Within this article an incorrect figure was included. The correct figure is shown below.
![](https://static.cambridge.org/binary/version/id/urn:cambridge.org:id:binary-alt:20160708122321-72924-mediumThumb-S0021859609008636_fig1g.jpg?pub-status=live)
Fig. 7. Leaf potassium concentrations for different K treatments in the Aplahoué-2004 (a) and Savalou-2005 (b) experiments. K was applied to the soil at 130°Cd post-emergence. K was determined for whole plant leaves and expressed on a dry weight basis. Vertical bars are confidence intervals at P<0.05.