Exogenous Application of Plant Extracts and Salicylic Acid to Mitigate Cucumber Mosaic Virus and Aphid Population in Cucumber

Abstract

Twenty cucumber varieties were evaluated for resistance to Cucumber mosaic virus (CMV) under greenhouse and field conditions. CMV disease severity was recorded with a disease rating scale and CMV was detected with Enzyme Linked Immunosorbent Assay. The use of salicylic acid (SA) for disease management in the greenhouse and field was also evaluated. Systemic acquired resistance was observed by measuring total phenolics and protein content. The varietal screening results showed that only two lines, Beit-alpha and Durga, were resistant to CMV, with 10% and 13.33% disease severity, respectively. Exogenous application of SA significantly increased total phenolics and protein content compared to control under both greenhouse and field experiments. Higher concentrations of SA proved to be most effective at inhibiting virus replication and disease severity. CMV severity is correlated with the aphid population, and plant extracts and detergent offered an eco-friendly approach to reduce the aphid population and disease severity, with neem extract being the most effective. This study shows that exogenous application of SA and plant extracts are good strategies for reducing CMV severity.