b'tion, epidemiology and management of apart,albeitsmall,ofourpathology formingevaluationsingrowerfieldsbacterial soft rot and blackleg funded by program.Weareworkingincoopera- near Lisbon, North Dakota. These evalu-a multistate NIFA grant. In cooperation tion with Dr. Susie Thompson to ensure ations are aimed at understanding thewith other researchers, we continue to thatNDSUbreedingmaterialdisplays relationship between on-farm practices,screenseedlotsforthepresenceof symptoms characteristic of BRR, aiding from fumigation to the incorporation ofDickeya to identify the cause of blackleg intheaccuratefielddiagnosisofthis manureandcroprotation,onsoilin the field, including samples from our devastatingdiseaseinanymaterial health and disease pressure. We are inregion.AfieldtrialattheOakes released from the program. Visual obser- the 3rd year of this 4-year study.Irrigation Research Site will be conduct- vation of BRR symptoms is crucial in theed to determine the economic impact of success of the seed certification system. FungicideresistancecontinuestobeDickeyadianthicolainfection.This We also continue towork to improve evaluated across several foliar and soil-work is in cooperation with ag econo- laboratorydetectionofthepathogen borne pathogens as we have done formists as part of the NIFA blackleg grant. that causes BRR, again aiding in accu- manyyears.Again,thisallowsustorate and cost-efficient seed certification. inform growers of the best disease man-Potatogenotypesfrommultiplepro- agement strategies based on data fromgrams,includingtheNDSUbreeding Trials are being conducted in the Park this region.program in cooperation with Dr. Susie Rapids, Minnesota area with the gener-Thompson, and Potatoes USA are being ous cooperation of RDO Farm Division We thank all of our generous coopera-grown at the Inkster site for evaluation to evaluate both chemical and biologi- torsincludingRDOFarmDivision,ofpost-harvestsusceptibilityto calproductsforthemanagementof Hoverson Farms, NPPGA, MN AII PotatoFusariumsambucinum dryrot,Dickeya Verticillium wilt.Growers, Cavendish Farms, Forest Riverdianthicola andPectobacterium softrot, Colony, JR Simplot Company, AgWorld,pink rot and leak. The identification of In addition, we are evaluating two cul- Minnesota and North Dakota Certifiedresistancetothesediseasesisdifficult turalmanagementtactics.Thisisthe Seed Growers and Black Gold Farms.and is a continuing project for our pro- 5th and final year evaluating the effectgrams. of vinekill date on the colonization of We encourage growers to reach out withpotato vines with the Verticillium wilt any disease-related questions, includingTobacco Rattle Virus (TRV), Potato Mop pathogen funded by the North Dakota diseasediagnosis,duringthisgrowingTopVirus(PMTV)andpowderyscab SpecialtyCropBlockGrantProgram. and storage season. We wish you a suc-have unfortunately been added to the Reduction in colonization will result in cessful season and thank you for yourlong list of pathogens growers must be reducingthepathogeninfestationin continued support.vigilant about avoiding. We are working the soil and subsequently reduce diseasewithmulti-statecooperatorsonthe pressure. This is the 2nd year evaluating NutrientManagementRe-Tuber Necrosis Specialty Crop Research the effect of planting date on the pro- search on Irrigated PotatoesInitiative (SCRI) Project towards sustain- gression of Verticillium wilt funded by Dr. Carl Rosen, UMN able solutions for PMTV and powdery MNAIIandCavendishFarms.Resultsscab. Our research on these pathogens fromthe1styearwerepromising, In 2021, five studies being conducted atincludes improving detection, working althoughtheseasonwascutshortby the Sand Plain Research Farm in Beckertowardsthedevelopmentofresistant frost. are summarized.An overarching goal ofcultivars and determining environmen- this research is to enhance yields andtal factors in our region associated with AspartofthemultistateSoilHealth improve nutrient management for pota-disease severity. SCRI Project lead by the UMN, we are toes grown on irrigated sandy soils.Theconducting a replicated small-plot trial objectivesandbriefdescriptionsofBacterial ring rot (BRR) continues to be nearParkRapids,Minnesotaandper- these studies are as follows:JULY/AUGUST 2021 POTATO GROWER 15'