Abstract:
This research was conducted in October 2019 until December 2019, at the Sungei Putih rubber Research Institute, Galang, Deli Serdang. The study was conducted in several stages, namely exploration of rhizosphere bacteria from rubber roots, rhizosphere bacterial antagonist test with pathogenic fungus Pestalotiopsis sp, and hypersensitivity test of rhizosphere bacteria on tobacco leaves. The design used is a non factorial Complete Randomized Design (RAL) consisting of B0 = Control / No Treatment, B1 = Use of isolate rhizosphere bacteria 01, B2 = Use of isolate rhizosphere bacteria 02, B3 = Use of isolate rhizosphere bacteria 03, B4 = Use of rhizosphere bacteria isolate 04, B5 = Use of rhizosphere bacteria isolate p 06 in this study consisted of 7 treatments with 3 replications of the linear model of the design.
Exploration results obtained by 6 isolates of Rhizosfer bacteria and had a very significant effect in inhibiting the growth of the fungus Pestalotiopsis sp with a percentage of inhibition of 5.71 - 6.839. There are abnormalities of Pestalotiopsis sp hyphae in the form of hyphae lysis, broken, bent, stunted, thinned, and curly. Hypersensitivity reaction found 2 isolates arising spots (necrotic ), and 4 isolates not arising spots (necrotic -).
