Winter weather increases leaf spot risk

Light leaf spot and phoma on OSR_275_206

Its latest forecast takes shows that risks remain high in all regions and have increased in the South.

“Growers may need to be particularly vigilant this spring,” explained Dr Neal Evans, who put together the forecast at Weather INovations (WIN).

“I suspect the model is underestimating the amount of disease we are seeing,” he added.

“We saw the first signs of the disease at a low level at the end of January. In some fields the disease remains at a low level but in other, perhaps less sheltered fields, the rain has certainly driven the epidemic along and we see patches of diseased plants where rain-splash has spread the disease from initial foci”.

Dr Jon West of Rothamsted Research said: "We were quite surprised when we assessed our experimental field plots this past week. Some varieties had very little infection whilst others had severe infections and it’s the severity of the infection that has an impact on yield loss. 

“Overall the level seems moderately high this season but there’s definitely a large varietal effect”.

Further details on varietal resistance to light leaf spot are available in the HGCA Recommended List.

In addition to WIN and HGCA, the leafspot forecast project involves scientists from SRUC, ADAS, Rothamsted Research and technical input from Bayer CropScience.