Evaluation of some botanicals against bacterial wilt of tomatoes

Abstract

Tomato production is affected majorly by pests and diseases; one of the major diseases being Bacterial wilt caused by Ralstonia solanacearum. Healthy tomato plants (variety Beske) were subjected to infection with the bacterium to determine its pathogenicity. Studies were also carried out to determine the anti-microbial effects of water extracts of Zingiber officinale, Azadirachta indica, Cymbopogon citratus, Ocimum gratissimum, Allium sativum, Venonia amygdalina, Jatropha curcas, Senna obtusifolia, Senna occidentalis and Senna sophera at varying concentrations on Ralstonia solanacearum. The crude extracts at various concentrations (0.5%, 1% and 10%) did not have any inhibitory effects on Bacterium. The use of other types of solvents may be necessary as the active ingredients of the plant materials may not be soluble in water. Sensitivity to antibiotics was tested on the bacterium. Seven of the fourteen antibiotics used showed zones of inhibition while the other seven did not have any effects. Ciprofloxacin, Ofloxacin, Pefloxacin, Drovid, Cotrimozazole, Norfloxacin and Clindomycin resulted in varying zoning diameters (2.5-13mm) while Tetracyclin, Amoxycylin, Gentamycin, Nitrofurantoin, Ceftriazone, Augmentin, and Erythromycin did not have effects on the bacterium. The effective antibiotics may be incorporated into the development of an integrated management approach for the control of bacterial wilt of tomatoes.