Powdered leaf and pod material of Caesalpinia coriaria (Jacq.) Willd. was extracted with
water and successively with different solvents viz., petroleum ether, benzene, chloroform,
methanol and ethanol. Anti-bacterial activity assays of all the extracts against the important
phytopathogenic Xanthomonas pathovars, known to cause diseases in tomato, french bean and
cotton, were carried out by cup diffusion method. Aqueous pod extract showed significant
activity. Among the five solvents extracts tested, methanol extract of both leaf and pod was
most active against all the test bacteria, followed by ethanol extract. Comparison of the
inhibitory activity of the extracts with the antibiotics bacterimycin 2000 and streptocycline
revealed that methanol and ethanol extract of both leaf and pod and aqueous extract of pod
were significantly higher than that of the antibiotics tested. Phytochemical analysis of leaf and
pod materials revealed that antibacterial activity is due to the presence of phenolic and acidic
fraction. Further separation of active fraction resulted in the loss of anti-bacterial activity,
indicating a synergistic effect of the isolated active fraction. The results suggest that C.
coriaria is a potential candidate plant for the management of phytopat