Tomato bacterial wilt in Saudi Arabia and the use of antagonistic bacteria for its control.
Ralstonia solanacearum was isolated from wilted tomato plants in Al-Qassim region, Central Saudi Arabia. Differential characterization tests revealed that the isolated bacterium belonged to race 1 and biovar 4 of R. solanacearum. Laboratory studies showed that the use of antagonistic bacteria (Bacillus subtilis (BI), Pseudomonas spp. (106, 115) and Pseudomonas cepacia [Burkholderia cepacia]) had a highly inhibitory effect against R. solanacearum on culture medium. Significant reductions in the number of wilted plants was achieved in greenhouse tests when the antagonistic bacteria were applied to tomato seedlings, which were then infested with R. solanacearum. It is suggested that the antagonistic bacteria tested are promising candidates for the biological control of R. solanacearum.