Some oilseed rape crops that are showing signs of premature ripening, could be down to a number of diseases, but verticillium stripe is one to be concerned about.

“It is worth going out to inspect crops and see if this disease can be found,” Neil Groom, technical director of Grainseed, told The SF.

“If you have verticillium in your soils, it can be there for more than 20 years and the only way to live with it is to grow a variety which has good resistance or tolerance. You have no other choice.

"Using crop intervals or rotations is impractical and there are no approved chemicals. If you don’t grow a resistant variety, you will have to suffer the consequences in future years.

"We suggest that those who are seeing verticillium stripe now or in the past few years make a proactive decision to grow a resistant variety this autumn.”

ADAS has reported that verticillium stripe symptoms are seen as the crops starts to ripen. What to look out for are yellowing leaves, premature ripening of branches and grey striping down stems, often on one side only but it can be the whole cross-section of a stem.

“Once you have identified verticillium, you need to start thinking seriously about how to handle it. Unlike other diseases of rape, there is no proven or approved fungicide to control it and so growers must rely on cultural control measures – and the only one you really have open to you is to choose varieties with known resistance," added Mr Groom.

"Grainseed oilseed rape varieties, including Es Mambo, have proven resistance to verticillium, following several years’ independent trials and commercial experience.

“In cereals you don’t think twice about studying disease resistance ratings in detail before choosing your variety. This needs to be the same for rape varieties now. A good variety needs to have resistance to verticillium, phoma, as well as to light leaf spot.

"When growers are looking more closely at their growing costs, choosing a variety such as Mambo where you can be sure of its strong disease resistance across the board can save you money," pointed out Mr Groom.

AHDB is looking at assessing and rating a range of varieties to verticillium and these could be added to the published listings in 2020.