MAGNETISM AND PLANT GROWTH: II. EFFECT ON ROOT GROWTH OF CEREALS

Most roots of Kharkov 22 M.C., Vakka, Jones Fife, Norin 62, Werla, and Capelle winter wheats (Triticum aestivum L.) and of Chinook spring wheat (Triticum aestivum L.) orientated themselves in a plane approximately parallel to the horizontal component of the geomagnetic field when grown in stationary pots at Lethbridge, Alta. Similarly, the roots of Kharkov 22 M.C. grown at St. John’s, Nfld., orientated themselves in approximately this same plane. In contrast, the roots of common fall rye (Secale cereale L.) were omni-directional.The roots of winter and spring wheats, oats (Avena sativa L.), and fall rye grown in a magneto-klinostat at Lethbridge orientated themselves in a plane approximately parallel to the lines of force of an introduced magnetic field that intersected the horizontal component of the geomagnetic field at right angles.A critical level of magnetic intensity may be necessary before the tropism occurs. This level probably differs between species and varieties.