Some wheat classes may be less susceptible to disease, but studies showed Canada Western Red Spring wheats are at the greatest risk
There are many ways to reduce the risk of ergot infection and limit financial losses, says Jim Menzies, a plant pathologist who has studied the disease.
Here are a few strategies farmers should consider:
- Don’t use seed that contains ergot sclerotia. Scrutinize farm-saved seed and if possible, use certified seed supplies, which have low tolerance for ergot.
- Rotate crops. Avoid wheat after rye and avoid growing wheat and rye side by side. “My personal opinion is that growing the same crops (every second year) is not a rotation,” Menzies said. “I think you have to be looking at a minimum of three years, and in some cases four might be better.”
- Mow or spray grasses in ditches and field edges. Grasses are a source of ergot inoculum, which can be minimized if grasses are cut before the crop comes into flower.
- Manage crops properly to ensure optimal plant health. The longer a crop’s flowering period, the greater its chance of infection. Unhealthy or stressed crops normally have longer flowering periods. Reduce the risk of infection by keeping the crop well fertilized. Watch copper and boron levels.
- Avoid late herbicide applications if possible.
- Deep plowing can be used in heavily infected areas to bury ergot sclerotia and limit the number of spores that are released. Burning can also have a limited impact but is generally not considered an effective control strategy.
- Grow uniform stands. Increase seeding rates to reduce the development of tillers. Research from the United Kingdom suggests that late tillers are often more prone to ergot infection than main heads on the main stems.
- Timing of plant development is a factor. Crops that flower earlier might be slightly less susceptible to ergot infection.
- There is some evidence to suggest that certain classes of wheat are less susceptible than others. Re-search conducted by Menzies showed that Canada Western Red Spring wheats were most susceptible, Canada Prairie Spring varieties were slightly better and durum was better yet.
However, Menzies cautioned that research in this area is limited and has produced variable results. Class by class assessments might be affected by the individual varieties that were examined within each class.
- Delay swathing if ergot bodies are plentiful in the standing crop and if harvest priorities can be adjusted. Wind in a ripe standing crop will cause ergot bodies to fall to the ground, reducing infected kernels in the harvested sample and limiting the risk of downgrading.
- Harvest fields in pieces if necessary and segregate grain from heavily infected areas. Ergot infection tends to be heaviest near the field’s perimeter. Harvesting headlands and border areas separately can reduce cleaning costs and negate grade losses.
- Clean heavily polluted grain with gravity tables, colour sorters and other equipment to maximize the crop’s value.
- Dump screenings in the landfill or bury them. Don’t try to sell them or salvage any value. Alkaloids contained in ergot are highly toxic and can cause serious health problems in humans and livestock.