Further Evidence of Persistence Of the 2,4-D Stimulus in Cotton

Although several reports in the literature indicate that 2,4-dichlorophenoxyacetic acid (2,4-D) or the stimulus therefrom does not normally persist in plants (3, 4, 5, 6,15), it has been demonstrated by the authors that cotton is an exception to this generalization (8,11,13). This fact became apparent upon demonstration of a transmission of the stimulus into seed embryos formed subsequent to 2,4-D application. In studies (7,11,12) dealing with the effects of 2,4-D on the vegetative characters of the cotton plant, it appears that persistence is also shown. This paper deals with further experiments designed to show the continuing activity of 2,4-D in vegetative organs of the cotton plant as evidenced by (a) malformation and (b) recovery of the growth substance.