Plant stands from Dubbo north have borne the brunt of the disease which began with early season infection and flared under wet August conditions and rising spring temperatures.

Outbreak levels in the south, where there has been less rain, are much lower to date.

NSW Department of Primary Industries plant pathologist, Dr Steven Simpfendorfer, Tamworth, said the next two or three weeks would be critical to the management of the disease.

He said there were three stripe rust pathotypes impacting on crops this year:

* The original WA pathotype that attacked varieties like Lang.

* The Jackie pathotype which not only affected wheats like Lang, but also some triticales.

* The WA Yr17 strain which hit varieties like Ventura, Sunstate, Sunvale and Ellison.

For the full report see this week's The Land, Thursday, September 25.