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.
The rust pathogen produces brick-red pustules on the underside of leaves and on the petioles. Pustules on petioles cause characteristic twisting.
Prevention and management
Graze infected plants.
Rust on clover petioles (left) & leaf. (photo: MAF, Lincoln)