EFFECT OF GARLIC EXTRACT, BELTANOL AND AGROMYCIN ON THE BACTERIA RALSTONIA SOLANACERUM

Abstract

This tests was carried out to evaluate the efficacy of water extract of garlic on Ralstonia solanacearum, the causal agent of bacterial wilt on tomato. Results showed that the addition of garlic extract at a concentration of 1%, 2%, 4% and 8% to the culture media containing Ralstonia solanacearum was efficient to prevent bacterial growth. The percentage of inhibition reached 14.8%, 100%, 100% and 100% for the four concentrations respectively. Filter paper discs 4 mm diameter saturated with 2% of garlic water extract, 0.2% Beltanol and 0.5 g/l Agromycin placed on the culture media led to prevent bacterial growth; it was found that garlic water extract was more efficient, with halo diameter in its treatment reached 19.90 mm compared with 14.60 mm for Belatnol of 0.2% concentration and 11.80 mm for the antibiotic Agromyicn 0.5 g/l concentration. Tomato plants inoculated with bacteria and treated with 2% garlic extract and the fungicide Beltanol (0.2 ml/l) showed to significant reduction in disease severity for all the treatments, so the different between the three treatments and the control became non significant. The percentage of disease severity for the plants treated with garlic water extract added to the irrigation water, Beltanol and garlic extract sprayed on plant shoots reached 2.5%, 2.5% and 6.25% respectively after 3 days of treatment. It has been found that the addition of garlic water extract with irrigation water was more efficient than Beltanol and garlic extract sprayed on plant shoots in the following days of the treatments. The disease severity was reached 5.00% for the plants treated with the garlic extract as soil treatment after 15 days of treatment compared with 11.5% for the plants treated with Beltanol and 16.25% for the plants sprayed with garlic extract. It has been found that addition of garlic extract to the plant gave a protection period of 24 days as determined by immunodouble diffusion test.