b'severeblackheartdisorderoftenrotsHerbicide Issues pHcancauseherbicidestobemore before emergence.Herbicide carryover in soil: Patterns ofactiveandincreaseinjurysymptoms. soilcarryoverwillhaveconsistentSome varieties are more susceptible to injurysymptomsintheareasoftheherbicidessuchasmetribuzin. field or where the herbicide carryover is a problem. Issues can be in the entire field or specific areas with higher herbi-cide carryover based on soil characteris-tics or previous herbicide application.Blackheartofpotatotuber.(John Nordgaard, Black Gold Farms) Sprout Inhibitor Contamination Metribuzin damage to CalWhite pota-Chlorpropham(CIPC)contaminationtoplant.(AndyRobinson,North Dakota State University/University of in storage. The sprouts of seed contami- Minnesota)nated by residues of CIPC in storages are cauliflower-shaped and will not produceChloroacetamide Herbicide Injuryplants. Herbicidecarryoverinsoil.(AndyCool and wet conditions will increase Robinson,NorthDakotaStateplant uptake and prolong plant metabo-University/University of Minnesota) MaleicHydrazide(MH-30)residuesinlismcausingslowgrowthandmal-seedfromcontactduringpreviousHerbicide Residue In Seedformed leaves.growingseason.MH-30suppressesSeed may not sprout, have cauliflower-sprouting and suppression of emergencelikesprouts,and/orcandelabra-likeThe active ingredient metolachlor and depends on the residue level and size ofstemscausedbyherbicidescausingadimethenamid can cause slowed emer-thetubers.Thelargerthetubersthelossofapicaldominance,mostcom- gence.highertheconcentrationofresidues.monlycausedbyglyphosate. Residues decline with time and sproutEmergencewillmostoftenappearas development occurs, but growth is sub- scattered injury throughout the seed lot stantiallydelayed.Ifaccumulatedinplanted with. Some plants will look nor-sufficientquantities,sprout-inhibitingmal; others will show varying leveling compoundsmaycausedelayedemer- ofherbicideinjurysymptoms. gence of seed tubers. Chloroacetamideherbicideinjury. (Andy Robinson, North Dakota State University/University of Minnesota)Variety Characteristics Erratic stand from glyphosate residue inseed.(AndyRobinson,NorthApical DominanceDakota State University/University ofTuberswitheyesconcentratedatthe Minnesota) budend(e.g.Ambra)orhavealow SproutsinhibitedbyCIPC.(SteveHerbicide Damage By Soil Typenumber of eyes (e.g. Bannock Russet).Johnson,UniversityofMaineSoils with low organic matter and high Cooperative Extension)MAY/JUNE 2023 POTATO GROWER 13'