Effect of different levels of NPK in combination with FYM on growth, mortality and establishment of kinnow (Citrus reticulata Blanco) under Kanpur agro-climatic region

Introduction

Citrus reticulata blanco is the scientific name for kinnow. According to botany, kinnow is a member of the Rutaceae family. According to W. Ahmed et al. (2007) [12] , kinnow is a wellknown citrus fruit that is favored for its pleasant flavor, appearance, color, taste, good yield, high processing value, therapeutic applications, delicious juice, smoothing character, vitamin C source, wider adaptability to various agroclimatic conditions, and high nutritive value. Kinnow is a cross between the citrus cultivars "willow leaf" (Citrus deliciosa) and "king" (Citrus nobilis). H.B. Frost created it in 1915 at the University of California Citrus Experimentation Station in the United States. In 1935, the hybrid was made available for commercial production (Y. H. Hui et al. 2006) [4] . Dr. J.C. Bakshi brought kinnow to India in 1954 at the Punjab Agriculture University Regional Research Station in Abohar (HAG 2017). Kinnow is a highly productive plant with a hot climate. The tree grows quickly and can grow up to 35 feet tall. The broad, shallow roots of the kinnow plant can reach a depth of seven to twelve feet, depending on the state of the soil. The shoot system has a columnar trunk with many long, thin, ascending branches that are almost entirely free of thorns. Branchlets have dense foliage made up of broadly lanceolate, medium-to-large leaves. www.justagriculture.in the leaves have unicostate reticulate venation, are simple, alternating, petiolate, and have a complete edge. Smooth essential oil glands in the lamina of leaves provide a pleasant scent. Off-white hermaphrodite solitaire pentaerous flowers are produced by kinnow. The hue of the anthers is yellow. Hesperidium fruit has between 0 and 9 seeds. The shape of kinnow fruit ranges from spherical to oblate. Kinnow has become the King of Fruits in Punjab due to farmers' passion for it (Rajesh Kumar 2020) [6] . One of the most significant fruit crops, citrus is grown on more than 109.6 million hectares of land and Punjab, Rajasthan, Madhya Pradesh, Haryana, Maharashtra, and Uttarakhand are among the Indian states where Kinnow, Mandarin, or orange is grown. With a great potential for production, kinnow farming is growing in Western Uttar Pradesh (Agra, Gorakhpur, etc.), with an average of 294 quintals/hectare (q/ha) in Agra. The flavedo/exocarp, a pigmented skin with glands that secrete essential oils, protects the inside, juicy part of kinnow fruit. White, spongy tissues called albedo, which vary in thickness and have a complex network of vascular bundles, are another significant component located immediately adjacent to flavedo (Lado et al., 2016) [7] . The edible portion of kinnow fruit consists of tiny, closely spaced sacs that hold seeds and fluid. Kinnow is well-known around the world for the flavor and nutritional value of its juice. Customer preference is another factor contributing to kinnow fruit's appeal. Customers want to purchase fruit that is easy to eat, dustfree, has few seeds, and has the most liquid possible. Kinnow fruit may be able to satisfy growing customer demands. The abundance of volatile chemicals in kinnow gives it its distinctive flavor. Before harvesting the fruits from the tree, the maturity level must be determined in order to market kinnow on a commercial basis. The amount of total soluble solids (TSS) in kinnow fruit pulp ranges from 9.5 to 16%. The amount of sugar in fruit's juicy sacs is greatly influenced by environmental factors, including temperature, light irradiance, and farming practices. Amino acids, vitamins (ascorbic acid, provitamin-A, and folate), and bioactive chemicals (limonoids, fla-vones, phenolics, and flavonoids) as well as carotenoids are all abundant in kinnow juice. The temperature and humidity of the storage chamber determine how much amino acid is in kinnow juice. Asparagine (3.5 μmol/g) is the main amino acid found in kinnow juice, followed by arginine (2.4 μmol/g), aspartic acid (2.0 μmol/g), proline (1.5 μmol/g), and glutamine (1.0 μmol/g) (Matsumoto 2012) [9] . A significant source of osmotic stabilizer and blood pressure-regulating minerals (potassium and salt) is kinnow juice. Kinnow juice's potassium content ranged from 1.6 to 2.5 mg/g, while its sodium content varied from 0.01 to 0.03 mg/g. According to the mineral profile of kinnow juice, calcium is present in the range of 014-0.47 mg/g, followed by magnesium (0.11-0.12 mg/g), phosphorus (0.10-0.30 mg/g), iron (0.0015-0.0060 mg/g), zinc (0.0007-0.005 mg/g), copper (6-8 mg/100 ml), and manganese (0.0005 mg/g) (Barros et al., 2012) [1] . The most crucial element for promoting plant growth is thought to be nitrogen. Despite being a naturally occurring element, nitrogen cannot be absorbed by plants. The environment's nitrogen is converted into nutrients that plants can easily access. Thick, green, and sustainable orchards are encouraged by the appropriate use of balanced fertilizer. In addition to being a necessary component of protein and chlorophyll, nitrogen is also found in numerous other substances that are physiologically significant to plant metabolism, including nucleotides, phosphatides, alkaloids, enzymes, hormones, vitamins, and more (Yawalkar et al. 1992) [13] . Adequate quantities of phosphorus support general growth and are necessary for root development and nutrient uptake. Numerous functions, including photosynthesis, the synthesis and breakdown of carbohydrates, and the transport of energy within the plant, depend on phosphorus (Obreza 2001) [10] . Applying optimal P levels greatly increases vegetative parameters [3] . The vegetative growth of Kinnow plants is greatly enhanced by applying varying amounts of farm yard manure (FYM).

When paired with balanced nitrogen fertilization, higher FYM levels typically improve plant height, canopy spread, leaf count, and general vigor. Excessive FYM over ideal levels, however, may result in decreasing returns and may not proportionately boost growth. The plant rhizosphere receives vital nutrients and organic materials from farm yard manure (FYM). Additionally, FYM increases the soil's porosity and water-holding capacity. Additionally, it keeps the soil's nutritional status balanced and reduces leaching losses. Nitrogen, on the other hand, is the most crucial nutrient for plants and is crucial for boosting vegetative growth and fruit production. Early, robust vegetative growth and green color are caused by nitrogen, which sets off the plant's physiological processes.

According to Sharma and Chopra (2000) [11] , nitrogen was crucial for boosting sweet orange growth and output.

Materials and Methods

The experiment was conducted during the Kharif season of 2025-2026 at the Horticulture Research Farm, Faculty of Agricultural Sciences and Allied Industries, Rama University, Kanpur, using

References

1. Barros HRDM, Ferreira TAPC, Genovese MI. Antioxidant capacity and mineral content of pulp and peel from commercial cultivars of citrus from Brazil. Food Chem. 2012; 134(4):1892-1898. doi:10.1016/j.foodchem.2012.03.090.
2. Food and Agriculture Organization (FAO). Citrus Fruit -Fresh and Processed Statistical Bulletin. Rome: FAO; 2023. Available from: http://www.fao.org/economic/est
3. Garhwal PC. Effect of FYM and nitrogen levels on growth, yield and fruit quality of Kinnow mandarin in sandy soils of hot arid region. Bikaner (Rajasthan): Central Institute for Arid Horticulture and Department of Horticulture, College of Agriculture; 2010.
4. Hui YH, Cano MP, Barta J. Handbook of Fruits and Fruit Processing. Hoboken (NJ): John Wiley & Sons; 2006. p. 312.
5. National Horticulture Board. Horticulture at a Glance 2017. Gurgaon: National Horticulture Board; 2017. Available from: http://nhb.gov.in
6. Kumar R. Kinnow: Punjab's king of fruit -a review. Vol. 1, Issue 1. Jalandhar (Punjab): Sant Baba Bhag Singh University; 2020. p. 1-10.
7. Lado J, Cuellar F, Rodrigo MJ, Zacarías L. Nutritional composition of mandarins. In: Simmonds MS, Preedy VR, editors. Nutritional Composition of Fruit Cultivars. London: Academic Press/Elsevier; 2016. p. 420-443. doi:10.1016/B978-0-12-408117-8.00018-0.
8. Lado J, Rodrigo MJ, Zacarías L. Maturity indicators and citrus fruit quality. Stewart Postharvest Rev. 2014;2:1-6.
9. Matsumoto H, Ikoma Y. Effect of different postharvest temperatures on the accumulation of sugars, organic acids, and amino acids in the juice sacs of satsuma mandarin (Citrus unshiu Marc.) fruit. J Agric Food Chem. 2012;60(39):9900-9909. doi:10.1021/jf303532s.
10. Obreza TA. Effects of P and K fertilization on young citrus tree growth. Gainesville (FL): Cooperative Extension Service, University of Florida, Institute of Food and Agricultural Sciences; 2001. p. 1-3.
11. Sharma KL, Chopra SK. Effect of nitrogen, phosphorus and potash on the growth and yield of blood red sweet orange (Citrus sinensis Osbeck) grown in foothill and valley areas of Himachal Pradesh. Punjab Hortic J. 2000;40:19-23.
12. Ahmed W, Ziaf K, Nawaz MA, Saleem BA, Ayyub CM. Studies on combining ability of citrus hybrids with commercial indigenous cultivars. Pak J Bot. 2007;39(1):47-55.
13. Yawalkar KS, Agarwal JP, Bokde S. Manures and Fertilizers. 7th ed. Nagpur: Agri-Horticultural Publishing House; 1992. p. 8.