Multivariate diagnosis of nutrient imbalances in different yield categories of litchi in north Indian lower Himalayas

In this study, multivariate compositional nutrient diagnosis (CND) norms were developed for diagnosis and identification of yield limiting nutrients in low yielding litchi orchards of Northern Himalayas of India. Data bank on leaf nutrient concentration vs. fruit yield was generated by conducting a regional survey in selected litchi orchards of Uttarakhand. Further, Principal component analysis (PCA) was used to study nutrient interactions in the Litchi plant.Results obtained indicate, in fruiting terminal (FT), CND norms for Nitrogen (V_N), Phosphorus (V_P) and Potassium (V_K) were 3.62, 2.41 and 3.40 respectively whereas CND norms for Calcium (V_Ca), Magnesium (V_M) and Sulphur (V_S) were 3.87, 2.82 and 1.51 respectively. Among micronutrients, Fe had higher norm value (V_Fe -0.45) in FT indicating higher Fe requirement as compared to Mn, Zn, Cu, B and Mo. Similarly, the CND norms in non-fruiting terminals (NFT) for V_N, V_P, V_K, V_Ca, V_Mg and V_s were 3.57, 2.40, 3.53, 3.93, 2.72 and 1.33 respectively. But, PCA performed on log transformed data of FT for P, S, Zn, Mn and B showed positive correlation whereas N, K, Ca and Fe have shown negative correlation whereas in NFT, P, K, Cu, B showed positive correlation compared to Ca, Mg, Mo which shown negative correlation in FT. Zn being a key micronutrient showed both positive and negative correlation in FT and NFT. Altogether, PCA indicated the existence of multi-nutrient interaction in litchi. The CND indices identified S, B, Zn and Mo as most common yield limiting nutrients in litchi.