Effect of Botanical Extracts and Essential Oils on Alternaria brassicae (Berk.) Sacc. of Mustard (Brassica juncea L.)

Mustard is an important oilseed crop in India. Alternaria leaf blight caused by Alternaria brassicae is an economically important disease of oilseed brassicas as it reduces the quality and quantity of the seeds. Botanical extracts and essential oils were tested on Alternaria brassicae at different concentrations to evaluate the effect in vitro by poison food technique in Completely Randomized Design (CRD). The study was done at the Department of Plant Pathology laboratory, Sam Higginbottom University of Agriculture, Technology and Sciences during 2021-2022. The results revealed that all the botanical extracts and essential oils tested significantly inhibited the mycelial growth of Alternaria brassicae. Among the botanical extracts, the highest mycelial growth inhibition was found in garlic bulb extract @ 15% (93.11%), followed by garlic bulb extract @ 10% (87.33%). Among essential oils the maximum mycelial growth inhibition per cent was observed in eucalyptus oil @ 3% (95.77%), followed by eucalyptus oil @ 2% (88.22%). The higher concentration of all the botanical extracts and essential oils shows significantly higher per cent mycelial growth inhibition as compared to their lower levels.