Respon Pertumbuhan dan Produksi Kacang Tunggak (Vigna unguiculata L.) terhadap Pemberian Plant Growth Promoting Rhizobacteria (PGPR) Akar Bambu

Abstract

Application of Plant Growth Promoting Rhizobacteria (PGPR) on Bamboo Roots is one of the effective efforts to increase the growth and production of Tunggak plants (Vigna unguiculata L.). PGPR is known to be able to increase nutrient availability, stimulate root growth, and increase the efficiency of water and nutrient use in Tunggak plants (Vigna unguiculata L.). This study aims to determine the effect of PGPR (Plant Growth Promoting Rhizobacteria) on Bamboo Roots on the growth and production of Tunggak plants (Vigna unguiculata L.). This study was conducted at Jl. Harmonika Baru, Padang Bulan Selayang II, Kec. Medan Selayang, Medan City, North Sumatra, at an altitude of ±25 meters above sea level (masl), with coordinates 3º33’17.532” N; 98º38’44.94”E from June to August 2025. The study was conducted using a non-factorial randomized block design (RAK) with six PGPR concentration treatments, namely 0 mL/Lwater (Control), 10 mL/L water, 20 mL/L water, 30 mL/L water, 40 mL/L water, and 50 mL/L water. The parameters observed included germination percentage, plant length, number of leaves, stem diameter, number of branches, chlorophyll content, initial flowering age, initial harvest age, number of pods per plant, seed weight per plant, and dry weight of 100 seeds. The results showed that the administration of bamboo root PGPR significantly affected the growth and production parameters of cowpea. Treatment P3 (30 mL/L water) yielded the best results, with significant increases in plant length, leaf number, pod number, and seed weight per plant. The best treatment is giving bamboo root PGPR with a concentration of 30 mL/L water is the optimal concentration to support maximum cowpea growth and production.