Effect of foliar application of nanonutrients on growth, yield and quality in radish (Raphanus sativus L. cv. Japanese white)

Introduction

Agriculture serves as the backbone of the Indian economy, providing livelihoods to a significant portion of the country's population. With the global population continuously increasing, there is a pressing need to boost agricultural productivity in a sustainable manner. This can be accomplished either by bringing more land under cultivation or, more preferably, by enhancing crop yields through improved nutrient management practices. In recent years, nano-fertilizers have emerged as a promising and innovative alternative to traditional chemical fertilizers. Nanotechnology has demonstrated considerable potential in vegetable production by improving seed germination, enhancing seedling vigour, reducing both abiotic and biotic stresses, and ultimately increasing yield and quality of produce. These developments have established nanotechnology as an important tool for achieving sustainable and precision agriculture.

Radish (Raphanus sativus L.), a member of the Brassicaceae family, is one of the most widely cultivated and popular root vegetables grown across tropical, subtropical, and temperate regions of the world. It can be grown as both an annual and biennial crop depending on the purpose. Although primarily a cool-season crop, Asiatic varieties show better tolerance to higher temperatures than European types. In areas with mild climatic conditions, radish can be cultivated throughout the year except during extreme summer months. Radish holds significant importance as a dietary component worldwide. Its crisp, tuberous roots are commonly consumed raw in salads or cooked as a vegetable, imparting a characteristic pungent flavour that stimulates appetite. The tender leaves are also used as a leafy vegetable. Medicinally, radish is valued for its beneficial effects on liver and gallbladder function. Different parts of the plant, including roots, leaves, flowers, and pods, exhibit antimicrobial properties and have been traditionally used to manage urinary disorders, piles, and digestive problems. Nutritionally, radish roots are a good source of vitamin C (15-40 mg per 100 g fresh weight) and several essential minerals. The young leaves are particularly rich in vitamins A and C, along with important trace elements such as manganese, silicon, and iodine. The continuous and excessive use of chemical fertilizers has raised serious global concerns due to its negative impacts on soil health, environmental quality, and produce safety. Issues such as soil degradation, nutrient imbalances, groundwater pollution, and declining crop quality have prompted a shift towards more sustainable and precisionbased nutrient management approaches. In this context, nano-fertilizers offer a smart and efficient solution. Owing to their ultra-small particle size, high surface area, and controlled-release mechanisms, nano-fertilizers significantly improve nutrient use efficiency while minimizing losses and environmental hazards. Nano-urea, developed by IFFCO and approved under the Fertilizer Control Order (FCO) in India, has shown superior performance compared to conventional urea. It facilitates better nitrogen availability, promotes vegetative growth, enhances flowering and fruit retention, and improves important quality attributes such as total soluble solids. Likewise, phosphorus plays a critical role in root development, while potassium regulates key physiological processes including photosynthesis, stomatal regulation, enzyme activation, and water-use efficiency. Zinc acts as a cofactor for numerous enzymes and is essential for hormone synthesis, protein formation, and overall plant metabolism. The distinctive properties of nanoparticles such as high reactivity, tunable characteristics, and targeted delivery make nano-fertilizers highly effective for modern nutrient management. They function as efficient carriers that enhance nutrient uptake, reduce dosage requirements, and lower environmental risks. Several studies conducted worldwide during 2020-2026 have consistently reported that nano-fertilizers (including Nano Urea, Nano DAP, and Nano ZnO) improve nutrient efficiency, crop productivity, and produce quality while reducing the overall cost of cultivation. In recent times, consumer demand for high-quality, nutrient-rich vegetables has increased significantly. However, there is still limited scientific information available on the foliar application of nano-nutrients for improving growth, yield, and quality in radish. Globally, China leads in radish production, while India has witnessed steady growth in radish cultivation. During 2024-25, India produced approximately 3.2-3.5 million tonnes of radish. West Bengal is among the major radish-producing states, with an area of about 39-41 thousand hectares and production ranging between 557-574 thousand tonnes during the same period, contributing substantially to the national output.

Materials and Methods

The present field experiment was conducted to assess the effect of foliar application of nano-nutrients on growth, yield, and quality parameters of radish at the Agricultural Experimental Research Farm, Institute of Agricultural Science, University of Calcutta, Baruipur, South 24 Parganas, West Bengal. The experiment was laid out in a Randomized Block Design (RBD) with three replications. The net plot size was 1 m × 1 m (1 m²). Healthy, diseasefree seeds of radish variety Japanese White were used for the study. Seeds were sown at a recommended spacing of 20 cm × 10 cm. The study consisted of 21 treatments involving different combinations of nano-fertilizers applied as foliar sprays. The nano-nutrient combinations used were: Combination 1 (C 1 ): IFFCO Nano Urea (3 ml) + IFFCO Nano DAP (5 ml) + IFFCO Nano ZnO (1 ml) Combination 2 (C 2 ): IFFCO Nano Urea (5 ml) + IFFCO Nano DAP (10 ml) + IFFCO Nano ZnO (2 ml)The treatments were as follows:T 1: Nano DAP (C 1 ) + 25% N + 25% P + 100% K of RDF as basal application T 2: Nano DAP (C 2 ) + 25% N + 25% P + 100% K of RDF as basal application T 3: Nano Urea (C 1 ) + 25% N + 100% P + 100% K of RDF as basal application T 4: Nano Urea (C 2 ) + 25% N + 100% P + 100% K of RDF as basal application T 5: Nano DAP (C 1 ) + Nano ZnO (C 1 ) + 25% N + 25% P + 100% K of RDF as basal T 6: Nano DAP (C 1 ) + Nano ZnO (C 2 ) + 25% N + 25% P + 100% K of RDF as basal T 7: Nano DAP (C 2 ) + Nano ZnO (C1) + 25% N + 25% P + 100% K of RDF as basal T 8: Nano DAP (C 2 ) + Nano ZnO (C 2 ) + 25% N + 25% P + 100% K of RDF as basal T 9: Nano Urea (C 1 ) + Nano ZnO (C 1 ) + 25% N + 100% P + 100% K of RDF as basal T 10: Nano Urea (C 1 ) + Nano ZnO (C 2 ) + 25% N + 100% P + 100% K of RDF as basal T 11: Nano Urea (C 2 ) + Nano ZnO (C 1 ) + 25% N + 100% P + 100% K of RDF as basal T 12: Nano Urea (C 2 ) + Nano ZnO (C 2 ) + 25% N + 100% P + 100% K of RDF as basal T 13: Nano DAP (C 1 ) + Nano Urea (C 1 ) + Nano ZnO (C1) + 25% N + 25% P + 100% K of RDF as basal T 14: Nano DAP (C 1 ) + Nano Urea (C 1 ) + Nano ZnO (C 2 ) + 25% N + 25% P + 100% K of RDF as basal T 15: Nano DAP (C 1 ) + Nano Urea (C 2 ) + Nano ZnO (C 1 ) + 25% N + 25% P + 100% K of RDF as basal T 16: Nano DAP (C 1 ) + Nano Urea (C 2 ) + Nano ZnO (C 2 ) + 25% N + 25% P + 100% K of RDF as basal T 17: Nano DAP (C 2 ) + Nano Urea (C 1 ) + Nano ZnO (C 1 ) + 25% N + 25% P + 100% K of RDF as basal T 18: Nano DAP (C 2 ) + Nano Urea (C 1 ) + Nano ZnO (C 2 ) + 25% N + 25% P + 100% K of RDF as basal T 19: Nano DAP (C 2 ) + Nano Urea (C 2 ) + Nano ZnO (C 1 ) + 25% N + 25% P + 100% K of RDF as basal T 20: Nano DAP (C 2 ) + Nano Urea (C 2 ) + Nano ZnO (C 2 ) + 25% N + 25% P + 100% K of RDF as basal T 21: Control (100% RDF with N:P:K ratio of 75:50:100 kg/ha applied as basal). Most treatments recorded significantly higher plant height compared to the control, except T 8 , T 17 , and T 18 .The increase in plant height under higher concentrations of nanonutrients, particularly in T 20 , can be attributed to the enhanced availability of nitrogen supplied through both Nano Urea and Nano DAP. Nitrogen plays a crucial role in promoting cell division, cell elongation, and metabolic activities, leading to improved vegetative growth and better assimilation of photosynthates. These findings are in agreement with the results of Tripathi et al. (2017) [24] and Baloch et al. (2014) [7] in radish.

Results and Discussion

Number of Leaves per Plant

The number of leaves per plant was significantly affected by different nano-nutrient combinations. [15] and Dash et al. (2018) [9] in radish. Nanoparticles are known to modulate gene expression, thereby influencing various physiological and biochemical pathways that support improved plant growth and development.

Leaf Area (cm²)

Leaf area was significantly influenced by the application of different nano-nutrient combinations at both 30 and 60 DAS. At 30 DAS, the maximum leaf area (55.60 cm²) was recorded in the control treatment (T 21 [17] , who reported significant improvement in leaf area and vegetative biomass in cabbage with higher doses of nano-nitrogen. The foliar application schedule (30 and 45 DAS) likely contributed to the enhanced leaf expansion during the later growth stage.

At 30 DAS, the maximum leaf length (20.55 cm) was recorded in the control (T 21 ), followed by T 10 (17.14 cm) and T 4 (16.40

Chlorophyll content in radish leaves was significantly influenced by nano-nutrient treatments at both growth stages. At 30 DAS, the highest chlorophyll content (6.81 mg g⁻¹) was recorded in the control (T 21 ), followed by T 10 (6.45 mg g⁻¹). The lowest value was observed in T 3 (2.34 mg g⁻¹). At 60 DAS, the maximum chlorophyll content (5.80 mg g⁻¹) was recorded in T 17 , while T 20 also showed comparatively high values. The minimum chlorophyll content was recorded in T 3 . The improvement in chlorophyll content with nano-nutrient application may be attributed to the role of zinc and nitrogen in chlorophyll biosynthesis and enzyme activation. These observations are supported by the findings of Abbasifar et al. (2020) [1] in basil and Babaei et al. (2017) [6] in wheat, who reported enhanced chlorophyll content with the application of nano-zinc and nano-nitrogen fertilizers.

Root length was significantly influenced by the foliar application of different nano-nutrient combinations. The maximum root length (17.88 cm) was recorded in T 20 [Nano DAP (C2) + Nano Urea (C2) + Nano ZnO (C2) + 25% N + 25% P + 100% K of RDF as basal application]. This was followed by T 19 (17.39 cm), T 18 (15.58 cm), and T 17 (15.49 cm). The minimum root length (11.90 cm) was observed in T 3 [Nano Urea (C1) + 25% N + 100% P + 100% K of RDF as basal]. Treatments T 13 , T 14 , and T 17 were statistically at par with the control.The increase in root length under higher nano-nutrient doses, especially in T 20 , may be attributed to better nutrient availability and uptake. Nitrogen, phosphorus, and potassium serve as fundamental components for the synthesis of various metabolites, enzymes, and co-enzymes, which enhance photosynthetic efficiency and improve the translocation of carbohydrates to the roots. These findings are in agreement with the results of Chang and Chang (2000) [8] and Ahmed et al. (2004) [3] in radish, turnip, and onion.

Fresh root weight was significantly affected by the application of nano-nutrients. The highest root weight (102.64 g) was recorded in T 20 [Nano DAP (C2) + Nano Urea (C2) + Nano ZnO (C2) + 25% N + 25% P + 100% K of RDF as basal], followed by T 19 (100.15 g) and T 18 (99.51 g). The lowest root weight (61.95 g) was observed in T 3 . All treatments showed significant differences over the control.The improvement in root weight can be ascribed to enhanced nutrient uptake, which promoted greater production of photosynthates, increased leaf number, and larger plant biomass, ultimately resulting in higher dry matter accumulation in the roots. These observations are consistent with the findings of Baloch et al. (2014) [7] and Kiran et al. (2016) [14] in radish.

Root diameter was significantly influenced by nano-nutrient treatments. The maximum root diameter (3.63 cm) was recorded in T 20 , followed by T [26] in mango.

Leaf: Root Weight Ratio

The leaf to root weight ratio was calculated by dividing leaf fresh weight by root fresh weight. The maximum leaf:root ratio (0.892) was recorded in T 3 [Nano Urea (C1) + 25% N + 100% P + 100% K of RDF as basal]. The minimum ratio (0.727) was observed in T 20 [Nano DAP (C2) + Nano Urea (C2) + Nano ZnO (C2) + 25% N + 25% P + 100% K of RDF as basal].A lower leaf:root ratio in T 20 indicates greater partitioning of assimilates towards root development rather than leaves, resulting in higher root yield. This shift in biomass allocation is desirable for root crops like radish. The variation in ratio across treatments was also influenced by prevailing environmental conditions during the growing period. These findings align with the results of Rasha et al.

(2019) [19] , who observed significant changes in leaf and fruit parameters in grapes with nano-zinc application.

Yield (q/ha) Total root yield (q/ha) was significantly influenced by the application of different nano-nutrient combinations. The highest yield (315.15 q/ha) was recorded in T 20 , followed by T 19 , T 18 , and T 17 . The lowest yield (208 q/ha) was observed in T 3 . Most treatments performed significantly better than the control, except T 8 and T 17 .The superior performance of T 20 can be attributed to the synergistic effect of nanonutrients, which enhanced overall plant growth, photosynthetic efficiency, and assimilate translocation to the roots. Nano-fertilizers improve nutrient use efficiency and support better metabolic activity, leading to higher root yield. These results are in conformity with the findings of Ramesh et al. (2020) [18] in black gram and earlier studies by Chang and Chang (2000) [8] and Ahmed et al. (2004) [3] in radish and other root crops.

Effect of foliar application of nano-nutrients on quality attributes of radish at 60 DAS Note: * = Significant difference from control at 5% level of significance.

References

1. Abbasifar A, Shahrabadi F, Valizadeh Kaji B. Effects of green synthesized zinc and copper nano-fertilizers on the morphological and biochemical attributes of basil plant. Journal of Plant Nutrition. 2020;43(8):11041118.
2. Abd El-Rahman MA, El-Sayed AA, El-Gazzar IA. Effect of nano-fertilizers on growth, yield and fruit quality of date palm. Journal of Horticultural Science & Ornamental Plants. 2022;14(2):78-89.
3. Ahmed F, Sarwar S, Khan BM. Effect of different combinations of NPK fertilizers on the growth and yield of turnip (Brassica rapa L.) at the northern areas of Pakistan. Pakistan Journal of Soil Science. 2004;23(3-4):43-48.
4. Alloway BJ. Zinc in Soils and Crop Nutrition. 2nd ed. Brussels: International Zinc Association; 2008.
5. Astaneh T, Mohammadi A, Gholami M. Effects of nano-chelated nitrogen and urea fertilizers on growth, yield and protein content of wheat (Triticum aestivum L.). Journal of Plant Nutrition. 2021;44(12):1785-1797.
6. Babaei K, Seyed Sharifi R, Pirzad A, Khalilzadeh R. Effects of bio fertilizer and nano Zn-Fe oxide on physiological traits, antioxidant enzymes activity and yield of wheat (Triticum aestivum L.) under salinity stress. Journal of Plant Interactions. 2017;12(1):381389.
7. Baloch PA, Uddin R, Nizamani FK. Effect of nitrogen, phosphorus and potassium fertilizers on growth and yield characteristics of radish (Raphanus sativus L.). Journal of Agriculture and Environmental Sciences. 2014;14(6):565-569.
8. Chang L, Chang J. Effect of potassium on yield quality of radish (Raphanus sativus L.). Journal of Hebei Agricultural University. 2000;23(2):20-24.
9. Dash SK, Pathak M, Tripathy L, Barik S. Studies on effect of integrated nutrient management on growth and yield attributes in radish (Raphanus sativus L.) and its residual effect in coriander (Coriandrum sativum L.) in radish-coriander cropping sequence. Journal of Pharmacognosy and Phytochemistry. 2018;8(1):319322.
10. Davarpanah S, Tehranifar A, Davarynejad G, Abadía J, Eshghi S. Effects of foliar nano-nitrogen and zinc fertilizers on pomegranate (Punica granatum L.) fruit yield and quality. Scientia Horticulturae. 2016;211:125130.
11. Elhindi K, El-Hendawy S, Abdel-Salam E, Elgorban A, Ahmed M. Impacts of fertigation via surface and subsurface drip irrigation on the growth rate, yield and flower quality of Zinnia elegans. Brigantia. 2016;75(1):96-107.
12. Greenwood DJ, Stone DA, Martinets TV. Dynamic model for the effects of soil P and fertilizer P on crop growth, P uptake and soil P in arable cropping: Experimental test of the model for field vegetables. Annals of Botany. 2001;88(2):293-306.
13. Jadhav PB, Patel DJ, Kireeti A, Patil NB, Dekhane SS, Harad NB, et al. Effect of different levels of vermicompost on growth and yield of radish cv. Local variety. International Journal of Research and Review. 2014;1(2):29-31.
14. Kiran M, Jilani MS, Waseem K, Sohail M. Effect of organic manures and inorganic fertilizers on growth and yield of radish (Raphanus sativus L.). Pakistan Journal of Agricultural Resources. 2016;29(4):363-372.
15. Lakra AS, Prasad D, Deepanshu VM, Shabi M. Effect of nitrogen and phosphorus on growth and yield of radish (Raphanus sativus L.) cv. Pusha Chetki under shade net condition. The Pharma Innovation Journal. 2017;6(11):768-770.
16. Manikandan A, Subramanian KS. Zeolite-based nanonitrogen fertilizer on growth and productivity of maize (Zea mays L.). International Journal of Agricultural Sciences. 2016;8(12):2785-2789.
17. Nofal AS, Ashmawi AE, Mohammed AA, El-Abd MT, Helaly AA. Effect of soil application of nano NPK fertilizers on growth, productivity and quality of lettuce (Lactuca sativa). Al-Azhar Journal of Agricultural Research. 2021;46:91-100.
18. Ramesh T, Rathika S, Sangeetha S, Satheesh S, Ponpradeepa M, Pavithra A. Enhancement of black gram productivity through foliar spray of nutrients and growth hormones: A review. International Journal of Current Microbiology and Applied Sciences. 2020;9(12):1-11.
19. Rasha EA, El-Sayed MA, El-Mogy MM. Effect of nano-zinc application on growth, yield and fruit quality of grapevines. Journal of Plant Production. 2019;10(11):1025-1032.
20. Sharaf-Eldin MA. Nano-nitrogen fertilization strategies for improving growth, yield and quality of vegetable crops. Journal of Soil Science and Plant Nutrition. 2022;22(3):3124-3137.
21. Sharifi RS, Khalilzadeh R, Pirzad A. Effect of zinc application on growth and some physiological characteristics of barley under water stress. Journal of Plant Nutrition. 2016;39(5):702-712.
22. Sharma S, Kumar V, Singh R. Effect of foliar nanonitrogen application on growth, yield and quality of pearl millet. Indian Journal of Agronomy. 2022;67(4):456-462.
23. Thapa U, Mohanto B, Chattopadhyay SB, Ghanti P. Growth and yield of some cultivars of radish (Raphanus sativus L.) with nitrogen levels. Environment & Ecology. 2003;21(4):836-838.
24. Tripathi AK, Ram RB, Rout S, Kumar A, Patra SS. Studies on the effect of nitrogen levels and spacing on quality traits of radish (Raphanus sativus L.) cv. Kashi Sweta. International Journal of Chemical Studies. 2017;5(6):537-540.
25. Vafa ZS, Nadian H, Heidari M. Effect of nano-zinc fertilizer on growth parameters and some biochemical traits of savory (Satureja hortensis L.). Journal of Medicinal Plants. 2015;14(4):67-78.
26. Zagzog OA, Gad MM, Hafez NK. Effect of nanochitosan on vegetative growth, fruiting and resistance of malformation of mango. Trends in Horticultural Research. 2017;7(1).