Here the fungus threads keep pace with the growth of the plant and reach maturity at or slightly before harvest-time.
"Since this disease is caused by an internal parasite, it is natural to expect certain responses to its presence.

It should be noted first that the smut fungus is living at the expense of its host plant, the wheat, and its effect on the host may be summarized as follows: The consumption of food, the destruction of food in the sporulating process, and the stimulating or retarding effect on normal physiological processes.
"Badly smutted plants remain in many cases under-size and produce fewer and smaller heads.

In the Fife and Bluestem varieties the infected heads previous to maturity exhibit a darker green color, and remain green longer than the normal heads.

In some varieties the infected heads stand erect, when normal ones begin to droop as a result of the increasing weight of the ripening grain.
"A crop may become infected with smut in a number of different ways.
Smut was originally introduced with the seed, and many farmers are still planting it every season with their seed wheat.

Wheat taken from a smutty crop will have countless numbers of loose spores adhering to the grains, also a certain number of unbroken smut balls.