Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 3/20/2005
Publication Date: 7/1/2005
Citation: Janisiewicz, W.J. 2005. Biological control of stem-end decay of "d'anjou" pears in storage. Phytopathology.
Technical Abstract: Stem-end decay of "d’Anjou" pears which is caused by Penicillum expansum or Botrytis cinerea is the major decay of fruit that is kept in cold storage for extended periods of time. The succulent thick stems of "d’Anjou" pear are prone to colonization by these fungi. We isolated bacteria and yeasts from pear and apple fruits, and screened them for their ability to colonize pear stem tissue. Populations of the best bacterial and yeast colonizers increased by more than 2 log units within 3 d at 24°C. They were then evaluated in cold storage at 1°C for their ability to prevent infection of pear stems by a very aggressive strain of P. expansum and a weak, pathogenic strain of a Penicillum spp. isolated from a pear stem. A few isolates reduced stem-end decay, and the biocontrol potential of some of these isolates has been confirmed in subsequent tests. Two bacteria were found to promote fungal infection of the stem and subsequent fruit decay by both pathogens. The abundance of the decay promoting bacteria in some years may be responsible for the high incidence of stem-end decay in those years.