Evaluation of the methanol extracts of Monsonia burkeana against Alternaria solani growth, leaf blight severity and tomato yield

Abstract

Abstract Alternaria leaf blight, caused by Alternaria solani, is one of the major foliar diseases of tomato. Synthetic fungicides remain an integral component of managing Alternaria leaf blight to reduce yield losses. However, their negative side effects on the environment, human health and increased pathogen resistance call for the exploration of alternative control measures that are environmentally safe. The current study was established to evaluate the effectiveness of Monsonia burkeana methanolic extract against A. solani growth under laboratory conditions, Alternaria leaf blight and its ability to increase tomato yield. The antifungal activities of Monsonia burkeana methanolic extract were tested under laboratory conditions through food poisoning assay at concentrations 1, 2, 3, 4, and 5g/100ml. The study was arranged in a Completely Randomized Design (CRD) replicated four times. Monsonia burkeana methanolic extract significantly (P ≤ 0.05) inhibited the mycelium growth of A. solani and a significant reduction was recorded at 5 g 100 ml− 1 (32.25%). Greenhouse and micro-plot experiments were established where treatments were: 5g/100ml M. burkeana extract, inoculate non-treated control and non-inoculated, non-treated control. Plants were arranged in a Randomized Complete Block Design (RCBD) and each treatments replicated four times. Disease severity was measured using a scale of 0–5 after 21 days. Monsonia burkearna methanolic extract significantly reduced Alternaria leaf blight severity of 10% and less under both greenhouse and micro-plot respectively when compared to inoculated non-treated control. Treated tomato plants had a significantly higher chlorophyll content and Normalized Difference Vegetative Index.