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Thesis (M.S.)--University of Nebraska--Lincoln, 1961. Department of Agronomy.


Copyright 1961, the author. Used by permission.


Biochemical, phonological and physiological studies of tanweed (Polygonum coccineum Muhl.) were undertaken to give a better understanding of bud dormancy. Bud activity, amino acids, percentage total nitrogen, protein nitrogen, peroxidase activity, polyphenolase activity and IAA oxidase activity were determined and characterization of an inhibitory substance(s) was done. Observations were made in the field on several phological aspects of tanweed and were recorded during the 1960-61 sampling period. Bud activity, date of emergence, new rhizome growth, date of flowering and date of seed maturity were recorded.

Greenhouse experiments have shown that tanweed infested soil and soil with ground tanweed material added significantly reduced the top growth of wheat, alfalfa and barley grown in the soil.

In the laboratory, tanweed rhizome and top extracts caused root inhibition of germinating wheat seedlings. The inhibitory substance(s) was found to be heat stable and dialyzable. It was shown that the molar concentration of tanweed extracts was causing a small part of the inhibition of root growth of wheat. Freezing, autoclaving, passing it through a celite and sand column, Dowex 1-X4 or Dowex 50W-X4 did not decrease the inhibition of root growth of wheat. Activated charcoal removed some of the inhibitory substance(s). The inhibitory substance(s) in tanweed rhizomes did not increase during the period of bud dormancy.