The membrane ruptures shortly after the heads emerge and the spores are dispersed by wind, leaving only the bare spike. The fungus overwinters within the embryo of the barley seed. When infected seed germinates in the spring, the fungus is activated and colonizes the growing point of the plant. As the heads begin to develop, all the tissues except the central spike and a delicate covering membrane are invaded and converted to spores. The spores are mature by the time the infected plant heads out and, following rupture of the delicate membrane, are spread by wind to nearby plants.
Infection occurs when spores land on open barley flowers.
Following infection the fungus becomes established in the developing seed embryo. Seeds of the crop being tested are placed in a beaker of sodium hydroxide water solution. The mixture is allowed to stand for an additional period of time. This will extract the embryos and they will rise to the surface of the container while the debris sinks to the bottom. Embryos are recovered from the surface of the container and prepared for clearing.