Northern Wyoming Daily News - Serving the Big Horn Basin for over 100 years

By Tesia Galvan
Staff Writer 

Two barley diseases addressed at WESTI Ag Days

 

February 20, 2016



WORLAND – A plant pathologist identified and gave tips for treatment for two barley diseases MillerCoors LLC wants growers to know about at Friday morning WESTI Ag Days presentation.

William Stump, an Extension plant pathologist, identified and gave tips for treatment for fusarium head blight and ergot.

Fusarium head blight is a fungal disease that can cause disease in both barley and wheat, Stump said. “A primary symptom is come bleaching of the florets prior to maturity.”

Stump said “Fusarium head blight has always been around but is becoming is starting to sneak back into the system because it really likes high temperatures during the flowering stage, and with some of our environmental changes, and global warming we’re starting to see changes in our environmental disease spectrum depending on environmental conditions. Also the wide adoption of minimum tillage … has also increased the problem.”

Fusarium head blight reduces yields, increases low test weights in barley because it infects the head and it also contaminates deoxynivalenol (DON) Stump said.

“Deoxynivalenol is a vomitoxin and it makes you throw up and causes diarrhea … Deoxynivalenol is caused by Fusarium head Blight and the FDA has limits on the amount for grain,” Stump said.

Deoxynivalenol is important to detect in barley that is used for beer because you don’t want your beer to make you throw up, Stump said.

Fusarium head blight is easy to confuse with other diseases but an easy way to detect if the crop is infected is to chop off the head of barley, put it in a bag with a moist paper towel and let it sit for a day or two. If the base of floret comes back pink or orange you can be sure it is infected, Stump said.

The disease has not been reported in Wyoming but it has been reported in parts of Montana and it’s a big problem in the Midwest, Stump said.

There are no resistant barley cultivars currently available, Stump said.

Some management tips Stump provided are to use certified seed with fungicide seed treatments, avoid irrigation during flowering period and to crop rotate fields and tillage the field to bury it.

“Burning is great for disease control,” Stump said. Burning fields helps reduce disease.

Ergot was the second barley disease identified by Stump.

“Ergot is another fungal disease from the fungus claviceps porpurea,” Stump said. “It infects flowering heads of the sclerstia instead of grain.”

“It looks like rat droppings,” Stump said. “The ergot sclerstia is toxic to humans and livestock and infects a wide range of grass.”

Once barley has been infected with ergot it will create a honeydew substance that attracts insects, and a lot of insects will eat it and the infection of ergot will travel to other plants and grasses. That’s why it is important to take care and mow areas of untamed grass, Stump said.

Ergot causes diseases in humans like gang green and can cause visions, Stump said.

Ergot is a disease with a lot of historical meaning, Stump said. In the 17th century medieval time’s ergotism was linked with the Salem Witch Trials because ergot would infect poor village rye grain and they would become infected. When they would get ergot-induced visions, women were accused of being witches, Stump said.

The life cycle of ergot is environmentally driven. Ergot forms in the spring under cool, wet weather conditions, like we had this year, Stump said.

There was a grower who contacted Stump because a load of his [barley] was rejected because it was infected with ergot.

Ergot control is based on prevention methods because there are no resistant pesticides for ergot, Stump said.

A management tip to protect barley from ergotism is crop rotation. “Crop rotation is an effective method due to short lived sclerstia,” Stump said.

It is important to protect barley form ergot infection because once barely is infected little can be done to help treat it, Stump said.

 
 

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