Seasonal variation in nutrient concentration in leaves and inflorescences of avocado

The concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were determined in leaves from the north and south sides of the tree canopy, and in apical and basal parts of winter and fall inflorescences of 20-year-old 'Colin V-33' avocado (Persea americana Mill.) trees, to observe the seasonal variation of all these nutrients in leaves and in inflorescences. The concentration of all the elements evaluated did not change considerably during the months of flowering and vegetative growth, but it changed with leaf age. The concentration of Ca and Mg were 14 and 7% higher, in the leaves on the south side of the canopy than in those on the north side. Inflorescences had higher P and K, and lower Ca and Mg concentrations than leaves. The concentration of Ca and Mg was higher in the winter inflorescences than in the autumn ones. The concentration of P was significantly higher in the apical part of the inflorescence than in the basal part.