Role of Azotobacter chroococcum and Foliar Feeding with Molybdenum and Copper in Improving Growth and Productivity of Eggplant (Solanum melongena L.)
DOI:
https://doi.org/10.64354/6yjzz134Keywords:
Azotobacter chroococcum; Foliar feeding; Molybdenum; Copper; Eggplant; Solanum melongena; Biofertilizer; Micronutrients; Sustainable agricultureAbstract
The present study was conducted during the two successive spring-summer seasons of 2023 and 2024 at the experimental farm of the College of Agriculture, University of Al-Qadisiyah, Iraq. The aim was to investigate the individual and combined effects of Azotobacter chroococcum inoculation and foliar application of molybdenum (Mo) and copper (Cu) on the vegetative growth, fruit yield and nutrient status of aubergine (Solanum melongena L., cv. Black Beauty The experiment was arranged in a randomised complete block design (RCBD) with three replications. Treatments consisted of two levels of biofertilizer (with and without A. chroococcum) and four foliar feeding levels (control, Mo at 50 mg L-1, Cu at 75 mg L-1 and Mo + Cu). It was found that the tallest plants, number of branches per plant, leaf area, chlorophyll content and individual fruit weight were observed in the plants treated with A. chroococcum + foliar spray of Mo + Cu. Moreover, total fruit yield per hectare was significantly raised with the combination treatment in comparison with the control by 34.6% and 37.3% in the first and second seasons, respectively. The combined application of A. chroococcum and micronutrient foliar feeding caused a significant increase in the uptake of N, P, K, Mo and Cu in leaves. These results imply that the combined application of biofertilizer inoculation with foliar nutrition of micronutrients is a potential green approach to increase aubergine productivity under the semi-arid conditions.
References
1] Sharma M, Delta AK, Brar NS, Yadav A, Dhanda PS, Baslam M, Kaushik P. Rhizophagus irregularis and Azotobacter chroococcum uphold eggplant production and quality under low fertilization. Int J Plant Biol. 2022;13(4):601–612.
[2] Sumbul A, Ansari RA, Rizvi R, Mahmood I. Azotobacter: A potential bio-fertilizer for soil and plant health management. Saudi J Biol Sci. 2020;27(12):3634–3640.
[3] Aasfar A, Bargaz A, Yaakoubi K, Hilali A, Bennis I, Zeroual Y, Meftah Kadmiri I. Nitrogen fixing Azotobacter species as potential soil biological enhancers for crop nutrition and yield stability. Front Microbiol. 2021;12:628379.
[4] Wani SA, Chand S, Ali T. Potential use of Azotobacter chroococcum in crop production: An overview. Curr Agric Res J. 2013;1(1):35–38.
[5] Víllora G, Moreno DA, Romero L. Response of eggplant to nitrogen supply: Molybdenum-nitrate relationships. Biol Plant. 2002;45(4):621–623.
[6] Víllora G, Moreno DA, Romero L. Potassium supply influences molybdenum, nitrate, and nitrate reductase activity in eggplant. J Plant Nutr. 2003;26(3):661–672.
[7] Steiner F, Zoz T, Zuffo AM, Machado PP, Zoz J, Zoz A. Foliar application of molybdenum enhanced quality and yield of crispleaf lettuce (Lactuca sativa L., cv. Grand Rapids). Acta Agron. 2018;67(1):73–78.
[8] Chen J, Shafi M, Li S, Wang Y, Wu J, Ye Z, Peng D, Yan W, Liu D. Physiological and molecular mechanisms of plant responses to copper stress. Int J Mol Sci. 2022;23(21):12950.
[9] Shahid M, Dumat C, Khalid S, Schreck E, Xiong T, Niazi NK. Foliar heavy metal uptake, toxicity and detoxification in plants: A comparison of foliar and root metal uptake. J Hazard Mater. 2017;325:36–58.
[10] Hamid B, Zaman M, Farooq S, Fatima S, Sayyed RZ, Baba ZA, Sheikh TA, Reddy MS, El Enshasy H, Gafur A, Suriani NL. Copper mitigates salinity stress by regulating water status, photosynthetic pigments and ion homeostasis and increases the yield of eggplant (Solanum melongena). Sci Hortic. 2024;336:113439.
[11] Barker AV, Pilbeam DJ. Handbook of Plant Nutrition. 2nd ed. Boca Raton: CRC Press; 2015.
[12] Marschner H. Marschner’s Mineral Nutrition of Higher Plants. 3rd ed. London: Academic Press; 2012.
[13] Pramanik P, Goswami AJ, Ghosh S, Kalita C. An indigenous strain of potassium-solubilizing bacteria Bacillus pseudomycoides enhanced potassium uptake in tea plants. J Appl Microbiol. 2019;126(1):215–222.
[14] Shahid MA, Balal RM, Khan N, Zotarelli L, Liu GD, Ghazanfar MU, Riaz A, Javed U, Hayat F, Mubeen M. Multi-micronutrient foliar fertilization in eggplant under diverse fertility scenarios. Sci Hortic. 2022;296:110903.
[15] Alloway BJ. Micronutrient Deficiencies in Global Crop Production. Dordrecht: Springer; 2008.
[16] Bhardwaj D, Ansari MW, Sahoo RK, Tuteja N. Biofertilizers function as key player in sustainable agriculture by improving soil fertility, plant tolerance and crop productivity. Microb Cell Fact. 2014;13:66.
[17] Pandey C, Gupta M. Selenium and auxin mitigate arsenic stress in rice (Oryza sativa L.) by combining the role of stress indicators, modulators and genotoxicity assay. J Hazard Mater. 2015;287:384–391.
[18] Rouphael Y, Colla G. Editorial: Biostimulants in agriculture. Front Plant Sci. 2020;11:40.
[19] Abd El-Mageed TA, Semida WM, Mohamed GF, Rady MM. Combined effect of foliar-applied salicylic acid and deficit irrigation on physiological–anatomical responses, and yield of squash plants under saline soil. S Afr J Bot. 2016;106:8–16.
[20] Hussain A, Shah M, Hamayun M, Iqbal A, Qadir M, Alataway A. Growing Azotobacter chroococcum and sweet pepper under deficit irrigation in greenhouse conditions. Sustainability. 2022;14(9):5653.
[21] FAOSTAT. Food and Agriculture Organization of the United Nations Statistics Division. Production quantities of eggplant. Rome: FAO; 2023.
[22] Gürbüz N, Uluişik S, Frary A, Frary A, Doğanlar S. Health benefits and bioactive compounds of eggplant. Food Chem. 2018;268:602–610.
[23] Hindersah R, Kalay M, Talahaturuson A, Lakburlawal Y. Nitrogen fixing bacteria Azotobacter as biofertilizer and biocontrol in long bean. Agric. 2018;30(1):25–32.
[24] Jaga PK, Singh V. Effect of biofertilizer, nitrogen and sulphur on sorghum-mustard cropping system. Proc Natl Seminar Agrotechnology. 2010;1:69–71.
[25] Kumar V, Narula N. Solubilization of inorganic phosphates and growth emergence of wheat as affected by Azotobacter chroococcum mutants. Biol Fertil Soils. 1999;28(3):301–305.
[26] Yruela I. Copper in plants: acquisition, transport and interactions. Funct Plant Biol. 2009;36(5):409–430.
[27] Shukla AK, Behera SK, Pakhre A, Chaudhari SK. Micronutrients in soils, plants, animals and humans. Indian J Fertil. 2018;14(2):30–54.
[28] Page AL, Miller RH, Keeney DR. Methods of Soil Analysis, Part 2: Chemical and Microbiological Properties. 2nd ed. Madison: ASA-SSSA; 1982.
[29] AOAC. Official Methods of Analysis. 18th ed. Arlington: Association of Official Analytical Chemists; 2005.
[30] Gómez KA, Gómez AA. Statistical Procedures for Agricultural Research. 2nd ed. New York: John Wiley & Sons; 1984.
[31] Wani SA, Chand S, Wani MA, Ramzan M, Hakeem KR. Azotobacter chroococcum – A potential biofertilizer in agriculture: An overview. In: Hakeem KR, et al., editors. Soil Science: Agricultural and Environmental Prospectives. Cham: Springer; 2016. p. 333–348.
[32] Ponmurugan KA, Sankaranarayanan C, Al-Dharbi NA. Biological activities of plant growth promoting Azotobacter sp. isolated from vegetable crops rhizosphere soils. J Pure Appl Microbiol. 2012;6(4):147–154.
[33] El-Lattief EA. Use of Azospirillum and Azobacter bacteria as biofertilizers in cereal crops: A review. Int J Res Eng Appl Sci. 2016;6(7):36–44.
[34] Nardi S, Pizzeghello D, Muscolo A, Vianello A. Physiological effects of humic substances on higher plants. Soil Biol Biochem. 2002;34(11):1527–1536.
[35] Pramanik P, Safique S, Jahan A, Islam MA. Effect of molybdenum on nodulation, plant yield and nitrogen uptake in hairy vetch (Vicia villosa Roth). Soil Sci Plant Nutr. 2015;61(4):664–675.
[36] Kumar M, Giri VP, Pandey S, Gupta A, Patel MK, Bajpai AB, Jenkins S, Siddique KHM. Plant-growth-promoting rhizobacteria emerging as an effective bioinoculant to improve the growth, production, and stress tolerance of vegetable crops. Int J Mol Sci. 2021;22(22):12245.
[37] Nazir F, Hussain A, Fariduddin Q. Hydrogen peroxide modulate photosynthesis and antioxidant systems in tomato (Solanum lycopersicum L.) plants accessed by drought stress. Dose-Response. 2019;17(3):1559325819896515.
[38] Pilon M, Abdel-Ghany SE, Cohu CM, Gogolin KA, Ye H. Copper cofactor delivery in plant cells. Curr Opin Plant Biol. 2006;9(3):256–263.
[39] Fageria NK, Filho MPB, Moreira A, Guimarães CM. Foliar fertilization of crop plants. J Plant Nutr. 2009;32(6):1044–1064.
[40] Rengel Z. Availability of Mn, Zn and Fe in the rhizosphere. J Soil Sci Plant Nutr. 2015;15(2):397–409.
[41] Ali WM, Sultan SME, Ali AM, Al-Sayed HM, Ismail HG, Teiba II, et al. Organic fertilizers and Azotobacter: effects on onion growth, yield, metabolites, and soil fertility. AMB Express. 2025;15. DOI: 10.1186/s13568-025-01895-5.
[42] Nabati J, Nezami A, Yousefi A, et al. Biofertilizers containing plant growth promoting rhizobacteria enhance nutrient uptake and improve the growth and yield of chickpea plants in an arid environment. Sci Rep. 2025;15:8331. DOI: 10.1038/s41598-025-93070-w.
[43] Dasgan HY, Aldiyab A, Elgudayem F, Ikiz B, Gruda NS. Utilizing the power of plant growth promoting rhizobacteria on reducing mineral fertilizer, improved yield, and nutritional quality of Batavia lettuce in a floating culture. Sci Rep. 2024;14. DOI: 10.1038/s41598-024-51818-w.
[44] Hindersah R, Yusuf AM, Adhiningtyas DI, Herdiyantoro D, Mulyani O, Suryatmana P. Azotobacter and chemical fertilizer for improving groundnut yield in field experiment. J Agrotek Tropika. 2024;12(4). DOI: 10.23960/jat.v12i4.8395.
[45] Nadeem M, et al. Biofertilizers in sustainable agriculture: mechanisms, applications, and future prospects. Discov Agric. 2025;3(1):224. DOI: 10.1007/s44279-025-00318-0.
[46] Delfim J, Moreira A, Moraes LAC. Foliar application of molybdenum combined with cobalt affects leaf nitrogen concentration, grain yield, and yield components of soybean. Agron J. 2025. DOI: 10.1002/agj2.70160.
Downloads
Published
Issue
Section
License
Copyright (c) 2026 New Journal of Biology and Medicine
This work is licensed under a Creative Commons Attribution 4.0 International License.
