Bio-efficacy of different antibacterial antibiotic, plant extracts and bioagents against bacterial blight of soybean caused by Pseudomonas syringae pv. glycinea

Abstract

An experiment was carried out to study efficacy of different antibacterial antibiotic, plant extracts and bioagents against bacterial blight of soybean caused by Pseudomonas syringae pv. glycinea. The results revealed that all the five antibiotics tested in vitro applying poisoned food technique against Pseudomonas syringae significantly inhibited the growth of the test pathogen over untreated control. However, antibiotic, Streptocycline + Copper oxychloride recorded minimum mean colony diameter (10.47mm) and maximum mean inhibition (83.65 mm) of growth of the test pathogen over untreated control (mean col. dia. 90.00 mm and mean inhibition, 0.00) followed by the antibiotic Streptocycline 100 ppm (mean col. dia., 15.64 mm and mean inhibition, 76.69%) and Copper oxycloride (mean col. dia., 21.42 mm and mean inhibition, 62.74%). In field, the highest mean per cent disease incidence 35.51 per cent was observed in poushamycin treatment. The lowest mean per cent disease incidence 12.74 per cent was found in treatment streptocycline 100 ppm + Copper oxychloride (@0.25%) and recorded highest seed yield (2605 kg/ha) and test weight (14.33 g). Plant leaf extract (@ 5 and 10%) of Neem recorded lowest mean colony diameter (34.72 mm) and highest mean mycelial growth inhibition (59.26%) of the test pathogen over untreated control followed by Ginger (mean col. dia, 44.42 mm and mean inhibition, 48.55%).