Effect of fungicide seed treatments on root pathogens of cereal crops under field conditions

Abstract

Fernandez, M. R., May W. E. and Lafond, G. P. 2010. Effect of fungicide seed treatments on root pathogens of cereal crops under field conditions. Can. J. Plant. Sci. 90: 905Á917. It is of importance to reduce the spread of Fusarium graminearum to western regions of the Canadian prairies where Fusarium head blight has so far occurred to a limited extent. Determining the effectiveness of fungicides against F. graminearum in infected seed under various growing conditions will help design a comprehensive strategy for preventing the spread of this pathogen. Field trials at various locations in eastern Saskatchewan were conducted (2003Á2005) to examine the performance of registered and experimental fungicides on Fusarium colonization of subcrown internodes (SIs) of plants derived from Fusarium-infected barley (Hordeum vulgare L.), common (Triticum aestivum L.) and durum [T. turgidum L. ssp. durum (Desf.) Husn.] wheat seed, and on SI discoloration. Among the fungi isolated from discolored SIs were Fusarium spp., including F. graminearum, and Cochliobolus sativus. Fusarium graminearum infections were mostly seed-borne whereas infection by other fungi appeared to be mostly soilborne. Compared with the untreated infected control, the combined seed treatments reduced discoloration of SIs, but no single fungicide reduced discoloration consistently across site-years or crops. Similarly, no product consistently reduced the isolation of F. graminearum or other Fusarium pathogens, although some fungicides appeared to be more effective than others in reducing isolation of F. graminearum or C. sativus. Our observations agree with results from a controlledenvironment study of effects of seed treatments on F. graminearum colonization of plants derived from infected common and durum wheat seed, thus confirming that treatment of F. graminearum-infected seed with fungicides will not likely prevent the spread of this pathogen.Key words: Root rot, Fusarium head blight, fungicides, seed treatments, Fusarium spp., Fusarium avenaceum, Fusarium culmorum, Fusarium graminearum, Cochliobolus sativus Fernandez, M. R., May W. E. et Lafond, G. P. 2010. Incidence du traitement des semences avec des fongicides sur la pre´sence de microorganismes pathoge`nes dans les racines des ce´re´ales au champ. Can. J. Plant. Sci. 90: 905Á917. Il est capital de freiner la propagation de Fusarium graminearum dans les re´gions des Prairies canadiennes, dans l'Ouest, ou`la bruˆlure de l'e´pi par Fusarium n'est encore que restreinte. Il sera plus facile d'e´chafauder une strate´gie ge´ne´rale pour pre´venir la propagation de ce pathoge`ne si on pre´cise l'action des fongicides contre F. graminearum dans les graines infecte´es, dans diverses conditions de croissance. Les auteurs ont proce´de´a`des essais sur le terrain a`divers endroits de l'est de la Saskatchewan (2003Á2005) afin d'e´tablir l'efficacite´des fongicides homologue´s et expe´rimentaux sur la colonisation des entrenoeuds infe´rieurs au collet par Fusarium chez les plants issus de graines d'orge (Hordeum...

Bipolaris sorokiniana-Induced Black Point, Common Root Rot, and Spot Blotch Diseases of Wheat: A Review

“…tritici -induced take-all diseases in wheat ( Wang et al., 2015 ). Fungicides are not a good choice for the management of wheat root and crown diseases ( Fernandez et al., 2010 ).…”

Efficacy of acetic acid vapours and dry heat to control Fusarium graminearum and Bipolaris sorokiniana in barley and wheat seeds

“…In the present study, the drier conditions deliberately used in the growth cabinets with a sand substrate that promotes root diseases may explain the differences observed between the two environments (in the cabinets and in the field). Fernandez et al (2010) also observed that seed treatments were less effective at reducing root discoloration caused by seed-borne Fusarium spp. and B. sorokiniana in a year when precipitation and mean temperature in late spring and early summer were higher than in the other years of the study.…”