Abstract:
Stowe, Stodola, Hayashi, and Brian (1961) during research on growth-stimulating substances produced by the fungus Fusarium heterosporium. noted that one of the substances concerned was fusaric acid, also known as, 5-n-butylpicolinic acid, with the following formula:
It will be noticed that this substance has close affinities to 4-amino-3,5,6-trichloropicolinic acid, (‘Tordon'), and also nicotinic acid. Both of these chemicals are pyrimidine carboxylic acids, and are known to cause changes in the metabolic activity of plant cells.
It has since been found that ‘Tordon’, is extremely toxic to many broad-leafed plants, Haymaker, Johnston, Martin, and Redemann (1963). The symptoms produced by ‘Tordon’ are, in many respects, similar to those produced by other growth-stimulating substances, such as 2,4-Dichloro-phenoxyacetic acid (2,4-D), and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T).
