Efficacy of Biocontrol Agents and Bactericides for the Management of Bacterial Blight Incited by Xanthomonas axonopodis pv. dieffenbachiae in Anthurium andraeanum

Bacterial blight of Anthurium incited by Xanthomonas axonopodis pv. dieffenbachiae (XAD) is one of the most serious and devastating disease causes severe losses to cut flower production. In vitro screening of antagonistic B. mojavensis strain KA3 inhibited the growth of X. axonopodis pv. dieffenbachiae over an area of 3730 mm². It was followed by B. subtilis isolate BSD4, which inhibited the pathogenic bacteria to an extent of 3430 mm². In vitro screening with bactericides and fungicides against X. axonopodis pv. dieffenbachiae reflected that streptomycin sulphate was most effective in inhibiting the bacterial blight pathogen at 2000 ppm which confers an area of inhibition of 1810 mm², which was significantly superior over all other treatments and succeeded by 1000 ppm of streptomycin sulphate, which recorded 1254 mm² area of inhibition against XAD. Screening with gentamycin, indicated that the mean maximum area of inhibition of the bacterial pathogen XAD was 1054 mm² at 2000 ppm against XAD under in vitro. However, comparison of the efficacy between streptomycin sulphate and gentamycin, indicated that, streptomycin sulphate was highly effective rather than gentamycin. Similarly, fungicides such as copper oxychloride, alliete, isotianil and bromopol (2-bromo 2-nitro propane 1, 3-diol) which had antibacterial activity were tested against XAD under in vitro.