Induction of primary root curvature in radish seedlings in a static magnetic field

Primary roots of radish ( Raphanus sativus L.) seedlings were exposed to an inhomogeneous static magnetic field generated by a permanent magnet, during continuous rotation on a 0.06 rpm clinostat, thereby reducing the unilateral influence of gravity. The roots responded tropically to the static magnetic field with the tropism appearing to be negative. These roots responded significantly ( P  < 0.05) to the south pole of the magnet. The significant tropic response was found for a magnetic flux density of 13–68 mT, for a field gradient of 1.8–14.7 T/m, and for the product of magnetic field and field gradient of 0.023–1.0 T 2 /m. A small, but insignificant, response of the roots to the north pole has also been found. Bioelectromagnetics 22:194–199, 2001. © 2001 Wiley‐Liss, Inc.