Varieties with virus resistance will be the key to the expansion of the pulse industry in northern New South Wales.

Nes South Wales Department of Primary Industries Tamworth researcher Joop van Leur says all pulse crops in the north are vulnerable to virus infection and this is standing in the way of industry growth.

"Australia's northern grains region is characterised by frequent summer rains that make summer crops possible but also provide the virus inoculum with ample opportunity to survive and allow virus vectors - like aphids - to build up before the start of the winter cropping season," Mr van Leur said.

"The presence of inoculum and vectors, as well as relatively mild winter temperatures, mean pulse crops in the northern region are more likely to be exposed to virus epidemics than crops in other parts of Australia."