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

Abstract

ABSTRACT 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) Ν0Ρ0.6Κ0.6, 2) Ν0Ρ1.2Κ0.6, 3) Ν0Ρ1.8Κ0.6, 4) Ν0.5Ρ0.6Κ0.6, 5) Ν1Ρ1.2Κ0.6, 6) Ν1Ρ1.8Κ0.6, 7) Ν0Ρ1.2Κ1.2, 8) Ν1Ρ1.2Κ1.2, and in 2009, 1) Ν0.3Ρ0Κ0, 2) Ν0.3Ρ0.6Κ0.6, 3) Ν0.3Ρ1.2Κ0.6, 4) Ν0.3Ρ1.8Κ0.6, 5) Ν0.5Ρ0.6Κ0.6, 6) Ν1Ρ1.2Κ0.6, 7) Ν1Ρ1.8Κ0.6, 8) Ν0.3Ρ1.2Κ1.2, and 9) Ν1Ρ1.2Κ1.2. 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 Ν1Ρ1.2Κ0.6. Interesting yields were recorded in the Ν1Ρ1.8Κ0.6 and Ν0.3Ρ1.2Κ0.6 treatments and the treatment Ν0.3Ρ1.2Κ0.6 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.