Fig. 1.

Relationships between root elongation rates, lunisolar gravimetric and geomagnetic parameters during early summer of 2008. Time series commenced 27 May 2008 and concluded 2 June 2008. Last Quarter Moon occurred on 28 May 2008. (A) Time series of the mean rates of root elongation (μm h⁻¹) estimated at half-hourly intervals for a set of 23 roots in free-running conditions (top panel), lunisolar tidal acceleration, δg (middle panel) and geomagnetic indices, PC, Dst and ap (lower panel). (B) Same time series as shown in (A), but after removal of the trends displayed by the data points. The normalized curve represents the root elongation rate variation δR. For clarity, the graph of the lunisolar tidal acceleration δg has been inverted relative to this same graph shown in (A), as denoted in the key by δg⁻¹.