Response of Plants to Root-absorbed Chemical Growth Substances applied in Culture Solutions

A CONTINUOUSLY available supply of biologically active chemicals from a large external pool during the course of experimentation with higher plants is often desirable. Foliage sprays or µl. solution applications of growth substances to the vegetative tips of plants result in the imposition of heroic dosages to restricted parts. Such treatments constitute a crude approach in duplicating an endogenous synthesis and in maintaining physiologically tolerable levels in the plant.