Jagung merupakan salah satu komoditas yang berperan penting di Indonesia, namun produksi jagung masih belum dapat memenuhi kebutuhan jagung secara nasional. Maka dari itu, diperlukan upaya untuk meningkatkan produksi jagung di Indonesia. Salah satu upaya yang dapat dilakukan adalah meningkatkan proses perkecambahan benih jagung. Perlakuan benih merupakan salah satu perlakuan yang bertujuan meningkatkan proses perkecambahan benih jagung di lapangan. PGPR yang mampu memproduksi hormon IAA merupakan salah satu bahan dalam perlakuan benih. Hormon IAA merupakan auksin yang berperan dalam merangsang imbibisi, mempercepat perkecambahan benih, meningkatkan aktivitas enzim, dan mendorong pemanjangan sel batang dan akar. Fakultas Pertanian Universitas Borneo Tarakan memiliki 14 isolat rhizobakteri indigenous penambat nitrogen dan 2 pelarut fosfat, namun belum diketahui dalam menghasilkan hormon IAA. Tujuan penelitian untuk mendapatkan isolat penambat nitrogen dan pelarut fosfat yang mampu menghasilkan hormon IAA dan mengetahui pengaruhnya terhadap perkecambahan benih jagung. Penelitian dilakukan dua tahap, yaitu uji rhizobakteri penghasil hormon IAA dengan metode spektrofotometri dan uji kemampuan rhizobakteri terhadap perkecambahan jagung dengan metode perendaman benih. Analisis data uji rhizobakteri penghasil hormon IAA menggunakan metode deskriptif kuantitatif sedangkan uji perkecambahan menggunakan metode Rancangan Acak Kelompok (RAK) yang terdiri dari 6 perlakuan dan 4 ulangan, yaitu : P0 (aquades), P1 (NB), P2 (B5(6)), P3 (B1(17)), P4 (B3(12)) dan P5 (B3(16)). Perlakuan P2, P3, P4 dan P5 benih direndam dengan kerapatan isolat rhizobakteri 108 cfu/ml. Parameter penelitian yaitu daya kecambah, laju perkecambahan, potensi tumbuh benih, kecepatan tumbuh benih, tinggi tanaman, panjang akar dan jumlah akar. Hasil penelitian menunjukkan isolat rhizobakteri penambat nitrogen dan pelarut fosfat mampu menghasilkan hormon IAA. Isolat B5(6) = 55,19 ppm, B1(17) = 31,99 ppm, B3(12) = 48,14 ppm dan B3(16) = 62,23 ppm. Hasil penelitian perlakuan isolat rhizobakteri terhadap perkecambahan jagung menunjukkan konsentrasi hormon IAA yang dihasilkan masih belum memenuhi kebutuhan jagung untuk meningkatkan proses perkecambahannya.
Kata kunci: Jagung, perkecambahan, PGPR, Hormon IAA, Perlakuan Benih

Corn is one of the commodities which plays an important role in indonesia, but corn production is still not able to meet the national demand for corn. therefore, efforts are needed to increase corn production in Indonesia. one of the effort that can be done is to improve the germination process of corn seeds. seeds treatment is one of the treatments which aims to improve the germination process of corn seeds in the field. plant growth promoting Rhizobacteria (PGPR) which is able to produce IAA hormone is one of the ingredients in seeds treatment. Indole Acetic Acid (IAA) hormone is an auxin that plays a role in stimulating imbibition, accelerating seeds germination, increasing enzyme activity, and promoting stem and root cell elongation. Agriculture Faculty of Borneo Tarakan University had 14 indigenous rhizobacteria isolates of nitrogen fixation and 2 phosphate solvents, but they had not been known to product IAA hormone. this research was to obtain isolates of nitrogen fixation and phosphate solvent which were capable of producing IAA hormones and to determine their effects on corn seed germination. this research was carried out in two stages, namely, first, testing rhizobacteria to produce IAA hormones by employing the spectrophotometric method in which he data were analyzed using a quantitative descriptive method. second, testing the ability of rizhobacteria to germinate corn by using the seed soaking method in whivh the data were analyzed using a Randomized Block Design (RBD) method consisting of 6 treatments and 4 replications : T0 (aquades), T1 (NB), T2 (B56), T3 (B117), T4 (B312), and T5 (B316). for T2,T3,T4, and T5 treatment, seeds were soaked with a density of rhizobacteria isolate 10^8 cfu/ml. the research parameters were germination capacity, germination rate, seed growth potential, seed growth speed, plant height, root lenght, ang number of roots. the results showed that isolates of nitrogen fixtation and phosphate solvents were able to produce IAA hormones, where isolate B56 = 55,19 ppm, isolate B117 = 31,99 ppm, isolate B213 = 48,14 ppm, and isolate B316 = 62,23 ppm. the results of the treatment of rhizobacteria isolates on corn germination showed that the concentration of IAA hormones still did not meet the needs of corn to increase the germination process. Keywords: corn, germination, PGPR, IAA hormone, seed treatment