| Abstract: | A series of studies were conducted to further understanding of the biological characteristics and pathogenic host plant relations of Sclerotiurn rolfsii. The purpose of these studies was to add to the science of plant pathology and to provide basic information which hopefully will aid in control of the disease caused by S. rolfsii. Oat seeds were inoculated with S. rolfsii and grown in paper- dolls. Beginning with 32 hr, seeds were taken periodically from the paper-dolls, surface sterilized, and sectioned aseptically into three parts; embryo, center, and brush. Roots and coleoptile or stem were also excised when they protruded from the seed. All sections were incubated on potato-dextrose agar at room temperature. It was determined that S. rolfsii attacks the embryo and coleoptile or stem because these were the parts from which the pathogen was isolated. Sixty five grasses were tested for their reaction to a hyphal tipped field isolate of S. rolfsii. Post-emergence survival of the grasses was recorded as a percent of the controls. Bermudagrass exhibited the greatest survival number of all grasses tested. Kentucky bluegrass, commercial orchardgrass and Kleberg bluestem also exhibited high post-emergence survival. ... |
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