Observation of important patchouli pests was aimed to observe and identify important patchouli pests in North Sumatra and Aceh. Mosaic virus was the common disease found in patchouli plant with mild severe of 5-18.75% and very severe 87.5%, followed by red yellow disease (nematode) with mild severity 1-20%. The important disease that categorized as severe was budok disease found in Pintu Padang II Sub district, South Tapanuli Regency at 67.50%, and very severe (87.50%) was mosaic virus disease found in Bulu Cina Subdistrict, Deli Serdang Regency. Grasshopper was a pest that commonly found in patchouli with mild attack intensity (6.25-18.75%) and moderate attack intensity (21.2-30%), then followed by leaf-eating caterpillars with mild attack intensity 1.25-15%.

<p>This research aimed to identify the the potential of <em>Trichoderma</em> isolates in controlling white root disease <em>Rigidoporus lignosus</em> in vitro. <em>Trichoderma</em> isolates were isolated from 7 (seven) smallholder rubber plantations. The locations were Serdang Bedagai, Langkat, Simalungun, Labuhan Batu, Batubara, Asahan and Labuhan Batu districts. The seven <em>Trichoderma</em> isolates were antagonized with <em>Rigidoporus lignosus</em> isolates from 4 (four) smallholder rubber plantations i.e from Serdang Bedagai, Langkat, Simalungun and Labuhan Batu districts. The antagonisme methods used dual culture on Potato Dextrose Agar (PDA) medium. Each <em>Trichoderma</em> isolate had a different potential to inhibit each <em>Rigidoporus lignosus</em> isolate.</p>

Metarhizium anisopliae is an important entomopathogenic fungus that mainly used for biological control. Isolates of M. anisopliae extracted from soil from 15 oil palm plantations located in several districts on the Province of North Sumatra, Indonesia have been investigated to identify their morphological diversity. The morphology of assessed fungi was constructed in the the form of conidia, conidia size, color and shape colony and growth diameter of the 15 isolates. All of conidia forms showed cylindrical shape and string together. The length/width (μm) ratio of conidia size was minimum 2,16 and maximum 3,54. The highest growth rate isolates were found in M3 (Bandar Selamat) and M12 (Mancang) treatment and the lowest rate was M11 (Teluk Parit Kaca) treatment. The color of colonies were varied among the isolates. They were greenish yellow, dark green, yellowish and showing zonation/no zonation.Keywords : Metarhizium anisopliae, biological character, morphological diversity

Metarizhium anisopliae (Metsch.) is an entomopathogenic fungus that attacks Oryctes rhinoceros (Linnaeus). This fungus is one of the potential bioagents that is environmentally friendly. The purpose of this study was to isolate the fungus M. anisopliae from various oil palm plantation soil samples and to see its genetic diversity based on RAPD markers. The method used in this research is the morphological and the molecular identification of M. anisopliae (ITS), and genetic diversity testing using RAPD markers. Fifteen isolates of M. anisopliae isolated from 15 oil palm plantation sites in North Sumatra were examined for their molecular diversity. On the basis of morphological characteristics, all isolates were identified as M. anisopliae. The result of sequencing with the ITS primer showed that all isolates of M. anisopliae isolated from soil had a 85–99% homology of with M. anisopliae and M. brunneum reference strains from gen bank database National Center Biotechnology Information (NCBI). Eight RAPD primers generated 39 scorable bands which 38 (98,44%) of them were polymorphic. Clustering analysis was performed based on RAPD profiles using Neighbour-Joining Tree method that formed 3 groups. Key words: entomopathogenic fungi, genetic diversity, ITS sequencing, RAPD