A ProMED-mail post <http://www.promedmail.org>
ProMED-mail is a program of the International Society for Infectious Diseases <http://www.isid.org>
Date: Wed 27 May 2020
Source: The Epoch Times [abridged, edited] <https://www.theepochtimes.com/china-reports-severe-epidemic-of-wheat_3358374.html>
Chinese state media recently reported that stripe rust was found in over 2.1 million acres of wheat fields in 9 provinces, the worst situation in a decade.
So far, only Shaanxi Province reported specific figures [with] nearly 494 000 acres affected, and it was estimated that the rust would eventually infect 1.5 million acres all over the province.
[One farmer said that] "the severity of stripe rust this year [2020] will hurt the final harvest. All crops have rusted leaves; not a single one is spared."
--
Communicated by: ProMED-mail <promed@promedmail.org>
[Stripe rust (also called yellow rust) of cereals is caused by the fungus _Puccinia striiformis_. The disease affects wheat (_Triticum aestivum_), durum wheat (_T. turgidum_), some barley varieties, triticale (wheat/rye hybrids), and a number of wild grasses. It causes yellow stripes on leaves, which leads to loss of photosynthetic ability and plant vigour as well as stunting of plants. Yield losses of 40-100% have been reported in wheat.
Spores are wind dispersed in several cycles during the cropping season. Grasses and volunteer crop plants may generate a "green bridge," providing inoculum for the next crop cycle. Disease monitoring is important so that timely action can be taken to limit the spread of the pathogen as well as a build-up of inoculum. Disease management may include the use of resistant varieties, fungicide applications, and control of pathogen reservoirs. Monitoring and resistance breeding programmes have been established in different regions for early detection of new rust strains and to attempt to stay ahead of pathogen evolution.
While stem rust (_P. graminis_) poses a huge potential threat to world wheat production, stripe rust is currently causing the most damage to wheat crops on a global scale. New strains of both rusts with increased virulence and additional fungicide resistances have been reported in recent years from wheat-growing areas worldwide. Climate warming allowing survival of wheat rusts on green bridges into higher latitudes is another example of pathogens extending their range due to climate change (see also ProMED-mail posts http://promedmail.org/post/20141024.2895414,
http://promedmail.org/post/20120809.1235745,
http://promedmail.org/post/20090914.3230,
http://promedmail.org/post/20110718.2172). Projects for double-resistance breeding to manage both stripe and stem rusts simultaneously are in progress (see ProMED-mail post http://promedmail.org/post/20120831.1274190).
In China, a stripe rust alert was issued (ProMED-mail post http://promedmail.org/post/20191219.6849959), and high levels of both stripe rust and fusarium head blight (caused by fungi including _Fusarium_ and _Microdochium_ species) were reported earlier in some provinces (ProMED-mail post http://promedmail.org/post/20200318.7104946). Factors favouring the current outbreaks are thought to include large amounts of available inoculum, rising temperatures, high rainfall, and susceptibility of crop varieties to the pathogens.
Maps
China:
<http://www.beijing-travels.com/image/chinamap.jpg>
China provinces:
<http://www.chinadiscovery.com/assets/images/customer-support/maps/china-provinces-map-600.jpg>
Pictures
Stripe rust symptoms on wheat:
<http://fyi.uwex.edu/fieldcroppathology/files/2015/05/Stripe-Rust-1.jpg>,
<http://www.plantmanagementnetwork.org/pub/php/brief/2005/stripe/image/wheat3.jpg>,
and
<https://www.agric.wa.gov.au/sites/gateway/files/styles/original/public/Stripe%20rust%20infected%20glume.JPG?itok=pYpeNYx0>
Stripe rust on barley:
<http://media.padil.gov.au/species/136639/7736-large.jpg> and <http://www.planthealthaustralia.com.au/wp-content/uploads/2013/04/Barley-stripe-rust-1.jpg>
Ryegrass with stripe rust:
<http://www.science.oregonstate.edu/bpp/Plant_Clinic/images/ryegrass_stripe%20rust.jpg>
and
<http://plant-pest-advisory.rutgers.edu/wp-content/uploads/2013/09/photo-15-e1378922274640.jpg>
Links
Information on stripe rust:
<https://www.plantwise.org/KnowledgeBank/Datasheet.aspx?dsid=45876>,
<https://www.ars.usda.gov/midwest-area/stpaul/cereal-disease-lab/docs/cereal-rusts/wheat-stripe-rust/>,
<https://www.agric.wa.gov.au/mycrop/diagnosing-stripe-rust-wheat>,
<http://www.planthealthaustralia.com.au/pests/barley-stripe-rust/>,
<http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0006/158964/stripe-rust-in-wheat.pdf>
and
<http://www.ipm.ucdavis.edu/PMG/r730100511.html>
_P. striiformis_ life cycle:
<https://www.nature.com/articles/ncomms3673/figures/1>
Stripe rust global tracking, current race analysis and distribution:
<http://wheatrust.org/yellow-rust-tools-maps-and-charts/> and <http://rusttracker.cimmyt.org/?page_id=9>
Stripe rust reviews:
<https://www.frontiersin.org/articles/10.3389/fpls.2017.01057/full>
and via
<https://www.cabdirect.org/cabdirect/abstract/20163358726>
_P. striiformis_ taxonomy and synonyms:
<http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=227064>
and
<http://www.speciesfungorum.org/Names/SynSpecies.asp?RecordID=227064>
Wheat rusts overview, including epidemiology and spore types:
<http://www.fao.org/3/y4011e/y4011e0g.htm>
Global Rust Initiative:
<http://www.globalrust.org/>
- Mod.DHA
HealthMap/ProMED map available at:
China: <http://healthmap.org/promed/p/155>]
[See Also:
Stripe rust, wheat - UK: new strain susp.
http://promedmail.org/post/20200410.7206768
Stripe rust & head blight, wheat - China
http://promedmail.org/post/20200318.7104946
Stripe rust & karnal bunt, wheat - India: (HR)
http://promedmail.org/post/20200204.6950281
2019
----
Stripe rust, wheat - China: alert
http://promedmail.org/post/20191219.6849959
Stripe rust, wheat - India: (JK)
http://promedmail.org/post/20190415.6422450
Stripe rust, wheat - Pakistan, India
http://promedmail.org/post/20190328.6390313
2018
----
Stripe rust, wheat - Australia: (VI) new strain
http://promedmail.org/post/20180614.5855829
Stripe rust, wheat - India: (PB) alert
http://promedmail.org/post/20180301.5659889
2017
Sent from my iPhoneStripe rust, wheat - UK: (02) Red 24 & Blue 7, new strains http://promedmail.org/post/20171023.5397303
Stripe rust, wheat - UK: new strains
http://promedmail.org/post/20170914.5317650
Stripe rust, wheat - Canada, USA
http://promedmail.org/post/20170608.5091941
Stripe rust, durum wheat - Mexico: new strain
http://promedmail.org/post/20170413.4967401
Stem & stripe rusts, wheat - Europe, Asia, Africa: new races
http://promedmail.org/post/20170206.4820305
2016
----
Stripe, stem & leaf rusts, wheat - Ethiopia
http://promedmail.org/post/20161117.4637042
Stripe rust, wheat - UK (02): new strains susp
http://promedmail.org/post/20160711.4337095
Stripe rust, wheat - USA: new strains susp
http://promedmail.org/post/20160610.4277039
Stripe rust, wheat - UK: Kranich strain, 1st rep
http://promedmail.org/post/20160219.4033809
Stripe rust, wheat - India: (PB) alert
http://promedmail.org/post/20160106.3916044
2015
----
Stripe rust, wheat - Europe: origin of strains
http://promedmail.org/post/20150717.3517395
Stripe rust, wheat - USA: (NE)
http://promedmail.org/post/20150612.3432029
Stripe rust, wheat - Pakistan, Mexico
http://promedmail.org/post/20150530.3396665
Stripe rust, wheat - India: (JK)
http://promedmail.org/post/20150323.3247875
and additional items on stripe rust in the archives]