Efficacy of Zn, Fe and Mg Nano Scale and Bulk Plant Nutrient Foliar Sprays in Biochemical Changes of Blackgram Genotypes under YMV Tolerance

Evidence-based synergistic effects of Nanoscale materials, which size typically falls below 100 nm, exhibit novel chemical, physical and biological properties which are different from their bulk counterparts. Here, we report for the first time comparision of nanoscale zinc oxide (n-ZnO), magnesium oxide (n-MgO), and iron oxide (n-FeO) with their respective bulk concentrations on biochemical variability of blackgram genotypes under yellow mosaic virus condition. Oxides of nano scale Zn, Mg and Fe materials were prepared by using a modified sol-gel method. Characterization was performed by using X- ray diffraction (XRD), Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM) Analysis and High- Resolution Transmission Electron Microscopy (HRTEM). Average sizes of ZnO, MgO and FeO (78.8, 60.8 and 12.4 nm respectively) and potentials (-36.7,-33.0 and -18.0 mV respectively). A field study was conducted during summer 2018 in split-plot design with two blackgram genotypes as main treatments (TBG-104 and LBG-623) and nine sub treatments (Control, ZnSO4 @ 0.2 %, n-ZnO @ 200ppm, MgSO4 @ 0.2 %, n- MgO @ 100ppm, FeSO4 @ 0.2%, n- FeO @ 200ppm, ZnSO4 @ 0.2 % + MgSO4 @ 0.2 % + FeSO4 @ 0.2 %, n-ZnO @ 200ppm + n- MgO @ 100ppm + n- FeO @ 200ppm) as foliar sprays with three replications. YMV infection was observed at 25 DAS. The foliar treatmental sprays were imposed at 30 and 50 DAS.

Results of the field study revealed that combined application of nanoscale treatmental spray ZnO @ 200 ppm + MgO @ 100 ppm + FeO @ 200 ppm resulted higher YMV tolerance interms of high chlorophyll content, total phenols, total proteins and lower total soluble sugars, followed by combined bulk treatmental spray ZnSO4 @ 0.2% + MgSO4 @ 0.2% + FeSO4 @ 0.2% and nano scale Magnesium Oxide @ 100 ppm. Here we concluded that either of these three foliar sprays can be recommended to blackgram crop prone to YMV condition to sustain plant growth and final yields. But, there should be study on the impact of different shape, size of nano particles on plant system and the promotery effects of nano scale Oxides of Zn, Mg and Fe particles at cellular level and transport mechanism in plant system needs to be understood.