A system for concurrent measurement of centripetal passage of eadiophosphorus and of water plow across hoots to the xylem

Abstract

Methods are described for the concurrent measurement of water flow and of Centripetal Passage (CP)¹ of radiophosphorus across the root to the xylem. The amount of isotope which completed CP and reached the plant top served as a measure of CP. Comparison of this value with ³²P in the xylem stream served as a guide to water flow. This comparison was made by means of a double ratio function for check and treated plants, and conclusions were based on whether the final values were at, below, or above unity. Illustrations of these methods were given for various test variables including potassium supply, magnesium supply, root temperature, and root oxygen tension.

Key words:

• Centripetal passage‐ions, water
• measurement‐water, ion passage
• ratio‐water to ion passage