Jim O’Mahony, Crops & Horticulture specialist, advises delaying the start date for sowing winter cereals until October so as to avoid problems with Barley Yellow Dwarf Virus.
Yield losses of up to 50% in winter barley have been recorded in trials by Teagasc. BYDV also attacks oats and wheat. Aphids introduce and spread BYDV in cereals. Crops at most risk are early sown (September) in sheltered locations in southern counties. Unfortunately, the Neonicotinoid seed treatment Redigo Deter, which was used to control cereal aphid and BYDV in winter cereals, is no longer available. Currently, we now have only one chemistry (pyrethroids) for BYDV control in winter and spring barley. Crops at highest risk are the early sown ones. For these, Jim advises that a pyrethroid insecticide should be applied at 2-3 leaf stage and repeated in early November. Crops sown after mid-October, he says, should receive a pyrethroid insecticide in November.