Yellow rust & The Importance of T1 Sprays
What situations favour yellow rust?
Temperatures of 10-15°C and a relative humidity of 100% are optimal for spore germination, penetration and production of new, wind-dispersed spores. The fungus is generally inhibited by temperatures over 20°C although strains tolerant of high temperatures do exist.
The complete cycle from infection to the production of new spores can take as little as seven days with ideal conditions and may be repeated many times in one season. During late summer, the dark teliospores may be produced. These can germinate to produce basidiospores, however, no alternate host has been found. Although the teliospores seem to have no function in the disease cycle they may contribute to the development of new races through sexual recombination.
Symptoms and diagnosis of yellow rust
- First appear as parallel rows of yellowish orange coloured pustules on the leaves of adult plants
- In the early spring small patches or foci of infected plants can be seen in fields
- On younger plants, yellow rust lesions tend to spread as a yellow band, moving ahead of the sporulating lesion
- In severe attacks, yellow rust infection of the ears can occur with the formation of masses of spores between the train and the glumes
Yellow rust: Drone View
The green sections of the image on the right recieved Epoxiconazole or Xemium. The proof is in the photo!