Disease biology & management

Sclerotinia stem rot in oilseed rape

Once the disease takes hold of a crop, yields can be absolutely devastated. In some advanced cases of the infection, yield loss can be up to 60%.

Determining fungicide control for sclerotinia is tricky due to its sporadic nature. Key factors to consider include: past infection levels, rainfall/humidity 10–14 days before and during flowering, plant density, crop rotation, and upcoming weather conditions.

How to control sclerotinia

Late blight in potatoes

In recent years, potato late blight has become more agressive and harder to control through the evolution of strains which produce ever greater spore numbers and cycle faster, as well as evolving mutations which confer resistance to some fungicide modes of action. It is for this reason that advice to alternate modes of action and maintain spray intervals as well as mixing active ingredients at each application are now strongly advised.

How to control late blight

Northern leaf blight 

Yield loss from northern leaf blight can be significant, resulting in a loss of as much as 30% to 50%. If lesions appear on the ear leaf 2 weeks before, or 2 weeks after tasseling and conditions are favourable for disease development, this will see the greatest yield loss. The best strategy to reduce yield loss from northern leaf blight is by using multiple management methods. 

How to control northern leaf blight

Common rust

Common rust is a problem for plants in the UK because it thrives in mild, moist conditions, leading to increased infections, leaf discolouration, reduced growth, and potential plant death if left untreated.

Yield loss from common rust can be slight, only affecting crops up to 10% when the disease is severe however, rust spores are easily spread by wind causing rapid outbreaks.

How to control common rust