Scottish barley growers have been urged to check their spraying programmes after trials by SRUC (Scotland's Rural College) confirmed signs of fungicide resistance in a key crop disease.

Early this year crop protection company Bayer announced that in Germany and Denmark crops infected with the Ramularia collo-cygni fungus were not responding to normal fungicide treatments containing triazole and SDHI fungicides. The SRUC studies indicate Scottish barley faces a similar threat if farmers do not make adjustments to their treatments.

Ramularia collo-cygni causes Ramularia Leaf Spot Disease which as well as posing a particular problem in spring sown crops also affects production in autumn sown crops. Farmers have used a well established protection regime based of triazole and SDHI fungicides, but testing by SRUC has revealed a significant shift in the sensitivity of the fungus to both of these chemicals between 2012 and 2016.

Loading article content

"Unless farmers take action there is a real risk that the fungicide resistant Ramularia strains will build up causing major problems in future" comments Senior Plant Pathologist Dr Neil Havis, adding: "But our research shows that the fungus is still sensitive to cholorothalonil so we are recommending farmers add it into their spraying programme, particularly at the T2 spray timing."

However, SRUC experts continue to warn against over reliance on one set of substances when they are suspected to be at risk. Combinations of chemicals, which include multi-sites, coupled with alternative strategies such as using varieties with known disease resistance, have proved best against infection from fungal diseases.

Dr Havis warns: "Using just one fungicide with one mode of action risks resistant strains to multiply and gather strength."

Market round-up

United Auctions sold 129 store heifers at Stirling on Wednesday to average 228.9p per kg (-2.7p on the week), while 166 store, beef-bred bullocks levelled at 244.4p (-0.6p). Sixty-five store, B&W bullocks averaged 165.2p (+9.8p).

C&D Auction Marts Ltd sold 4 prime heifers in Dumfries to a top of 233p and an average of 223.1p).

In the rough ring 43 beef cows averaged 145.1p and 20 dairy cows levelled at 105p.

The firm also sold 438 prime lambs to a top of £123.50 per head and 261p per kg to average 237p (-29p), while 125 prime hoggs peaked at £89.50 and205p to level at 179p (-7p).

A small show of 102 cast sheep saw heavy ewes sell to £136.50 for Texels and average £85, while light ewes peaked at £74.50 for Cheviots and levelled at £55.

Messrs Craig Wilson Ltd sold 664 prime lambs in Newton Stewart on Wednesday to a top of £117 and 265p to average 232p (-21.1p on the week, but up 58p on the corresponding sale last year).