Fusarium head blight onwheat in Louisiana,USA

Publish time: 28th May, 2015      Source: A ProMED-mail post<http://www.cnchemicals.com/;
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Fusarium head blight onwheat in Louisiana,USAFusarium head blight onwheat in Louisiana,USA" title="Share this link on Facebook">A ProMED-mail post<http://www.cnchemicals.com/;ProMED-mail is a program of theInternational Society for Infectious Diseases <http://www.isid.org>Date: Tue 26 May 2015Source: Richland Today [edited]<http://www.richlandtoday.com/news/wheat-crop-headed-disaster-2015>Excessive rain across Louisiana is compounding already existing problems with the 2015 wheat crop and leading to what LSU [Louisiana State University] experts call a disastrous season. Some of the wheat being harvested has low test weight and, thus, reduced value. Some of the wheat is not worth harvesting."The 2014-2015 wheat-growing season has been challenging, to say the least," Josh Lofton, LSU, said. There were freezes in March, then bad storms hit. These conditions can cause wheat to fall over, harvesting becomes less efficient and more costly. The continual wet conditions are favorable for development of a disease on wheat called Fusarium head blight, commonly known as scab, which can lead to low yields, low test weight and even rejection."This is the worst year by far for scab," said Boyd Padgett, LSU."It's 10 times worse than I've ever seen," Steve Harrison, LSU, said.Even though many growers noticed scab appearing in their fields, there was little they could do. The crop was infected at flowering in April, at the same time as heavy rains. Applying fungicides would not have been effective, Lofton said.Last year's [2014] big corn crop contributed to scab development because corn serves as a host for the fungus, Harrison said. Because of all the problems, he expects yield losses of 30 to 40 percent for the 2015 wheat crop. This does not address the quality issues that could result in lower prices.Because of the severe scab problem, Harrison expects that less wheat will be planted in 2016. However, he and other wheat breeders are developing Fusarium-resistant varieties. "We're about to release one with good resistance," Harrison said. "It should be available to farmers in a couple of years."--Communicated by:ProMED-mail<promed@promedmail.org>[Fusarium head blight (FHB; also called ear blight, scab) of small grain cereal crops (wheat, barley, rye, oats, maize) is caused by several fungal species originally classed into the genus _Fusarium_.FHB causes yield losses of up to 45 percent and reduces the grade of harvested grain. The fungi can also cause foot rot and seedling blight and form a complex of diseases on seeds, seedlings and adult plants.Current names of the fungi include _Gibberella zeae_ (previously _Fusarium graminearum_), _Fusarium poae_, _Monographella nivalis_ var._nivalis_ (previously _Fusarium_ or _Microdochium nivale_), and _Microdochium majus_. The pathogens are favoured by humid conditions.Depending on fungal strains involved and environmental factors during plant growth and grain storage, infection may also contaminate the grain with fungal toxins. The total crop may be lost because of toxin levels. The fungi persist and multiply on infected crop residues, spores are spread by wind, water, mechanical means and with infected plant material (including seeds). For seedling blights, the main pathogen source is contaminated seed. Disease management includes fungicides as crop sprays or seed treatments, long crop rotations with non-hosts and planting of cereal varieties with reduced susceptibility. Use of certified clean seeds is essential.New fungal strains are emerging worldwide and continued breeding for new resistant varieties is needed to stay ahead of pathogen evolution.Re-emergence of some fusarium diseases thought to be driven mainly by changes to climate and agronomic practices has been reported from the UK (ProMED-mail post 20100726.2497). In Canada, the emergence of a new FHB strain with increased mycotoxin levels has been reported in 2009 (ProMED-mail post 20091210.4211).MapsUSA:<http://www.mapsofworld.com/usa/usa-state-and-capital-map.html>Louisiana:<http://www.mapsofworld.com/usa/states/louisiana/louisiana-map.html>PicturesFusarium head blight (FHB) on wheat:<http://c.photoshelter.com/img-get/I0000urHINoyGOUw/s>Photo galleries of pathogen symptoms on wheat via:<http://wheatdoctor.cimmyt.org/en/image-galleries> and <http://www.ipmimages.org/browse/Areasubs.cfm?area=128>FHB symptoms on other cereals:<http://agdev.anr.udel.edu/weeklycropupdate/wp-content/uploads/2009/05/fusarium-barley.jpg>(barley),<http://www.grainscanada.gc.ca/str-rst/fusarium/images/photo-oats-avoine.jpg>(oat),<http://www.grainscanada.gc.ca/str-rst/fusarium/images/photo-rye-seigle.jpg>(rye) and<http://www.ppdl.purdue.edu/PPDL/images/fusarium-ear-rot.jpg> (maize) Fusarium seedling blight on wheat:<http://www.omafra.gov.on.ca/english/crops/pub811/14cerealf1.jpg>LinksAdditional news stories:<http://theadvocate.com/news/12442970-123/rain-hurting-louisiana-wheat-crop>,<http://www.hannapub.com/franklinsun/state-wheat-crop-headed-for-disaster-experts-say/article_823bdc66-00a4-11e5-a36f-27f5933101e4.html>and<http://www.thenewsstar.com/story/news/local/2015/05/22/weather-batters-states-wheat-crop/27786421/>Information on fusarium head blight of cereals:<http://bit.ly/LfuDNu>,<http://www.agriculture.gov.sk.ca/Default.aspx?DN=24a3bb18-a096-4bcd-889c-b1e2c94a03e9>and<http://www.grainscanada.gc.ca/str-rst/fusarium/fhbwc-foc-eng.htm>(with pictures)FHB disease and toxin information:<http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex92>_F. graminearum_ current species complex and FHB information:<http://www.ars.usda.gov/Main/docs.htm?docid=9821>_G. zeae_ taxonomy and synonyms:<http://www.speciesfungorum.org/Names/SynSpecies.asp?RecordID=255496>Taxonomy of other fungal pathogens via:<http://www.indexfungorum.org/Names/Names.asp>- Mod.DHA][See Also:Fusarium head blight, wheat - Canada: (AB) spread 20150121.31070002013----Fungal diseases, barley - UK: (Scotland) alert 20130315.15878282012----Fusarium & undiagnosed blight, wheat - China 20120620.11737382011----Stripe rust & foot rot, wheat - USA, UK 20110713.2109 Fusarium, maize - Peru: (JU) 20110405.10592010----Fusarium head blight, cereals - UK: re-emergence 20100726.2497 Fusarium head blight & stagonospora, wheat - USA: (OH) 20100708.2277 Fungal diseases, maize, wheat - USA 20100331.10172009----Fusarium head blight, wheat - Canada: new strain 20091210.4211 Fusarium head blight, wheat - Uruguay 20091127.4066 Fusarium species, maize - Switzerland 20090911.3202 Fusarium head blight, oats - Canada: screening 20090621.2280 Fusarium head blight, wheat - USA 20090605.2078 and older items in the archives] .................................................sb/dha/pg/mppMore news from: ISID (International Society for Infectious Diseases)Website: http://www.isid.orgPublished: May 28, 2015The news item on this page is copyright by the organization where it originatedFair use notice