Research Article Growth Promotion of Rice (Oryza sativa L.) Seedlings Using Plant Growth-Promoting Rhizobacteria (PGPR) Isolated from Northwest Ethiopia Zewdu Teshome Awlachew 1 and Gebeyehu Yibeltie Mengistie 2 1 Department of Biology, College of Natural and Computational Sciences, University of Gondar, P. O. Box 196, Gondar, Ethiopia 2 Department of Biology, College of Natural and Computational Sciences, Debark University, P. O. Box 90, Debark, Ethiopia Correspondence should be addressed to Zewdu Teshome Awlachew; teshomeawlachew@gmail.com Received 15 June 2022; Accepted 6 October 2022; Published 26 October 2022 Academic Editor: Jiban Shrestha Copyright © 2022 Zewdu Teshome Awlachew and Gebeyehu Yibeltie Mengistie. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Plant growth-promoting rhizobacteria (PGPR) are beneficial soil microorganisms that colonize plant roots and enhance plant growth by a wide variety of mechanisms. In this work, five Bacillus and two Cyanobacteria isolates were successfully isolated and characterized. A pot experiment was conducted to evaluate the effect of PGPR on the growth of three cultivars of rice seedlings. Pots were laid down in a complete random design and 100 ml of spore and Cyanobacteria suspension were poured on the soil surface surrounding each seedling. After 45 days, the seedlings were uprooted and shoot and root parameters were recorded. All the Bacillus and Cyanobacteria isolates showed positive effects on the growth of rice seedlings as compared to control; however, their effectiveness varies from isolate to isolate and also from cultivar to cultivar. Bacterial isolates B3 and B5 showed the highest mean value and statistically significant difference (P < 0.05) in most of the root and shoot parameters of cultivars Jegna and Getachew, respectively, as compared to other bacterial isolates. Both cyanobacterial isolates showed the highest and statistically significant difference (P < 0.01) in almost all the above ground and underground growth parameters compared to other bacterial isolates in all the three cultivars of rice. Similarly, C2 and C1 recorded the highest growth promotion efficacy of shoot and root length (50.07% and 78.27%) on Edget and Getachew cultivars, respectively. Hence, the present study suggests that the use of PGPR isolates such as B3, B5, C1, and C2 as inoculant biofertilizers might be beneficial for rice cultivation as they enhanced the growth of rice seedlings. 1. Introduction Agriculture is one of the human activities that contributes most to the increasing amount of chemical pollutants through excessive use of synthetic chemical fertilizers and pesticides, which leads to environmental damage with potential risks to human health. In order to feed the ever-growing human population, sustainable agriculture is very important. Ethiopia is endowed with a broad diversity of climates suitable for successful growth of most types of temperate and tropical crops. However, the country is suffering with food insecurity and famine due to climatic variability and the poor performance of the agricultural sector. e importance of rice crops (Oryza sativa L.) in the Ethiopian agriculture is increasing from time to time [1]. However, an increasing trend of importing rice is practicing which proved that de- mand of rice is quite higher than the domestic production [2]. Rice is the most important staple food in several de- veloping countries [3, 4]. ere is an increasing trend in area coverage and volume of production of rice in Ethiopia [2]. However, the mean national rice productivity (2.8 t/ha) of Ethiopia is quite low compared to the global average pro- ductivity (4.4 t/ha) even though 6 tones ha-1 has been re- ported on research fields [5] which calls for the concerted effort in increasing the productivity. Rice ranked second after maize in terms of productivity among cereals, which proved as it will play a significant role for food security in Ethiopia [6]. Hindawi Advances in Agriculture Volume 2022, Article ID 1710737, 8 pages https://doi.org/10.1155/2022/1710737