The recent rain and humidity is bringing on black sooty mold in wheat, which is just naturally occurring fungal species colonizing the heads as they senesce. Anything that prematurely killed the wheat, including abiotic stress such as drought or diseases like take-all and root rots, will be seeing more of this black sooty mold. Areas of lodged wheat may also develop more of this sooty mold as they will hold moisture for longer than standing grain.
Generally, this sooty mold should not be much of a problem and will blow out the combine during harvest. However, we might see some black point on the grain caused by some of these fungal species, which shows as a black discoloration typically on one end of the grain. Although black point of the grain will not reduce yield, it can affect quality. This will depend on wheat growth stage of infection and disease pressure.
Fungicides applied for head scab may help to reduce the amount of black point. Head scab pressure in general is at low levels across Michigan as the risk for head scab was low during the critical flowering period. No new head scab infections will occur, but any fields that were infected with head scab may accumulate additional mycotoxin during these periods of excessive moisture.
Source : msu.edu