Managing soil diseases
Once you've had a soil-bourne disease present in your field, it's likely going to be there for a long time. But, whether they continue to cause crop damage depends on how you manage specific conditions each year, one expert says.
"Managing diseases starts with knowing what is present in the fields," says Purdue University Extension plant pathologist Kiersten Wise. "Growers need to know what diseases have shown up in their fields in the past, and they need to plan for those diseases even if they haven't seen them in a few years."
Environmental conditions, planting date and seed variety planted all go into the prospects a disease returns at harmful levels in the future. So, keeping track of those variables and managing them in the future is crucial to keeping soil-bourne disease pressures are kept at bay.
"Soil diseases don't go away, so growers need to plan to manage them," Wise says. "Knowing the field history can help growers choose varieties that are resistant to previous disease pressures."
If you're planting corn into soils where soil diseases have been present in the past, consider planting later on in the season if possible. And, consider adding at least one disease treatment during the growing season.
"Foliar disease organisms won't be as affected by the mild winter. Instead, they will depend more on the weather during the reproductive stages, probably in July," Wise says. "At that point, if growers are seeing foliar diseases, they can consider fungicide treatments."
And, don't forget to take into account your production system and its influence on disease management. Namely, if you're planting into a no-till field, you may need to pay closer attention to crop residue than you normally would to prevent soil disease from flaring up.
"If farmers are planting into fields with a lot of residue, if they're planting susceptible varieties and if their fields are continuous corn, they could possibly benefit from a fungicide later in the season if the environment is favorable for disease development," Wise says.