The Relation of Certain Bacteria to the Development of Roots

Abstract

Root stimulation and the development of some types of "hairyroot" followed inoculations with certain bacteria. Hairyroot has followed inoculations through punctures in the underground parts of the current season''s growth of apple grafts with approximately 40 strains of bacteria isolated from overgrowths on apple from 40 sources. Reisolations and re-inoculations have been attempted with 6 strains and have been successful in each case. Parallel inoculations with known cultures of the closely related Bacterium tumefaciens resulted in typical crowngalls and in no case showed any stimulation of roots. The initiation of roots has also followed inoculations on rose and honeysuckle.