1979 Volume 48 Issue 3 Pages 279-287
To examine whether there exist growth inhibitors other than the hydrolysates of cyanogenic glucosides, which have been known to be responsible for the peach replant problem, extracts of peach roots, leaves and orchard soils and leaf leachates from peach trees were separated by column chromatography.
Condensed tannins were detected in the main inhibiting fractions of peach root extracts. They yield a red bright color by drastic heating in 2 N HCl. The behavior of the growth inhibiting fractions always coincided with that of the fractions containing the condensed tannins in different kinds of column chromatography and partition systems. More condensed tannins were excreted from peach roots under anaerobic than aerobic conditions. One of these compounds was purified and tested for root growth of peach seedlings on agar media. It greatly reduced the root growth at 5×102 and 1×103ppm. These findings are discussed in relation to the peach replant problem.