safiye Tul, Georgios Koubouris *

Leaf analysis is essential for diagnosing nutritional status and guiding fertilization applications. The lack of available information on the appropriate time for leaf collection and nutritional requirements for a range of cultivars indicates the necessity of a study aiming at physiological aspects of olive nutrition dependent on cultivar. Samples of olive ( Olea europaea L.) leaves developed in 2019 were collected from mature rainfed trees in an "off" year, at monthly intervals, from May 2019 to April 2020. We determined leaf-nutrient concentrations of calcium (Ca), iron (Fe), and manganese (Mn) in five Greek cultivars ('Amfissis', 'Chondrolia Chalkidikis', 'Koroneiki', 'Mastoidis', and 'Kalamon') and 1 from Spain (Picual). Concentrations of Ca, Fe, and Mn were significantly affected by the genotype and the season, while the interaction of both affected only Ca and Mn. The highest concentrations for all the nutrients were determined in April, while the lowest was in May, June, and October. The lowest Ca and Mn concentration was found in 'Mastoidis' leaves, yet the lowest Fe concentration was determined in 'Amfissis' leaves. Leaves of 'Koroneiki', 'Mastoidis', and 'Kalamon' had the highest Ca, Fe, and Mn concentrations, respectively. Nutrient accumulation is dependent on season and cultivar, showing the increased complexity of nutrient transportation in leaf tissues. Funding: This research has been partially financed by i) Greek national funds through the Action "Establishment of a National Research Network in the Olive Value Chain", code 2018ΣΕ01300000 of GSRT, ii) the General Secretariat for Research and Innovation of the Ministry of Development and Investments under the PRIMA Programme for the project Freeclimb (PRIMA is an Art.185 initiative supported and co-funded under Horizon 2020, the European Union's Programme for Research and Innovation) and iii) the European Union's Horizon 2020 research and innovation programme under grant agreement No. 101000427 for the project Gen4Olive.