Take steps to reduce stress in winter and spring barley crops and it will improve resilience to ramularia infection, pointed out Alistair Gordon, regional technical manager in Scotland for leading agronomy firm and in this case aptly named, ProCam.

Although physiological stress that produces superficial brown spots on upper leaf surfaces of barley can cause some yield loss, he said the bigger issue is it can trigger ramularia 'flare ups' in infected plants.

With no AHDB varietal resistance ratings available for this disease, knowing how to reduce stress could become particularly relevant when chlorothalonil is no longer available in future, he argued, adding that micro-feeding the crop with bio-stimulants, could help fight off the disease.

“Ramularia appears with a vengeance in crops under stress,” said Mr Gordon. “You can’t do anything about weather-related stress factors, such as bright, hot days and cold nights that exacerbate the problem. But you can ease stress from other sources.

“As well as factors such as correcting soil pH to reduce stress, and avoiding large tank mixtures with excessive amounts of adjuvants, make sure barley isn’t held back through limited availability of manganese, copper or zinc. These are key trace elements for cereals.

“Improved ramularia resilience was clearly visible last season in spring barley crops where nutrition was used to create healthier canopies. This applied whether the nutrition was from farmyard manure or foliar sprays.”

With many farmers opting to plant stubble turnips or kale last autumn after the fodder shortage of the dry summer, Mr Gordon said that sheep grazing had naturally boosted soil fertility through their manure. However, ProCam has also been evaluating micronutrient and biostimulant treatments in spring barley, he added and found significant improvements in both root and shoot growth.

“We have tested a number of these treatments and seen clearly which ones give the best improvements. To help the crop, I would look at applying one of these treatments at stem extension. At this timing, there should be enough leaf on the plant for effective spray absorption but without requiring an extra spray pass, because the treatment can be co-applied with a herbicide.

“If growing a crop of winter barley that develops ramularia, remember that this can provide a source of infection for neighbouring spring barley fields. Similarly, because Ramularia is also seed borne, if you have a winter or spring barley crop that develops a problem, don’t be tempted to home save seed from it for next year.”

Any future development of variety resistance ratings for ramularia could become useful when choosing feed barley varieties, he added. But uptake of malting barley resistance ratings could be slower, as malting variety choice is largely driven by end market requirements.