AssessyourFusariumHead BlightRisk IfyouareconcernedaboutyourriskforanFHBoutbreak inyourarea,visittheFusariumDiseaseSeverityRisk websiteatagriculture.alberta.ca/acis/m#!fusarium.The siteisamobile,local,diseaseseverityriskassessment toolthatcanbeusedbygrowersthroughoutAlberta. TheriskassessmenttoolwasdevelopedbytheAlberta WheatCommissionincollaborationwithRalphWright andDr.PavelPytlakatAlbertaClimateInformation Services(ACIS),AgricultureandForestry(AF)plant pathologistDr.MichaelHarding,AFcropspecialistNeil Whatley,AgricultureandAgri-FoodCanada(AAFC) plantdiseaseresearcherDr.KellyTurkingtonand industrypartners. Thetooltakesdatafromover300weatherstationsfrom aroundtheprovincetoprovidelocalriskwarnings. ACIScollects120,000hourlyweatherobservations frommorethan370stationseachday.Thesiteuses weatherdatatohelpgrowersmakeinformeddisease managementdecisions. Todetermineyourrisk,clickontheredpininthetop rightofthepagetoopenamapoftheprovince.Each weatherstationismarkedwithagreendot.Zoomin onthegreendotnearestyourfieldandclickonthedot toviewtheFHBdiseaseseverityindex(DSI)gauge forthatlocation.Thesitedevelopersusedariskmodel createdinManitobawhichdeterminesDSIbasedon airtemperature,relativehumidityandrainfalloverthe pastweek. ThetoolisnotaFHBforecast;itisusedtogaugeriskin ordertomaketimelyfungicideapplicationdecisions. Thereareotherriskfactorssuchascropstaging,the amountofFusariuminthesoil,thevarietalsusceptibility, ifaseedtreatmentwasapplied,andtherotationand stubblemanagementhistoryinthefield.However,this toolwillhelpyoumakeaninformeddecision. “Treated seed is exposed to less stress early in the season so it has a better chance for success after emergence.” —Michael Harding 12 www.seed.ab.ca | Advancing Seed in Alberta While you want to have your field come into maturity at the same time, high risk FHB areas should consider seeding different fields at different times. “You really don’t want to plant all of your wheat during the same week,” says Harding. “If they are all coming into anthesis at the same time, your entire season is at risk. But if fields mature at different times, you are spreading out the risk of a total loss.” Rotation is another way to reduce the disease pathogen in the soil, but given Alberta’s short growing season and cropping options, effective rotations can be challenging. “Ideally you would only have one crop in four years that is a host for Fusarium,” says Beres. “But that’s impractical as many of the crops that comprise today’s cropping systems are hosts for the disease. Even if the field is rested in chemical fallow, the undisturbed stubble, tissue and plant roots can be colonized with Fusarium.” Harding says even though ideal rotations are difficult, inoculum levels can be reduced by managing that rotation. “Durum and corn are the best hosts for the disease, so if you are growing corn, which is likely to have more Fusarium residue, don’t grow durum right away. Allow the residue to break down on a less susceptible crop. You should work out your field selection in the fall and winter so that you can minimize the buildup of the pathogen.” If the plant is more uniform and flowering more even, the timing window to apply a fungicide is also easier. More heads will come out of the boot at the same time, and the more heads available to the fungicide, the better its efficacy. Recent research shows that waiting until as many heads are visible will reduce Fusarium and DON at harvest. A fungicide will remain effective four to six days after flowering, or seven to 10 days following head emergence. You also have to take caution as to how you apply the fungicide,” says Beres. “You need to consider ground speed, keep your boom levels low around 30 centimetres above the canopy for better coverage, and make sure your nozzle is configured so that the angle and pattern covers as much of the plant as possible utilizing a coarse spray pattern. You’ll get as much out of an input that you put into how you apply it.” Harvest management can be tricky once Fusarium has infected a field. Many growers will increase the fan speed on their combine and blow the lighter, infected seed out the back end. However, then the stubble has been seeded with infected material. “The opinions around the utility of tillage for FHB management in the science community are somewhat mixed,” says Beres. “However, studies conducted on the Canadian Prairies show no increase in FHB under no-till, and there is only agreement that F. avenaceum has been controlled with tillage, not F. graminearum.” Jennifer Barber