Nature and Source of Inoculum of Aspergillus niger Causing the Aspergillus Black Mold Disease of Onions in New York 1997
Project Leader: J. W. Lorbeer
1. Develop fundamental knowledge concerning inoculum sources and environmental conditions leading to the development of the Aspergillus black mold disease under New York conditions, with emphasis on the seedborne aspect of the disease.
2. Determine the effectiveness of thiram and progro seed treatments in controlling the pathogen.
3. Allow onion growers in New York to better focus on ways to minimize the threat of the black mold disease.
During 1996 and 1997 both home-grown and commercial onion seed lots were detected as harboring A. niger. The detection of this pathogen in home-grown seed produced in Orange County has so far been related to specific farms. Usually, all seed lots of home-grown seed tested (different varieties or strains) from these farms have been found to be infested by A. niger. When surface infestations and shallow infections of onion seed occur, future growth of the fungus appears to be controlled by thiram seed treatments, whereas when deep infections of the seed occur, future growth appears not to be controlled by it.