I think Fe and Zn nanofertilizer would be most effective ones. You may try with the concentration of 10ppm nano-Zn or 30ppm of nano-Fe with the average particle size is less than 20nm, I hope, you will get the results. Best of luck.

If you want to prepare own nanofertilizers then go for biosynthesis which are environment friendly and naturally encapsulated by mother protein thats why relatively stable. To biosynthesis of Zn you may take the salts of either ZnO or ZnSO4 or ZnNO3 and for Fe, you may take either Fe2O3 or FeCl3. The best organism for biosynthesis of Zn is Aspergillus oryzae TFR9 and for Fe Aspergillus fumigatus TFR 22 .

Thank you so much dear Dr. Tarafdar.

I wish best for you