Kanchanaburi province. Plant disease that often found in marigold is Alternaria leaf spot, in which it cause low production. Farmers have to was chemicals and consequently increase the production cost and has an effect on the environment.
Zine Oxide nano material has been using in agriculture interestingly. In this study, ZnO nano material was used in spray on marigold flower in order to inhibit the growth of Alternaria fungus on marigold leaf.