September 28, 2004
From: ProMED-mail<promed@promedmail.org>
Source: Australian Broadcasting Corporation, Rural News transcript, 28 Sep
2004 [edited] <http://www.abc.net.au/rural/news/stories/s1208689.htm>

Push to wipe out stripe rust in New South Wales wheat

New South Wales agronomists and wheat breeders are leading a push to wipe out stripe rust, so it doesn't affect next season's crop. The state's wheat growers are dealing with the worst case of stripe rust in history, which is
expected to significantly affect crop yields. Test control strips are being sprayed with a fungicide in an attempt to reduce spores drifting and spreading the disease.

Agronomist Bill Adams says safeguards need to be investigated now, to avoid more crop devastation next season. There are a few new strains of the fungus following on the Western Australian pathotype that appeared last year. The disease is certainly going into more tolerant varieties than what [had been] thought.

[Wheat stripe rust (also known as yellow rust or glume rust) is caused by _Puccinia striiformis_f. sp. _tritici_ [Ps]. It is a major problem of wheat grown in cooler climates and at high elevations in Australia. As with rust diseases in general, Ps reduces plant vigour, limits seed maturing in adult plants, and is most damaging just before or during flowering. It is different from other rusts in that it does not have a sexual stage nor does it require an alternate host to complete its life cycle. The only spore form on wheat is the urediospore. Ps infects over 18 genera of grasses including rye and barley in addition to wheat. Of particular significance is that many perennial grass species can serve as reservoir hosts for Ps, thus providing a ready supply of inoculum. Crop losses of 40 percent are not uncommon, and some fields can be totally destroyed. Disease management utilizes resistant cultivars, control of volunteer wheat and seeding dates, and applications of recommended chemical fungicide sprays.

Links: <http://www.ento.csiro.au/research/pestmgmt/IPMModellingNetwork/Wheat_Rust.htm>
<http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=134396>
<http://www.grdc.com.au/growers/res_upd/north/04/wellings2.htm>  -Mod.DH]