Antibiotics and garlic clove extract--inhibitory agents of cell wall degrading enzymes.

Four antibiotics were tested against Erwinia causing soft rot of onion (Allium cepa var. aggregatum) of which streptomycin sulphate 90% and tetracycline hydrochloride 10% (streptocycline) recorded the maximum inhibition zone of 27.66 mm. In the enzyme studies the maximum inhibition of pectinlyase (PL), polygalacturonase (PG) and protopectinase production was recorded by the same antibiotic. The antibiotics have a significant influence on the production and activity of cell wall degrading enzymes produced by the plant pathogenic microorganisms. Garlic clove extract was equally effective in inhibiting the growth and enzyme production.