THERE ARE always challenges in properly managing disease in Scottish cereal crops and a warmer than usual autumn and winter means that foliar disease is already present in overwintering crops.
Professor Fiona Burnett, head of crop research at SRUC said that is crucial this year that growers carefully consider the best solutions for both themselves and the industry at large, especially with regard to disease resistance to certain chemistry.
During its recent winter meetings, SRUC crop scientists highlighted some emerging issues with fungicide resistance in cereal pathogens, and Professors Burnett warned that particular care is needed in planning cereal fungicide programmes this season.
"Unless fungicides are carefully used this year, there is a risk that crops could be left open to disease and also that the demise of key chemical groups could be hastened. The developing threats include resistance risks to the newer SDHI chemistry," she added.
"If played badly, these would threaten septoria control in wheat crops and this comes on top of well documented declines in the efficacy of azole fungicides against that disease."
In barley, there is unwelcome news about rhynchosporium and net blotch. SRUC's work with Irish researchers in Teagasc show that there are mutant strains of rhynchosporium which have developed resistance to strobilurin fungicides.
Net blotch is developing increasing issues with both the SDHI and strobilurin chemistry. Trial work last year showed a decline in the efficacy of these important two chemistry groups against net blotch and more of that disease in crops as a result.
Professor Burnett chairs the UK’s Fungicide Resistance Action Group and the key advice in a shifting situations such as we are in at the moment is that fungicides should be applied in well balanced mixtures that don’t over expose one of the partners.
The other thing she is keen to promote is the use of multi-site fungicide where possible. "These offer a safe haven in terms of resistance development and represent a cheap and effective way to bolster wheat and barley programmes," she said.
"This type of balanced and mixed usage represents a win:win in terms of managing crop disease and meeting individual crop needs as well as stewarding the products against resistance so that the industry can keep them for the longer term."