Multivariate interpretation of the foliar chemical composition of essential nutrients in mango under Peninsular India

Abstract

The nutrient concentration vs yield performance data bank was established for Alphonso mango grown in Peninsular India to develop multivariate diagnostic norms with high diagnostic sensitivity. Well performing orchards in Ramanagara, Srinivaspur, Chittoor, Krishnagiri, Vengurla and Ratnagiri regions were intensively surveyed to develop the data bank. The diagnostic norms for N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, B and Mo were developed by using compositional nutrient diagnosis (CND) technique. The interactions among different nutrients were elucidated by principal component analysis (PCA). It was evident that wide variation in plant nutrient concentration exists in different geographic locations. The mean N concentration showed wide variations from 1.03% to 2.87%, P from 0.09 to 0.33 % and that of K from 0.78 to 1.35% depending upon the geographic location. Among the micronutrients, Zn concentration showed variation from 14.01 to 24.97 mg kg-1 and B from 3.50 to 16.63 mg kg-1. The CND norms showed higher diagnostic precision compared to the bivariate techniques. The application of PCA indicated that as many as eight nutrient elements were found integrated with first principal component in many locations. Involvement of several nutrients in a single principal component indicated that it was not possible to diagnose nutrient imbalance of any particular nutrient in isolation in mango and multi nutrient involvement on governing yield potential. The extent to which a particular nutrient interacting with other nutrients was a function of nutrient in question and geographic location. The nutrient interaction observed for different locations in general mimicked nutrient behaviour reported earlier. There is a need for integration of the all nutrients for diagnosis of nutrient imbalance in high performing fruit crop like mango.