Mulberry plants (Morus sp.) are one of the non-timber forest products that are used as feedfor silkworms, foodstuffs, or medicines. Plants that are attacked by disease can certainly harmvarious aspects, one of which can reduce the quality and quantity of plants. Vegetable pesticidescan be a solution to prevent the spread of the disease. This study aims to determine the symptomsof diseases that appear in mulberry plants and their spread in mahogany and find out theinhibitory power and concentration of essential oils that work optimally. Observations weremade using eucalyptus essential oil, turmeric essential oil, and a combination of both withconcentrations of 1%, 3%, and 5% on PDA media and GDP media. Based on observations, thetype of fungus found is Rhizoctonia sp.. The results of the observations showed that the optimalessential oil as an inhibitor of pathogenic growth is turmeric essential oil with a concentration of3% and a combined essential oil concentration of 5%. The results of the inoculation showed thatthere was fungal growth activity on mahogany seedlings so that the fungus could attack otherplants such as forestry plants.