By Pierce Paul and Dennis Mills, Ohio State University Extension
The damage left by above-average rainfall is now showing up in parts of Ohio. Wheat fields that were under water for several days are now dying. Wheat can recover from a few days of excess water, once the water dries out quickly. But the frequent and heavy rains we have had left the crop under water for close to a week in some locations.
Excess water replaces the air in the soil and deprives the plant roots of much-needed oxygen. Roots that are deprived of oxygen for an extended period will die. This is soon followed by death of the stems, and eventually, the entire plant, and the dead plant tissue is quickly invaded by opportunistic organisms. While wet, saturated, and poorly aerated soils do favor some plant pathogens such as Pythium and could lead to root rot, the problems we are seeing in most of the flooded fields are not caused by diseases.
In fields affected by root rot, dead plants or groups of dead plants are usually found among healthy-looking plants. What we are seeing in these problem fields are huge sections of fields or entire fields with dead or dying plants, which indicates that this is caused more from an abiotic or stress-related situation. In this case it is most likely due to flooding.
So, whether or not the entire crop is lost and should be abandoned depends on the length of time that there was standing water and the size of the area of the field that was affected. It is easy to tell whether wheat plants were flooded for too long; they either die or become rotted and stunted, with a chlorotic appearance (light green-yellow discoloration). These plants will eventually lodge and will not recover. If this occurred in a small section of the field, then you may still be able to get a decent crop, but if the majority of the field was affected, then the crop may not be worth keeping.