Minimize ergot risk next year
Ergot was a problem in wheat in South Dakota this year. So what should you do next year to make sure it is not a problem next year?
Here are four steps that South Dakota State University Extension agronomist Bob Fanning and SDSU Extension plant pathologist Emmanuel Byamukama suggest:
• Select seed free of the ergot sclerotia.
• Don’t plant wheat in a field that had ergot this year.
• Rotate to a different crop.
• Mow grasses around the border of fields with a history of ergot before heading. It will reduce the risk of the disease spreading.
The majority of the 2014 wheat crop was very good in South Dakota, but ergot was widespread, Fanning says.
Many of the ergot-infested fields seemed to be those that matured later than most, such as some of the spring wheat, later-planted and later-maturing winter wheat varieties, and fields with thin stands. In at least one field of winter wheat, many of the heads containing ergot bodies were late tillers.
There are at least a couple of explanations of what happened, according Byamukama. Infected fields were flowering when particularly wet, humid conditions prevailed. There also may have been some secondary infection from wheat, rye and/or grasses that developed ergot earlier, along with ergot developing from primary infection via spores. Prior to the dark purple to black sclerotia (ergot bodies) found replacing the grain, infected florets exude “honeydew,” which can spread ergot to by physical contact and insects.
Ergot bodies forming in the heads of grasses can increase the incidence of ergot in wheat due to secondary infection .
Ergot has been around for many years, and whether it will become more common depends on weather conditions when wheat is flowering and the amount of inoculum in around the field, the specialists say.
If you do see ergot next year, don’t waste money on fungicide trying to control it. No fungicide is labeled, and none is believed to provide significant reduction of ergot. Fungicide decisions at wheat flowering should be based on the risk of scab and other diseases, and weather conditions during that time.
Source: SDSU Extension
This article published in the October, 2014 edition of DAKOTA FARMER.
All rights reserved. Copyright Farm Progress Cos. 2014.