b'US No. 1s ranged from 192 cwt./acre for on the UDSA color chart, in addition to forND113065-2Russ.ThesescoresND13245C-3Russto339cwt./acrefor unmanageablesugarends.Several (Tables1-3)combinedwithinternalUmatillaRusset,whilepercentageUS entries demonstrate sugar end resistance quality attribute scores serve as a guideNo. 1s ranged from 66% for ND13245C- includingDakotaRussetandRanger inidentifyingimprovedpotatogeno-3Russto88%forND12108CAb-3Russ. Russet, and while most clones consid- typesadvancinginourbreedingThepercentageof6to10-ouncesize ered resistant to sugar ends had some, pipeline toward the national French frytubersforclonesrangedfrom13to our rating of sugar ends is more strin- processingtrial,growerandprocessor22%, with a mean of 20%.Percentage gent than that of processors in an effort evaluation and potential release.oversized tubers (10 oz. size category) to identify durable resistance, thus mak-ranged from 7 for ND13245C-3Russ to ing them manageable during processing AspecialthankyoutotheNorthern35%forRangerRusset.Percentage (seefootnote3onTable3fordefini- Plains Potato Growers Association, thetubers in the 4 to 6-ounce grade, ranged tion).Sugar ends are a physiological dis- MinnesotaAreaIIResearchandfrom 30% for ND13103B-1Russ to 45% order resulting from sugar deposition on PromotionCouncil,Simplot,andtheforND13245C-3Russ.Undersized the stem end of the tuber rather than NIFA Special Potato program for fund-tubers were most prevalent for siblings starch in the damaged cells (low starch ingandotherresources.AdditionalND13245C-3RussandND13245C- and high reducing sugar, Type 1 or clas- thanks to Team Potato for helping with4Russ.Russet Burbank and ND13103B- sic sugar ends).A second type is typified planting, harvest, grading, and evalua-1Russ had the most US No. 2 and culled byhavingbothlowstarchandhigh tion,particularlyDickNilles,Felicitytubers primarily misshapes.Tubers per reducing sugars on the apical end, and a Merritt,JamesBjerke,EdoardoPolettiplantrangedfrom5.2forND13103B- third, rare, type where the basal (stem) and Hashim Andidi.1Russ to 11.9 for ND13245C-3Russ, dif- endaccumulatesreducingsugarwhileferingsignificantlyacrossgenotypes maintaininghighstarchlevels.Sugar(Table 1).endformationisspo-radicandoccursinallSpecific gravity (Table 3) was very low fallproductionareas;itforND113065CB-2Russ(1.0741)to is caused by heat stress,extremelyhighforND13245C-4Russ exacerbatedbywater \x18\x11\x17\x01/\x0f\x018FCFS\x01"WF\x0f(1.1004).While specific gravity varied stress during early tuber 4JPVY\x01\'BMMT\x014%\x01\x16\x18\x12\x11\x14significantlyacrossentries,mosthad bulking.Hollow heart/ XXX\x0fFMTUPONGH\x0fDPNlevels more suitable for processing than browncenterwasnot- 1SPUFDU\x01ZPVS\x011PUBUPFT\x01GSPN\x01GSFF[JOH\x01BOE\x01industrystandardRussetBurbankat ableinRussetBurbank, EJTDPMPSBUJPO\x01XJUI\x01&MTUPO\x01.GH\x011SPQBOF\x01$BSHP\x01)FBUFS\x02\x01*OFYQFOTJWF\x01FBTZ\x01UP\x01NBJOUBJO\x01BOE\x011.080.All entries had acceptable French Russet Nor-kotah, Uma- FOWJSPNFOUBMMZ\x01GSJFOEMZ\x0ffrycolorwhenfriedatharvest(field tillaRusset,andafew 1VUT\x01PVU\x01\x14\x18\x11\x11\x11\x01#56\x01BOE\x01SVOT\x01P\x01CPUIfry),includingRussetNorkotahour advancingselections "$\x01BOE\x01%$\x01QPXFS\x0f\x01*O\x01UIF\x013FE\x013JWFS\x017BMMFZ\x01poor French fry quality check.Stem end (Table 1).A general rat- DBMM\x01/PSUI8FTU\x015SVDL\x01\x07\x015SBJMFS\x01JO\x01\'BSHP\x01/%\x01frycolorvariedsignificantlyacross ing score is given to each GPS\x01RVFTUJPOT\x01BOE\x01QSJDJOH\x02genotypes, as did sugar end formation plot at grading (Table 1). \x18\x11\x12\x0e\x15\x18\x17\x0e\x18\x12\x12\x14that was evident for several NDSU selec- ThescoreisbasedontionsincludingsiblingsND113065C- yield,appearance,and1RussandND113065CB-2Russ, tubersizeprofile,ND13245C-3Russ,RussetBurbankand amongstothertraits.RussetNorkotah.Following8-weeks Clonesdifferedsignifi-storage at 45 o F (7.7 o C), many selections cantly, ranging from 2.6had an overall fry color exceeding 2.0 for Russet Burbank to 3.9 \x12\x0e\x19\x11\x11\x0e\x19\x15\x16\x0e\x12\x14\x19\x16JULY/AUGUST 2020 POTATO GROWER 11'