Rothamsted Research have updated its oilseed rape online disease risk forecasts for light leaf spot and phoma leaf spot for the 2012/13 growing season.
Due to the dreary and wet summer enjoyed by most of the UK, they suggest that disease pressure will be high. Increased light leaf spot risk is predicted for many crops, as well as an early onset of phoma leaf spot outbreaks in most regions. The extended harvest experienced by many growers has compounded the threat, resulting in many crops being sown very late which are either yet to emerge or which consist of small vulnerable plants.
"It's become the 'forgotten disease' somewhat," Dr Neil Evans says. "The high incidence of light leaf spot in crops of all regions last year means that there is a lot of inoculum about for the 2012-13 season and this is reflected in the forecast. There is a real need for extra vigilance this year."
The phoma leaf spot forecast prediction dates are generally seven to fourteen days earlier than last year across most of the arable growing region. An early onset of the epidemic combined with backward crops could prove disastrous to industry.
“They have already seen leaf spotting on volunteer plants in western counties”. Says Dr Peter Gladders of ADAS Boxworth
"Early infections, particularly on emerging cotyledons could lead to severe losses," Gladders says.
The forecast updates were done in association with Weather INNovations with support from HGCA and Bayer CropScience Ltd.
Source: Rothamsted Research