IN-VITRO SCREENING OF SOME CHEMICALS AGAINST ERWINIA CAROTOVORA THE CAUSAL AGENT OF SOFT ROT OF POTATO

Abstract

In vitro efficacy six selected chemicals were evaluated against Erwinia carotovora subsp. carotovora the causal agent of potato soft rot disease. The experiment was done at Molecular Plant Pathology laboratory of the department of Plant Pathology of Sher-e- Bangla Agricultural University. E. carotovora was isolated from infected potato tubers by dilution plate method and different biochemical tests and pathogenicity test were performed to confirm the bacterial species. Six chemicals viz. Sunvit 50 WP (Copper Oxychloride) @ 0.2%, Dithane M-45 (Mancozeb) @ 0.2%, Boric acid (Boric Powder) @ 0.1%, Kasumin (Kasugamycin) @ 0.02%, Autostin 50 WG (Carbendazim) @ 0.3% and Chlorox (Sodium Hypochlorite) @ 0.2% were tested against E. carotovora by well diffusion method. For each treatment there were four replications and tested chemical volume was 100 μl. Data were recorded up to five days of incubation. Among six chemicals only four chemicals viz. Sunvit 50 WP, Dithane M-45, Boric acid and Kasumin showed bactericidal activity against E. carotovora subsp. carotovora. Maximum zone of inhibition (mm) was obtained after 48 hours of incubation with Sunvit 50 WP (30.35 mm), followed by Dithane M-45 (20.15 mm), Boric acid (19.15 mm) and Kasumin (16.28mm). While the least zone of inhibition was recorded with Autostin 50WG (3.83mm) and Chlorox (2.42mm). Sunvit 50 WP produced the maximum growth inhibition (33.79%) of the pathogen, on the other hand Cholorx (3.47%) did not effectively inhibit the growth of E. carotovora. No inhibition was recorded with untreated control/water. Sunvit 50WP proved to be the best chemical followed by Dithane M-45 under in-vitro screening test against E. carotovora subsp. carotovora.