The Effectiveness of The Inhibition of Local Bacterial Isolate From The Rhizosphere of Oil Palm Plant on Leaf Spot Disease in Purple Eggplant (Solanum melongena L.)

Abstract

Longterm use of pesticides can cause side effects on the environment and human health. PGPR is an environmentally friendly solution for biological control of leaf spot disease. This research aims to obtain bacterial isolates from the rhizosphere of oil palm plants which have the potential as biological agents to control fungal leaf spot diseases in eggplant plants. The research was carried out using 10 treatments, namely giving 9 samples of different bacterial isolates and 1 control and repeated 2 times, bringing the total to 20 plant samples. The results showed that there were 4 bacterial isolates from the rhizosphere of oil palm plants that had great potential to inhibit the growth of leaf spot fungi, namely isolate R5 (99.35%), isolate R2 (98.1%), isolate R6 (94.69%) and isolate R10 (94.29%). The bacterial isolates that were able to reduce the percentage of disease attacks compared to the first week of observation to the fourth week were isolates R4, R2 and R10, with a reduction in the percentage of disease attacks respectively of 15.15%, 7.14% and 1.98%. Based on the data, it can be seen that the R2 bacterial isolate is an isolate that has the potential to inhibit fungal isolates and reduce the percentage of leaf spot disease attacks on eggplant plants.