Brown blight (BB) is caused by the fungus Drechslera siccans. It...

Brown blight (BB) is caused by the fungus Drechslera siccans. 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 Drechslera dictyoides, usually in autumn and winter. NB can seriously affect winter pasture.

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

Powdery mildew (PM) is caused by the fungus Erysiphe graminis. It usually occurs in spring and autumn and is only a problem 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 fungus Rhynchosporium orthosporum, typically...

Scald, caused by the fungus Rhynchosporium orthosporum, typically occurs April-October, from Manawatu and Hawke's Bay south.

Snow mould is a rare but serious disease, caused by the fungus...

Snow mould is a rare but serious disease, caused by the fungus Monographella nivalis (asexual phase – Microdochium nivale or Fusarium nivale). 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 leaf disease is caused by the fungus Leptosphaerulina...

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

Pseudopeziza leaf spot (PLS) is caused by the fungus Pseudopeziza...

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.

Clover rust is caused by the fungus Uromyces trifolii-repens and...

Clover rust is caused by the fungus Uromyces trifolii-repens and is found occasionally on clover throughout NZ. It can cause loss of forage quality.

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

Sooty blotch (SB) is caused by the fungus Cymadothea trifolii. It can appear in early summer, but is most common in late summer and early autumn.

Watery soft rot (WSR) is caused by the fungus Sclerotinia...

Watery soft rot (WSR) is caused by the fungus Sclerotinia trifoliorum. It usually occurs in late autumn and winter, particularly on pure swards. Generally it is not a serious disease.