Effective management of the “green bridge” over the coming months will place grain growers on the front foot in their efforts to control Russian wheat aphid (RWA) in 2018.
Eliminating the green bridge – volunteer cereals and weeds – well ahead of sowing this year’s winter crops will reduce the aphid’s host plants and thereby minimise the risk of crop infestation.
Crop pest experts, supported by the Grains Research and Development Corporation (GRDC), said RWA established most successfully where there was a continual green bridge of host plants over the summer and autumn period.
These host plants allow RWA populations to persist from one growing season to the next.
Green bridge control is therefore a key element of an overall RWA integrated management strategy that growers are encouraged to implement this year.
Entomologist Maarten van Helden from the South Australian Research and Development Institute (SARDI), a division of Primary Industries and Regions SA (PIRSA), said it was important growers removed all volunteer cereals and weeds at least four weeks before sowing this year’s winter crops.
Dr van Helden said green bridge control at least a month before sowing would drive down over-summering populations of RWA well in advance of crop emergence.
“Paddocks kept bare – either by spraying, cultivating or heavy grazing – for at least a month prior to sowing will protect crops from early infestation of RWA, enabling better establishment,” Dr van Helden said.