Foliar selenium application for controlling fungal diseases in greenhouse

Potato is the third most important food crop consumed globally. However, potato yield and production are compromised by diseases including late blight, the most devastating potato disease. Despite the availability of effective fungicides for controlling late blight in conventional production systems, fungicide resistance has become common and not many options are available for organic production systems. Selenium as a mineral micronutrient is essential to human and animal health in trace amounts, is widely used for crop and livestock biofortification and its roles for protection against fungal infection and aphid feeding has been purported. In this study, the effect of selenium on late blight was assessed in potato and tomato plants and its mode of action determined in vitro. Our results showed that foliar selenium applications increase the production of secondary metabolites in potato leaves and tubers and reduce the late blight severity and incidence in potatoes and tomatoes. Selenium’s disease control effect was attributed to its direct toxicity to a wide range of pathogenic fungi at level as low as 2 ppm. The data will be presented and discussed in relation with the potential use of selenium as disease control agent in greenhouse horticultural crops while contributing to bio fortify crops.