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.

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%.

<p>Maize is one of the most important worldwide agricultural crops that their seed is considered a valuable international trading item. The seeds are mainly originated from United States, where the world most intensive development of new varieties occurs. Pantoea stewartii is a pathogenic bacteria of maize that occurs primarily in the US. Stewart wilt disease in maize caused by the bacterium Pantoea stewartii is become a new disease of maize in Indonesia. The stewart wilt disease was first reported in West Sumatra with the disease incidence of 1−15%. This paper discusses the epidemiology and control efforts of the bacterial stewart wilt disease in maize. Stewart wilt disease is a seed borne disease and it can transmitted by insect vector Chaetocnema pulicaria. P. stewartii has a wide host range including maize plant. In addition to maize plants, the pathogen also attacks sugarcane, sorghum, wheat, green beans, cucumbers, and several types of grasses. The abundant availability and wide range of its hosts, allows the pathogen to easily find the host to survive and develop. P. stewartii attacks maize in all stages of plant growth. The emergence of this disease on maize plant is mainly due to imported seeds from outside of Indonesia. Seed is the most suitable carrier media for pathogens to spread across its natural boundaries. One of the efforts to prevent the outbreak of the disease in Indonesia is to control its insect vectors. Several efforts that can be done to control the disease are environmental sanitation and by chemical pesticides with active ingredient such as imidacloprid, thiamethoxam, and clothianidin.</p><p>Keywords: Maize, Pantoea stewartii, host plant, seed treatment</p><p> </p><p><strong>Abstrak</strong></p><p>Jagung merupakan salah satu komoditas pangan dan pakan penting dunia dan benihnya diperdagangkan secara internasional. Volume tertinggi perdagangan benih jagung berasal dari Amerika Serikat yang merupakan negara penghasil utama varietas unggul baru jagung di dunia. Pantoea stewartii adalah bakteri patogenik penting pada tanaman jagung, khususnya di Amerika Serikat. Penyakit layu stewart pada tanaman jagung disebabkan oleh bakteri Pantoea stewartii yang merupakan penyakit baru di Indonesia. Penyakit ini pertama kali dilaporkan di Sumatera Barat dengan insidensi 1−15%. Makalah ini membahas epidemiologi dan upaya pengendalian penyakit layu bakteri stewart pada tanaman jagung. Penyakit layu stewart merupakan penyakit tular benih dan tular serangga melalui vektor Chaetocnema pulicaria. P. stewartii memiliki inang yang luas, termasuk tebu, sorgum, gandum, kacang hijau, mentimun, dan beberapa jenis rumput-rumputan. Melimpahnya ketersediaan inang menjadikan patogen ini mudah dan cepat berkembang. Penyakit layu bakteri stewart pada tanaman jagung dapat berasal dari benih impor. Benih merupakan media pembawa penyakit yang paling efektif dan menyebar luas dengan melintasi batas alaminya. Salah satu upaya untuk mencegah wabah penyakit layu stewart ialah mengendalikan serangga vektor. Sanitasi lingkungan dan penggunaan pestisida berbahan aktif imidacloprid, thiamethoxam, dan clothianidin merupakan alternatif pengendalian.</p><p>Kata kunci: Jagung, Pantoea stewartii, tanaman inang, perlakuan benih</p>

Downy mildew caused by Peronosclerospora maydis is an important disease in the centers of corn cultivation in Java. The aim of this study was to determine the effectiveness of a combination of metalaxyl fungicide and varieties that have a high sustainability of downy mildew caused by P. maydis. The study was conducted in Kediri, East Java, which is an endemic area of downy mildew caused by P. maydis. The Split Plot Design with 3 replications was used in this study. The main plots were 5 corn varieties (1) Bima-3 Bantimurung, (2) Bima-20 URI, (3) Lagaligo, (4) Bima-15 Sayang, and (5) Anoman as a susceptible check. The subplots were 5 levels of seed treatment dose with metalaxyl fungicide (0 g/kg, 2 g/kg, 3 g/kg, 5 g/kg, and 7 g/kg seeds). The combination of resistant varieties with metalaxyl at a dose level of 5 g and 7 g/kg of corn seeds was effective in controlling downy mildew caused by P. maydis. In Bima-3 varieties Bantimurung and Lagaligo showed low infection reactions of 7.7-8.1%, and 10.4–11.2% respectively. In a combination of treatment conditions of susceptible varieties (Anoman) with 2, 3, 5 and 7 g/kg seeds, disease incidence reach 100% or most of the plants die. The lower incidence was also followed by yield, ear length and weight of a 1000 seeds that higher than other treatments. The combination of the use of susceptible variety with 2 g to 7 g/kg of metallaxyl doses was not effective in controlling downy mildew caused by P. maydis.