b'Andys Advice:Sampling For Herbicide Injury In Potatoes By Andy Robinson, Extension Potato Agronomist and Associate Professor, NDSU/UMN3. Pull off leaves from the most sympto- Whenpotentialherbicidesinjury matic areas (about 5 to 10 plants) andappears,understandingwhatiswrong placetheminaventilatedzip-toporwith your crop is important to make the paperbag.Gatheraboutapoundofrightmanagementdecisionsforthat leaves, which will fill up the bag. Dig upfield. Herbicide injury can cause prob-one to two tubers from each plant sam- lems in potato growth and subsequent pled and place in a separate bag. Repeattuber yield and quality.this process for any other areas in the field you would like to sample. Technology today allows us to test plant material in specialized laboratories and 4.Gatherleavesandtubersfromandetectextremelylowlevelsofchemi-unaffected area and place them in sepa- cals. An herbicide test either confirms or rate bags.deniesthepresenceofanherbicide.5. If you are concerned about residue inThisdatacanhelpyoumakeproper seed tubers, dig up 10-12 mother seeddecisions for those fields. Using the fol-Supplies: pieces and place them in a separate ven- lowing detailed steps will ensure accu-Pen or markertilated or paper bag.rate results and records are kept. Disposable gloves Newgallonsizezip-topbagswith6.Labeleachofthebagswithdate,Document Everythingholes poked through in several places totime, and what it is (sample ID).Whenanherbicideinjuryoccurrenceprovideaeration(ventilatedbag)or7. Place samples on ice in a cooler.happens,immediatelydocumentthe injury.Aslowresponsecouldmean paper bagsmissing the height of injury and symp-8.Outofthefield,gentlycleanany Cooler with icedebris or soil off the tubers and place intoms key to determining the herbicide Submissionformforlaboratoryofa new ventilated zip-top or paper bag.causingthedamage.Injurycaneven choicebecome less apparent over time to the 9.Storethesamplesinarefrigeratorpoint of no longer being visible, howev-Quick Steps:until you can ship the sample.er yield and tuber quality could still be1. Take photographs of the injury symp- 10. Fill out the sample submission formaffected.tomsandrecordGPSlocation.Writefor the laboratory of choice, being sure down the date you first noticed symp- to include the requested herbicide testItisimportanttodocumentthedate toms,whatthesymptomsare,andtobecompleted.Keepacopyofthisinjury was first observed, map the area where in the field you observed it. Keepform for your records. affected(withGPScoordinates),and this information in your records.takephotographsofinjuryincluding above and below ground symptoms and 2. Use a new pair of disposable gloves11. Pack the sample in an insulated box withiceandusenextdayshippingtoexternal and internal tuber symptoms. for each sample bag you collect.Patternsandotherimportantfactors the laboratory of choice.MARCH 2022 POTATO GROWER 19'