Seasonal fluctuation and intracanopy variation in leaf nitrogen level in olive

Seasonal fluctuation and intracanopy variation in leaf nitrogen (N) of bearing olive (Olea europaea L.) was assessed. The N concentration was high and stable during the wintertime (about 1.8% dwt). With the advancement of vegetative growth and reproductive development, N concentration in the leaves decreased sharply, reaching the lowest value (about 1.45 to 1.50% dwt) in summer months June, July, and early August, coincident with early fruit development. Among intracanopy factors studied, the largest single influence on N concentration was light exposure. Thus on average, over all leaf types and canopy heights, leaves from the south side of the tree had 11.8% more N than north side leaves. Consistencies with regarding sampling time, canopy locations, height, and nodal position of the leaf are critical for diagnosis of N status in the olive.