Bayer’s SpotCheck initiative – which helps oilseed rape growers identify light leaf spot – has re-opened, with farmers advised to be alert for the disease.
In a wake-up call for growers across the region, results from three years of SpotCheck, with over 1,800 samples of leaves tested, show that the disease is endemic across the UK and no longer confined to crops further north.
There was a 19% increase in positive samples received by SpotCheck In 2019-20. The warm, wet autumn – which favours disease development – was the likely cause for infections detected in October, a month earlier than in 2018.
Light leaf spot is an airborne polycyclic disease. It is capable of several infection cycles a season and this is what makes it so hard to control, because the fungus repeatedly releases spores which infect new growth.
ADAS plant pathologist Philip Walker, who is involved with assessing samples sent to Spot- Check, says light leaf spot can be hard identify in the early stages, when it expresses itself as small white dots scattered across the top or underside of the leaf.
“They can look like tiny grains of sugar but without a hand lens or microscope they are difficult to spot. Additionally, they may not appear on every leaf, or on every plant, so when walking the field, it is very easy to miss.”
To send in a leaf sample to SpotCheck, call 01954 268200.