Antibacterial effect of Chromolaena odorata extracts on some Erwinia isolates, causal agents of tomato fruit rot in Dschang, Cameroon

Abstract Background In spite of the fact that tomato fruits do not only serve as food but as medicine, nutrient supplement, flavouring ingredient, detoxificant and human system cleanser, the household consumption is on a constant increase worldwide. The microbial deterioration of tomato fruits causes reduction in market value and nutritional quality and at times renders the fruits unfit for consumption. This study was carried out to determine the in vitro and in vivo antibacterial effects of Chromolaena odorata leaves extracts on some Erwinia isolates, agent of post-harvest decay of tomato fruits. Results The results showed that the in vitro test of aqueous and ethanol extracts more significantly inhibited the growth of the two Erwinia isolates to the respective concentrations of 3 and 9 mg/ml with inhibition zones attaining 30 mm. The in vivo test revealed that these extracts have efficiency against bacterial isolates growth on the Cobra variety with 100% inhibition of EJD16 isolate for the ethanol extract. Conservative effect assessment revealed that the two extracts showed best preserved fruits of Cobra variety more than those of Rio Grande variety with a low rate of tomato fruit rot. Conclusion Based on the results obtained, the ethanol extract was more effective than the aqueous extract and completely inhibited the growth of EJD16 isolate on tomato fruits. Ethanolic extract of C. odorata could be recommended to extend the life span of tomato fruits