After three years of research, a significant paper for the grains industry and growers has been published by a Victorian scientist, reporting on yield losses caused by barley yellow dwarf virus (BYDV) infection in wheat and barley.
Agriculture Victoria molecular epidemiologist Narelle Nancarrow said her research will help growers understand the importance of disease control and the devastating effects viruses can have if left untreated.
“We investigated the effects of BYDV on wheat and barley under typical south-eastern Australian conditions; and we harvested the grain to measure yield and yield components.
“We found the virus infection severely reduced grain yield by up to 84 per cent in wheat and up to 64 per cent in barley, with the grain number being the most affected,” Ms Nancarrow said.
BYDV is transmitted by aphids and significantly reduces the yield and quality of cereals worldwide.
With previous studies showing BYDV is prevalent in cereal fields in south-eastern Australia, especially in higher rainfall regions, yield losses caused by BYDV infection may be flying under the radar.
Ms Nancarrow said there is little that can be done once a plant is infected with the virus, therefore prevention and management are vital.
“Typical symptoms of BYDV infection include stunted growth and yellow or red leaf discoloration that starts at the tip of the leaf and spreads towards the base,” she said.
“Leaf discoloration is typically bright yellow in barley, and yellow and/or reddish in wheat.”
Ms Nancarrow hopes the publishing of this research is a timely reminder to grain growers about the importance of managing disease risk year-round.
“It is important to control the grasses and volunteer cereals around the crop that could potentially be reservoirs for viruses and aphids, and to monitor crops regularly for the presence of aphids, virus symptoms and beneficial insects,” Ms Nancarrow said.
Management options include use of an appropriate insecticide if aphid numbers are high, particularly at sowing or early in the growing season, taking into consideration insecticide resistance and the effects on beneficial insects.