@phdthesis{digilib78911, month = {August}, title = {POTENSI BAKTERI KULIT KATAK Sumaterana crassiovis SEBAGAI BIOKONTROL FUNGI Phytophthora capsici PENYEBAB PENYAKIT BUSUK BATANG PADA TANAMAN CABAI RAWIT (Capsicum frutescens L.)}, school = {UIN SUNAN KALIJAGA YOGYAKARTA}, author = {NIM.: 22106040030 Tiara Novantika Fitri Nabila}, year = {2026}, note = {Lela Susilawati, Ph.D.}, keywords = {stem rot; Biocontrol; P. capsici; S. crassiovis; Indigenous bacteria}, url = {https://digilib.uin-suka.ac.id/id/eprint/78911/}, abstract = {Phytophthora capsici is a pathogen that causes stem rot in cayenne pepper plants; it is difficult to control and leads to a decline in both the quality and quantity of cayenne pepper production. The use of biocontrol agents can serve as an environmentally friendly alternative, one of which is a frog skin bacterium capable of producing antifungal compounds. This study aimed to evaluate the efficacy of the frog-skin bacteria ScD9 and ScV9, isolated from the frog S. crassiovis, both in vitro and in planta. A P. capsici isolate of the PhC strain was successfully isolated from the stems of ORI 212 chili pepper plants affected by stem rot. Based on the results of the antagonistic test using the dual-culture method, the ScV9 bacterial isolate showed a higher inhibition rate of 35.09\% compared to ScD9 (34.654\%). The highest mycelial inhibition was observed for ScD9 and ScV9 at a density of 1{$\times$}10{$^6$} CFU/mL, with average colony radii of 34.248 mm and 32.841 mm, respectively lower than that of the PhC control (39.717 mm). In the hyphal and sporangial abnormality test, various morphological changes were observed, including hyphal lysis, swelling, stunting, and sporangial lysis. In-plant tests on four-week-old cayenne peppers showed that the application of ScD9 and ScV9 bacteria at a density of 1{$\times$}10{$^6$} CFU/mL was able to reduce disease severity to 6.67\% and 0.00\%, respectively, compared to the control, which reached 80\%.} }