512 Vegetalika. 2020. 9(4): 512-524 VEGETALIKA | https://doi.org/10.22146/veg.47812 Pengaruh Aplikasi Plant Growth Promoting Rhizobacteria terhadap Pertumbuhan dan Hasil Tanaman Bawang Merah (Allium cepa L. Aggregatum group) Effects of Plant Growth Promoting Rhizobacteria Application on Growth and Yield of Shallot (Allium cepa L. Aggregatum group) Nanda Dwi Hafri 1) , Endang Sulistyaningsih 1*) , Arif Wibowo 2) 1) Departemen Budidaya Pertanian, Fakultas Pertanian, Universitas Gadjah Mada, 2) Departemen Hama dan Penyakit Tumbuhan, Fakultas Pertanian, Universitas Gadjah Mada Jalan Flora No. 1, Bulaksumur, Sleman, Yogyakarta 55281, Indonesia. *) Penulis untuk korespondensi Email: endangsih@ugm.ac.id ABSTRACT One method to control twisted disease is by Thrichoderma application. Trichoderma is also able to synthesis plant growth regulator. Other microbes that can increase plant phytohormon is Plant Growth Promoting Rhizobacteria (PGPR). The aim of this study were to determine effect of PGPR to growth and yield of shallot var. Crok Kuning in the field. This research was arranged in Randomized Complete Block Design (RCBD) with single factor and three blocks as replication. The factors were five PGPR, there were Bp.25.7 Bacillus subtilis, BrSG.5 Bacillus amyloliquofaciens, Bp.25.2 Bacillus methylotrophicus, BrsM.4 Burkholderia cepacia, andBp.25.6 Bacillus amyloliquofaciens, also two controls, there were positive control, using Trichoderma and negative control without treatment. The plant growth analysis results showed that Bp.25.2 Bacillus methylotrophicus could increase net assimilation rate compared to the other 4 PGPR isolates and negative control but not gave significant result when compared to Trichoderma treatment. The increase of net assimilation rate impacted by Bp.25.2 Bacillus methylotrophicus had higher plant growth rate than BrSG.5 Bacillus amyloliquofaciens and Bp.25.6 Bacillus amyloliquofaciens but showed the similar plant growth rate when compared to 2 other PGPR isolates, negative control, and Trichoderma. As the conclusion, application of five PGPR isolates had similar result to the Trichoderma application in increasing the growth of shallots on leaf surface area variable and total dry weight compared to control. An increase in the growth variable was not followed by an increase in the yield variable, while the productivity of shallots was not significantly different between treatments. Keywords: PGPR, Shallot, Trichoderma INTISARI Salah satu upaya penanganan penyakit moler bawang merah dilakukan melalui aplikasi Trichoderma. Aplikasi Trichoderma pada bawang merah memiliki beberapa keunggulan, yaitu mampu mensintesis hormon pertumbuhan tanaman. Terdapat jenis mikroba lain yang juga mampu meningkatkan fitohormon pada