This is an open access article d istributed under the terms of Creative Commons Attribution-NonCommer cial-ShareAl ike 4.0 International License, which permits unrestricted non-commercial use, d istribution, and reproduction in any med ium, provide d the original author and source are credited. INTRODUCTION Pummelo [Citrus maxima Merr., (C. grandis Osbeck; C. decumana L.)], family Rutaceae, was known in the western world mainly as the principal ancestor of the grapefruit. The areas in southern Thailand and northern Malaysia are most likely the centre of origin of pummelos (Wen et al., 2010). In India, it is grown in home gardens in all states of India and maximum diversity is reported from North-East (NE) Region Bihar and Bengal (Roy et al., 2014). Pummelo is now gaining popularity in India due to its high nutritional value and antioxidant property. It has played an important role as a parent of many citrus fruits, such as lemon, oranges and grapefruit (Youseif et al., 2014). Pummelo fruit has several health benefits because of its super-rich Vitamin C and Vitamin B content. It also contains Vitamin A, bioflavonoids, healthy fats, protein, fiber, antioxidants and enzymes. It contains high amount of beta carotene and folic acid and is very beneficial for pregnant women. Nutrients are required for supporting the metabolism within the tree-ecosystem and also to support quality fruit production (Tha mr in et al. , 2014). Both maximum fruit quality and yield of pummelo will occur only in the presence of optimum nutrient balance and intensity. Maintaining orchards at optimal leaf nutrient concentrations is one of the key issues for maximizing yield. Low fruit quality and yield is often associated with poor soil fertility and poor nutrient management (Zhuang, 1995). Leaf analysis is a method of determining plant nutrient requirement based on assumption that within certain limits, there Original Research Paper J. Hortic. Sci. Vol. 18(1) : 142-149, 2023 https://doi.org/10.24154/jhs.v18i1.2157 Stionic effects on leaf mineral nutrient contents in Pummelo (Citrus maxima Merr.) grafted on different rootstocks Kalaivanan D.1*, Sankaran M.2 and Patil P.3 1Division of Natural Resources, 2Division of Fruit Crops, 3Project Co-ordinator, AICRP on Fruits, ICAR-Indian Institute of Horticultural Research, Bengaluru - 560089, Karnataka, India *Corresponding author Email : Kalaivanan.D@icar.gov.in ABSTRACT A study was conducted to determine the mineral nutrients concentration in the index leaf of pummelo accessions. Index leaf samples from 25 pummelo accessions grafted on pummelo and 12 pummelo clones grafted on Rangpur lime rootstocks were collected for assessing leaf mineral nutrient status. The results revealed that pummelo plants grafted on pummelo, the concentration of leaf N (1.43-2.49 %), P (0.17-0.22 %), K (0.75-4.45 %), Ca (2.37-6.29 %), Mg (0.60-1.04 %), S (0.06-0.22 %), Fe (124-245.45 mg kg-1), Mn (9.85-50.05 mg kg-1), Zn (17-69 mg kg-1) and Cu (8.8-25.15 mg kg-1) showed significant variation with different accessions. Out of 25 pummelo accessions, twenty-four accessions were deficient in N and S, fourteen were deficient in K, four were deficient in Mn and five were deficient in Zn and all accessions were sufficient in P, Ca, Mg, Fe and Cu. The observed trends in the leaf nutrient concentration of pummelo accessions clearly indicated the significance of the genotypic variation when chemical analysis is used for diagnosing the leaf nutrient status of pummelo trees. Similarly, leaf N, P, K, Ca, Mn, Cu and Zn varied significantly among twelve pummelo clones grafted on Rangpur lime. Among the clones grafted on Rangpur lime, 18-3 and 18-5 found to have higher and lower leaf nutrient content in most of the mineral nutrients, respectively. The leaf nutrient content of pummelo varies among genotypes, but there is no genotype that stands out in all macro and micronutrients evaluated. The N, P, K, Ca, S, Fe, Mn and Cu leaf contents in pummelo were always higher in plants grafted on Rangpur lime. However, the foliar Mg and Zn contents were continually higher in plants grafted on ‘pummelo’ compared to Rangpur lime which eventually reduces leaf yellowing/chlorosis in pummelo. Pummelo rootstocks were found to respond well in terms of Mg and Zn nutrient uptake and tolerance to Phytophthora as compared to Rangpur lime. Therefore, it is concluded that pummelo can be an ideal rootstock for commercial pummelo cultivation. Keywords : Accessions, grafting, leaf mineral nutrient, pummelo, Rangpur lime, rootstock 143 Stionic effects on leaf mineral nutrient contents in pummelo J. Hortic. Sci. Vol. 18(1) : 142-149, 2023 is positive relationship between nutrient availability, leaf nutrient content, yield and quality of fruits (Srivastava and Singh, 2004a; 2004b). Stebbins and Wilder (2003) r epor ted tha t lea f nutr ient concentrations can be used as a guide to determine nutrient status of plant that are directly linked/related to the pattern of growth and development. Impact of stock on scion and scion on stock is known as stionic effect. Rootstock choice is one of the most important aspects in orchard management because scion cultivars respond differently to growth, fruit quality, disease resistance and nutrients accumulation when grown on diverse rootstocks. Plant nutrient concentrations in scion cultivar may differ even though they are grown in the same conditions. Rootstocks directly affect the ability of plants to uptake the water and nutrients from the soil. Similarly, different scions exhibit variable quantities of nutrients from different rootstocks. The long-term performance of stionic combinations and their significant effects on leaf nutrient levels in different fruit crops have been studied for different climatic conditions across the world (Dubey and Sharma, 2016). However, no such studies were carried out in pummelo. Hence, selection of an appropriate graft/stionic combination with better leaf nutrient absorption is very critical to produce pummelo commercially. Therefore, the main purpose of the present research was to determine the status of various macro and micronutrients in the leaf of pummelo genotypes grafted on Pummelo and Rangpur lime for choosing the right graft combination with enhanced nutrient absorption. It is also possible to reduce the application of nutrients in pummelo by employing perfect stionic combination that have high nutrient absorption capacity. MATERIALS AND METHODS To determine the nutrient concentration of leaf as influenced by genotypes and rootstocks, index leaf samples (4th and 5th leaf from tip of new shoots/flush with a ge of 4 to 6 months) from 25 pummelo genotypes (>15 years old) grafted on pummelo and 12 pummelo clones (4 years old) grafted on Rangpur lime rootstocks were collected in the month of June 2019 from the field gene bank maintained at ICAR-IIHR, Bengaluru, which is situated in south-east tract of Karnataka state at 12058 North latitude and 77034 East longitude and at an altitude of 900 m above mean sea level. The study area comes under semi-arid, sub-tropical climate with hot summer and cold winter with an average rainfall of 866 mm. Most of the rainfall is received from the south-west monsoon during July to August. Twenty leaf samples, five leaves from each direction of east, west, north and south were taken individually from five trees per genotypes from non bearing fruit terminals. The samples were washed first under tap water followed by 0.1 N HCl, distilled water and finally with double distilled water. The cleaned leaf samples were then dried by spreading on clean blotting papers and final drying was done in an oven at 68oC (Chapman and Pratt, 1961) by separately packing in labeled paper bags. The dried leaf samples were sequentially ground by electrical grinder for further analysis. The nitrogen (N) content in the leaf samples was a na lysed by Kjelda hl method (AOAC, 1970). Phosphorus (P), potassium (K), ca lcium (Ca ), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn) and copper (Cu) were estimated by diacid mixture (9:4 HNO3: HClO4) as given by Jackson (1973). Phosphorus content in leaf samples was determined by vanadomolybdo phosphoric acid yellow colour method (Jackson, 1973). The intensity of yellow colour was read at 430 nm in the spectrophotometer. Potassium content was estimated using fla me photometer (Jackson, 1973). Calcium and magnesium content was determined by Atomic Absorption Spectrophotometer (AAS) (Sarma et al., 1987). Micronutrient content viz. Fe, Mn, Cu and Zn was determined using Atomic Absorption Spectrophotometer (AAS) (Sarma et al., 1987). The data were statistically scrutinized using analysis of variance of SAS 9.3 statistical package. RESULTS AND DISCUSSION Leaf macronutrients Index leaf samples of 23 pummelo genotypes grafted on pummelo rootstock and 12 pummelo clones grafted on Rangpur lime rootstock were analyzed for N, P, K, Ca, Mg, S, Fe, Mn, Zn and Cu contents and presented in Table 1, 2, 3 and 4 and Fig.1, 2. The data on leaf macronutrients content in pummelo grafted on pummelo and Rangpur lime is presented in Table 1 & 2 and Fig. 1. The concentration of different nutrients in leaf exhibited a wide variation among the genotypes irrespective of the rootstocks. However, the N concentration of leaves was not differed significantly among pummelo genotypes grafted on own rootstocks. Genotype ‘Kunigal selection’ had the highest leaf N 144 Kalaivanan et al. Fig. 1 : Leaf macronutrient content in pummelo grafted on pummelo (P) and Rangpur lime (RL) Genotype N (%) P (%) K (%) Ca (%) Mg (%) S (%) Devenahalli Selection-1 1.53 0.19 0.95C 4.70BCDEF 0.74 0.13 Midnapur Selection 1 1.57 0.21 1.90BC 4.10DEFG 0.80 0.22 Midnapur Selection 1 1.64 0.21 1.30BC 3.83EFGHI 0.86 0.09 Tirupati-1 1.86 0.18 1.45BC 4.17DEFG 0.77 0.06 Hyderabad Selection 1.97 0.20 2.00BC 5.51ABCD 0.85 0.15 Kallar Selection 2.11 0.20 0.85C 3.46FGHI 0.82 0.15 Raichur Selection 1.58 0.22 1.15C 3.77EFGHI 0.72 0.11 Khanapur Selection 1.95 0.21 2.10BC 4.11DEFG 0.76 0.12 IKP-1 2.03 0.17 0.75C 4.37CDEFG 0.82 0.17 IKP-2 1.92 0.20 1.15C 2.40HI 0.60 0.07 Tirupati-2 1.43 0.19 0.90C 4.26CDEFG 0.81 0.11 Tirupati -2A 1.89 0.19 0.75C 5.76ABC 1.04 0.12 Kalenahalli-1 1.53 0.19 1.55BC 3.97DEFG 0.75 0.15 Devenahalli Selection-2 1.54 0.19 1.95BC 5.95AB 0.88 0.08 Midnapur Selection-2A 1.90 0.19 2.75B 6.29A 0.93 0.14 Kunigal Selection 2.59 0.20 4.45A 3.94EFGH 0.83 0.11 Devenahalli Selection-3 1.64 0.17 1.00C 4.02DEFG 0.83 0.14 Accession-18 1.54 0.20 1.75BC 3.84EFGHI 0.69 0.13 Accession-19 1.62 0.22 1.25BC 3.41FGHI 0.75 0.17 Devenahalli Selection -4 1.93 0.18 1.25BC 2.37I 0.71 0.12 Devenahalli Selection-5 1.61 0.18 2.25BC 4.45BCDEFG 0.92 0.14 Devenahalli Selection-6 1.69 0.19 1.05C 3.02GHI 0.70 0.14 Devenahalli Selection-7 1.79 0.20 1.10C 5.27ABCDE 1.01 0.12 Gollehalli 2.07 0.20 1.65BC 4.01DEFG 0.94 0.13 Kalenahalli-1A 1.62 0.19 0.80C 2.99GHI 0.73 0.15 General Mean 1.78 0.19 1.52 4.16 0.81 0.13 p-Value 0.7806 0.3407 0.0176 0.0014 0.3237 0.9886 SE(d) 0.413 0.018 0.734 0.753 0.133 0.075 LSD at 5% NS NS 1.5139 1.5549 NS NS Table 1 : Leaf macronutrient content in pummelo grafted on pummelo J. Hortic. Sci. Vol. 18(1) : 142-149, 2023 145 (2.59%) and ‘Tirupati Selection’ had the lowest leaf N (1.43%) when grafted with pummelo. Zhuang et al. (1991) reported that leaf N content ranging from 2.5 to 3.1% indicated sufficiency in Guanximiyou’ pummelo leaves. The concentration of leaf N in most of the pummelo accessions was below the critical value of 2.50% except in genotype ‘Kunigal Selection. Similar trend was observed in leaf N content of pummelo accessions grafted on Rangpur lime also (Table 2). The highest mean leaf N content (2.00%) was observed in the pummelo grafted on Rangpur lime rootstock compared to pummelo grafted on pummelo (1.78%). The range of N levels in leaf of pummelo accessions grafted on pummelo and Rangpur lime was compared well with the reported values of 1.7 to 2.81 per cent in citrus by Srivastava and Singh (2002; 2003; 2005; 2006; 2008). The pummelo accessions grafted on pummelo did not influence the P concentration of leaves significantly. The values ranged from 0.17 to 0.22% with a mean value of 0.19%. The range of P levels in leaf matched well with the va lues 0. 14-0. 18 % r eported by Zhuang et al. (1991) in pummelo and 0.09-0.17 % reported by Srivastava and Singh (2002; 2003; 2005; 2006; 2008) in citrus. The concentration of leaf P was the highest in the genotype ‘Raichur selection’ (0.22%) and was the least in ‘Devenahalli Selection-3’ (0.17%) accession. Of the 23 accessions, the values of P in the foliage were found to be sufficient in five accessions and excess in twenty accessions. According to Zhuang et al. (1991), leaf P content ranging from 0.14 to 0.18% indicated sufficiency, whereas, P content below 0.14% indicated P deficiency in pummelo. Similar to leaf N, the highest mean leaf P content (0.22%) was also observed in the pummelo grafted on Rangpur lime rootstock compared to pummelo grafted on pummelo (0.19%). The leaf K concentration of pummelo accessions grafted on pummelo ranged from 0.75 to 4.45% with a mean value of 1.52%. Leaf K was significantly higher in the Kunigal Selection (4.45%) and genotypes Tirupati-2 (0.75%) recorded the lowest leaf K content. However, the concentration of leaf K was below the critical value of 1.40% in 14 pummelo accessions. The range of K levels in leaf were almost similar to that reported by Srivastava and Singh (2002; 2003; 2005; 2008) (1.02-2.59%) in citrus. According to Zhuang et al. (1991), the leaf K content ranging from 1.4 to 2.2% indicated sufficiency. Like leaf N and P, the highest mean leaf K content was observed in the pummelo grafted on Rangpur lime (2.73%) rootstock compared to pummelo on pummelo (1.52%). The concentration of Ca and Mg in leaf of pummelo genotypes exhibited wide variation. Highest Ca concentration of 6.29% was observed in accession ‘Midnapur Selection-2A’ and the lowest Ca concentration of 2.37% was in genotype ‘Devena ha lli Selection-4’. T he Ca concentration of leaf was at par in ‘Devenahalli Table 2 : Leaf macronutrient content in pummelo grafted on Rangpur lime Genotype N (%) P (%) K (%) Ca (%) Mg (%) S (%) Clone 19-1 1.59D 0.23BCD 3.30AB 3.03EF 0.72 0.13 Clone 18-5 1.57D 0.17G 2.30BCD 2.72F 0.67 0.13 Clone 24-4 2.39A 0.18FG 3.07ABC 4.80ABC 0.81 0.14 Clone 8-4 1.83CD 0.22BCDE 1.10D 5.04A 0.77 0.14 Clone 25-5 2.03BC 0.19EFG 1.73CD 3.85CDE 0.73 0.10 Clone 18-4 1.79CD 0.24BC 2.73ABC 3.96CDE 0.75 0.13 Clone 21-4 2.33AB 0.21CDEF 2.40ABCD 4.95AB 0.71 0.15 Clone 18-1 1.66D 0.24B 3.23AB 4.00BCD 0.67 0.12 Clone 10-5 2.25AB 0.20DEFG 3.17AB 3.57DEF 0.65 0.10 Clone 18-3 2.52A 0.31A 3.67A 4.95AB 0.69 0.20 Clone 25-2 1.73CD 0.22BCDE 2.53ABC 4.74ABC 0.75 0.13 Clone 20-4 2.28AB 0.21BCDEF 3.47AB 4.40ABCD 0.72 0.13 General Mean 2.00 0.22 2.73 4.17 0.72 0.13 p-Value <.0001 <.0001 0.0224 0.0003 0.9196 0.9228 SE(d) 0.171 0.016 0.649 0.461 0.096 0.054 LSD at 5% 0.3542 0.0328 1.3465 0.9568 NS NS Stionic effects on leaf mineral nutrient contents in pummelo J. Hortic. Sci. Vol. 18(1) : 142-149, 2023 146 Selection-2, ‘Tirupati-2’ and ‘Hyderabad Selection’ genotypes. The range of Ca level in leaf (2.37-6.29%) was higher than the range reported by Zhuang et al. (1991) (2.0-3.8%) and Srivastava and Singh (2002; 2003; 2005; 2008) in citrus (1.80-3.28%). The concentration of leaf Ca in all the genotypes was higher than the critical level (2.0%). The concentration of Mg in leaves of pummelo genotypes varied from as low as 0.6% in genotype ‘Tirupati-2’ to as high as 1.04% in genotype ‘A-10’ which was above the critical levels (0.32%). The range of Mg level in leaf was compared well with standards of Zhuang et al. (1991) (0.32-0.47%) and Srivastava and Singh (2002; 2003; 2005; 2008) (0.43-0.92%). The mean leaf Ca (4.16%) and S (0.13%) in pummelo genotypes grafted on pummelo were found almost comparable with the pummelo genotypes grafted on Rangpur lime (4.17% and 0.13%). However, the pummelo genotypes grafted on pummelo had better mean leaf Mg content (0.81%) than the plants grafted on Rangpur lime (0.72%). With r espect to lea f sulphur content, no significant differ ence wa s obser ved in differ ent pummelo genotypes grafted on pummelo nevertheless found to be matching with leaf S content of pummelo clones grafted on Rangpur lime. The range of S levels in leaf (0.06-0.22%) was noticeably lower than those reported by Zhuang et al. (1991) (0.2-0.39%). Leaf micronutrients The data on leaf micronutrients in pummelo grafted on pummelo and Rangpur lime is presented in Table 3 & 4 and Fig. 2. Considerable differences were observed, in the micronutrient concentration of leaf in pummelo genotypes. A relatively wide range of leaf Fe was found among the pummelo genotypes. The concentration of leaf Fe was found to be statistically significant in pummelo genotypes grafted on pummelo and the genotype ‘IKP-1’ recorded the highest leaf Fe (245.45 mg kg-1). The lowest leaf Fe content (124 mg kg-1) was recorded in genotype ‘Devenahalli Selection- 4’. The range of Fe levels in pummelo leaf (124- 245.45 mg kg-1) of the present study was compared well with standards of Srivastava and Singh (2002) reported in Khasi mandarin (84.6-249.0 mg kg-1). Pummelo genotypes differed significantly with respect to leaf Mn concentration. Higher concentration of leaf Mn was recorded in genotype ‘Tirupati-2’ (50.05 mg kg-1), and ‘IKP-1’ (36.40 mg kg-1). The range of Mn levels in leaf (9.85-50.05 ppm) was appreciably lower than those reported by Zhuang et al. (1991) (15-140 mg kg-1). The concentration of leaf Zn ranged from 17 to 69 mg kg-1 with a mean value of 33.3 mg kg-1. The accession ‘IKP-1’ recorded the highest leaf Zn concentration of 69 mg kg-1 whereas; accession ‘A- 20’ had the lowest leaf Zn concentration of 17 mg kg- 1. The values of Zn levels in leaf of most of accessions wer e r ela tively higher tha n those r epor ted by Zhuang et al. (1991) (24-44 mg kg-1). T he concentration of Zn in the leaves were in the deficient range (<24 mg kg-1) in few pummelo genotypes (A- 18, Devenahalli selection-4, Devenahalli Selection-5, Devenahalli Selection-6 and Kalenahalli) grafted on pummelo. Copper concentration of the pummelo leaf ranged from 8.80 to 25.15 mg kg-1 with a mean of 15.36 mg kg-1. Higher concentration of leaf Cu was r ecor ded in a ccessions ‘Golleha lli Selection, ‘Devenahalli Selection-2’ and ‘Kalenahalli. The concentration of leaf Cu was statistically significant among the pummelo accessions. The ranges of Cu levels in leaves were much higher than the values of 8-17 mg kg-1 reported by Zhuang et al. (1991). The values of Cu in the foliage of all the accessions under study were above the critical value of 8.0 mg kg-1. Pummelo genotypes grafted on Rangpur lime recorded the highest Fe, Mn, and Cu except Zn. Low leaf Zn might be one of the causes for wide spread appearance of severe yellowing/chlorosis in pummelo trees grafted on Rangpur lime. The highest leaf Zn was recorded in the pummelo accessions grafted on pummelo might be reason for reduced level of leaf yellowing/chlorosis. The Zn is required in plants for synthesis of auxins which act as plant growth promoter in various phenophases of the plant. The data recorded on leaf macro and micronutrient status of pummelo grafted on different rootstocks revealed that the nutrient content of the leaf samples was significantly influenced by the rootstocks and scions as well. Differences in leaf nutrient content among the stionic combinations could be due to the variances among the rootstocks in the morphology, density of the roots in the soil profile, rooting pattern, root volume, and variations in nutrient absorption capacity of the roots (Zhuang et al., 1991; Srivastava and Singh 2002). The rootstock having higher root volume can be more efficient in absorbing nutrients from the soil. Variation in leaf nutrient content could also be caused by scions of different genotypes, and Kalaivanan et al. J. Hortic. Sci. Vol. 18(1) : 142-149, 2023 147 Table 3 : Leaf micronutrient content in pummelo grafted on pummelo Genotype Fe (mg kg-1) Mn (mg kg-1) Zn (mg kg-1) Cu (mg kg-1) Devenahalli Selection-1 180.45BC 19.30GHIJ 31.60FG 13.85FGHI Midnapur Selection 1 163.60BCDE 19.35GHIJ 27.45GH 15.70EF Midnapur Selection 1 133.05DE 18.60GHIJ 32.40F 15.05EFGH Tirupati-1 176.05BCD 21.45FGHI 39.65D 15.45EFG Hyderabad Selection 176.35BCD 24.90DEF 34.70EF 11.75HIJ Kallar Selection 157.50BCDE 17.45HIJKL 29.95FG 11.50IJ Raichur Selection 192.00B 17.80GHIJK 46.90C 16.00EF Khanapur Selection 170.65BCD 21.90FGHI 33.40EF 12.05GHIJ IKP-1 245.45A 36.40C 69.00A 13.70FGHI IKP-2 186.45BC 16.95IJKL 27.40GH 11.70HIJ Tirupati-2 195.40B 50.05A 47.35BC 14.95EFGHI Tirupati -2A 172.70BCD 44.30B 42.90CD 20.35BCD Kalenahalli-1 174.90BCD 22.90EFG 38.15DE 16.90DEF Devenahalli Selection-2 182.40BC 29.45D 52.20B 22.50AB Midnapur Selection-2A 157.60BCDE 19.30GHIJ 30.35FG 18.25CDE Kunigal Selection 146.40CDE 12.45LM 26.85GHI 11.90HIJ Devenahalli Selection-3 146.55CDE 15.15JKL 24.00HIJ 8.80J Accession-18 134.95DE 14.45JKLM 23.50HIJ 9.35J Accession-19 162.05BCDE 15.75JKL 24.10HIJ 12.10GHIJ Devenahalli Selection -4 124.00E 9.85M 17.00K 10.10J Devenahalli Selection-5 146.80CDE 17.20HIJKL 23.30HIJ 21.25BC Devenahalli Selection-6 145.30CDE 12.80KLM 20.10JK 18.00CDE Devenahalli Selection-7 181.90BC 22.30EFGH 33.85EF 16.25EF Gollehalli 188.10BC 27.25DE 34.35EF 25.15A Kalenahalli-1A 145.55CDE 22.00FGHI 22.05IJ 21.50BC General Mean 167.45 21.97 33.30 15.36 p-Value 0.0080 <.0001 <.0001 <.0001 SE(d) 21.819 2.513 2.391 1.717 LSD at 5% 45.033 5.1872 4.9356 3.5442 Fig. 2 : Leaf micronutrient content in pummelo grafted on pummelo (P) and Rangpur lime (RL) Stionic effects on leaf mineral nutrient contents in pummelo J. Hortic. Sci. Vol. 18(1) : 142-149, 2023 148 Table 4 : Leaf micronutrient content in pummelo grafted on Rangpur lime Genotype Fe (mg kg-1) Mn (mg kg-1) Zn (mg kg-1) Cu (mg kg-1) Clone 19-1 147.20 38.37CDE 21.67BC 13.57D Clone 18-5 156.40 33.80CDEF 15.73C 14.30CD Clone 24-4 223.27 28.50EF 26.60AB 13.73D Clone 8-4 221.37 42.70BC 26.80AB 25.60A Clone 25-5 201.23 50.27AB 21.27BC 17.87BCD Clone 18-4 170.73 42.70BC 24.03AB 22.43AB Clone 21-4 175.87 27.27F 23.97AB 20.83ABC Clone 18-1 167.43 39.97BCD 22.33BC 16.03BCD Clone 10-5 188.97 54.80A 21.90BC 14.33CD Clone 18-3 183.73 36.00CDEF 23.10B 21.90AB Clone 25-2 230.97 30.50DEF 25.90AB 19.00ABCD Clone 20-4 223.97 37.93CDEF 30.77A 18.63BCD General Mean 190.93 38.57 23.67 18.19 p-Value 0.1478 0.0007 0.0396 0.0202 SE(d) 31.527 5.273 3.401 3.346 LSD at 5% NS 10.935 7.0538 6.939 differences in the incorporation from the roots to shoots and then leaves (Srivastava and Singh 2003; 2005 and 2008). CONCLUSION Present investigation, clearly indica ted the leaf nu t r ient c ont ent of p u mmelo va r ies a mong genotypes, but there is no genotype that stands out in a ll ma c r o ( N , P, K , C a , M g a nd S ) a nd micronutrients (Fe, Mn, Zn and Cu) ana lyzed. However, Hyderabad Selection, Raichur Selection, IKP-1, Tirupa thi-2, and Kalenahalli Selction-1 c ou ld b e c ons ider ed a s s u p er i or p u mmelo a ccessions offer ing a gr ea t scope for genetic imp r ovemen t p r ogr a mmes a nd ma x imiz ing productivity with less inputs. Average leaf nitrogen, p ot a s siu m, ir on, a nd ma nga nes e cont ent s in pummelo were higher in plants grafted on Rangpur lime. Phosphorus, calcium, sulphur, and copper contents in pummelo-pummelo stionic combination were found almost comparable with the pummelo- Rangpur lime stionic combination. However, the foliar magnesium and zinc contents were found higher in pummelo - pummelo stionic combination which eventually reduces leaf yellowing/chlorosis in pummelo. Pummelo rootstocks were found to respond well in terms of P, Ca, Mg, S, Zn and Cu nutrient uptake and tolerance to Phytophthora as compared to Rangpur lime. Therefore, it can be concluded that pummelo can be an ideal rootstock for commercial pummelo cultivation with better nutrient absorption capacity, reduced chlorosis, and phytophthora incidence. Wider variations in leaf nutrients contents in pummelo accessions indicated the differential response of pummelo germplasm u nder s imila r s oil- c lima t ic c ondit ions whic h emphasize due consideration while formulating leaf nutrient standards of pummelo for diagnostic and future nutrient management strategy as well. REFERENCES AOAC. 1970. Official Methods of Analysis, 11th edition, Association of Official Agricultural Chemists, Washington, DC. 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