Nutation of growing and georsacting roots

Growth and geocurvature of the primary roots of maize (cv. LG 11) were analyzed by a filming technique allowing continuous recording, root by root. Typical nutations, in vertical growth and following the downward curvature of the roots, have been observed. The possible relations between these nutations, the elongation, the georeaction and the hormonal mechanisms which control georeaction, are discussed.