Cereal growers should spray for Barley Yellow Dwarf Virus (BYDV) this autumn, according to Teagasc’s Michael McCarthy.

The tillage advisor for South Tipperary said that seed dressings will only give six weeks’ cover, where protection against the aphid-borne disease is concerned.

“Most of the barley and wheat crops have now been planted in this part of the world. Emergence levels to date have been very good. But the current warm spell of weather is encouraging the movement of aphids across the country.

“It is for this reason that growers should include an aphicide in their autumn herbicide tank mix. Most growers will be going back into fields during early November.

“This would be the appropriate time to deal with the significant threat posed by aphids at the present time. The good news is that the insecticides available to do the job are not expensive.

Turning to the issue of weed control in winter cereals McCarthy confirmed that Sterile Brome and Black Grass infestations are becoming a serious challenge for Irish tillage farmers.

“Black Grass has already been identified in Cork and Kildare,” he said.

“It’s likely that we have imported the problem from the UK on either imported machinery or in seed consignments. This means that the plant populations we are now dealing with are herbicide resistant.

“In cases where only small numbers of plants are evident, hand rouging should be undertaken immediately in order to get on top of the problem. Heavy infestations of Black Grass have the potential to reduce crop yields by up to 50%.

“Sterile Brome is a problem which cereal growers in Ireland have been dealing with for a number of years now. But, again, this weed grass has the potential to devastate cereal crop yields.”

McCarthy said that the implementation of effective crop rotation practises is the only way to get on top of Black Grass and Sterile Brome.

“It’s all about breaking the cycle of following one cereal crop after another. And oilseed rape, fodder beet, sugar beet and beans meet this requirement to a tee.”