Calcium deficiency

Marginal necrosis developing on young leaves (J. O'Sullivan).

(only some of the following features may be present)

- necrosis on lateral margins of young, expanding leaves (but not youngest leaf and tip except in severe cases).

- necrotic young leaves may be shed, leaving bare stem below the tip.

- necrotic spots on mid and older leaves, roundish but irregular in shape and symmetrically arranged.

- storage roots may be soft, very small and misshapen.

- fibrous root growth is inhibited.

Occurs in light-textured acid soils, with low cation exchange capacity. May be exacerbated by heavy application of potassium fertiliser (which can inhibit calcium uptake).