ISHS Acta Horticulturae 696: VII International Symposium on Temperate Zone Fruits in the Tropics and Subtropics - Part Two
BACTERIAL ANTAGONISTS IN MANAGEMENT OF COLLAR ROT AND ROOT ROT DISEASES IN APPLE |
| Authors: | I.M. Sharma, S.S. Bhardwaj |
| Keywords: | apple, bacterial antagonists, collar rot, root rot |
| Abstract:
Bacterial antagonists were evaluated in controlling two important soil-borne diseases viz., collar rot (Phytophthora cactorum (Leb. & Cohn) Schroeter) and root rot (Dematophora necatrix Hartig) of apple under laboratory, pot culture and field conditions during the years 2000 to 2002. Out of 55 bacterial antagonists, isolated from apple orchards and nurseries’ soil including four procured from PDBC-Bangalore (India), only four viz., Bacillus subtilis-3, Pseudomonas fluorescens (KB6), Enterobacter aerogenes-2, and P. putida-1, and seven namely, E. aerogenes-3, P. fluorescens (KB6, KB15, chickpea and cotton isolates), B. subtilis-2 and B. subtilis-4 were quite effective against collar rot (75.3-82.1% inhibition) and root rot (71.1-84.1% inhibition) pathogens, respectively under laboratory conditions. Bacillus spp. (NA1, NA11) E. aerogenes-3, and P. fluorescens (KB6, chickpea and cotton isolates) were also observed to inhibit (in vitro) toxin production by root rot pathogen. Pot culture evaluation of in vitro effective bacterial isolates against collar rot pathogen revealed that five namely, B. subtilis-3, E. aerogenes-2, P. putida-1, B. subtilis-2 and endophytic bacterium from mustard roots (B. subtilis) were individually effective (72.5-89.2%). Further, P. fluorescens (KB6, chickpea and cotton isolate), B. subtilis-2, E. aerogenes-2 and Bacillus sp. (NA11) were effective against root rot pathogen under pot culture conditions and provided disease control of 72.3 – 82.1 per cent. Under field conditions in nursery, B. subtilis–3, E. aerogenes–2, P. putida-1, and B. subtilis-2 and endophyte from mustard root were almost equally effective (76.4-79.6%) in controlling collar rot disease whereas, P. fluorescens (KB6, cotton isolates), B. subtilis-2, and Bacillus sp. (NA11) were effective (75.2– 78.1%) in checking the root rot disease. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
