Skrining Kemangkusan Mikroba Antagonis terhadap Penyakit pada Tanaman Krisan

Abstract

ABSTRAK. Penelitian untuk mengetahui efikasi agens hayati terhadap penyakit pada tanaman krisan telah dilakukan di rumah kaca dan di lapangan. Sebanyak 20 isolat bakteri telah diuji efektivitasnya dengan cara disemprotkan dengan konsentrasi 108 cfu/ml merata seluruh tanaman. Evaluasi terhadap intensitas penyakit dilakukan pada saat panen. Hasil penelitian menunjukkan bahwa di rumah kaca penyakit hawar daun kurang bisa berkembang, namun penyakit yang bukan merupakan target berkembang cukup berarti, yaitu penyakit layu fusarium dan embun tepung (Oidium sp). Di lapangan selain Pseudomonas cichorii dijumpai penyakit karat putih yang disebabkan oleh Puccinia horiana, dan penyakit busuk basah yang disebabkan oleh Erwinia sp.. Pseudomonas fluorescens isolat Pf 2 dan Pf 4A, serta Bacillus subtilis isolat Ba 13, Ba 16, dan Ba 17 efektif menekan intensitas penyakit hawar daun. Pseudomonas fluorescens isolat Pf 2, Pf 4A, dan Pf 16 efektif terhadap penyakit karat putih. Semua isolat yang diuji tidak efektif terhadap penyakit busuk basah dan penyakit layu fusarium. Pseudomonas fluorescens isolat Pf 2, MR 9, dan B. subtilis isolat Ba 9 efektif terhadap embun tepung di rumah kaca.

Bacillus subtilis; Agens hayati; Pengendalian biologi.
ABSTRACT. Suhardi, Hanudin, W. Handayati, and A. Saepulloh. 2007. Screening of the Efficacy of Biological Agents Against Pseudomonas cichorii and Other Diseases of Chrysanthemum. Research to know the efficacy of biological agents to control the diseases on chrysanthemum were done in a glasshouse and field. As many as 20 bacterial isolates were tested by spraying bacterial cells at 108 cfu/ml until run off. Evaluation was done at the harvest time in relation to disease intensity. Results indicates that leaf blight did not develop in the glasshouse, but other diseases such as fusarium wilt and powdery mildew progressed significantly. In the field, besides leaf blight, other diseases were found i.e. white rust caused by Puccinia horiana and soft rot caused by Erwinia sp.. Pseudomonas fluorescens isolate Pf 2 and Pf 4A, Bacillus subtilis isolate Ba 13, Ba 16, and Ba 17 were effectively suppressed blight intensity. Pseudomonas fluorescens isolate Pf 2, Pf 4A, and Pf 16 were effective to white rust. All isolates were not effective against soft rot. Pseudomonas fluorescens isolate Pf 2 and MR 9 and B. subtilis isolate Ba 9 were effective in controlling powdery mildew on chrysanthemum in glasshouse.