Leaf and neck anthracnose is incited by Colletotrichum coccodes (Wallr.) Hughes, a new foliar disease of onion (Allium cepa L.) in Michigan that has been observed in the state since 2010. Symptoms include elliptical lesions on the leaves, necks, or both that appear bleached with a pale salmon to dark brown center. To develop an effective integrated disease management strategy, field studies were conducted in 2011 and 2012 to evaluate 16 commercial onion cultivars for their susceptibility to the pathogen. The incidence and severity of anthracnose were evaluated weekly following inoculation. Onion cultivars differed significantly in disease severity and incidence; differences between years were also observed. ‘Hendrix’ had the lowest disease severity, whereas ‘Highlander’ and ‘Candy’ exhibited severe onion leaf and neck anthracnose symptoms. Using less susceptible onion cultivars combined with effective fungicides against C. coccodes may limit crop losses for Michigan growers.
This work was supported by MSU GREEEN GR11-030 and GR11-020 and the Michigan Onion Committee.We thank all the members of the Hausbeck Lab for their valuable help; special thanks to A. Worth and J. Munoz for guidance with statistical analysis assistance.
DillardH.R.1988Influence of temperature, pH, osmotic potential, and fungicide sensitivity on germination of conidia and growth from sclerotia of Colletotrichum coccodes in vitroPhytopathology7813571361
Dillard,H.R.1988Influence of temperature, pH, osmotic potential, and fungicide sensitivity on germination of conidia and growth from sclerotia of Colletotrichum coccodes in vitro7813571361)| false
LeandroL.F.S.GleasonM.L.NutterF.W.WeguloS.N.DixonP.M.2003Influence of temperature and wetness duration on conidia and appressoria of Colletotrichum acutatum on symptomless strawberry leavesPhytopathology93513520
Leandro,L.F.S.Gleason,M.L.Nutter,F.W.Wegulo,S.N.Dixon,P.M.2003Influence of temperature and wetness duration on conidia and appressoria of Colletotrichum acutatum on symptomless strawberry leaves93513520)| false
LeesA.K.BrierleyJ.L.StewartJ.A.HiltonA.J.WaleS.J.GladdersP.BradshawN.J.PetersJ.C.2010Relative importance of seed-tuber and soilborne inoculum in causing black dot disease of potatoPlant Pathol.59693702
Lees,A.K.Brierley,J.L.Stewart,J.A.Hilton,A.J.Wale,S.J.Gladders,P.Bradshaw,N.J.Peters,J.C.2010Relative importance of seed-tuber and soilborne inoculum in causing black dot disease of potato59693702)| false
Rodríguez-SalamancaL.M.EnzenbacherT.B.DerieM.du ToitL.FengC.CorrellJ.C.HausbeckM.K.2012First report of Colletotrichum coccodes causing leaf and neck anthracnose on onions (Allium cepa) in MichiganPlant Dis.96769
Rodríguez-Salamanca,L.M.Enzenbacher,T.B.Derie,M.du Toit,L.Feng,C.Correll,J.C.Hausbeck,M.K.2012First report of Colletotrichum coccodes causing leaf and neck anthracnose on onions (Allium cepa) in Michigan96769)| false
Rodríguez-SalamancaL.M.NaegeleR.P.Quesada-OcampoL.M.HausbeckM.K.2018Inoculation methods, temperature, and relative humidity affect leaf and neck anthracnose, a new onion disease in MichiganPlant Health Prog.196468
Rodríguez-Salamanca,L.M.Naegele,R.P.Quesada-Ocampo,L.M.Hausbeck,M.K.2018Inoculation methods, temperature, and relative humidity affect leaf and neck anthracnose, a new onion disease in Michigan196468)| false
Tsror (Lahkim)L.JohnsonD.A.2000Colletotrichum coccodes on potato p. 362–373. In: S.F. Dov Prusky and M.B. Dickman (eds.). Colletotrichum host specificity pathology and host-pathogen interaction. Amer. Phytopathol. Soc. Press St. Paul MN
WhartonP.S.Diéguez-UribeondoJ.2004The biology of Colletotrichum acutatumJardín Botanico de Madrid61322
Wharton,P.S.Diéguez-Uribeondo,J.2004The biology of Colletotrichum acutatum61322)| false