Abstract. Nontji M, Muis A, Nonci N, Nonci N, Amran FD. 2019. Evaluating the potential of indigenous Rhizobacteria as biofertilizer and biopesticide against Rhizoctonia solani. Nusantara Bioscience 11: 79-83. Rhizobacteria are living in area of plant roots, some of them are potential as biofertilizers and biopesticides agents. This study aims to evaluate the potential of 10 isolates indigenous rhizobacteria as biofertilizer and biopesticide against banded leaf and sheath blight disease on corn. The potential of biofertilizer was evaluated by ability fixing nitrogen in Burk’s N free medium, dissolving phosphate and producing Indole Acetic Acid (IAA) hormone with spectrophotometry method. The potential of biopesticide was evaluated by synergistic of analysis with double culture method. The result of study showed that the best indigenous rhizobacteria was isolated code 10. It has potential as a biofertilizer agent (0.22% for fixing nitrogen, 18.875 ppm for dissolving phosphate and producing IAA hormone 1.524 ppm). It is also having potential as biopesticide agent against Rhizoctonia solani with relative inhibition level (RIL) of 31.3%. Isolate code 10 and code 6 are able to live in synergy so that it can be recommended as biofertilizer and biopesticide agent to form the consortium as a biological fertilizer.

Evaluation of five inner carriers and Bacillus subtilis formulation to control banded leaf and sheath blight (Rhizoctonia solani Kuhn). One alternative control method against plant pathogens is the use of antagonistic microorganisms, such as Bacillus subtilis. The use of the antagonistic bacteria on corn especially in Indonesia is still lack. The objective of this research was to evaluate some inner carrier and to make formulated antagonistic B. subtilis to be used as biological control agents on corn diseases. This research consists of laboratory and greenhouse activities. The laboratory activities consist of B. subtilis biomass production, formulation of B. subtilis, and evaluation of five types of inner carrier. In the greenhouse, testing the formulation B. subtilis with talc as an inner carrier, which is compared with the treatment solution of B. subtilis, nordox, metalaxyl fungicides. The data collected in this study were percentage of germination, damping off due to pathogen R. solani, plant height, plant fresh weight, and percentages of R. solani incidence on 14 DAP. The results showed that talc powder and corn flour were the best inner carrier to be used in sorage formulation of antagonistic Bacillus. Formulated Bacillus subtilis TM4 showed no negative affect on seed germination and able to suppress the development of R. solani in greenhouse. Key words: Bacillus subtilis, formulation, inner carrier, Rhizoctonia solani ABSTRAKEvaluasi lima jenis inner carrier dan formulasi Bacillus subtilis untuk pengendalian hawar pelepah jagung (Rhizoctonia solani Kuhn). Salah satu alternatif pengendalian patogen tanaman yaitu pemanfaatan mikroorganisme antagonis seperti Bacillus subtilis. Penggunaan bakteri antagonis tersebut pada tanaman jagung di Indonesia masih sangat kurang. Penelitian ini bertujuan mengevaluasi beberapa inner carrier dan membuat formulasi bakteri antagonis B. subtilis untuk digunakan sebagai agensia pengendali hayati penyakit pada tanaman jagung. Kegiatan penelitian ini terdiri dari kegiatan laboratorium dan rumah kaca. Di laboratorium dilakukan produksi biomass B. subtilis, pembuatan formulasi B. subtilis, dan evaluasi formulasi dari lima jenis inner carrier. Di rumah kaca, dilakukan pengujian formulasi B. subtilis dengan talc sebagai inner carrier yang dibandingkan dengan perlakuan larutan B. subtilis, fungisida nordox, dan fungisida metalaxyl. Pengamatan dilakukan terhadap daya kecambah, damping off akibat patogen R. solani, tinggi tanaman, berat segar tanaman, dan persentase serangan R. solani pada 14 HST. Hasil penelitian menunjukkan bahwa talc dan tepung jagung merupakan inner carrier yang terbaik untuk digunakan dalam pembuatan formulasi bakteri antagonis B. subtilis. Formulasi B. subtilis TM4 tidak berpengaruh negatif terhadap daya kecambah benih serta mampu menekan perkembangan R. solani di rumah kaca.

<p>Salah satu kendala dalam penyimpanan jagung adalah serangan hama<br />gudang. Salah satu hama gudang jagung adalah <em>Sitophilus zeamais</em><br />Motschulsky (Coleoptera: Curculionidae). Hama ini ditemukan di<br />daerah panas maupun lembap. Hama ini bersifat polifag, dapat<br />merusak serealia seperti beras/gabah, jagung, gandum, dan sorgum,<br />namun dilaporkan sebagai hama penting pada jagung. Kehilangan<br />hasil jagung di wilayah tropis akibat <em>S. zeamais</em> berkisar antara 30-<br />100%. Biji jagung yang disimpan selama 6 bulan menunjukkan<br />kerusakan 85% dan bobot biji menyusut 17%. Telur hama tersebut<br />diletakkan di dalam biji dan dalam beberapa hari akan menetas<br />menjadi larva. Larva menyelesaikan siklus hidupnya di dalam biji.<br />Telur berwarna putih bening, berbentuk lonjong, lunak dan licin,<br />berukuran 0,7 mm x 0,3 mm. Larva berwarna putih kekuningan,<br />tidak bertungkai, kepala berwarna cokelat, terdiri atas empat instar,<br />panjang 1,5–4 mm. Periode larva berlangsung 25 hari. Imago <em>S.</em><br /><em>zeamais</em> berukuran 3-4,5 mm. Hama <em>S. zeamais</em> dapat dikendalikan<br />dengan cara: 1) menyimpan jagung dalam wadah maupun gudang<br />secara higienis, 2) menanam varietas tahan, 3) menggunakan<br />musuh alami yaitu parasit, predator, dan patogen, seperti parasitoid<br /><em>Lariophagus distinguendus</em> dan <em>Anisopteromalus calandrae</em>, serta<br />patogen <em>Beauveria bassiana</em>, 4) memanfaatkan insektisida nabati<br />yang memiliki toksisitas tinggi terhadap <em>S. zeamais</em>, yaitu <em>Ageratum</em><br /><em>connyzoides</em> (bandotan), <em>Andropogon nardus</em> (serai), <em>Allium sativum</em><br />(bawang merah), <em>Nicotiana tabacum</em> (tembakau), <em>Zingiber officinale</em><br />(jahe), dan <em>Azadirachta indica</em> (mimba), serta 5) menyemprotkan<br />insektisida sintetis metil pirimifos.</p>

The compulsory requirement for releasing new high yielding maize varieties is resistance to downy mildew. The study aimed to determine the level of homozygosity, genetic diversity, and  genetic distance of 30 S3 genotypes of maize. Number of primers to be used were 30 polymorphic SSR loci which are distributed over the entire maize genomes. The S3 genotypes used were resistant to downy mildew with homozygosity level of &gt;80%, genetic distance between the test and tester strains &gt;0.7, and anthesis silking interval (ASI) between inbred lines and tester lines was maximum 3 days. The results showed that 30 SSR primers used were spread evenly across the maize genomes which were manifested in the representation of SSR loci on each chromosome of a total of 10 chromosomes. The levels of polymorphism ranged from 0.13 to 0.78, an average of 0.51, and the number of alleles ranged from 2 to 8 alleles per SSR locus, an average of 4 alleles per SSR locus. The size of nucleotides in each locus also varied from 70 to 553 bp. Cophenetic correlation value (r) at 0.67 indicated that the Unweighted Pair-Group Method Using Arithmetic Averages (UPGMA) was less reliable for differentiating genotypes in five groups. Of the total of 30 genotypes analyzed, 17 genotypes had homozygosity level of &gt;80% so it can be included in the hybrid assembly program.

Indigenous fungi can suppress infection by pathogens and produce secondary metabolites that directly or indirectly affect plant growth. This study aimed to test indigenous fungi collected from corn plants as biological control agents and their effects on the viability and vigor of corn seeds. Purposive sampling method was used for sampling where soil samples taken from the rhizosphere zone, corn stem and leaf tissue from three locations namely Maros-South Sulawesi, Bone-South Sulawesi, Sigi-Central Sulawesi, Indonesia. Rhizospheric fungi were isolated from soil collected at the rhizosphere and rhizoplane using a serial dilution technique, while the endophytic fungi isolated from the leaves and stem tissues using surface sterilization method. The isolated fungi were cultured on a potato dextrose agar (PDA) medium. An antagonism test was performed using the dual culture method on PDA media with F. verticillioides as target pathogen. Pathogenicity test and the effect of fungi on corn seed germination was carried out using the blotter test method. Parameters observed were; necrotic symptoms on seedlings, growth potential, germination, growth rate, growth simultaneity, vigor index, germination rate, and time needed for 50% of the total germination. The effect of the isolated indigenous fungi on corn growth was carried out in-planta using seedling trays. The results of the blotter test and in-planta test were further confirmed by a physiological characteristic test. And assessing the fungi's ability to dissolve potassium, phosphate, and produce protease enzymes. A total of 89 fungal isolates were isolated and collected from various parts of the corn plant. Nineteen of the 89 fungal isolates showed inhibitory activity against F. verticillioides by ! 50% inhibition. The fungal isolates JRP 5 MRS, JRP 9 MRS, JRP 10 MRS, JRP 7 MRS, and JEDF 1B BN were selected based on the tests and showed a consistently positive effect on seed viability and vigor with a value of !90%. The isolates did not cause necrosis in corn, and had the ability to suppress the growth of pathogenic F. verticillioides by ! 50%.