Brown blight (BB) is caused by the fungus Pyrenophora lolii. It...

Brown blight (BB) is caused by the fungus Pyrenophora lolii. It is most common in spring and autumn but damage can occur all year.

Crown rust (CR) occurs throughout NZ, but is found mainly in the...

Crown rust (CR) occurs throughout NZ, but is found mainly in the North Island. It is caused by the fungus Puccinia coronata, mainly in warm, moist conditions from early summer to late autumn. CR depresses pasture growth and palatibility.

Damping off covers a range of fungi that cause plant death in...

Damping off covers a range of fungi that cause plant death in establishing pasture. Causal pathogens are Pythium and Fusarium spp.

Ergot is caused by the fungus Claviceps purpurea. It occurs in...

Ergot is caused by the fungus Claviceps purpurea. It occurs in summer when ergots (or sclerotia) develop on seed heads.

Net blotch (NB) is common throughout NZ, caused by the fungus...

Net blotch (NB) is common throughout NZ, caused by the fungus Pyrenophora dictyoides, usually in autumn. NB can seriously affect winter pasture.

Powdery mildew (PM) is caused by the fungus Blumeria graminis. It...

Powdery mildew (PM) is caused by the fungus Blumeria graminis. It usually occurs in spring and autumn. It is normally a minor disease in NZ, only causing significant yield reductions under heavy infection.

The fungus Ramularia pusilla causes Ramularia leaf spot (RLS...

The fungus Ramularia pusilla causes Ramularia leaf spot (RLS), most commonly in spring and autumn, when it can seriously reduce yield and quality.

Scald, caused by the fungal species of the Rhynchosporium genus...

Scald, caused by the fungal species of the Rhynchosporium genus, typically occurs between April and October, from Manawatu and Hawke's Bay south.

Snow mould is caused by the fungus Microdochium nivale and can...

Snow mould is caused by the fungus Microdochium nivale and can sporadically cause serious disease. It can be a problem in establishing autumn sown pasture following cereals. Long, rank pasture swards can also become infected in winter, especially under snow.

Stem rust (SR) occurs throughout NZ, caused by the fungus...

Stem rust (SR) occurs throughout NZ, caused by the fungus Puccinia graminis, mainly in warm, dry conditions in summer and autumn.

Caused by the fungus Cercospora zebrina, Cerospora leaf spot (CLS...

Caused by the fungus Cercospora zebrina, Cerospora leaf spot (CLS) is more common in summer and autumn, mostly in the North Island.

Several viruses that attack clover are often seen together...

Several viruses that attack clover are often seen together, including:
White clover mosaic virus, Alfalfa mosaic virus, Soybean dwarf virus, Clover yellow vein virus, Bean yellow mosaic virus, Watermelon virus

This clover disease is caused by the fungus Leptosphaerulina...

This clover disease is caused by the fungus Leptosphaerulina trifolii and is very similar to common leaf spot. However, the pathogen only sporulates on the dead tissue in the bottom of the pasture.

Common leaf spot (CLS) is caused by the fungus Pseudopeziza...

Common leaf spot (CLS) is caused by the fungus Pseudopeziza trifolii and mainly occurs in the cooler, moister winter months. This disease is common throughout NZ. Quality of conserved feed may be lost.

Clover rust is caused by a complex of rust species in the...

Clover rust is caused by a complex of rust species in the Uromyces genus and is sometimes found on clover throughout NZ. It can reduce forage quality.

Sooty blotch (SB) is caused by the fungus Polythrincium trifolii...

Sooty blotch (SB) is caused by the fungus Polythrincium trifolii and is common on white and red clovers. It can appear in early summer but is most common in late summer and early autumn, rarely causing economic loss.

Sclerotinia rot is caused by the fungus Sclerotinia trifoliorum...

Sclerotinia rot is caused by the fungus Sclerotinia trifoliorum. It usually occurs in late autumn and winter, particularly on pure swards of clover. Generally it is not serious.