The infected florets exude a sugary substance referred to as honeydew. The honeydew contains a large number of asexual spores called conidia. Because the honeydew has a rotten-smelling odor a large number of flies and other insects are attracted to the infected heads. The insects become contaminated with conidia and inadvertently spread the disease to other healthy flowers. Rain splash and wind can also carry the conidia to other florets.
New infections occur as long as flowering occurs.
The purplish-black ergot body develops in place of the kernels. For grain produced in 1999 grain cleaning is an option. Though this is an added cost, the cleaning process can often improve the grade significantly. Rotate to crops outside the grass family like oilseeds and pulses. Fortunately ergot bodies do not remain viable for more than one year.