PENGARUH PEMBERIAN RHIZOBIUM TERHADAP MORFOLOGI DAN FISIOLOGI KEDELAI (Glycine max L. Merril) PADA KONDISI CEKAMAN KEKERINGAN

Abstract

ABSTRACT "Effect of Rhizobium Application on Morphology and Physiology of Soybean (Glycine max L. Merril) under Drought Stress Conditions". This study aims to examine the morphological and physiological responses of soybean (Glycine max L. Merril) to the provision of rhizobium under drought stress conditions. This research was conducted in a plastic house on Jl. Karya Wisata Johor, Medan with an altitude of 25 meters above sea level (masl) and in January-August 2023. This research consisted of 2 stages. The first stage used a Separate Plots Design (SPD) in a factorial Randomized Group Design (RBD), with the first factor being variety consisting of 3 levels, namely Grobogan, Dering-1 and Devon, while the second factor was Rhizobium japonicum inoculation consisting of 3 levels, namely, no inoculation, 3 g/kg soybean seeds and 6 g/kg soybean seeds. The second stage also used a Separate Plots Design (SPD) in a factorial Randomized Group Design (RBD), with the first factor being rhizobium-treated varieties consisting of 3 levels, namely Grobogan, Dering-1 and Devon, while the second factor was the watering interval consisting of 3 levels, namely, every day, every 3 days and every 6 days. The results showed that drought stress with a watering interval treatment of 6 days once decreased the morphological and physiological parameters of soybean. Grobogan is a drought-tolerant soybean variety based on morphological characters (plant height, number of plants, number of leaves, and number of seeds). Inoculation of Rhizobium japonicum 6 g gives the best effect on improving the morphology and physiology of soybean. Inoculation of Rhizobium japonicum 6 g in drought stress conditions with a watering interval treatment of 6 days had an effect on improving the morphology and physiology of the three soybean varieties tested. Keywords: morphology, physiology, soybean, drought stress, rhizobium