Ergot in Wheat

Ergot is a problem that has been showing up in wheat crops in the area in the last few years. At a minimum, it is a marketing problem. In the worst case scenario it becomes a down-grading factor in the wheat and will significantly reduce the dollars per acre that a producer can generate. There are some things that can be done to reduce the level of ergot, but the weather of the specific growing season is the biggest cause of ergot each year. Ergot is caused by a fungus that is released from ergot bodies or sclerotia that are in the soil. They have been dropped to the dirt from infected plants or grasses in the field previous year. The spores that can infect a wheat head with ergot must be present when the plant is flowering. Timing of the release of the spores is critical for disease formation in the seed head of this year’s wheat crop. In the last couple of years, the wet and cool spring conditions have allowed for disease development. Wheat variety selection is one way to reduce ergot. Selecting the right variety can help. Ergot bodies do not always release spores at the same time as flowering wheat heads are present. Certain environmental conditions must be present in the top inch of the soil for the sclerotia to germinate and release spores. The soil must be wet and the temperature must be warm enough in the soil to allow the spores to germinate. If these conditions are right, the flowers on the wheat plants will be open to allow the spores to infect the developing seeds. Certain varieties flower at specific times or flower for longer periods of time. These varieties are more susceptible to ergot infection. The variety can be a factor in the development of ergot is that some varieties flower longer. Copper can help reduce ergot. If the copper levels in the soil are adequate, the flowering period for the wheat plant is shortened. This means that the time exposed to the potential spores released from germinating ergot sclerotia bodies is reduced. This will reduce the levels of exposure of the wheat plants to the diesese. Copper levels of 1 ppm will reduce the potential ergot infection significantly. Most of our soils in the area are at 0.5 ppm or less, so copper is an issue in the Meadow Lake area. Mowing headlands to reduce the production of ergot from adjacent grasses and using ergot free seed are two other ways to reduce the potential for this disease. Two year old seed with ergot bodies in it is less risk to the new wheat crop because the ergot bodies are not viable after the first year. Cultural practices should be looked at as tools to reduce ergot infections. There is no solution that works all the time that will eliminate the ergot. There are some things like picking the right variety and using copper if your soils require it that will reduce the risk. Use the ones the work for you.
By Dave Cubbon, P Ag