February 18, 2020
In Proposition 1.6 of [1], to guarantee harmonicity of \(\phi _i\), the configuration given by the right-hand diagram in the statement of the proposition must also not occur with no arrow from \(k\) to \(i\). Thus no diagram of the form below can appear: this is needed to ensure that \(A’_{\beta ,\alpha }=0\).
This omission does not affect any other results in the paper.
We thank N. Correia, R. Pacheco and M. Svensson for bringing this error to our attention.
[1] F. E. Burstall, F. E. & J. C. Wood, The construction of harmonic maps into complex Grassmannians, J. Differential Geometry 23 (1986), 255–297; MR0852157 (88i:58038) .