The research objective was to determine the best composting time on the growth and yield of two types of fungi (white oysters and brown oysters) by comparing the contaminated media and the new sawdust media. The design used was a factorial CRD consisting of two factors. The first factor type of oyster mushroom (J) consists of two levels (j1 = white oyster mushroom and j2 = brown oyster mushroom). The second factor was composting time (P) consisting of 4 levels (p0 = without compost, p1 = 7 days of composting, p2 = 14 days of composting and p3 = 21 days of composting) and added new sawdust media as a comparison. The results showed that the use of contaminated media can still be used as a growth medium and the yield of oyster mushrooms is almost the same as new sawdust media. The highest growth of oyster mushroom species was found in the uncomposted media treatment. Total fresh weight of fruit bodies, respectively 291.16 g / bag-log (without composted) and 209.62 g / bag-log (composting time 7 days), 193.60 g / bag-log (composting time 14 days ) and 87.90 g / bag-log (composting time is 21 days

Key words: Contaminated media, time of composting, white oyster mushrooms, and brown oyster mushrooms

Tujuan penelitian untuk mengetahui lama pengomposan terbaik terhadap pertumbuhan dan hasil dua jenis jamur (tiram putih dan tiram coklat) dengan membandingkan media terkontaminasi dan media serbuk gergaji baru. Rancangan yang digunakan adalah RAL Faktorial yang terdiri dari dua faktor. Faktor pertama jenis jamur tiram (J) terdiri dari dua level (j1= jamur tiram putih dan j2= jamur tiram coklat). Faktor kedua lama pengomposan (P)terdiri dari 4 level (p0= tanpa dikomposkan, p1= 7 hari pengomposan, p2= 14 hari pengomposan dan p3= 21 hari pengomposan) dan ditambahkan media serbuk gergaji baru sebagai pembanding. Hasil penelitian menunjukkan penggunaan media yang terkontaminasi masih dapat digunakan sebagai media pertumbuhan dan hasil jamur tiram yang hampir sama dengan media serbuk gergaji baru. Pertumbuhan jenis jamur tiram tertinggi terdapat pada perlakuan media tanpa dikomposkan. Bobot segar total badan buah masing-masing sebesar 291,16 g/bag-log (tanpa dikomposkan) dan 209,62 g/bag-log (lama pengomposan 7 hari), 193,60 g/bag-log (lama pengomposan 14 hari) dan 87,90 g/bag-log (lama pengomposan 21 hari).

Kata kunci : Media terkontaminasi, lama pengomposan, jamur tiram putih, dan jamur tiram coklat