Vermicompost Reduces Disease in Crops

ANTIMICROBIAL POTENCY OF EUDRILUS EUGENIAEEXTRACTS ON CERTAIN PLANT PATHOGENS

Summary 2006 By Shobha S.V* and Dr. Radha Kale**

*Dept of Env. Science, Mount Carmel College, Bangalore **Dept of Zoology, Univ. of Agricultural Sciences

Use of vermicompost as an organic amendment to agricultural lands is practiced by many Indian farmers and they opine that the application of vermicompost brings down the incidence of many soil borne diseases in crops. To investigate the facts about this view the laboratory research was carried out to study the effect of different preparations from the body of Eudrilus eugeniae earthworms on selected bacterial and fungal pathogens. Since earthworms are soil residents and they play an active role in improving soil quality, it was hypothesized that worm extracts may have inhibitory/suppressive effect on soil-borne pathogens. Hence 3 bacterial and 5 fungal soil-borne plant pathogens were selected for the study. The result showed that the body wall and gut extract had both antibacterial and antifungal activities while coelomic fluid was found to have only antibacterial activity.

Body wall and gut extracts were found to have inhibitory effect on Xanthomonas campestris, Ralstonia solanacearum and Fusarium oxysporum. Erwinia carotovora was inhibited by gut extract and coelomic fluid. Botryodiplodia theobromae, soil-borne fungal plant pathogen, was suppressed by body wall extract, but at slightly higher concentrations. There was no inhibitory effect recorded by any of the worm extracts at the used concentrations during this study on Rhizoctonia solani, Alternaria solani, and Sclrotium rolfsii. Only delayed sporulation was observed in all the cases, but this was only a visual observation. There was no further work like hyphal length measurements or germination study conducted for these fungal pathogens due to various limitations.

Further studies are in progress to assess the concentration effect of extracts on response of organisms to the earthworm extracts.