White Leaf Spot Brassicas OSR
Mycosphaerella capsellae (Pseudocercosporella capsellae)
Pathogen
Fungus
Hosts
Oilseed Rape, brassicas and cruciferous weeds such as such as shepherd`s purse and charlock.
Symptoms
Small, white spots (up to 20 mm in diameter) which darken to grey/black spots on leaves as the season progresses.
Development
The disease develops in the early spring by means of ascospores released from infected rape stubble and other susceptible brassicas. Secondary spread within crops is by conidia which are dispersed by rain-splash. Infected seed can also be a source of infection.
Favourable Factors
Cool, wet conditions with associated leaf wetness in the spring.
Importance
Localised infections have occurred on winter crops in Southern England, but the disease is generally of little economic importance in the UK.
Control
Control is not usually necessary in the UK
Destroy or dispose of stubble as soon as possible after harvesting
Foliar fungicides can give useful levels of control.
White leaf spot leaf symptoms
White leaf spot leaf symptoms
