IN VITRO ANTIFUNGAL ACTIVITIES OF MANCOZEB/PHYTOSYNTHESIZED ZINC OXIDE NANOPARTICLES AGAINST PATHOGENS ISOLATED FROM DISEASED CASSAVA PLANTS (Manihot esculenta Crantz)

ABSTRACT

Nanoparticles are substances ranging from 1 – 100 nm in size and they have improved property such as increased surface area to volume ratio. In this study, in vitro antifungal activities of mancozeb/phytosynthesized zinc oxide nanoparticles against pathogens isolated from diseased cassava plants (Manihot esculenta crantz) were determined. Synthesis of zinc oxide nanoparticles was carried out using Moringa leaf extract and characterization of the biosynthesized nanoparticles was done using UV-Vis spectrophotometer. Different combinations of zinc oxide nanoparticles and mancozeb were prepared corresponding to 25/75, 50/50 and 75/25. Fungal pathogens were isolated from diseased cassava using direct plating method. Antifungal testing using the test nanoparticles/mancozeb combinations was carried using the food poisoning method. The isolated fungal pathogens in this study were identified as Eurotium sp and Aspergillus sp. The results obtained from this study indicate that zinc oxide nanoparticles/mancozeb combinations significantly inhibited the growth of the test pathogens with varying rates of inhibition. One hundred percent (100 %) inhibition of Eurotium sp was obtained by 25/75, 75/25 and 100 % nanoparticles treatments. One hundred percent (100 %) nanoparticles treatment gave the highest inhibition (73.30) against Aspergillus sp. Future direction to this study is to investigate how ZnO nanoparticles/mancozeb combinations could be used for crop protection against phytopathogens. The mode of action of the test nanoparticles should be further investigated.