UK: Fusarium fears extend to spring barley
Cereal growers with crops still to sow, including spring barley, are being urged to test home-saved seed, think hard before omitting treatment and be prepared to raise sowing rates, FWi reported November 28.
Although several factors, not least dry early seed-beds and seed dormancy, led to poor establishment this autumn, disease hit harder than usual, and must be taken into account, warn several commentators.
Infection by Microdochium nivale seedling blight - the disease most farmers and agronomists still refer to as fusarium - was exceptionally heavy this autumn, noted Scottish Agricultural Science Agency seed pathologist Valerie Cockerell.
"I don't think I've ever seen it quite as high. Average levels on Scottish wheats have been 50%."
In previous "bad" years the highest average was about 30%, and more recently it had been nearer 10%, noted Mrs Cockerell."Without doubt seed treatment for late-sown wheat will be necessary."
Fusarium infection in Bayer CropScience trials was up to 70% with up to half the plants lost, noted the firm's Adrian Cottey."Even in early-drilled crops we lost a lot.With 70% infection in later sowings without seed treatment, you could expect to lose most of the infected seedlings."
Much depended on growing conditions, he said.Fusarium seedling blight was not normally seen as a problem in spring barley. But many growers liked to sow the crop early when initially favourable conditions could quickly turn against it.
"Most farmers treat most, if not all their wheats. But with spring barley there is a lot more risk-taking, with up to 15% not getting treatment.In Scotland the figure is certainly over 20%, which would be crazy this season."
Hutchinson's Dick Neale noted that growers needed only an extra 50kg/ha of yield to pay for the average Ј5.50-60/ha seed treatment.
"Seed treatment for fusarium and a multitude of other reasons should always be applied to cereals," he said.
Independents' views
East Lothian-based AICC agronomist Andrew Riddell would not normally consider treating spring barley unless the seed loading was above 20%.
But given that fusarium had been particularly troublesome this autumn, his policy might change."If the weather stays ideal, then crops could be OK. But if we got a cold spell things could be very different. Seed treatment is probably more justified this year."
Lincolnshire-based Ruth East, also AICC, looks after plenty of spring barley following sugar beet."I always use seed dressing on spring barley," she said. "It's false economy to cut corners. Like a good woman, seed deserves to be welltreated."
Fusarium levels in wheat were so high this autumn that it had not been worth running tests, she added. But other factors had contributed to poor emergence."Seed dormancy has been extremely high even though germination has been good."
28 November, 2007
