Effect of N-P-K Fertilization on the Yield and Nutrient Status of Fig (Ficus Carica L. Cv. Kalamon) Trees Grown under Mediterranean Conditions

In a fig (Ficus carica L. cv. Kalamon) orchard, located in Peloponnese (Greece), the effect of fertilization with nitrogen (N), phosphorus (P) and potassium (K) (NPK) on the yield and the nutritional status of trees was studied. The particular fig orchard is rainfed, producing figs for drying. The experiment was carried out in 2005 and 2009, including the following treatments (the indexes show the application rates of the respective nutrients in Kg per tree): In 2005, 1) N0P0.6K0.6, 2) N0P1.2K0.6, 3) N0P1.8K0.6, 4) N0.5P0.6K0.6, 5) N1P1.2K0.6, 6) N1P1.8K0.6, 7) N0P1.2K1.2, 8) N1P1.2K1.2, and in 2009, 1) N0.3P0K0, 2) N0.3P0.6K0.6, 3) N0.3P1.2K0.6, 4) N0.3P1.8K0.6, 5) N0.5P0.6K0.6, 6) N1P1.2K0.6, 7) N1P1.8K0.6, 8) N0.3P1.2K1.2, and 9) N1P1.2K1.2. The results showed that N is an important nutrient for the yield of the fig tree. The highest fruit production was recorded in the trees treated with N1P1.2K0.6. Interesting yields were recorded in the N1P1.8K0.6 and N0.3P1.2K0.6 treatments and the treatment N0.3P1.2K0.6 was suggested that it requires further research as the most economical one. These treatments gave the highest yields with relatively early harvest maturity. Yield in relation to the doses of NPK nutrients can be described by a multiple secondary regression equation.