Akta Agrosia. 2020. 23(1):33-37 33 Cited this as: Ariska, F ., W. Widodo, and M. Marlin. 2020. Morphological responses of bawang dayak (Eleutherine palmifolia (L.) Merr.) to plant growth promoting rhizobacteria application. ISSN: 1410-3354 / e-ISSN:2615-7136 ARTICLE INFO Keywords: growth and yield component immersion time medicinal plant plant production Article history: Received: Nov 22, 2019 Accepted: June 26, 2020 Published June 29, 2020 *Corresponding author: E-mail: marlin@unib.ac.id ABSTRACT Bawang dayak is one of the important medicinal plant that need to be devel- oped in cultivation techniques and production. The use of Plant Growth Pro- moting Rhizobacteria (PGPR) recently known to be effective to increase plant growth and yield. This research aimed to determine the optimal concentration and immersion time of PGPR on the growth and yield of bawang dayak. The experiment was arranged in complete randomized block design, consisting of two factors. The first factor is the concentration of PGPR with 4 levels name- ly K 0 = 0 g L -1 , K 1 = 5 g L -1 , K 2 = 10 g L -1 and K 3 = 15 g L -1 . The second fac- tor is immersion time of seed, namely P 1 = 10 minutes, P 2 = 20 minutes, P 3 = 30 minutes and P 4 = 40 minutes. The results showed that there was an inter- action between concentration and immersion time of PGPR on the number of leaves and the number of tillers. The immersion time of PGPR for 10 minutes with a concentration of 15 g L -1 produced the highest number of leaves (58 leaves) and produced the highest number of tillers (27.67 tillers). The treat- ment of PGPR concentration or immersion time of PGPR singly did not affect all observed variables of growth and yield of bawang dayak. Akta Agrosia Morphological Responses of Bawang Dayak (Eleutherine palmifolia (L.) Merr.) to Plant Growth Promoting Rhizobacteria Application Fera Ariska, Widodo Widodo, and Marlin Marlin Department of Crop Production, Faculty of Agriculture, University of Bengkulu, Jl. WR Supratman Kandang Limun Bengkulu 38121 Indonesia INTRODUCTION Bawang dayak is a medicinal plants typical of the forests of Central Kalimantan, originating from Tropical America. Bawang dayak is beneficial to reduce hypertension, cholesterol, boils, diabetes, colon cancer, stomach pain after childbirth and also can prevent strokes (Galingging, 2007). According to Heyne (1987) bawang dayak bulbs contain alkaloids, glycosides, flavonoids, phenolics, quinones, steroids, tannins and essential oils. The leaves and roots contain polyphenols and flavonoids. In Indonesia, bawang dayak are not yet widely cultivated intensively. Cultivation techniques of bawang dayak are also not yet developed. Efforts to improve bawang dayak production should be done with environmentally friendly cultivation techniques. One of them is by providing plant growth promoting rhizobacteria (PGPR) applied to bawang dayak seeds. PGPR is a group of beneficial bacteria that can stimulate plant growth, increase crop yields and soil fertility (Rahni, 2012). Bacteria in PGPR are Pseudomonas sp, Bacillus sp, Azobacter sp and, A zospiriumsp, and fungi Aspergilussp (Saraswati and Sumarsono, 2015). According to Sayuti (2018) the administration of PGPR has a significant effect on the number of bulbs per clump in shallot (70 HST) due to the presence of phytohormone in PGPR such as auxin and gibberellins.