Dinitrophenol, anoxia, and starvation reduced the absorption and retention of 2,4-D in roots and leaves of bean, cotton, barley and soybean plants. Phloem translocation of the compound was likewise reduced. Apoplast mobility of the compound was, however, increased.

In 6-hour pH series tests, absorption of 2,4-D by roots of intact bean plants was many times greater at pH 3 than at pH 11. At pH 3, roots had absorbed 25 per cent of its supplied 2,4-D applied in 10^-6 M concentration in 100 ml of nutrient solution. One third (loosely adsorbed) of this absorbed amount was leached out by tap water in 2 hours; the residual two-thirds was considered metabolic absorption. The amount of this metabolic absorption seemed directly related to the degree of loose adsorption of 2,4-D.