The potential use of Titanium, Silver and Selenium nanoparticles in controlling leaf blight of tomato caused by Alternaria alternata

Leaf spot and blight symptoms caused by Alternaria alternata have been widely occurred on tomatoes and potatoes in Egypt. In attempts to improve the sustainability of crop protection, the use of nanotechnology in producing nano-fungicides as an eco-friendly convenient approach was needed to control such diseases. Titanium dioxide nanoparticles (TiO2NPs) and Silver nanoparticles (AgNPs) were biosynthesized by Aspergillus versicolor KY509550 through surface resonance peaks at 340 and 400 nm, respectively. The preparation of Selenium nanoparticles (SeNPs) was done using glucose solution method at 387 nm. The sizes of the prepared nanoparticles were 47.15, 36 and 78 nm for TiO2NPs, AgNPs and SeNPs, respectively. It was detected from Transmission Electron Microscope (TEM) analysis that TiO2NPs and AgNPs were well dispersed in the solution without any agglomeration compared with SeNPs. The antifungal activity of TiO2NPs, AgNPs and SeNPs at three concentrations viz.50, 75 and 100 ppm were estimated against A. alternata by laboratory trials. The biosynthesized TiO2NPs exhibited the highest inhibitory effect at100 ppm against A. alternata and in turn resulted in 90% decrease of its mycelial growth in vitro trials. The greenhouse and field trials explored also that TiO2NPs was significantly effective in reducing disease severity (DS) as shown by the calculated area under disease progressive curve (AUDPC). SeNPs revealed close results to that obtained by TiO2NPs for both trials. AgNPs showed a moderate effect at the tested concentrations in all trials. Nanoparticles could be powerful and eco-friendly nano-fungicides for biological control of tomato leaf blight.