<p>ABSTRAK. Layu Fusarium merupakan penyakit penting yang menjadi kendala dalam memproduksi tanaman anggrek. Untuk mengendalikannya, petani masih menggunakan fungsida. Tanaman anggrek kerap ditampilkan sebagai hiasan yang dekat dengan lingkungan manusia, maka penggunaan pestisida perlu diperhatikan. Oleh karena itu sangat penting dicari cara pengendalian lainnya yang aman terhadap lingkungan, antara lain dengan pengendalian hayati. Tujuan penelitian ialah mendapatkan isolat bakteri antagonis yang dapat mengendalikan layu Fusarium pada tanaman Phalaenopsis. Percobaan dilakukan di Laboratorium dan Rumah Kasa Balai Penelitian Tanaman Hias Segunung (1100 m dpl.) serta untuk mikrob diisolasi dari lokasi tanaman hortikultura di Jawa Barat dan DKI Jakarta, mulai Bulan Januari sampai dengan Desember 2010. Penelitian meliputi isolasi Fusarium spp. sebagai patogen pada tanaman anggrek di beberapa lokasi, isolasi bakteri antagonis, uji kemangkusan bakteri terhadap pertumbuhan Fusarium spp. di laboratorium, dan uji kemangkusan bakteri antagonis terhadap layu Fusarium di rumah kasa. Hasil penelitian menunjukkan bahwa penyebab layu Fusarium pada tanaman Phalaenopsis ialah Fusarium oxysporum. Dari 154 isolat bakteri yang diisolasi dari lapangan, hanya ada tiga isolat yaitu nomor B23, B 26, dan B37 yang dapat menekan pertumbuhan F. oxysporum pada media PDA. Sampai dengan pengamatan minggu ke-10 setelah inokulasi, ketiga bakteri tersebut masing-masing menekan jumlah tanaman yang terserang layu Fusarium, yaitu sebesar 46,9; 48,9; dan 65,3%, dan masing-masing menekan intensitas penyakit layu 50,5; 43,9; dan 55,1%.</p><p>ABSTRACT. Djatnika, I 2012. Selection of Antagonistic Bacteria for Controlling of Fusarium Wilt on Phalaenopsis Plants. Fusarium wilt is an important disease as constraint on production of orchid plants. The control of Fusarium wilt of orchids with fungicides often use by farmers. Orchid plants are often displayed as a decoration which is close to the human environment, so the application of pesticides have to get attention. It is therefore necessary to find another method that is safe for environments, such as using of biological control. The purpose of the study was to get isolates of bacterial antagonists for controlling of Fusarium wilt of Phalaenopsis plants. The experiment was conducted at Laboratory and Screenhouse of Indonesian Ornamental Plant Research Institute, Segunung (1100 m asl.) and the microbes were isolated from horticultural area in West Java and DKI Jakarta since January until December 2010. The research comprised of isolation of Fusarium spp. from orchid plants in some location, isolation of bacterial antagonists, the effectiveness of the bacteria to suppress Fusarium spp. growth in laboratory, and the effectiveness of the bacteria to control Fusarium wilt on Phalaenopsis plants in the screenhouse. The results showed that the causal Fusarium wilt of Phalaenopsis plants was identified as Fusarium oxysporum. Three of 154 isolates of bacteria, i.e. isolates number of B23, B26, and B37, could suppress of F. oxysporum growth on PDA media. Observation up to 10 weeks after inoculation, the three bacteria could reduce the number of plants attacked by Fusarium wilt , which were 46.9; 48.9; and 65.3% respectively, and each of them suppress wilt disease intensity 50.5, 43.9, and 55.1% respectively. <br /><br /></p>
Influence of Fungal and Bacterial Antagonists on Some Causal Agents of Cucumber Root and Crown Rots
