Crops Journal

Root and crown rot are among the most widespread and damaging diseases of cereal crops, including common (Triticum aestivum L.) and durum [T. turgidum L. ssp. durum (Desf.) Husn.] wheat, on the Canadian Prairies. Due to the drier growing conditions experienced in the western Prairies over the last decade, these diseases have been increasing in incidence and severity, especially in durum wheat. Root and crown rot can cause significant yield losses in wheat. In western Canada, they are mostly caused by Cochliobolus sativus (Ito & Kurib.) Drechs. ex Dast. [anamorph Bipolaris sorokiniana (Sacc.) Shoemaker] and Fusarium spp. Many of the Fusarium spp. causing root and crown rot have also been associated with Fusarium head blight (FHB), such as F. avenaceum (Fr.:Fr.) Sacc. (teleomorph Gibberella avenacea Cook). Colonization by Fusarium pathogens of roots and crowns, and their subsequent survival and multiplication in those tissues after harvest, might play a role in the future development of FHB and contribute to its westward spread. Past research has shown that the presence of C. sativus and Fusarium spp. in underground tissue of wheat was affected by crop rotation, tillage method, and chemical input. Furthermore, results from a study in west-central Saskatchewan showed a differential effect of chemical input system on the presence of the most common Fusarium spp. in subcrown internodes and crowns of spring wheat. The pathogens F. avenaceum and F. culmorum (Wm. G. Sm.) Sacc. were less associated with organic systems than the weak pathogen/saprophyte F. equiseti (Corda) Sacc. present at its highest levels in organic-managed treatments. These observations agree with results from European studies on organic versus conventional systems. The expected hotter and drier weather is likely to promote the development of root and crown rot on the Prairies, and increase yield losses. Thus, research on these diseases and their management should be of greater importance in the future. Root and Crown Rot in Common and Duru