DRIS norms for identification of yield limiting nutrients in acid lime orchards of Viajaypura district of Karnataka

A survey was conducted during 2018-19 in acid lime orchards of Indi and Sindagi taluks of Vijayapura district. Leaf samples (n=85) of acid lime (selecting 3-5 months shoot of new growth 1^st leaf during June month) collected and analysed for macro-and micro-nutrient status to develop nutrient diagnostic norms and identification of most yield limiting nutrients in low yielding acid lime orchards. The entire population was divided into two i.e. low- and high-yielding population based on cut-off yield of 1500 fruits/tree/year. The mean of leaf nutrient concentration of N, P, K, Ca, Mg and S in acid lime is 1.29, 0.74, 1.04, 1.26, 0.42 and 0.33 percent respectively. Whereas, micronutrient mean of Fe, Mn, Zn, Cu and B in acid lime are 32.35, 2.16, 28.4, 5.66 and 98.55 µg/g respectively. Fifty-five nutrient expressions were chosen as diagnostic norms, important are: K/N(0.79), Ca/N(0.94), N/S(3.28), Fe/N(24.66), Mn/N(21.22), Cu/N(4.29), Ca/K(1.25), K/S(2.94), K/Cu(0.19), S/Mg(0.59), Cu/Mg(9.21), S/Fe(0.01), Mn/Fe(0.89), Mn/Cu(5.07) and Cu/B(0.06) etc. The diagnosis of nutrient imbalance through DRIS indices indicated that Mg is a most yield limiting nutrient followed by P and S. Whereas among the micronutrients, most yield-limiting nutrients were Zn, followed by B and Fe in the low yielding acid lime orchards. Thus, DRIS was concluded to offer a holistic approach to identify nutrient imbalances in acid lime and proved to be an important technique for evolving nutrient management strategies for realizing higher yields. The optimum nutrient ranges can be serving as a guide for the routine diagnosis and advisory purpose for the acid lime orchardist.