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DISSEMINATION AND SURVIVAL OF SCLEROTINIA SCLEROTIORUM PROPAGULES IN DRY EDIBLE BEAN FIELDS IN WESTERN NEBRASKA
Abstract
Aerial sampling and falling rain-water collections on acidified potato sucrose agar (PSAA) demonstrated the presence of a viable Sclerotinia sclerotiorum propagules in the atmosphere near bean fields after pod set. Honeybee activity on and in bean blossoms with subsequent isolation of S. sclerotiorum from 16% of bees sampled indicated that this insect could disseminate the white mold fungus. Propagules other than sclerotia were isolated from irrigation water. When randomly collected bean blossoms were plated on PSAA, 35% were found to have S. sclerotiorum. Whether insects, splashed water, or aerial dissemination was the source of S. sclerotiorum on blossoms could not be determined. The majority of ('14)C-labeled ascospores produced from apothecia placed beneath bean plant canopies were deposited at the inoculum source, but large numbers of spores did escape into the atmosphere through the plant canopy. ('14)C-labeled ascospores were disseminated by wind to the upper leaves of bean plants located up to 50 m from the inoculum source. White mold mycelium placed 6 cm above the plant canopy on stainless steel rods survived in the field for less than one hour. Mycelial growth on detached bean blossoms placed beneath the plant canopy survived for the duration of a 34-day test period. Ascospores were more ephemeral than mycelia; they survived for 11 days in soil and on attached bean leaves, for 7 days on glass microscope slides placed in the plant canopy, and less than one day when suspended on microthreads above the plant canopy.
Subject Area
Plant pathology
Recommended Citation
MUCKEL, ROBERT DALE, "DISSEMINATION AND SURVIVAL OF SCLEROTINIA SCLEROTIORUM PROPAGULES IN DRY EDIBLE BEAN FIELDS IN WESTERN NEBRASKA" (1982). ETD collection for University of Nebraska-Lincoln. AAI8308790.
https://digitalcommons.unl.edu/dissertations/AAI8308790