Nano-fertilisers have only recently been introduced to intensify plant production, and there still remains inadequate scientific knowledge on their plant-related effects. This paper therefore compares the effects of two nano-fertilisers on common sunflower production under field conditions. The benefits arising from the foliar application of micronutrient-based zinc oxide fertiliser were compared with those from the titanium dioxide plant-growth enhancer. Both the zinc oxide (ZnO) and titanium dioxide (TiO2) were delivered by foliar application in nano-size at a concentration of 2.6 mg·L-1. The foliar-applied nanoparticles (NPs) had good crystallinity and a mean size distribution under 30 nm. There were significant differences between these two experimental treatments in the leaf surfaces' trichomes diversity, ratio, width, and length at the flower-bud development stage. Somewhat surprisingly, our results established that the ZnO-NPs treatment induced generally better sunflower physiological responses, while the TiO2-NPs primarily affected quantitative and nutritional parameters such as oil content and changed sunflower physiology to early maturation. There were no differences detected in titanium or zinc translocation or accumulation in the fully ripe sunflower seeds compared to the experimental controls, and our positive results therefore encourage further nano-fertiliser research.

Department of Chemistry Rajiv Gandhi University of Knowledge Technologies AP IIIT Nuzvid 521202 Krishna District India

Department of Crop Production and Grassland Ecosystems Faculty of Agrobiology and Food Resources Slovak University of Agriculture in Nitra Tr A Hlinku 2 949 76 Nitra Slovakia

Department of Earth and Environmental Studies Montclair State University 1 Normal Ave Montclair NJ 070 43 USA

Department of Environment and Biology Faculty of Agrobiology and Food Resources Slovak University of Agriculture in Nitra Tr A Hlinku 2 949 76 Nitra Slovakia

Department of Soil Science and Geology Faculty of Agrobiology and Food Resources Slovak University of Agriculture in Nitra Tr A Hlinku 2 949 76 Nitra Slovakia

Institute of Electrical Engineering Slovak Academy of Sciences Dúbravská cesta 9 841 04 Bratislava Slovakia

Institute of Laboratory Research on Geomaterials Faculty of Natural Sciences Comenius University in Bratislava Mlynska dolina Ilkovičova 6 842 15 Bratislava Slovakia

Laboratory of Growth Regulators Faculty of Science Palacký University Šlechtitelů 27 7837 Olomouc Czech Republic

Nanotechnology Centre VŠB Technical University of Ostrava 17 listopadu 15 2172 708 00 Ostrava Poruba Czech Republic

School of Ecology and Environmental Science Yunnan University 2 Cuihubei Lu Kunming 650091 China

Zobrazit více v PubMed

Jiang W., Mashayekhi H., Xing B. Bacterial toxicity comparison between nano- and micro-scaled oxide particles. Environ. Pollut. 2009;157:1619–1625. doi: 10.1016/j.envpol.2008.12.025. PubMed DOI

Li C., Wang P., Van Der Ent A., Cheng M., Jiang H., Read T.L., Lombi E., Tang C., De Jonge M.D., Menzies N.W., et al. Absorption of foliar-applied Zn in sunflower (Helianthus annuus): Importance of the cuticle, stomata and trichomes. Ann. Bot. 2018;123:57–68. doi: 10.1093/aob/mcy135. PubMed DOI PMC

Jaberzadeh A., Moaveni P., Moghadam H.R.T., Zahedi H. Influence of Bulk and Nanoparticles Titanium Foliar Application on some Agronomic Traits, Seed Gluten and Starch Contents of Wheat Subjected to Water Deficit Stress. Not. Bot. Horti Agrobot. Cluj-Napoca. 2013;41:201–207. doi: 10.15835/nbha4119093. DOI

Kouhi S.M.M., Lahouti M., Ganjeali A., Entezari M.H. Comparative phytotoxicity of ZnO nanoparticles, ZnO microparticles, and Zn2+ on rapeseed (Brassica napus L.): Investigating a wide range of concentrations. Toxicol. Environ. Chem. 2014;96:861–868. doi: 10.1080/02772248.2014.994517. DOI

Pištora J., Vlček J., Lesňák M., Blažek D., Kolenčík M. Optical Methods in Diagnostics of Nanostructured Materials. 1st ed. Akademické nakladatelství CERM; Brno-Královo Pole, Czech Republic: 2015.

Vandana B., Syamala P., Venugopal D.S., Sk S.R.K.I., Venkateswarlu B., Jagannatham M., Kolenčík M., Ramakanth I., Dumpala R., Sunil B.R. Magnesium/fish bone derived hydroxyapatite composites by friction stir processing: Studies on mechanical behaviour and corrosion resistance. Bull. Mater. Sci. 2019;42:122. doi: 10.1007/s12034-019-1799-z. DOI

Chen X., Mao S.S. Titanium dioxide nanomaterials: Synthesis, properties, modifications, and applications. Chem. Rev. 2007;107:2891–2959. doi: 10.1021/cr0500535. PubMed DOI

Holišová V., Urban M., Kolenčík M., Nemcova Y., Schröfel A., Peikertová P., Slabotinský J., Kratošová G. Biosilica-nanogold composite: Easy-to-prepare catalyst for soman degradation. Arab. J. Chem. 2019;12:262–271. doi: 10.1016/j.arabjc.2017.08.003. DOI

Konvičková Z., Holišová V., Kolenčík M., Niide T., Kratošová G., Umetsu M., Seidlerová J. Phytosynthesis of colloidal Ag-AgCl nanoparticles mediated by Tilia sp. leachate, evaluation of their behaviour in liquid phase and catalytic properties. Colloid Polym. Sci. 2018;296:677–687. doi: 10.1007/s00396-018-4290-2. DOI

Medina C., Santos-Martinez M.J., Radomski A., I Corrigan O., Radomski M.W. Nanoparticles: Pharmacological and toxicological significance. Br. J. Pharmacol. 2009;150:552–558. doi: 10.1038/sj.bjp.0707130. PubMed DOI PMC

Prasad T.N.V.K.V., Sudhakar P., Sreenivasulu Y., Latha P., Munaswamy V., Reddy K.R., Sreeprasad T.S., Sajanlal P.R., Pradeep T. Effect of nanoscale zinc oxide particles on the germination, growth and yield of peanut. J. Plant Nutr. 2012;35:905–927. doi: 10.1080/01904167.2012.663443. DOI

Prasad R., Bhattacharyya A., Nguyen Q.D. Nanotechnology in Sustainable Agriculture: Recent Developments, Challenges, and Perspectives. Front. Microbiol. 2017;8:1014. doi: 10.3389/fmicb.2017.01014. PubMed DOI PMC

Kolenčík M., Nemček L., Šebesta M., Urík M., Ernst D., Kratošová G., Konvičková Z. Effect of TiO2 as plant-growth stimulating nanomaterial on crop production. In: Singh V.P., Singh S., Prasad S.M., Chauhan D.K., Tripathi D.K., editors. Plant Responses to Nanomaterials, Recent Interventions, and Physiological and Biochemical Responses. 1st ed. Springer Nature Switzerland AG; Cham, Switzerland: 2020. p. 302. in press.

Gkanatsiou C., Ntalli N., Menkissoglu-Spiroudi U., Dendrinou-Samara C. Essential Metal-Based Nanoparticles (Copper/Iron NPs) as Potent Nematicidal Agents against Meloidogyne spp. J. Nanotechnol. Res. 2019;1:043–057. doi: 10.26502/jnr.2688-8521004. DOI

Liu R., Lal R. Potentials of engineered nanoparticles as fertilizers for increasing agronomic productions. Sci. Total. Environ. 2015;514:131–139. doi: 10.1016/j.scitotenv.2015.01.104. PubMed DOI

Estrada-Urbina J., Cruz-Alonso A., Santander-González M., Méndez-Albores A., Vázquez-Durán A. Nanoscale Zinc Oxide Particles for Improving the Physiological and Sanitary Quality of a Mexican Landrace of Red Maize. Nanomaterials. 2018;8:247. doi: 10.3390/nano8040247. PubMed DOI PMC

Wagner G., Korenkov V., Judy J.D., Bertsch P.M. Nanoparticles Composed of Zn and ZnO Inhibit Peronospora tabacina Spore Germination in vitro and P. tabacina Infectivity on Tobacco Leaves. Nanomaterials. 2016;6:50. doi: 10.3390/nano6030050. PubMed DOI PMC

Feidantsis K., Kalogiannis S., Marinoni A., Vasilogianni A.-M., Gkanatsiou C., Kastrinaki G., Dendrinou-Samara C., Kaloyianni M. Toxicity assessment and comparison of the land snail’s Cornu aspersum responses against CuO nanoparticles and ZnO nanoparticles. Comp. Biochem. Physiol. Part C: Toxicol. Pharmacol. 2020;236:108817. doi: 10.1016/j.cbpc.2020.108817. PubMed DOI

Raliya R., Nair R., Chavalmane S., Wang W.-N., Biswas P. Mechanistic evaluation of translocation and physiological impact of titanium dioxide and zinc oxide nanoparticles on the tomato (Solanum lycopersicum L.) plant. Metallomics. 2015;7:1584–1594. doi: 10.1039/C5MT00168D. PubMed DOI

Kaya Y. Sunflower. In: Gupta S.K., editor. Breeding Oilseed Crops for Sustainable Production. Academic Press; San Diego, CA, USA: 2016. pp. 55–88.

Kirkham M.B. Principles of Soil and Plant Water Relations. 2nd ed. Academic Press; Boston, MA, USA: 2014. Leaf Anatomy and Leaf Elasticity; pp. 409–430.

LaRue C., Castillo-Michel H., Sobanska S., Trcera N., Sorieul S., Cécillon L., Ouerdane L., Legros S., Sarret G. Fate of pristine TiO2 nanoparticles and aged paint-containing TiO2 nanoparticles in lettuce crop after foliar exposure. J. Hazard. Mater. 2014;273:17–26. doi: 10.1016/j.jhazmat.2014.03.014. PubMed DOI

LaRue C., Veronesi G., Flank A.-M., Surblé S., Herlin N., Carrière M. Comparative Uptake and Impact of TiO2 Nanoparticles in Wheat and Rapeseed. J. Toxicol. Environ. Health Part A. 2012;75:722–734. doi: 10.1080/15287394.2012.689800. PubMed DOI

Torabian S., Zahedi M., Khoshgoftar A.H. Effects of Foliar Spray of Two Kinds of Zinc Oxide on the Growth and Ion Concentration of Sunflower Cultivars under Salt Stress. J. Plant Nutr. 2015;39:172–180. doi: 10.1080/01904167.2015.1009107. DOI

Kötschau A., Büchel G., Einax J., Fischer C., Von Tümpling W., Merten D. Mapping of macro and micro elements in the leaves of sunflower (Helianthus annuus) by Laser Ablation–ICP–MS. Microchem. J. 2013;110:783–789. doi: 10.1016/j.microc.2012.12.011. DOI

Pal D. Sunflower (Helianthus annuus L.) seeds in health and nutrition. In: Preedy V.R., Watson R.R., Patel V.B., editors. Nuts and Seeds in Health and Disease Prevention. Academic Press; San Diego, CA, USA: 2011. pp. 1097–1105.

Muhlbauer W., Muller J. Drying Atlas: Drying Kinetics and Quality of Agricultural Products. Woodhead Publishing; Cambridge, UK: 2020.

Adesodun J.K., Atayese M.O., Agbaje T.A., Osadiaye B.A., Mafe O.F., Soretire A.A. Phytoremediation Potentials of Sunflowers (Tithonia diversifolia and Helianthus annuus) for Metals in Soils Contaminated with Zinc and Lead Nitrates. Water Air Soil Pollut. 2009;207:195–201. doi: 10.1007/s11270-009-0128-3. DOI

Maj G., Krzaczek P., Stamirowska-Krzaczek E., Lipińska H., Kornas R. Assessment of energy and physicochemical biomass properties of selected forecrop plant species. Renew. Energy. 2019;143:520–529. doi: 10.1016/j.renene.2019.04.166. DOI

Osman N.S., Sapawe N., Sapuan M.A., Fozi M.F.M., Azman M.H.I.F., Fazry A.H.Z., Zainudin M.Z.H., Hanafi M.F. Sunflower shell waste as an alternative animal feed. Mater. Today Proc. 2018;5:21905–21910. doi: 10.1016/j.matpr.2018.07.049. DOI

Brazil O.A.V., Vilanova-Neta J.L., Silva N.O., Vieira I.M.M., Lima Á.S., Ruzene D.S., Da Silva D.P., Figueiredo R.T. Integral use of lignocellulosic residues from different sunflower accessions: Analysis of the production potential for biofuels. J. Clean. Prod. 2019;221:430–438. doi: 10.1016/j.jclepro.2019.02.274. DOI

Shahhoseini R., Azizi M., Asili J., Moshtaghi N., Samiei L. Effects of zinc oxide nanoelicitors on yield, secondary metabolites, zinc and iron absorption of Feverfew (Tanacetum parthenium (L.) Schultz Bip.) Acta Physiol. Plant. 2020;42:1–18. doi: 10.1007/s11738-020-03043-x. DOI

Hussain A., Ali S., Rizwan M., Rehman M.Z.U., Javed M.R., Imran M., Chatha S.A.S., Nazir R. Zinc oxide nanoparticles alter the wheat physiological response and reduce the cadmium uptake by plants. Environ. Pollut. 2018;242:1518–1526. doi: 10.1016/j.envpol.2018.08.036. PubMed DOI

Velasco E.A.P., Galindo R.B., Valdez-Aguilar L.A., González-Fuentes J.A., Urbina B.A.P., Lozano-Morales S.A., Sanchez-Valdes S. Effects of the Morphology, Surface Modification and Application Methods of ZnO-NPs on the Growth and Biomass of Tomato Plants. Molecules. 2020;25:1282. doi: 10.3390/molecules25061282. PubMed DOI PMC

Sturikova H., Krystofova O., Huska D., Adam V. Zinc, zinc nanoparticles and plants. J. Hazard. Mater. 2018;349:101–110. doi: 10.1016/j.jhazmat.2018.01.040. PubMed DOI

Sabir S., Arshad M., Chaudhari S.K. Zinc Oxide Nanoparticles for Revolutionizing Agriculture: Synthesis and Applications. Sci. World J. 2014;2014:1–8. doi: 10.1155/2014/925494. PubMed DOI PMC

Kołodziejczak-Radzimska A., Jesionowski T. Zinc Oxide—From Synthesis to Application: A Review. Materials. 2014;7:2833–2881. doi: 10.3390/ma7042833. PubMed DOI PMC

Rehman S., Ullah R., Butt A., Gohar N. Strategies of making TiO2 and ZnO visible light active. J. Hazard. Mater. 2009;170:560–569. doi: 10.1016/j.jhazmat.2009.05.064. PubMed DOI

Kolenčík M., Ernst D., Komár M., Urík M., Šebesta M., Dobročka E., Černý I., Illa R., Kanike R., Qian Y., et al. Effect of Foliar Spray Application of Zinc Oxide Nanoparticles on Quantitative, Nutritional, and Physiological Parameters of Foxtail Millet (Setaria italica L.) under Field Conditions. Nanomaterials. 2019;9:1559. doi: 10.3390/nano9111559. PubMed DOI PMC

Lyu S., Wei X., Chen J., Wang C., Wang X., Pan D. Titanium as a Beneficial Element for Crop Production. Front. Plant Sci. 2017;8:597. doi: 10.3389/fpls.2017.00597. PubMed DOI PMC

Khater M.S. Effect of titanium nanoparticles (TiO2) on growth, yield and chemical constituents of coriander plants. Arab. J. Nucl. Sci. Appl. 2015;48:187–194.

Hong F., Zhou J., Liu C., Yang F., Wu C., Zheng L., Yang P. Effect of Nano-TiO2 on Photochemical Reaction of Chloroplasts of Spinach. Biol. Trace Element Res. 2005;105:269–280. doi: 10.1385/BTER:105:1-3:269. PubMed DOI

Hong F., Yang F., Liu C., Gao Q., Wan Z., Gu F., Wu C., Ma Z., Zhou J., Yang P. Influences of Nano-TiO2 on the Chloroplast Aging of Spinach Under Light. Biol. Trace Element Res. 2005;104:249–260. doi: 10.1385/BTER:104:3:249. PubMed DOI

Lei Z., Mingyu S., Chao L., Liang C., Hao H., Xiao W., Xiaoqing L., Fan Y., Fengqing G., Fashui H. Effects of Nanoanatase TiO2 on Photosynthesis of Spinach Chloroplasts Under Different Light Illumination. Biol. Trace Element Res. 2007;119:68–76. doi: 10.1007/s12011-007-0047-3. PubMed DOI

Wang Y., Sun C., Zhao X., Cui B., Zeng Z., Wang A., Liu G., Cui H. The Application of Nano-TiO2 Photo Semiconductors in Agriculture. Nanoscale Res. Lett. 2016;11:529. doi: 10.1186/s11671-016-1721-1. PubMed DOI PMC

Weng W., Ma M., Du P., Zhao G., Shen G., Wang J., Han G. Superhydrophilic Fe doped titanium dioxide thin films prepared by a spray pyrolysis deposition. Surf. Coatings Technol. 2005;198:340–344. doi: 10.1016/j.surfcoat.2004.10.071. DOI

Cox A., Venkatachalam P., Sahi S., Sharma N.C. Silver and titanium dioxide nanoparticle toxicity in plants: A review of current research. Plant Physiol. Biochem. 2016;107:147–163. doi: 10.1016/j.plaphy.2016.05.022. PubMed DOI

Moaveni P., Talebi A., Farahani A., Maroufi K. In Study of nano particles TiO2 spraying on some yield components in barley (Hordem vulgare L.); Proceedings of the International Conference on Environmental and Agriculture Engineering; Chengdu, Sichuan, China. 29–31 July 2011; Singapore: IACSIT Press; 2011. pp. 115–119.

Kořenková L., Šebesta M., Urík M., Kolenčík M., Kratošová G., Bujdoš M., Vávra I., Dobročka E. Physiological response of culture media-grown barley (Hordeum vulgare L.) to titanium oxide nanoparticles. Acta Agric. Scand. Sect. B Plant Soil Sci. 2017;67:1–7. doi: 10.1080/09064710.2016.1267255. DOI

Singh J., Kumar S., Alok A., Upadhyay S.K., Rawat M., Tsang D.C.W., Bolan N., Song H. The potential of green synthesized zinc oxide nanoparticles as nutrient source for plant growth. J. Clean. Prod. 2019;214:1061–1070. doi: 10.1016/j.jclepro.2019.01.018. DOI

Skala O. Complex Technology for Oil Crops Cultivation. Česká Zemědělská Univerzita; Praha, Czech Republic: 2016.

Harčár J., Priechodská Z., Karolus K., Karolusová E., Remšík K., Šucha P. Vysvetlivky ku Geologickej Mape Severovýchodnej Časti Podunajskej Nižiny. Geologický ústav Diolíza Štúra; Bratislava, Slovakia: 1988.

Šimanský V., Kováčik P. Long-term effects of tillage and fertilization on pH and sorption parameters of haplic Luvisol. J. Elem. 2015;20:1033–1040. doi: 10.5601/jelem.2015.20.1.857. DOI

Banerjee A.V., Duflo E.M. Handbook of Field Experiments. Vol. 1. Elsevier; Amsterdam, The Netherlands: 2017. pp. 1–24.

Hrivňáková K., Makovníková J., Barančíková G., Bezák P., Bezáková Z., Dodok R., Grečo V., Chlpík J., Kobza J., Lištjak M., et al. The Uniform Methods of Soil Analysis. VÚPOP Bratislava; Ružinov, Slovakia: 2011. p. 136.

Wierzbowska J., Kovačik P., Sienkiewicz S., Krzebietke S., Bowszys T. Determination of heavy metals and their availability to plants in soil fertilized with different waste substances. Environ. Monit. Assess. 2018;190:567. doi: 10.1007/s10661-018-6941-7. PubMed DOI PMC

Kováčik P., Macák M., Ducsay L., Halčínová M., Jančich M. Effect of ash-fly ash mixture application on soil fertility. J. Elem. 2011;16:215–225. doi: 10.5601/jelem.2011.16.2.05. DOI

Šimanský V., Jonczak J., Kováčik P., Bajčan D. Impact of crop residues and biopreparations on nitrogen changes in Haplic Luvisol—Model experiment. Soil Sci. Annu. 2018;69:251–258. doi: 10.2478/ssa-2018-0026. DOI

Alberio C., Izquierdo N., Aguirrezábal L. Sunflower Crop Physiology and Agronomy. In: Martínez-Force E., Dunford N.T., Salas J.J., editors. Sunflower. AOCS Press; Champaign, IL, USA: 2015. pp. 53–91.

Koutroubas S.D., Vassiliou G., Damalas C.A. Sunflower morphology and yield as affected by foliar applications of plant growth regulators. Int. J. Plant Prod. 2014;8:215–230.

Ernst D., Kovar M., Černý I. Effect of two different plant growth regulators on production traits of sunflower. J. Central Eur. Agric. 2016;17:998–1012. doi: 10.5513/JCEA01/17.4.1804. DOI

Meier U. Growth Stages of Mono-And Dicotyledonous Plants. Blackwell Wissenschafts-Verlag; Kurfürstendamm, Berlin, Germany: 1997.

Aschenbrenner A.-K., Horakh S., Spring O. Linear glandular trichomes of Helianthus (Asteraceae): Morphology, localization, metabolite activity and occurrence. AoB PLANTS. 2013;5:plt028. doi: 10.1093/aobpla/plt028. DOI

StatSoft Inc. STATISTICA (Data Analysis Software System), Version 10. [(accessed on 20 May 2020)]; Available online: www.statsoft.com.

Shahidi F. Current Protocols in Food Analytical Chemistry. Volume 7. John Wiley & Sons, Inc.; New Jersey, NJ, USA: 2003. Extraction and measurement of total lipids; pp. D1.1.1–D1.1.11.

Gamon J.A., Penuelas J., Field C. A narrow-waveband spectral index that tracks diurnal changes in photosynthetic efficiency. Remote. Sens. Environ. 1992;41:35–44. doi: 10.1016/0034-4257(92)90059-S. DOI

Jones H.G., Serraj R., Loveys B.R., Xiong L., Wheaton A., Price A.H. Thermal infrared imaging of crop canopies for the remote diagnosis and quantification of plant responses to water stress in the field. Funct. Plant Biol. 2009;36:978. doi: 10.1071/FP09123. PubMed DOI

Nair R., Varghese S.H., Nair B.G., Maekawa T., Yoshida Y., Kumar D.S. Nanoparticulate material delivery to plants. Encycl. Appl. Plant Sci. 2010;179:154–163. doi: 10.1016/j.plantsci.2010.04.012. DOI

Wang W.-N., Tarafdar J.C., Biswas P. Nanoparticle synthesis and delivery by an aerosol route for watermelon plant foliar uptake. J. Nanoparticle Res. 2013;15:1. doi: 10.1007/s11051-013-1417-8. DOI

Eichert T., Kurtz A., Steiner U., Goldbach H.E. Size exclusion limits and lateral heterogeneity of the stomatal foliar uptake pathway for aqueous solutes and water-suspended nanoparticles. Physiol. Plant. 2008;134:151–160. doi: 10.1111/j.1399-3054.2008.01135.x. PubMed DOI

Ditta A., Arshad M. Applications and perspectives of using nanomaterials for sustainable plant nutrition. Nanotechnol. Rev. 2016;5:209. doi: 10.1515/ntrev-2015-0060. DOI

Monreal C.M., DeRosa M., Mallubhotla S.C., Bindraban P.S., Dimkpa C. Nanotechnologies for increasing the crop use efficiency of fertilizer-micronutrients. Biol. Fertil. Soils. 2015;52:423–437. doi: 10.1007/s00374-015-1073-5. DOI

Priyanka N., Geetha N., Ghorbanpour M., Venkatachalam P. Chapter 6—Role of Engineered Zinc and Copper Oxide Nanoparticles in Promoting Plant Growth and Yield: Present Status and Future Prospects. In: Ghorbanpour M., Wani S.H., editors. Advances in Phytonanotechnology. Academic Press; Cambridge, MA, USA: 2019. pp. 183–201.

Chaudhuri S.K., Malodia L. Biosynthesis of zinc oxide nanoparticles using leaf extract of Calotropis gigantea: Characterization and its evaluation on tree seedling growth in nursery stage. Appl. Nanosci. 2017;7:501–512. doi: 10.1007/s13204-017-0586-7. DOI

Tarafdar J.C., Raliya R., Mahawar H., Rathore I. Development of Zinc Nanofertilizer to Enhance Crop Production in Pearl Millet (Pennisetum americanum) Agric. Res. 2014;3:257–262. doi: 10.1007/s40003-014-0113-y. DOI

Jabeen N., Maqbool Q., Bibi T., Nazar M., Hussain S.Z., Hussain T., Jan T., Ishaq A., Maaza M., Anwaar S. Optimised synthesis of ZnO-nano-fertiliser through green chemistry: Boosted growth dynamics of economically important L. esculentum. IET Nanobiotechnology. 2018;12:405–411. doi: 10.1049/iet-nbt.2017.0094. PubMed DOI PMC

Lu C., Zhang C., Wen J., Wu G., Tao M. Research of the effect of nanometer materials on germination and growth enhancement of Glycine max and its mechanism. Soybean Sci. 2002;21:168–171.

Gao F., Hong F., Liu C., Zheng L., Su M., Wu X., Yang F., Wu C., Yang P. Mechanism of Nano-anatase TiO2 on Promoting Photosynthetic Carbon Reaction of Spinach: Inducing Complex of Rubisco-Rubisco Activase. Biol. Trace Element Res. 2006;111:239–254. doi: 10.1385/BTER:111:1:239. PubMed DOI

Drissi S., Houssa A.A., Bamouh A., Benbella M. Corn Silage (Zea mays L.) Response to Zinc Foliar Spray Concentration When Grown on Sandy Soil. J. Agric. Sci. 2015;7:68. doi: 10.5539/jas.v7n2p68. DOI

USDA . Standards for Sunflower Seeds, U.S. Standards for Grain Subpart K. USDA; Washington, DC, USA: 1996.

FAO (Food and Agriculture Organization of the United Nations) Sunflower. [(accessed on 25 May 2020)]; Available online: http://www.fao.org/land-water/databases-and-software/crop-information/sunflower/en/

Bulgari R., Cocetta G., Trivellini A., Vernieri P., Ferrante A. Biostimulants and crop responses: A review. Biol. Agric. Hortic. 2014;31:1–17. doi: 10.1080/01448765.2014.964649. DOI

Kalia A., Sharma S.P., Kaur H., Kaur H. Multifunctional Hybrid Nanomaterials for Sustainable Agri-Food and Ecosystems. Elsevier; Amsterdam, The Netherlands: 2020. Novel nanocomposite-based controlled-release fertilizer and pesticide formulations: Prospects and challenges; pp. 99–134.

Ali F., Bano A., Fazal A. Recent methods of drought stress tolerance in plants. Plant Growth Regul. 2017;82:363–375. doi: 10.1007/s10725-017-0267-2. DOI

Kuang T. Mechanism and Regulation of Primary Energy Conversion Process in Photosynthesis. Science and Technology Press; Nanjing, Jiangsu, China: 2003. pp. 22–68.

Tucker C.M., Cadotte M.W., Carvalho S.B., Davies T.J., Ferrier S., Fritz S.A., Grenyer R., Helmus M.R., Jin L.S., Mooers A.O., et al. A guide to phylogenetic metrics for conservation, community ecology and macroecology. Biol. Rev. 2016;92:698–715. doi: 10.1111/brv.12252. PubMed DOI PMC

Ali A.M., Darvishzadeh R., Skidmore A.K., Van Duren I. Specific leaf area estimation from leaf and canopy reflectance through optimization and validation of vegetation indices. Agric. For. Meteorol. 2017;236:162–174. doi: 10.1016/j.agrformet.2017.01.015. DOI

Gamon J.A., Serrano L., Surfus J.S. The photochemical reflectance index: An optical indicator of photosynthetic radiation use efficiency across species, functional types, and nutrient levels. Oecologia. 1997;112:492–501. doi: 10.1007/s004420050337. PubMed DOI

Hafeez B., Khanif Y.M., Saleem M. Role of Zinc in Plant Nutrition—A Review. Am. J. Exp. Agric. 2013;3:374–391. doi: 10.9734/AJEA/2013/2746. DOI

Kabata-Pendias A. Trace Elements in Soils and Plants. CRC Press, Inc.; Boca Raton, FL, USA: 2010.

Mirzapour M.H., Khoshgoftar A.H. Zinc Application Effects on Yield and Seed Oil Content of Sunflower Grown on a Saline Calcareous Soil. J. Plant Nutr. 2006;29:1719–1727. doi: 10.1080/01904160600897430. DOI

Rizwan M., Ali S., Ali B., Adrees M., Arshad M., Hussain A., Rehman M.Z.U., Waris A.A. Zinc and iron oxide nanoparticles improved the plant growth and reduced the oxidative stress and cadmium concentration in wheat. Chemosphere. 2018;214:269–277. doi: 10.1016/j.chemosphere.2018.09.120. PubMed DOI

Rizwan M., Ali S., Rehman M.Z.U., Adrees M., Arshad M., Qayyum M.F., Ali L., Hussain A., Chatha S.A.S., Imran M. Alleviation of cadmium accumulation in maize (Zea mays L.) by foliar spray of zinc oxide nanoparticles and biochar to contaminated soil. Environ. Pollut. 2019;248:358–367. doi: 10.1016/j.envpol.2019.02.031. PubMed DOI

Bellesi F.J., Arata A.F., Martínez M., Arrigoni A.C., Stenglein S.A., Dinolfo M.I. Degradation of gluten proteins by Fusarium species and their impact on the grain quality of bread wheat. J. Stored Prod. Res. 2019;83:1–8. doi: 10.1016/j.jspr.2019.05.007. DOI

Kirnak H., Irik H., Unlukara A. Potential use of crop water stress index (CWSI) in irrigation scheduling of drip-irrigated seed pumpkin plants with different irrigation levels. Sci. Hortic. 2019;256:108608. doi: 10.1016/j.scienta.2019.108608. DOI

Candogan B.N., Sincik M., Buyukcangaz H., Demirtas C., Goksoy A.T., Yazgan S. Yield, quality and crop water stress index relationships for deficit-irrigated soybean [Glycine max (L.) Merr.] in sub-humid climatic conditions. Agric. Water Manag. 2013;118:113–121. doi: 10.1016/j.agwat.2012.11.021. DOI

Ahmad B., Shabbir A., Jaleel H., Khan M.M.A., Sadiq Y. Efficacy of titanium dioxide nanoparticles in modulating photosynthesis, peltate glandular trichomes and essential oil production and quality in Mentha piperita L. Curr. Plant Biol. 2018;13:6–15. doi: 10.1016/j.cpb.2018.04.002. DOI

Shabbir A., Khan M., Ahmad B., Sadiq Y., Jaleel H., Uddin M. Efficacy of TiO2 nanoparticles in enhancing the photosynthesis, essential oil and khusimol biosynthesis in Vetiveria zizanioides L. Nash. Photosynthetica. 2019;57:599–606. doi: 10.32615/ps.2019.071. DOI

Enhancing Maize Yield and Quality with Metal-Based Nanoparticles without Translocation Risks: A Brief Field Study

Agronomic Investigation of Spray Dispersion of Metal-Based Nanoparticles on Sunflowers in Real-World Environments

Mycosynthesis of Metal-Containing Nanoparticles-Fungal Metal Resistance and Mechanisms of Synthesis

Interaction of the Nanoparticles and Plants in Selective Growth Stages-Usual Effects and Resulting Impact on Usage Perspectives

Effects of Foliar Application of ZnO Nanoparticles on Lentil Production, Stress Level and Nutritional Seed Quality under Field Conditions