Dwarf bunt

Host plants / species affected

Agropyron (wheatgrass)
Elymus (wildrye)
Hordeum vulgare (barley)
Poaceae (grasses)
Secale cereale (rye)
Triticum (wheat)
Triticum aestivum (wheat)

List of symptoms/signs

Inflorescence  -  black fungal spores
Whole plant  -  dwarfing
Whole plant  -  unusual odour

Symptoms

Identification is difficult, since both the characteristics of the causal organism and symptom expression of the host vary widely; its only consistent characteristics are the long incubation period (at least 21 days) and the low temperature (<15°C) required for teliospore germination.

An infected plant shows no obvious sign of disease until the ears emerge, but its stem is usually shorter than in healthy plants and it may have more tillers. Bunted ears are somewhat narrower than healthy ones, but, as ripening proceeds, the glumes are pushed apart laterally so giving them a characteristic dishevelled appearance. Sori are spherical (elliptical in common bunt - T. caries) and contain a blackish powdery mass of teliospores surrounded by a thick grey-brown tegument. For more information, see Grassner and Niemann (1954), Baylis (1958), Purdy et al. (1963), Rapilly et al. (1966).