Integrated management of bacterial wilt of brinjal using bactericides, bio-control agents and cultural practices

Bacterial wilt of brinjal caused by Ralstonia solanacearum is a serious soil-borne disease that significantly reduces crop yield in tropical and subtropical regions. The present study was conducted to evaluate the efficacy of selected bactericides and integrated disease management (IDM) strategies against bacterial wilt under laboratory and field conditions. The pathogen was isolated from infected plants and identified based on cultural characteristics on Yeast Extract Peptone Sucrose Agar (YPSA) and Triphenyl Tetrazolium Chloride (TTC) media, producing typical fluidal colonies with pinkish centers. Pathogenicity was confirmed following Koch’s postulates, with wilting symptoms appearing eight days after inoculation. In-vitro evaluation using the well diffusion method revealed that tetracycline-based antibiotics, including tetracycline, oxytetracycline hydrochloride and streptomycin sulfate + tetracycline hydrochloride, exhibited strong antibacterial activity against R. solanacearum. In contrast, bleaching powder, calcium nitrate, and bismerthiazol showed little or no inhibition under laboratory conditions. Field experiments were conducted using a Randomized Complete Block Design (RCBD) with three replications to assess the performance of different bactericide treatments and IDM combinations. The two consecutive year results indicated that bismerthiazol-based treatments, reducing disease incidence to 5.66-13.33% compared to 56.33% in the untreated control, corresponding to up to 76.34% disease reduction. These treatments also produced the higher yields (10.23-10.33 kg per plot), with up to 93.81% increase over the control. Oxytetracycline hydrochlorride treatments showed 68.50-79.88% disease suppression and yield improvement (35.50-97.56%), while streptomycin-based treatments were comparatively less effective. Integrated treatments combining polythene-covered ridge beds, bio-control agents, and bactericides further enhanced disease suppression and yield performance. The combination of Trichoderma harzianum with bismerthiazol under polythene covering proved most effective. Overall, the study demonstrates that IDM approaches integrating cultural practices, biocontrol agents, and selective bactericide use are more effective and sustainable than relying solely on antibiotics for managing bacterial wilt and improving brinjal productivity. Bangladesh J. Agri. 2026, 51(1):105-125