b'2022 Post Harvest TestBy Kent Sather, North Dakota State Seed Department, Potato Program DirectorOur North Dakota Certified Seed Potato growersinNorthDakotamaintained consistent and highly successful produc-tionprotocolsfortheir2022crop. 14,230 acres were entered by 23 growers in June of 2022. This amounted to be 455 unique seed lots, ranging from less that a tenth of an acre to 180 acres. 53% of the acreage were russet potatoes, 24% were red potatoes, 19% were white pota-toes,andtheremaining4%werespe-cialty type potatoes.NorthDakotaseedgrowersallpartici-pate in a seed production increase pro- Field year 1 and 2 seed lots at Enander Seed Farms being inspected July 2022.gramthathasprovenitsvalueover many years. All seed in the state origi- Department potato inspectors. Leaf sam- ed in the eastern parts of the state, as nates from totally disease free laboratoryples of many of the seed lots also werethose lots are more exposed to commer-producedtissuecultureplantletsandserologicallytestedintheSeedcialpotatoesthatdohavesomePVY greenhouse minitubers. The minitubersDepartmentdiagnosticlaboratoryload in the crop.Inspectors and lab test-are planted in western North Dakota atagainst certain potato viruses. After alling can readily identify PVY in the field Enander Seed Farms, isolated from anyfieldinspectionsandlabresultswerewhen it is seed borne, meaning the virus other potato production. This farm willcomplete,12,985acresremainedasis already in the seed piece that is plant-raiseFieldYear(FY)1andFY2crops.foundationseedatthefieldyeartheyed. As the plant grows, the virus grows Thesecropswillbemovedtobewere entered. 984 acres were downgrad- withit,oftenexpressingvisualsymp-increased as FY2, FY3, and maybe FY4 toed to certified seed. This was due to thetoms.JohnsonFoundationSeedandJordelevels of PVY (also called Mosaic) rang-Certified Seed in Cando, ND. This area ising from .3 to 1% that were identifiedHowever, if PVY is transmitted by aphids a restricted growing area allowing onlyduring field inspections. later in the growing season, visual symp-seed potato production. This isolation istomsdonotdevelop,socannotbe another important step to increase theAnd finally, 5 lots representing 261 acresdetermined during summer inspections. volumeofdiseasefreeseedforotherwere rejected. Reasons included PVY lev- The amount of latent spread can impact NorthDakotaseedgrowersintheels over 1%, serious wilt, and chemicalproduction the following year.Walhalla,RedRiverValley,Oakesanddrift. Some of the lots that were down-Lisbon areas. These other areas will raisegradedorrejectedwereseedlotsthatWinter test grow-outs help to estimate FY3throughFY5seed,ingeneral,towereimportedfromotherstatespro- howmuchlatentspreaddidhappen. eventually be sold to their commercialgrams.Thenewlyharvestedtubersthatmay grower customers. have been infected later in the growing All seed lots from western North Dakotaseason will produce visual symptoms. A All 455 lots received three field inspec- and Cando area were disease free. PVYprotocol of our seed program includes tionsbyNorthDakotaStateSeedstarts to show in seed lots that are plant- growers pulling random samples of har-28 POTATO GROWER APRIL 2023'