Olives are rarely grown in New Zealand, but on the few trees observed this leaf spot occurs in late spring causing considerable defoliation. Again if this crop is to be grown, resistant varieties should be introduced.

Type: Foliicolous Fungi; Description: Mycelium internal, subcuticular, composed of hyaline, smooth, radiating hyphae, 3–8 m wide. Conidiophores emerging through the cuticle, aggregated or widely separated, straight, erect, flask shaped, with a cylindrical neck, pale brown to dark brown at the base, becoming paler towards the apex, verruculose, up to 30 μm long, bearing several closely spaced annellations. Conidia obclavate, 1-septate, 19–28 × 9–12 μm, verrucose, yellow brown to pale brown, somewhat flattened at the base. Leaf spots dark brown, annular or zonate with a green centre, up to 5 mm in diameter, sometimes effuse, covering the whole leaf, often surrounded by concentric pale yellow, violet or pale brown halo, on upper surfaces of leaves.

Distribution: Northland, Auckland, Waikato, Bay of Plenty.; 1st Record: Brien & Dingley (1955).

Significance: Infection occurs in late spring and can cause considerable defoliation in susceptible varieties (Dingley 1969). An important disease of olives in Mediterranean countries.; Host(s): Olea europaea.