.gif)
Covered smut (barley)
Encyclopedia
Covered smut of barley is caused by the fungus Ustilago hordei. The disease is found worldwide and it is more extensively distributed than either loose smut or false loose smut.
while the grain is being formed. Infected seeds give rise to systemically infected plants. The mycelium
advances through the host tissue and becomes established behind the growing point.
The spores are not readily blown or washed away by wind or rain. At harvest, spore masses are broken up, scattering spores on grain. Frequently, masses of spores remain intact and appear in harvested grain. The fungus overwinters as teliospores on seed or in soil.
Symptoms
Infected plants do not demonstrate symptoms until heading. Kernels of infected plants are replaced by masses of dark brown smut spores. Smutted heads are hard and compact. Infected plants may be stunted. Occasionally smut sori may also develop in leaf blades, where they appear as long streaks.Disease cycle
Infection is seed-borne within the seed, the fungus penetrating the endospermEndosperm
Endosperm is the tissue produced inside the seeds of most flowering plants around the time of fertilization. It surrounds the embryo and provides nutrition in the form of starch, though it can also contain oils and protein. This makes endosperm an important source of nutrition in human diet...
while the grain is being formed. Infected seeds give rise to systemically infected plants. The mycelium
Mycelium
thumb|right|Fungal myceliaMycelium is the vegetative part of a fungus, consisting of a mass of branching, thread-like hyphae. The mass of hyphae is sometimes called shiro, especially within the fairy ring fungi. Fungal colonies composed of mycelia are found in soil and on or within many other...
advances through the host tissue and becomes established behind the growing point.
The spores are not readily blown or washed away by wind or rain. At harvest, spore masses are broken up, scattering spores on grain. Frequently, masses of spores remain intact and appear in harvested grain. The fungus overwinters as teliospores on seed or in soil.