A PROPOSAL OF NEW CRITICAL LEAF NITROGEN CONCENTRATIONS IN OLIVE

The use of leaf analysis as a tool for the diagnosis of nutritional status of olive orchards (Olea europaea L.), as in other fruit trees species, has been made possible through the establishment of reference values of leaf concentrations for each of the essential elements.
For nitrogen, deficiency was established when leaf nitrogen concentration drops below 1.4%. An excess or toxicity level is not established because of the fast transport of the excess nitrogen in leaves to other storage organs.
Based on several experiments dealing with nitrogen fertilization carried out with both young and mature plants, and due to the lack of effects on yield and vegetative growth parameters observed, doubts about the accuracy of the nitrogen deficiency threshold established are raised.
Similarly, these results suggest a new threshold of excess, above which fruit quality decreases and adverse effects on the horticultural performance of the tree can be observed.
According to these preliminary data, we can suggest that the deficiency threshold could be located between 1.22 and 1.35% and an excess threshold is noticed, from which there are negative effects on flower and oil quality, to around 1.7%.

VI International Symposium on Olive Growing

C. Molina-Soria , R. Fernández-Escobar

olive-fertilization, leaf-analysis, nitrogen-deficiency, nitrogen-toxicity, Olea europaea L.

https://doi.org/10.17660/ActaHortic.2012.949.41