Penapisan Rizobakteria Toleran Kekeringan Pemacu Tumbuh Tanaman Kedelai dan Aplikasinya di Rumah Kaca

Abstract

Drought stress can reduce the productivity of crops. Therefore, strategies to promote growth of plants that can grow well in drought conditions is required. One of the way is by using the plant growth promoting rhizobacteria (PGPR). The aim of this study was to screen rhizobacteria in drought stress and apply them on soybean in greenhouse. A total of 27 rhizobacteria consisted of 14 Pseudomonas sp. (Crb), 11 Bacillus sp. (Cr), and 2 Bradyrhizobium japonicum. (Bj) was screened on drought conditions using media supplemented with Polythylene Glycol (PEG) 6000 then quantitatively tested for exopolysaccharide product. Selected bacteria were tested for antagonistic assay tested before combining them in a package formula in the peat. Bacteria were grown in media skim milk and molasses then inoculated into 50 g of peat soil. The formula were tested for the viability and effectiveness on soybeans in green house. Total of 17 bacteria were successfully screened and all grow well at low osmotic potential (-2 Mpa) medium and produced exopolysaccharide ranging 1.7-8.0 mg/ml. Based on the exopolysaccharide produced and antagonist test, five packages of formula were selected. Viability of five formulas were stable until the three months of storage period. Application of the formulas for soybean in green house, formula F4 showed significant effect on plant height, shoot and root fresh weight and root dry weight in both wet and dry conditions.