Assessment of Biological and Chemical Exogenous Elicitors in Inducing Plant Systemic Resistance Against Southern Corn Leaf Blight Disease (Bipolaris maydis) and Its Role in Enhancing Corn Growth and Yield

Abstract

One of the alternative control efforts for Southern corn leaf blight (SCLB) disease is using biological agents and certain chemicals as elicitors to induce systemic resistance through increasing secondary metabolites. This study aims to evaluate several types of biological and chemical exogenous elicitors in inducing plant systemic resistance to SCLB disease caused by Bipolaris maydis and their effect on corn growth and yield. Testing was carried out under field conditions with planting spreader rows as inoculum source plants which were planted around the experimental block. This experiment was set up in a randomized block design consisting of eight elicitor treatments, one synthetic fungicide as a control (-), and sterile distilled water as control (+). AUDPC analysis based on disease severity showed that B. cereus strain J6, Chitin, and Chitosan could significantly suppress the SCLB disease progression in the field with the lowest AUDPC values, namely 1230, 1255, and 1255, respectively, and the highest protection index values of 30.31, 28.90, and 30.88%, respectively. Suppression of the SCLB disease progression was related to increasing plant resistance levels through increasing protein and phenolic content. Correlation analysis showed that B. cereus strain J6, Chitin, and Chitosan had a very strong positive correlation with the protection index value. Besides inducing plant resistance, elicitor treatments significantly affected maximum growth potential and plant height variables. Elicitor materials play a beneficial role in protecting corn occurrence by activating the induced systemic resistance system and inducing plant growth.