Pseudopeziza leaf spot (PLS) is caused by the fungus Pseudopeziza trifolii, mainly in autumn and winter in the North Island. Quality of conserved feed can be affected.
First symptoms are buff coloured, circular spots varying in size, with a darker fringe, on the upper surface of the leaves. In severely infected pastures leaves can curl up and turn brown. PLS occurs mainly in cool, moist, winter conditions and is exacerbated by infrequent grazing.
Spores produced by the fungus are forcibly ejected into the air, where they spread infection to new sites.
Prevention and management
Timely grazing or cutting minimises damage of infected pastures.
Pseudopeziza leaf spot of clover. (Photo: MAF, Lincoln)