Polar and Lateral Transport of Water in an Apple Tree

Abstract

An apparent polar movement of nutrients associated with polar water transport has been demonstrated for plants with a particular arrangement of vascular tissues. Rinne and Langston (1960) studied the movement and distribution of 32p in peppermint (Mentha piperita L.) and showed polar transport to occur when half the root system was fed with 32p. In the short term 32p was even confined to half leaf blades of leaves in the median orthostichies. Caldwell (1961), who used a split-root technique to grow Ooleus sp., demonstrated the apparent polar transport of nutrients to be maintained over a long period when half the root system was grown in nutrient-rich soil and half was grown in nutrient-deficient sand. Much less growth occurred in the side of the plant supplied by the roots in the nutrientdeficient sand.