PENGENDALIAN Sclerotium rolfsii Sacc. PENYEBAB PENYAKIT REBAH-SEMAI KACANG TANAH DENGAN PEMANFAATAN Streptomyces sp. SEBAGAI AGEN PENGENDALIAN HAYATI CONTROL OF Sclerotium rolfsii Sacc. CAUSE OF GROUNDNUT DAMPING-OFF BY UTILIZING Streptomyces sp. AS A BIOLOGICAL CONTROL AGENT

Abstract

ABSTRAK

Penelitian ini bertujuan untuk mengetahui kemampuan Streptomyces sp. dalam menghambat pertumbuhan dan perkembangan jamur Sclerotium rolfsii. Penelitian ini dilaksanakan di Laboratorim Mikrobiologi dan Rumah Kaca Fakultas Pertanian Universitas Mataram dengan metode eksperimental. Pada percobaanin-vitro, 5 isolat Streptomyces sp. (isolat Gi, IMi, BSi, Sh dan BSc) diuji efektifitasnya dalam menghambat pertumbuhan jamur S. rolfsiipada media YMA dalam cawan petri. Zona hambatan pertumbuhan S. rolfsii diukur 3 hari setelah inokulasi. Isolat Gi menunjukkan daya hambat tertinggi (43.33%) dan isolat Gi digunakan pada percobaan in-vivo.Percobaanin-vivo ditata dengan rancangan acak lengkap dengan perlakuan inokulasi Streptomyces sp. di media tanam pada saat tanam, 7 hari setelah tanam, 14 hari setalah tanam, dan perlakuan perendaman benih dengan Streptomyces sp. 10 menit, 20 menit dan 30 menit. Kontrol positif dan kontrol negatif disiapkan. Masing-masing perlakuan diulang sebanyak 5 kali sehingga diperoleh 40 unit percobaan.Pada percobaan in-vivo perlakuan Streptomyces sp. Isolat Gi tidak mampu menekan masa inkubasi tetapi mampu menekan insiden penyakit rebah-semai oleh Sclerotium rolfsii.

ABSTRACT

The aim of this study was to determine the ability of Streptomyces sp. to inhibit the growth and development of fungus Sclerotium rolfsii. This research was conducted in the Laboratory of Microbiology and Greenhouse Faculty of Agriculture, Mataram University with experimental methods. In in-vitro experiments, five isolates of Streptomyces sp. (Isolates Gi, Imi, BSi, Sh and BSc) were tested their effectiveness in inhibiting the growth of fungusS. rolfsii on YMA medium in Petri dishes. Inhibitionzone of S. rolfsii growth was measured 3 days after inoculation. Isolate Gi showed the highest (43.33%) so that it was used in in-vivo experiment. The experiment was Completely Randomazed Designed with 6 treatments, inoculation of Streptomyces sp. at planting time, 7 days, 14 days after planting, seeds soaking treatment in Streptomyces sp. suspension for 10, 20 and 30 minutes. Positive and negative controls were provided. Each treatment was repeated 5 times resulting in 40 experimental units. Result showed that although isolate Gi of Streptomyces sp. was unable to suppress incubation periode, but it was capable suppressing incident of dumping-off disease caused by S. rolfsii.