Establishing leaf nutrient norms for arecanut (Areca catechu L.) by boundary line approach

Abstract

Critical and optimum leaf nutrient standards for arecanut are unknown. As nutrients are becoming yield limiting factors in arecanut, corrective measures require development of leaf nutritional standards. The objective of this paper was to determine optimum concentration and range of all nutrients through boundary line approach. Optimum foliar concentrations for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) were established as 2.70, 0.23, 1.12, 0.61, and 0.20%, respectively, using leaf composition data from 12-year old arecanut plantation. Optima of major nutrient concentrations were nearly identical between boundary line approach and mean of high yielding population. Optimum micronutrient concentrations (mg kg−1) were estimated at 146 for iron (Fe), 56.5 for manganese (Mn), 2.6 for copper (Cu), 45.8 for zinc (Zn), 39.5 for boron (B), 432 for aluminum (Al) and 63 for sodium (Na). Optimum ranges and ratios of different nutrients were found out from second degree polynomial equations.