McGranahan Dr, Gale H

Tulecke, Walt : Professor emeritus of Biology

The Walnut Germplasm Collection of the University of California , Davis A Description of the Collection and a History of the Breeding Program of Eugene F . Serr and Harold I . Forde Walt Tulecke and Gale McGranahan Report No . I3 + July 1994 Genetic ResourcesConservation Program Division of Agriculture and Natural Resources University of California Davis , California This report is one of a series published by the University of California Genetic Resources Conservation Program ( technical editor : P.E . McGuire ) as part of the public information fundion of the Program . The Program sponsors proiectsin the collection , inventory , maintenance , preservation , and utilizationof genetic resources importantfor the these activities take place on the State of California as well as research and education in conservation biology . Universityof Californiawith funds provided by the State of Californiato the University . several campuses of the be obtained from : Additional copies of this report may Genetic ResourcesConservation Program Universiiyof CrComM Davis , CA 95616 USA ( 91 6 ) 757 - 8920 FAX ( 91 6 ) 757 - 8755 email : grcp9ucdavis.edu CITATION : Tulecke , W . and G . McGranahan . 1994 . The Walnut Germplasm Collection of the University of California , Davis . A Description of the Collection and a History of the Breeding Program of Eugene F . Serr and Harold I . Forde . Report No . 13 . University of California Genetic Resources Conservation Program , Davis , CA . Walt Tulecke is Professor emeritus of Biology , Antioch University , Yellow Springs , Ohio and Gale McGranahan is Pornologist and director of the Walnut Breeding Program , Dept of Pomology , University of California , Davis , California . PHOTOGRAPCHRYEDIT Front cover , pages 4 , 5 , and I 7 - 22 : Don Edwards , Dept . of Pomology , University of California , Davis , California In accordance with applicable Federal laws and University policy , the University of California does not discriminate in any of its policies , procedures , or practices on the basis of race , religion , color , national marital status , sexual orientation , age , veteran status , medical condition , or handicap . origin , sex , Inquiries regarding this policy may be addressed to the AfErmative Action Director , University of California , Agriculture and Natural Resources , 300 Lakeside Drive , 6th Floor , Oakland , CA 94612 - 3560 . ( 510 ) 987 - 0097 . Contents Dedication Preface Acknowledgements Introduction History of the breedingprogram Personalhistories 9 Eugene Frank Serr 11 HaroldI.Forde Description of germplasm Old cultivarsand introductions Cultivarsreleased by the University of California University of California numbered selections in the collection Paradox and black walnuts F . Serr and Harold I . Forde Publications of Eugene Literature cited Appendix 1 - Pedigree diagramfor cultivars released fromthe 35 Serr / Forde breedingprogram 37 Appendix 2 - - Germplasm evaluationdata Dedication his publicationis dedicated to Eugene F . Sen and Harold I . Forde who conducted thewalnut breeding programat the University of California , T andForde's collaboration was collegal and Davis from 1948 to 1978 . Serr productive . This brief history of some of their work and the description of their walnut germplasm collectionis a tribute to them and to their success . Harold I . Forde F . Serr Eugene his document has been prepared with support of the University of TCaliforniaGeneticResourcesConservationProgram ( UCGRCP ) aspart of its continuing effort to assess the value , status , and needs for access and Cali - conservation of crop genetic resources important for California . The forniawalnutindustryhasbeenremarkably successful , accountingfor 99 % of the US walnut production with a $ 267million contributionto the state's economy ( CaliforniaDept . of Food and Agriculture 1993 ) . Components of this success , of course , include cultivars accepted by the producers and consumers , skillfulhorticulturalpractices , astutemarketing , fortuitouscli - mate , and available water . These were detailed and discussed in a report recently produced by a Walnut Industry Study Group convened by the California Agricultural Issues Center ( Coppock 1994 ) . This University of documentemphasizesthe geneticcontributionsto the success of walnutsin is key to the sustained productivity of crops . California . Genetic diversity Without it , there can be no new cultivars to meet society's future needs , which areunpredictable . Itisapparentthat the transitionfromwalnutcultivarsthatwerederived from variants that occurred by chance to cultivars produced by plant breedjng , that is , selectionof progeny fromcontrolled crosses , had a major impacton the culturalpractices that could be applied . Central to thiseffort this has been access to the geneticdiversityfor the crop . That is the story of report and since the effort was largely the work of two men over long is alsotheir story.The report presents anoralhistory and careers , thereport GermplasmCollectionin the UC Davis Dept . documentation of the Walnut of Pomology , revealingthe logic of plant breedingand providinghistorical germplasa insightinto the system and personalitiesthat developed the The amassing and maintenance of a large germplasm collection takes combined and sustained efforts and support of several individuals and organizations.In the caseofwalnut , therehasbeencontinuedsupportfrom the California industry , the US National Plant Germplasm System , and , to asmallextent , the UC GRCP , aswellasindividualsinvolvedintheextension thisdocunent and research efforts of the University of California . We feel willaid in sustainingthat effortand support.We congratulateDrs . Tulecke and McGranahan fortheir effortsin bringing thisstory to us . Cdvin 0 . Qualset Fredrick A Bliss Di ~ ctor Chair Genetic Resources Dept of Pomology Conservation Program University of California University of California Davis or thisbrief history of the walnut breeding program at the University 1948to 1978 , a number of individualswere con - of California , Davis , F Special thanks go to them for their tacted for information and assistance . I . helpfulness . Each had a specialrelationship to Eugene F . Serr and Harold Forde . Robert Livermore , President of Zendex Corporation , and a former Sen ; helped initiatethisproject with his interestand with finan - student of cial support and the University of California Genetic ResourcesConserva - his support to get the project going . Bill Stuke , tion Program matched nurseryman in Gridley , California , worked closely with Serr for 43 years Serr , Jr . of Red Bluff and and was a close friend.Two sons of Serr , Eugene Sem of Orindasharedrecollectionsof their father.Professorsemeriti John J . Olmo , OmundLilleland , andDillonBrownand extensionspecial - Harold ist Dave Ramos , all of UC Davis , were helpful with information . Dillon Brown's book on the history of the Pomology Departmentwas particularly useful ( Brown1990 ) . We thank farm advisors Wilbur Reil and Bill Coates for reviewing the germplasm section of the manuscriptand Herb Phillips for data compilation . We are grateful to the California Walnut Marketing Board for its support of the Walnut Breeding Program and ongoing Diamond Walnut Growers , Inc . for itscontri - germplasmevaluationand to this project . bution to I . Forde , who gave The one person who was most helpful is Harold also many hours of his time to provide informationonwalnutcultivars.He read the manuscript at different stages of preparation . At 79 years , Forde's with many memory broughtforth a clear and steady stream of information thanks to Harold I . Forde . stories of the good old days . Special Introduction his account of the early history of walnutbreedingand a descriptionof T germplasm collection at the University of California , Davis the walnut useful to plant breeders , walnut growers , farm advisors , is intended to be informationabout some of the important and the generalpublic . It contains c o l l d and used in controlled crosses made by Serr and breeding stock 1948 to 1978 . Descriptions and illustrations of cultivars and Forde from selections from different crosses as well as five - year averages for leafing date , harvest , shell , and kernel charactersare given . Also includedaresome recollections of Harold I . Forde about interestingand importantaspects of This information comes from interviews which were recorded their work . and transcribed as part of anoralhistory of walnut breedingat UC Davis . Germplasm Collection is contained in a reserve block of The Walnut QS theStukeBlocklocatedintheWolfskillExperimental walnuttreesknown StukeBlock is named after William E . Stuke , Farm , Winters , California.The in Gridley , California , who was afriend and cooperatorwith a nurseryman Eugene F . Serr for more than 43 years , beginning in 1924when Stuke was Serr was farm advisor in Sutter County . Much of startinghis nursery and Serrand the materialin the StukeBlock comesfromtheold Variety Block of has since been taken out . The Stuke Block consists of genetic Forde which lines of special interest to California , including old and new cultivars , Thiscollection selectedparentalstock , and representativerootstock species . a d stock of potential is the only source of old California walnut cultivars breedmgatDavis . Thecollectionisintendedtoserve valueforfuturewalnut as a source of material which is already adapted to California and for also serves as a studyingand solvingfutureproblems in walnut culture . It resource for student research , for growers and farm advisors , and for teaching . Complementing the UC Davis collection , the USDA National Germplasm Repository at Davis maintains a collection of some 400 acces - Juglans species , with an emphasis on representing the sions of several than on maintainingwalnut cultivars . diversity of the genusrather There are some 20 species of the genus Jughs , all of which produce and widely cultivated edible nuts . The most horticulturally developed is J . re @ L . , the English or Persian walnut . A recent review of the species distribution and utilization of Juglans species as genetic resources for the by McGranahan and Leslie ( 1990 ) . Several cultivatedwalnutwas presented Jughs species are important as rootstocks for J . = gin production ( see Maranahan and Chtlin1987for review ) . Specimens of the Juglans species , in either the cultivars , and numbered selectionsdiscussed here are located Stuke Block or in the National GermplasmRepository - Davissection of the Wolfskill Experimental Fann Californialeadsthe nation accountingfor 99 % of US walnutproduction CentralValley counties ( Butte , SanJoaquin , Stanislaus , Sutter , and and five Tulare ) account for the bulk of California's output ( CaliforniaDepartment Food and Agriculture 1993 ) . The leadingcultivar inCalifornia , Chandler , of was released from the UC Davis breeding program initiated by Serr and ( McGranahanand Leslie 1990 ) . Forde hewalnutbreedingprogram of Serrand Fordebeganin 1948when Serr T Pornologist in the Pomology was appointed Lecturer and Associate Agriculture , University of California.Serrwas 50 Division of the College of years old at the time and was ExtensionSpecialistfor deciduous fruitsand nuts for the state of California . the spring of 1947 , Warren P . Tufts , Chair of the Somewhat earlier , in I . Forde and a botanist , Richard King , Pomology Division , called in Harold and said that a walnut breeding program was to be initiated . Forde was 34 years old at the time ; King was only temporarily involved . Forde and King made some prehmary crosses and worked on pollen preservation and stiU ( 1944 ) , Eugene F . Serr bagging methods duringthe 1947season.Earlier and Assistant Professor Arthur Davey in the Pomology Division had col - lected and evaluated 12selections of the cultivar Franquette to see which was superior . Unfortunately , Davey passed away in February , 1947 . Tufts then encouragedSerr and Forde to take up the walnutwork together.Tufts chair of the Division had a reputation for being a well - liked and efficient and he was very supportive of Serr and Forde . Webber Historical accounts of walnuts in California ( Smithet al . 1912 ; and Goodspeed 1919 ; Batchelor 1924 ; Batchelor et al . 1945 ) mention the hard - shelled walnutsbroughtinfromSouthAmerica by the Missionfathers 17709 . Ahundred years later ( 1869 ) , JosephSextonpurchased a large in the sack of walnuts at the dock in San Francisco and planted a thousand trees Goleta , California . The origin of these nuts is uncertain , at his ranch in China.TheselectionsfromthesetreesgaverisetotheSanta perhapsChileor Barbara soft shells , such as Placentia . About the same time ( 1870 ) , Felix Gillet , anurserymaninNevada City , California , was importingscionwood French and nursery stock from France . He is credited with introducingthe cultivarsFranquette , Mayette , and others to California . As a result of these introductions by Sexton and Gillet , walnut growers found superior open - pollinated seedlings that led to the cultivars Eureka , Placentia , Concord , Payne , Hartley , and others . All of the early walnut cultivars were obtained by selecting seedlings that occurredby chance , rather thanfromcontrolledcrosses , which wasthe method of Serr and Forde . However , somewalnutbreedingwork was done by Luther Burbank between 1879and 1885 ( Whitsonet al . 1914 ) which gave U.hindsii rise to Paradox , the hybrid fromnorthern California black walnut ( Jeps . ) Rehder ) and J . regia . He also crossed J . hindsii and the eastern black walnut U . nigra L . ) to get the Royal walnut . It was Paradox that was especiallyusefulforrootstockssinceitprovidedrootvigorand somedisease resistance . The walnut breeding program initiated by Serr and Forde emphasized yield asone of themost importantcharactersforeconomicreasonsandyield was related to a great extent to the number of pistillate flowers produced . Hence , those cultivars which produced pistillate flowers on lateral buds , known as lateral fruitfulness or fruitful laterals , would have the potential than those that only flowered on the terminals . The for bearing more nuts time and abundance of pollen sheddingwas importantto assure adequate pollinationwhen thepistillateflowerswere receptive.Later leafingto avoid frost and minimize blight was also desirable . Shell qualities of thickness , smoothness ( Fig.I ) , color , and seal , the size of the nut , the proportion of the nut weight contributed by the kernel ( spoken of as ' percent kernel ' ) , and kernel color , flavor , and plumpness ( Fig . 2 ) were other traits systematically evaluated for the materials in the breeding program . Early maturity of the nuts was needed to allow adequate time for the harvest , processing , and shipment of nuts to market in the fall . Tree vigor and strength suitable to orchard practicesaswell assomediseaseresistancewere alsorecognized as important considerations in evaluating progeny . Constant attention to all these criteria through field observation , record keeping , and the collection crackout of nutsresulted ina detailedevaluationof atree's performance and over many years . By 1956 Serr and Forde were able to state clearly the objectives of the walnut breeding program which had begun in 1948 . The characters they were selecting were now very specific . They were making crosses to get at leasttwoflowersper inflorescence , withlateralfruitfulnessof 50 % or better . 42 rnm length with kernels of 8 to 10 g dry weight was Nut size of 38 to desirable . Pollen sheddingneeded to be coordinated with pistil receptivity or another pollenizer had tobe available.A leafingdate of 14to 21daysafter Payne for interior valleys and some upland orchards was desirable . Other importanttraits were nut maturity in lateSeptemberto early October and a kernelthat was 50to 60 % of thenut weight , withlightcolor and goodflavor . A fairlysmoothshellwitha strongsealand lightcolor wasalsoneeded.Tree vigor included strengthin both the scaffold and branches . In their summary of resultsafter the firstsevenyears of walnut breeding with selected lines , Serr and Forde came to the conclusion that certain characterswere inheritedina morepredictablemanner and othercharacters were less reliable.Leafing dates of 14to 21 days after Payne , a character of Franquette , and pistillate flowering on lateral buds , a character of Payne , selected progeny by crossing Franquette with could be obtained in a few Payne . If Payne was selfed then some progeny were dwarfed , giving short gene ( s ) for internodes , smallnuts , and russeted hulls , indicatinga recessive thischaracter.Overall , by 1956Serrand Fordehad made39differentcrosses , pollinated 15,691pistillateflowers in controlled pollinations , and derived a population of 833 seedlingprogeny to be evaluated and selected for desir - able characters . in a Their general procedure after deciding on the crosses to be made given season was to collect pollen , storing it when necessary , and enclose unopened flowersin small ( 4 " x 6 " ) gabardinebags to excludepollen . When the flowers were receptive they would inject with a hypodermic needle a smallamount of pollenfrom the selected male parent into the bag . The nuts Figure 1 . Illustratedare eight of the nine degrees of shell smoothness used in scoring this character in the breeding program . were collected in the fall , dried , and stratified for about two months and then germinated in deep flats ( 8 " ) in the greenhouse.A typicalflatcontained a 4 " layer of potting soil , a layer of sand onwhichwere placed about 24 seeds covered by another layer of sand . The seedswere allowed to germinate and after the seedlings ' first flush of growth , the flat was transferred to the lath house where it remained until the dormant seedlings were transplanted to a nursery bed the following winter . In the nursery a seedling would be assigned a permanent number which consisted of the year of germination , followed by a number indicatingits position in the row , e.g . , seedling49 - 46 germinated in a flat in 1949 and was the 46th seedling in the nursery row . Once they were big enough , usually the followingyear , wood was collected and treeswere grafted to northern Califor - nia black walnut U.hindsii ) in a " seedling block " orchard for evaluation . ( In later years seedlings were transplanted rather than grafted . ) A minimum of 20 seedlings per cross was desired and the cross was repeated if it showed particular promise . If a grafted seedling exhibited some superior traits it was " selected and bud - J . ded or grafted to two Paradox and two hindsii in a selection block orchard to con - firm and extend observations on progeny performance . Field trials of selected lines were made through arrangements with nurserymen and walnut growers usually working with the farm advisors . Duringthe 1948 - 1955 period , the culti - vars used for crosses included Early Ehrhardt , Hodges , Payne , Concord , Conway Eureka , Hartley , Waterloo , Mayette , Franquette , and others with less familiar names like Myrtleford and Har - riette . Payne was used in many of the crosses because it was the only source of Marchetti became lateralfruitfulnessuntil available . Hartley was also used exten - Figure 2 . Plumpness is one sively but did not prove to be a good par - component of kernel quality , ent . along with color and flavor . De - From the early records ( 1948 - 1955 ) , it grees 3 , 5 , and 7 ( from top to is apparent that Serr and Forde assembled bottom ) in a nine - point plump - at the campus orchards and the Wolfskill ness scale are shown here . Experimental Orchard a wide variety of the available genetic resources of walnut . Their initial baseline was very broad . Besides the standard cultivars at that time , such as Payne , Hartley , Franquette , and others , they acquired more suchas King , Khagazi , Schlapp , Doc Lock , Mammoth , Sorrentina , Belliciti , DonJuan , Simonet , andHarriette . From Dr . H.P . Olmo of the Viticulture Department of UC Davis they obtained about 35 numbered collections of nuts gathered from such loca - Tabriz area of Iran.Serr and Forde also brought in scionwood tions as the fromtheUnitedStatesDepartmentof AgriculturePlantIntroductionStation This included 22 walnut linesintroducedfromvarious in Chico , California . parts of the world . Eventually , the constraints of time and spaceforced Serr and Forde to eliminate many of these genetic lines as being of no value for their work , sincethese lines did not containthe desirabletraits which they were seeking . In 1956 , Serr and Forde began using the best seedlings from their controlledcrossesas parents , thus beginning a breedingprogram of recur - all the crosses made were between rent mass selection . By 1972 almost This resulted in a narrowing of the germplasm base and an selections . increasing frequency of deleterious traits such as the short inter - node / russeted hull phenotype which had been first observed when Payne was selfed . Also in 1956they began getting requestsfor their selections . One of the first selectionsout for field trials was 49 - 49 , later released as Vina . In 1957 , they had requestsfrom 67 growersand farm advisorsfor scion wood from until 1967when their collection . The number of requests per year increased 100requestswere received , eachfor one or more selectionsor cultivars.The popularity of their germplasm and selectionsfor field trialswas in part due to the fact that Serr and Forde reported annually on their evaluation of in the tradejournal , Diamond Walnut News , comparing the walnut cultivars performance of old and new cultivarsand promising selections . in After his retirement in 1965 , Serr continued to work with Forde evaluatingtheir most promisingselections . He recommended that 10culti - vars be named and released by the University . Serr named all of these ( 59 - 129 ) , which was named after Serr by the Pomology cultivarsexceptone DepartmentafterSerr's deathin1968 . TheotherninecultivarswereLompoc ( 52 - 48 ) , Gustine ( 52 - 61 ) , Vina ( 49 - 49 ) , Amigo ( 56 - 226 ) , Pioneer ( 51 - 170 ) , Tehama ( 5 & 11 ) , Pedro ( 53 - 113 ) , Midland ( 49 - 47 ) , and Chico ( 56 - 206 ) . These cultivars were the culmination of 20 years of work with controlled crosses and represented the selectionand evaluation of 1,734 walnut seedlings . From 1965to 1978Forde continued the walnut breeding program and in 1963and 1965 : in 1978 released three new cultivars from crosses made Chandler ( 64 - 172 ) , Howard ( 64482 ) , and Sunland ( 66 - 4 ) . Chandler is now the most popular cultivar in California , making up about 70 % of nursery Cisco ( 66 - 178 ) and Tulare ( 67 - 11 ) from the sales . Another two cultivars , Serr / Forde breeding program have been released recently . Pedigrees of Serr / Forde cultivars are diagranunatically illustrated in Ap - many of the 1 @ age35 ) . pendix Until his retirement Forde continued making between five and 10 per year , thusincreasingthe total number of crosses in the program crosses and the number of progeny evaluatedto 5,916 . He alsofound to almost 200 , time to publish in two excellent chapters some of the information he had subpdsinflowering gatheredovertheyears ( Forde1975,1979 ) . Thesecover pollination , breeding , and culturalpracticesand havebeen anessential and Serr / Forde walnut resource for the current breeders . The success of the iswidely recognized and similarprogramshavebeen set breedingprogram up in Europe . Important to the success of the program were the keen observations They developed the habit of accurate made in the field by Serr and Forde . record keeping of the data from many crosses , measuringmany traits from time . This covered many cultivars and selections over a long period of observations of thousands of trees over these three decades . The data they ( Hanscheet al . 1972 ) and collected were essentialfor studieson heritability phenologicalchangesassociated with aging ( McGranahanand Forde 1985 ) . mutually resourceful relationships with nursery - Further , they cultivated This provided the basis for field men , growers , USDA , and the University . orchard plots of the progeny coming from their breeding program . . tests in Altogether , these elements of cooperation and keen observationmade for a w $ nuts . successfullong - termbreedingprogram for The walnut breeding program has not stopped although there was a hiatus after Forde retired . In 1982 , G . McGranahan was hired by the brief blackline prob - US Department of Agriculture to breed for solutionsto the In 1989 , shejoined the Dept . of Pornology and continued her activities lem . curating the Walnut Germplasm Collection . The of breeding walnuts and earlyyears of her programwere directedtowardsexaminingtheinheritance virus that causes the disease and of the hypersensitive response to the culti - beginning a backcross breeding program to develop hypersensitive vars , as well as introduction of germplasm so that the traditional cultivar improvement program could be continued . The new germplasm is now in the breedingprogramand over 1,000 seedlingsfromcontrol - being used be evaluated . led crosses are ready to Personal histories ugene Frank Serr was bornin Hubbard , Texas on March 1,1898 . At an E his sister , Anna earlyagehisfamily , includinghisbrother , Edward , and Marie , moved to southern California . Here , Gene Serr attended San Ber - nardino High Schooland graduated in 1915 . Gene worked for two to three years as an assistantbaggage clerk for the SouthernPacific Railroad , a good job , which he left in 1918 to attend the University of California , Berkeley . this decision and pro - Gene's father , an upholsterer by trade , was against vided him no support . However , his sister , Anna Marie sent him money from time to time . Gene graduated with a degree in plant physiology on May 17 , 1922 , with " Honors in Agriculture " on his diploma . His first job an " itinerant " farm advisor , as they called them in after graduationwas as those days ; he was located in Yuba City , Sutter County from 1924 to 1930 . It was onJuly12,1924that Anna GraceRaub , age 23 , married EugeneFrank Serr , age 26 , according to the marriage certificate . They had two sons : Eugene Frank Serr , Jr . , born May 14,1925 and John Serr , born January 5 , 1927 . John recalls that his father was a good singer around a campfire . He liked to go to the mountains or the seashoreand he liked weekend picnics with the family . In 1930 Gene Serr and his family moved to Linden , California , near Stockton , where they lived ona smallranch of 40 acresand Serrbecamefarm advisor in San JoaquinCounty . According to his sonJohn , Serr was " never happy without a ranch . " On the Linden ranch Serr raised 20 acres " of the best Elberta peaches you ever tasted , " according to John.Serr remained at this position of farm advisor until 1938 . Finally , in 1939 the family moved to Davis , California where Serr became the Extension Specialistfor decidu - ousfruitsand nuts , travelingextensivelyoverthewholestate , butheadquar - tered at the University.During all this time Serr was learning and teaching , two things he did very well . He believed in applied research , experimenta - tion , and demonstrationas the keys to move agricultural practices forward with the growers . and he believed in working closely Areview of the Annual Reportswhich Serr submitted to the University duringhis eightyearsas ExtensionSpecialist ( 1939 - 1 947 ) givesanindication of Serr's totalinvolvementwith the fruitand nut crops of Californiaand the people who raise them . Duringonetypicalyear he made 383farmvisitsand in the field 165 days , covering more than 35,000 miles . In 1943 he was arranged 27 Grower Conferences with 2,189 attendees . His own special interest was in mineral deficiencydiseases , but he also was knowledgeable and helpful in areas such as propagation , pruning , cover crops , soils , plant diseases , and irrigation.Serr was constantly encouraging " active coopera - tion , " as he described it , between the University , USDA , Farm Bureau , Cooperative Marketing Associations , growers , and nurserymen . Serr was a gentle , quiet , and shy person , but it did notseemto stop often described as him from getting people together to help one another . In 1948 Serr was appointed Lecturer and Associate Pomologist in the Division of Pomology of the University of California , Davisand later ( 1952 ) asfull Pomologist , a position whichhe held untilhe retired in 1965 . He was Pomologistemeritusuntil his death from a heart attack on January26,1968 whileworkingin anorchardat the Kearney Field Station ( Brownetal . 1969 ) . Earlier , in 1956 , Serrwas seriouslyill withheart troubleandhe had to curtail some of his activities , including his forays into the mountains at higher altitudes . Serr was responsible for both almond and walnut crops from 1948 to 1951 , but from 1951 to 1965 he specialized in walnuts and the walnut breeding program . His early interest in the mineral nutrition of tree crops continued and led to the recognition of phosphorus deficiency in walnuts in Lake County and to methods to remedy it . He was also interested in the selection of improved rootstocks of the Paradox type and worked with others to locate black walnut trees which produced high percentages of hybridswhichwereparticularly useful.Serralsowasinvolvedinimproving pruning practices and mechanical harvesting . At the University , Serr taught orchard operationsfrom1948to 1956and a course in subtropicalpomology from 1958 to 1965 . In 1963 - 1964 he was on leave and went to Turkey on a Fulbright grant at the request of the Turkish Government . At Ege University , Ismir , Turkey , Serr lectured in pomology , participated in research , and traveled widely in the country . Dr . Omund Lilleland , 92 years of age when interviewed in 1991 and a long - timeprofessor emeritus of the Pomology Department , knew GeneSerr as a " persistent tenacious person who would not give up . " Dr . Harold P . Olmo , also a senior retired professor emeritus in Viticulture at Davis , described Serr as an " exceedingly gentle person . " He knew Serr as a very man who was always in the field . Olmo described Serr's and practical Forde's relationship over the twenty years of their collaborationin thisway : " They were like brothers . " In May 1956 the Board of Directors of Diamond Walnut Growers , Inc . conferred The Order of the Golden Walnut for Distinguished Service to the Walnut Industry on Eugene Frank Serr , Pomologist , University of Califor - nia , Davis . Figure 3 . Eugene F . Serr , Farm Advisor , 1924 arold I . Forde was bornin Fullerton , California onAugust 6,1914 . Two yearslaterhis familymoved to Marysville , California , where his father H went into farming on his own 80 and later 160 acres . Forde worked on the farm through the Depression helping with the peach , prune , and almond orchards . Forde lived there with his parents and three sisters until he graduated from Marysville High School and attended Yuba College . He work and then went to the University of California , Davis took a year off to where he completed his degree in Pomology in 1938 ; he was a member of OnSeptem - Alpha Zeta and Sigma Xi and graduated with " highest honors . " ber 10,1938 , Christina Arrild and Harold I . Forde were married and later raised a family of one son , Richard , and two daughters , Ruth and Roberta . a part - time student when he worked as an analyst in Pomology Forde was from 1938to 1942 . For a couple of years Fordetaught hydraulics as a civilian inLincoln , Nebraska.He was later drafted instructor for the Army Air Corps and entered the service.Forde served in the 3rd Infantry Divisionin Europe and , near the Battle of the Bulge , he was wounded , suffering permanent damage to his right hand and lower arm . He had to convert to being left - handedwhen he returned to work at the University . While Forde was away he was promoted to Senior Laboratory Techni - cian . Dr . Lilleland , of the Pomology Department , observed , when Forde returned from the war , " that changed him . He lost some of his drive . " And Forde agrees that the war did take its toll . Dr . Walter Howard , former chair Forde's place of work , of the PomologyDepartment , with an office opposite urged Forde to " drop the shovel and take up the pen , " when he returned from the service , meaning that Forde go for a Ph.D . Dr . Lilleland also remarked , " Too bad he did not get a Ph.D . ; he had the knowledge and the in the department . " respect of people Without the degree , Forde advanced fromPrincipalLaboratoryTechni - cian in 1948to Senior or Staff Research Associate in 1971 . Forde worked as a partner and colleague with Gene Serr from 1948to 1966 . In the beginning , Serr , with his 16 years of field experience as farm advisor and extension I knew specialist , was the teacher . As Forde recalls , " I learned everything about walnuts in the beginning from Gene Serr . " After Serr's retirement , Forde continued the walnut breeding program by continuing to make crosses and selections and evaluate the progeny , cooperating with other faculty in Pomology until his own retirement in 1978 . Among those faculty Hansche , George Martin , Bill Griggs , and Julian were Aldo Rizzi , Paul Crane . From 1966 to 1978 Forde was relied upon as the most experienced and knowledgeable person associated with the walnut breeding program . He alsocontinuedhis work as anadvisor and consultantinwalnut breeding for more than fifteen years after his retirement in 1978 , and continues to participatein decisionsaboutnew cultivars.In 1979Forde was a consultant at the Agriculture College of the University of Chile . He worked with Monica Ortiz de Bustos onwalnut propagation and with CarlosRojas in the evaluation of seedling walnuts . In 1994 , Forde received recognition fromthe Californiawalnut industry with a Distinguished Service Award : I ' Whereas , Harold I . Forde has pioneered the successfil Breeding Programfor walnuts at the University of California during his many years of outstand - ing service to the . roalnut industry . It Whereas , thefixit of these labors included the development of the Chandlerva - riety which is becoming the mainstay of the California walnut industry and halfof all nursery sales . presently accountsfor than " Whereas , he devoted his career to an amalgamation of efirts by the Univer - industry in developing close and sity of California and the California walnut workzng relationshipswhich continue to this & y . positive " Nowtherefore be it resolved , that in honor of his many years of meritori - ous sewice to tlze Calzjornia walnut industry , the California Walnut Com - I . Forde as mission and the WalnutMarketing Board do hereby name Harold of the Distinguished Sewice Azuard , an award originally estab - a recipient by Commission and Board action on September 15,1989 . " lished err and Fordeworked closely and effectivelyfrom1948 until1968 , when Serr died . Their relationship was friendly and cooperative . According S to Forde , they wereinthefieldtogetherondifferenttrips andinthe orchards makingtheir selectionsand evaluatingthe treesandnuts for desirabletraits . They alsotook time to go deer hunting on a couple of occasionsand dosome fishing at Dillon Beach . They were successful in those activities , as well as in their walnut work . Description of germplasm he term germplasm can be used to describe the plant material used for the genetic improvementof a crop.It canincludetreesfrom the wild as T It includeseverythingthebreeder well ascultivarsand advanced selections . has to workwith . The description of germplasmhere is taken from a variety of sources . This includes published accounts , five - year averages of data collected on the performance of trees at the University of California , Davis , I . Forde , William Stuke , and others having as well as commentsby Harold experiencewith walnut cultivars . The purpose of listingthese descriptions is to provide information on the genetic resources which were available to Serr and Forde and additional material that is now available to other breeders . These descriptions will help the grower , farm advisor , and plant breeder to know the origin of the material and the useful characterswhich are represented in the Walnut Germplasm Collection in the Stuke Block in the WolfskillExperimental Orchard , Winters , California . ( + ) by the name of a In the followinglists of descriptions , a star symbol cultivar or accession indicates that it is also represented by a color photo - graph of nut characteristics on pages 17through 20 . Additional evaluation data are tabulated in Appendix 2 ( page37 ) . Additionalwalnut germplasm and cultivarsare slowly being added to the collection . New introductionsand breeding material are usually evalu - ated for severalyears before beingconsidered for inclusioninthe collection . Recommendation for inclusion is based on importance to California and need for permanent preservation . Recent additions include several geno - Donan ' and types with unique attributes such as red kernels ( ' Rouge de la ' Purpurea ' ) , cut leaves ( I.regia laciniata and J . nigra laciniata ) , and weeping habit ( ' Weeper ' ) , as well as representative genotypes from other countries ( e.g . , China , Hungary , Pakistan , Spain ) that do well in California . Old cultivars and introductions nuts were brought to Canada by the Dukobor Adams refers to several numbered cultivars people who settled north of the Okanagan Val - which originated from open - pollinated seedlings ley . Cascade is presumably a seedling from a of PI 18256 , and were selected by Moses Adams backcrossto Manregian . 1940 . They are frost hardy , It leafs out with Hartley in Salem , Oregon in and is late harvesting . The nuts are large , dark - maturing at midseason , but are not laterally fruit - ful . The nuts have a strong shell , but the kernels shelled with a large kernel . Yield is moderate . Cascade won " Grand Champion " in the North - are somewhat dark . Adams was used in only a ern Nut Growers nut evaluation in 1983 . few crosses by Serr and Forde . The Adams in the Stuke Block is Adams 10 . It was evaluated by E . Concha ( O ) , an introduction from Chile , was Germain in France . It leafs out slightly later than selected from the orchard of Alfredo Concha as other Adams and shows some resistance to " better than average " by Forde in 1979 . Many of blight . the orchards in Chile are propagated from seed instead of by grafting , thus each tree ( + ) is a seedling or budsport that was first is geneti - Ashley noticed by Pallas Neal Ashley about 1945 in the cally different . Forde wandered the orchards Wendall Payne ( not relatedto George orchard of there in search of superior trees . Carlos Rojasand Payne ) located in southern Colusa County . The Monica Ortiz de Bustos directed him to the best trees in Concha's orchard . Concha leafs out with Ashley cultivar was patented and assigned to Payne , Stuke Nursery . This cultivar is very similar to is laterally fruitful , and is harvested with 90 % fruitful on lateral is good , kernel weight is 47 % Payne in phenology and is Hartley . Nut seal Ityields well , somewhat better than Payne , of nut weight , and kernel color is variable . Con - buds . cha was a late arrival in the collection and was but is more susceptible to blight . The shell seal is about 52 % of is adequate and kernel weight not used in the breeding program . is light ; flavor is the nut weight . The kernel color is small and ( 46 ) is a chance seedling , or pos - good , and quality is high . The tree Early Ehrhardt early bearing , requiring regular pruning . Forde sibly a budsport , of Ehrhardt found by George says that some crosses were made but they did Rutherford in Refugio Canyon near Goleta , Cali - not give exceptional progeny . Ashley has been fornia about 1940 . It is a soft - shelled Santa Bar - widely planted on the west side of the San bara type with low winter chill requirement and joaquin Valley and in the Sacramentovalley , but It leafs out almost two weeks earlier than Payne . is no longer popular . is protogynous and bears only on the terminals . Nuts are of lower quality than Ehrhardt . Kernel Carmello comes from an open - pollinated seed - weight is 55 % of the nut weight , but the kernel ling of Payne which was discovered by C.E . is poor . Early Ehrhardt is subject to sunburn color Sullivan near Yuba City , California about 1948 . in California's Central Valley . Forde considers it Carmello was patented and assigned to Sierra of no practical value , but walnut researchers Gold Nursery . Carmello leafs out with Payne but often use it to signal the beginning of the breed - is harvested later . It is protogynous but not later - Ing season . is a largebijou type with low ally fruitful . The nut is poor . It is percent kernel and the shell seal ( O ) originated about 1903 as a seedling Eureka important only as a novelty nut . tree on the Stone Ranch near Fullerton , Califor - nia from nuts obtained from the Meek estate in ( O ) is a selection made by William Cascade Hayward , California . The parent tree was Loomis , Schildgen from the Okanagan Valley , thought to bea Persianor Kaghazitypefrom Iran . Washington , being one progeny of a series of In 1912 , R.E . Smith wrote : " The Eureka comes crosses of a Russian , perhaps Carpathian , walnut very close to satisfying the requirement of an with a Manchurian type , probably Manregian , ideal walnut for California . " Five - year averages which he obtained from Oregon . The Russian indicate leafingone week and harvest oneto two nine days beyond other Franquettes . Graves weeks after Payne , with little fruitfulness on lat - Franquette ( O ) is a chance seedling selected by eral buds . Yield is only moderate . The nut is elongated and rounded at both ends , shell qual - a grower in Merced County . It has a phenology similar to Scharsch Franquette , but the nuts pro - is excellent , seal good , but kernel color is ity poor . Eurekais not highly susceptibleto sunburn , duce a higher percentage of light - colored ker - nels . but it is late maturing and susceptible to frost . If selfed , Eureka gives one quarter albinos , hence Hartley ( f ) originated in the orchard of John possesses a recessive gene for this character . Other Eureka types include Blackmer , Waterloo , Hartley in Napa Valley , California ; it may be a Marchetti , and Trinta . seedling of a Franquette x Mayette cross . This was one of the selections made by William Franquette was brought to California from Hunter , a nurseryman , who planted seeds in France in the 1870s by Felix Gillet . It is still Hartley's orchard in 1892 , selected the best in widely planted in France and is one of the high 1909 , and later introduced the Hartley as a cul - " noix de Grenoble " . The name Fran - quality tivar in 1925 . It was exhibited as the Hartley nut quette has beenapplied to a number of selections at the World's Fair in 1915 and won a blue made over the years by different growers , but ribbon . According to Forde , John Fisk , the farm they all have certain traits in common . Fran - advisor in Napa County , called Gene Serr's at - quette is a large terminal bearing cultivar which tention to the Hartley . Serr brought scions of it to is notfruitful on lateral buds . It is the standard for San JoaquinCounty in 1932 . Fromthere it spread late leafing in Californiaand often escapes blight up and down the Central Valley . In 1940 it was and codling moth . It comes into production late commercialized , becauseitwas particularlywell and requires little pruning . The nut quality is suited to the in - shell market . Hartley is the stand - usually good but yields are only fair . Forde has is about two ard for midseasonphenology which suggested that Franquette has a lower yield than weeks after Payne and a week or more before Hartley , both terminal bearers , because Hartley Franquette.The Hartley nut is fairly large , broad branches moreandtherefore has moreterminals . based with apointedtip . the shell is light incolor Franquette also produces one or two nuts per and thin , with a good seal ; the kernel is light Hartley produces two or three . terminal while Hartley is colored but percent kernel is low . susceptible to deep bark canker when stressed Arthur Davey and Gene Serr brought about 12 by a lack of water or poor soil . The problem with selections of Franquette to the Wolfskill Experi - codling moth is minimal . Hartley is less suscep - mental Orchard beginning in 1944 and evalu - tible to blight than Payne , since it leafs out two ated them . They concluded that the original weeks later . Hartley is a consistent producer , Franquette was superior . William Stuke and it is only slightly fruitful on lateral even though Gene Serr gathered about 17 selections of Fran - buds . There are more Hartleys than any other quette at the Stuke Nursery in Gridley about ten cultivar in California , but in recent years the years later , including Lattin , Treat , Scharsch , and number of new Hartley plantings has declined . others . Scharsch Franquette ( . Wc ) originated from a single tree of JosephScharsch near Ord Bend , Howe is a chance seedling discovered by Cecil is also a good Glenn County , California . It B . Howe of Brownsville , Oregon and brought to Hartley and bears catkins at a pollenizer for California by Serr for evaluation . It resembles younger age than regular Franquette . As with is Franquette but leafs out earlier ; the shell seal other Franquettes it leafs out three to four weeks poor and weaker than Franquette . The growth later than Payne , and the harvest is late . The nuts habit is upright with a central leader . It is report - have a medium - thin shell , good seal , light col - edly tolerant to blight . The nut is oval and the ored kernels , and good fill . Moyer Franquette shell and kernel qualities , other than seal , are was brought to California from Oregon by Wil - satisfactory . Itisonlyavailable at the US National liam Stuke . Its distinctive character is that it ex - Germplasm Repository - Davis . tends the duration of pollen shedding for eight to Scharsch - Franquette 1 I Mevlan 1 Sharkey Tehama ~ Sunland ( + ) is a French type originally from Meylan ldaho ( + ) is a protogynous selection from among ( Is & re ) , France . It is terminal bearing , Meylan is said to have the large bijou - type nuts . ldaho protogynous , late leafing , and late in shedding Parma , ldaho and was introduced originated in is poor , yield is fair , kernel pollen . The nut seal to California by E.T . Rice about 1947 . It leafs out is good , but the percent kernel is low . quality with Payne and bears mostly on terminals . The Fran - Meylan has been used as a pollenizer for is large , but the kernel is of poor quality and nut quette in Lake County . Some say that the kernel its weight is only 35 % of the nut weight . Yield is is therefore a good nut for lacks astringency and poor . ldaho is a cold - hardy Carpathian type now kept only as a curiosity . people sensitive to walnuts . Marchetti ( * ) is a chance seedling which oc - ( + ) , a chance seedling with fruitful lateral Payne curred in the orchard of Guilio Marchetti near buds , was found by George Payne , a farmer from Stockton , California about 1948 . Guilio Santa Clara County , who sold scions of it as a Marchetti was the foreman of a Dr . Fitzgerald business . It soon becamean outstandingcultivar Ac - ley . who willed him some land when he died . in the coastal valleys and the San JoaquinVal cordingto Forde , the nut isvery much like Eureka It has been speculated that Payne is derived from and several other characters resemble Payne . To a cross of a French cultivar introduced by Felix quote Forde , " It is quite possible that Marchetti Gillet in the 1870sand a Chinese seedling intro - is a natural cross of Eurekaand Payne . " Marchetti duced by immigrants because the character of leafs out almost a week after Payne , is more than lateral fruitfulness is found in certain Chinese types and in Payneand its relatives . Recent DNA 8O0l0 fruitful on lateral buds , bears heavily , and is very Pomology Depart - analysis by Robert Fjellstrom , requires avigorous rootstock . The nut seal is of variable color but of satis - is good , the kernel ment , UC Davis , however , suggests that Payne not related to typical Chinese germplasm . Payne factory quality . Yields are excellent and harvest is an early leafing , precocious , and high yielding is a week after Payne . The trees tend to overbear , phenol - cultivar that has become the standardfor so they must be pruned every year . It adapts well is more susceptibleto ogy descriptorsin California . - the nut seal is good to hot summers . Marchetti blight than Payne but some growers , like Walt and kernel quality is satisfactory . Payne is suscep - Deardorf , still like it better . Marchetti was used tible to frost , blight , codling moth , and sunburn , by Serr and Forde for many crosses in their and its growth slows with heavy production . In walnut breeding program . 1948 when Serr and Forde were beginning the walnut breeding program there were only two GiIlet . Mayettewas brought from Franceby Felix old , low - vigor Payne trees in the campus or - Mayettes are characterized by their late leafing chards for experimental work . They needed is flat on the stem date and their nut shape , which Payne for its lateral fruitful character and other end like Hartley . They tend to have defective traits . Serr and Forde obtained wood from the seals . Several selections have been made . Con - Anderson Barngrover orchard near Linden , Cali - ( + ) is a slightly later - leafing selec - way Mayette fornia . They chose this source because Pearly Conway in Los Molinos , tion made by a Mr . Payne , the brother of George Payne , had grafted California about 1915 . The trees are large and part of the Anderson Barngrover orchard over to Payne . This assured Serr and Forde that their ( + ) is difficult to shake for harvest . XXX - Mayette Payne material was authentic . Payne was the protogynous and sheds pollen late enough to only cultivar with fruitful lateral buds until they cover the pistillate bloom of Franquette , unlike obtained Marchetti . Payne was one of the most other Mayettes . Nut seal is excellent andthe shell important parents in the walnut breeding pro - is is strong . The kernels are small , percent kernel gram and almost all the University of California low , but kernel color is good . It is somewhat walnut releases have Payne in their background . difficult to use in breeding because the flowers is selfed it always gives some seedlings If Payne tend to be receptivewhile still very much hidden with a compressed growth habit , russeted hulls , by the leaves . and small nuts . little if any walnut blight . 159568 nutsalso seem Placentia ( + ) is one of the Santa Barbara soft - to be resistant to sunburn . " shells derived from the nuts bought at the wharf in San Francisco by Joseph Sexton about 1869 . PI 18256 ( + ) Walnuts collected by Frank Meyer The origin of this sack of nuts is not clear , both of the USDA in 1906 in the mountains 40 miles Chile and China have been suggested . The Pla - north of Beijing , China were brought to the centia was the standard in - shell walnut until the USDA Plant lntroduction Station at Chico , Cali - Hartley came along . Placentia is earlier leafing fornia . One seedling ( PI 18256 ) was selected out than Payne and therefore also susceptible to Joley at the Chico of several hundred by Lloyd is protogynous blight and frost damage . Placentia Station . Scions were taken to Salem , Oregon by - theshell is thin but strong , and terminal bearing . Man - MosesAdams in 1927where it was named with a good seal . Kernel color is poor . For many regian . The name comes from a contraction of years Placentia was considered the best cultivar juglans regia . It is now referred Manchuria and for southern California . Placentia was not used to commonly as Manregian . Seedlingsfrom Man - for any crosses by Serr and Forde , but it may be regian are sometimes used as rootstock and bear a source of genes for low chilling requirement . is similar to the same name . In phenology it is not laterally fruitful . The nut is Payne , but it PI 125249 is a seedling of PI 65870 which came large and round , the shell thin but strong . Kernel from Fa Hua Ssu Temple near Beijing , China in is good , but the kernel is somewhat dark . quality October , 1925 . Itwas obtained by Serr and Forde It is known for its hardiness to frost and some from the USDA Plant lntroduction Station in resistanceto blight . Since the 1950s its seedlings is earlier in leafing Chico , California . PI 125249 have been recommended as a rootstock for wal - is protogynous . and harvesting than Payne and nut cultivars in Oregon to avoid blackline dis - is large with a high percent kernel . The nut ease . Trees grafted on Manregian are reported to is listed as being 75 % Although in one year it fruitful on lateral buds , inother years the percent - grow more rapidly than on black walnut root - age is so low that it must beconsidered aterminal stocks . However , their tolerance of salt accumu - is only avail - is low . Fordecomments , " It may be a good bearing cultivar . This introduction lation able at the US National Germplasm rootstock in Oregon . It Repository - is not good here . " Davis . Olmo 13 - 1048,20 - 1072 ( + ) , 38 - 1207 , 70 - 1307 PI 159568 represents a seedling selection made Dr . Harold P . Olmo , Department of Viticulture , from PI 127460 which was collected in Pagham , UC Davis , collected walnutsfrom the Tabriz area ( 10 miles west of Kabul ) in 1937 by Afghanistan of northern Iran ; scions from these seeds were a USDA plant explorer and brought to the USDA evaluated as part of the walnut breeding pro - Plant lntroduction Station at Chico , California . phenol - gram . 0 - 13 - 1048 and 0 - 20 - 1072 havea Serr and Forde obtained their breeding material ogy similar to Payne and are unique in that their from this source . The tree has a phenology simi - is about nuts are " paper shelled " . Kernel weight is not fruitful on lateral buds . It lar to Payne but 70 % of nut weight . 0 - 20 - 1072 has surprisingly bears an elongated nut with a good quality ker - light - colored kernels . 0 - 38 - 1207 and 0 - 70 - nel . PI 159568 was used by Serr and Forde in a 1307 are both midseason cultivars with only fair Sunland number of crosses , and it gave rise to Forde's comment : " Gene thought kernel quality . and Serr . To quote from a letter of Forde to the we should forget it ; Idid some crosses on myown Chico Station , dated October 31 , 1968 : " P.I . because I was curious . Nothing very good hap - 159568 was used as a parent because of a num - is in the Walnut Germplasm pened . " 0 - 20 - 1072 is well filled , ber of good characteristics . The nut Collection in the Stuke Block ; the others are is plump , kernel color is fairly good , the kernel retained by the US National Germplasm Reposi - is good - about 54 % . The the percent kernel tory - Davis . shell is smooth and light colored . Perhaps most important , our P.I . 159568 trees have had very is a midseason to late leafing cultivar from Poe Lake County , California . Poe was selected by Oscar Poe near Lakeport around 1900 . It is ter - available at the US National Germplasm Reposi - minal bearing , protogynous , and low yielding . tory - Davis . The nut is thick shelled , and the kernel is small . Trinta may be a budsport or chance seedling of One gourmet food writer described Poe as less Waterloo since it occurred on two trees in the astringent than other walnuts and tasting slightly Waterloo orchard of Manuel Trinta near Patter - like butterscotch . son , California . Forde believes that whoever grafted the trees got the scion from a seedling by Sharkey ( 9 ) parentage is unknown , but Forde mistake . Trinta was patented and assigned to suggests that it may be derived from seed from Sierra Gold Nursery . Trinta is fruitful on lateral China . The Tribble Brothers Nursery in Elk buds and leafs out four days after Payne and it is Grove , California discovered it about 1925 and harvested two weeks after Payne . The shell is named it after Millard Sharpe of Vacaville , Cali - moderately strong , seal is satisfactory , but the fornia , whose nick - name was " Sharkey . " Sharpe kernel quality is poor . the trees arevigorous , fast also worked as a nurseryman for the University . growing , dense , and heavy bearing . The Sharkey cultivar is early bearing and some - what fruitful on lateral buds . It leafs out at the Waterloo ( + ) was first described by Gene Serr same time as Payne , is protogynous with pistil - ( while still a farm advisor ) , who discovered it late bloom two weeks earlier than Payne , and about 1934 in a plantingof Eurekaseedlings near sheds pollen 10 days later than Payne . The nut Stockton , California . It is named after Waterloo is round and well filled , with a fair seal . Forde Road in Linden ( near Stockton ) , where Serr considers it the best nut for eating that we have . owned a 40 - acre ranch . Waterloo is not laterally Many crosses were made using Sharkey , one of fruitful , but it is a good producer . It leafs out with which led directly to Amigo and Chico and Hartley , but it is harvested after Hartley and indirectly to Chandler and Howard . before Franquette . The nut is strong with a good seal , but kernel color is poor . Waterloo is a Sinensis ( + ) Gene Serr requested seed of ) . sinen - parent of Gustine , Lompoc , and Tehama . Forde sis Dode from Japan but received seed of what comments , " Waterloo is a fairly decent cultivar ; appeared to be / . regia . Fifteen seedlings were it came out about the same time as Hartley , but obtained from these seeds and numbers 5 and 7 Hartley is better . " were selected for some crosses . Both are pro - togynous and bear nuts primarily on terminals . Westside ( + ) is a chance seedling from the San Sinensis 5 leafs out five days after Payne and JoaquinValley that was patentedand assignedto pistillate bloom is nine days earlier than Payne . Stewart Nursery . It is protogynous and highly The nut seal is good . Kernel weight is 50 % of nut fruitful on lateral buds . Westside requires an weight , but kernel quality is poor . Sinensis 7 leafs early pollenizer . The nut of Westside is small and out seven days after Payne and its pistillate thick - shelled with low percent kernel . The culti - bloom is four days earlier than Payne . The nut var Chico came along and proved better than seal is good . Kernel weight is 55 % of nut weight Westside . is fair . Sinensis 7 is only and kernel quality Cultivars released by the University of California , Davis Chico is a small , upright tree that leafs out at Amigo ( 56 - 226 ) ( + ) is from a Sharkey x about the same time as Payne and is very fruitful Marchetti cross made by Serr and Forde in 1955 , on laterals with the potential for heavy yields . selected in 1963 , and introduced in 1968 ; it is a Chico is protogynous like its sibling Amigo . The sibling of Chico and 56 - 224 . The tree is produc - nut is small , round , with a good seal and good tive with many clusters of four nuts , 80 % fruitful quality kernel , but the kernel is sometimes diffi - on lateral buds , and leafs out about two weeks cult to extract from the shell . The trees grow after Payne . It is protogynous and was originally vigorously when young and need frequent prun - selected as a pollenizer for Midland , Pioneer , ingto prevent overbearing . If overbearing occurs Tehama , and Pedro . The nut is of satisfactory the nuts may be numerous but smaller . Chico quality but the shell seal is poor in some years . stands up well to the heat and was used in some is 56 % of nut weight . The The kernel weight of the original hedgerow orchard trials . kernel is light colored and has good quality . Forde remarked , " One thing we did not know Cisco ( 66 - 1 78 ) is from a cross between Meylan was that the new seedlings shed pollen and leaf and Pedro made by Serr and Forde in 1965 . out earlier as they got older . " This lesson was Cisco was named and released in 1990 as a learned from evaluating Amigo and other selec - pollenizer for midseason cultivars , especially for tions . Some farm advisors have noted that the orchards that require a pollenizer tree that is hulls of Amigo nuts sunburn easily but the kernel smaller and more precocious than Franquette . is not severely affected . It is also quite susceptible Cisco is a late - leafing , late - maturing cultivar to codling moth and walnut husk fly . which is fruitful on laterals . It sheds pollen in moderate amounts and covers the peak pistillate Chandler ( 64 - 1 72 ) ( 0 ) is from a cross made by bloom of Chandler and Howard . The nut has a Serr and Forde in 1963 between Pedro and medium light color with a good seal . Kernel 56 - 224 . Chandler was patentedand released by weight is 47 % of nut weight . Kernel color is the University of California in 1979 . Chandler is variable . highly fruitful on lateralsand quite vigorous , thus it needs pruning , particularly to avoid shoots Gustine ( 52 - 61 ) ( 0 ) originated from a cross be - with a narrow crotch angle . Growth starts mid - tween Waterloo and Payne made by Serr and season , about the same time as Hartley . The nuts Forde in 1951 and released by the University in are oval , smooth , with some weakness in the 1968 . Gustine is highly fruitful on lateral buds , shell so they may not be suitable for the in - shell leafs out with Payne , and is very productive . It market . However , Forde suggests that the shell is a Eureka type , matures at midseason . The nut may firm up as the trees get older and put less pointed , with a good shell seal and good fill , but energy into wood . Nut seal is good and the the kernel color is sometimes poor . It is more kernel is particularly lightcolored , almost pearly . vigorous than most other laterally fruitful culti - The nuts easily crack out in halves and some say vars and requires heading back when young to that it stores better than other cultivars . Occa - prevent the breakage of limbs . Two defects are sionally one finds some shrivel on the lobes of brittle wood and greater susceptibility to bark the kernel but this has not been an economically canker than other cultivars . Gustine is no longer important flaw . Chandler yields well if polleniz - planted . ers are present . It is now the most frequently planted walnut cultivar and Forde regards it as Howard ( 64 - 1 82 ) ( + ) is a sibling of Chandler the most important cultivar coming from their from the cross Pedro x 56 - 224 . Howard was breeding program . patented and released by the University of Cali - fornia in 1979 . It is a laterally fruitful , midseason Chico ( 56 - 206 ) ( 0 ) is from a cross between cultivar with heavy bearing potential . It is not as Sharkey and Marchetti made by Serr and Forde vigorous as Chandler and must be pruned heav - in 1955 and released by the University in 1968 . ily . Some farm advisors recommend removing ( + ) is from a cross between Pioneer ( 51 - 1 70 ) nuts for the first two bearing years to encourage Franquetteand Payne made in 1950 by Serr and growth . The nuts are not as light colored as Forde , selected in 1957 , and released by the Chandler , but they are larger and havea stronger University of California in 1968 . The cross that produced Pioneer , was madetwo years laterthan shell . the cross that gave its siblings , Vina ( 49 - 49 ) and Lompoc ( 52 - 46 ) ( 0 ) is from a Waterloo x Payne Midland ( 49 - 47 ) . The leafing date is one to two cross made by Serr and Forde in 1951 and re - weeks after Payne . It is moderately fruitful on leased by the University of California in 1968 . lateral buds and shell seal is fair to good . the nut Lompoc is moderately fruitful on lateral buds , is more suitable for in - shell than cracking ; kernel leafing date is close to Payne , but harvest is late . weight is 45 % of nut weight , and only 62 % of The nut is largeand pointed with a good seal ; the the kernels are light colored . the overall nut kernel weight is 54 % of the nut weight . It is a quality is not very good . It requires little pruning and productive cultivar , but does not do well in a hot is harvestedat midseason . Forde says that he interior valley . Lompoc is named after a city in would like to forget this cultivar . It was only the Santa Ynez Valley , California . It is a parent of released because some growers were going to Sunland . grow it anyway . Midland ( 49 - 47 ) ( + ) isfrom a Franquettex Payne Serr ( 59 - 1 29 ) ( + ) was selected by Serr and Forde cross made by Serr and Forde in 1948 , selected from a Payne x PI 159568 cross made in 1958 . in 1955 , and released by the University of Cali - It was released by the University of California in fornia in 1968 . It is moderately fruitful on lateral 1968 . f he trees are vigorous , leaf out close to buds and leafs out 11 days after Payne . The shell Payne , and are moderately fruitful on lateral seal is good , the kernel weight is 48 % of the nut buds . The nut is thin shelled with a good seal and weight , and under the right conditions the kernel well filled . The light - colored kernel is of excel - can be of high quality . Midland matures at mid - lent quality . Serr is well adapted to the hot cli - season and does not tolerate very high heat . Its mate of the San Joaquinand Sacramento Valleys adaptability to the mid - Central Valley suggested and is somewhat resistant to sunburn . As Forde the name . Midland is more vigorous than Vina , puts it , Serr seems to " thrive on adversity " and is a sibling , and does not require heavy pruning as used in replant situations because of its vigor . Vina does , but it never has had a strong follow - However , the Serr cultivar does have a problem ing . with pistillateflower abscission which appears to be related to excess pollen . The Serr cultivar was Pedro ( 53 - 1 13 ) ( + ) is from a Conway Mayette x named to honor Gene Serr after his death in Payne cross made by Serr and Forde in 1952 , 1968 . Forde recalls that the faculty discussed selected in 1958 , and released by the University namingthe best of the ten new cultivars released of California in 1968 . Pedro leafs out about two in 1968after Serr . Fordesaid , " We thought it was weeks after Payne and sheds abundant pollen the best one . Too bad we did not give Vina his over a long period of time , covering such culti - name ; it was the best of the ten . " vars as Ashley , Lompoc , Marchetti , Serr , Gustine , and Vina . It is laterally fruitful and highly produc - Sunland ( 66 - 4 ) ( + ) is from a cross between tive and matures at midseason or later . The nut Lompoc and PI 159568 made by Serr and Forde is largewith a good shell and fair seal . The kernel in 1965 . It was patented and released by the weight is 50 % of nut weight and kernels are of University of California in 1979 . Sunland is a fair quality . Pedro does not withstand the heat vigorous , early - leafing cultivar , with good bear - well and has been found to do well in the cooler ing potential on lateral buds . The nuts are large , parts of Europe , especially Hungary . Pedro was oval , with a good shell and seal and have high used in the crosses that produced Howard and percent kernel . While the kernel is of good qual - Chandler and is still being used in the breeding ity , large , and plump , its color has been a prob - program . Sunland is a lem in recent years . Although at midseason , is laterally fruitful , and sheds pol - half - sib of Serr it does not appear to have the Sunland is pistillate flower abscission problem . len during most of its pistillate bloom period . Growth habit susceptible to blight ( like other early leafers ) and is upright , with moderate vigor . It is precocious , with heavy nut production . The also to shallow bark canker and stress from rapid is of medium texture and color , the nut shell growth . The large leaves increase water use and kernel weight is 54 % of nut weight , and kernels the long season , 173 days , makes for a late is considered are mostly light colored . Tulare is somewhat difficult to use harvest . The pollen suitable for hedgerow and other high - density in breeding because it clumps and sticks to - planting systems . gether . Tehama ( 58 - 1 1 ) ( + ) is from a cross between Vina ( 49 - 49 ) ( + ) is from a cross between Fran - Waterloo and Payne made by Serr and Forde in quette and Payne made by Serr and Forde in 1957 , selected in 1963 , and released by the 1948 , selected in 1955 , and released by the University of California in 1968 . This cultivar University of California in 1968 . Vina is a pro - which can be very productive ductive and consistent bearer , being80 % is 8O0t0fruitful on fruitful on lateral buds and leafingout about a week after lateral buds , leafsout two weeks after Payne , and is harvested at midseason . The nut is suited for is good . Kernel weight is 48 % Payne . Shell seal is good but the shell tends to of nut weight . The kernel is of good quality , but cracking ; the seal be weak . Kernel weight color is 54 % of nut weight . is sometimes a problem . The nuts mature The kernel has good quality and early to midseason . Serr and Forde reported that 70 % are light the trees are tolerant of summer heat and show colored . The tree requires pruning to prevent overbearing . Its name is derived from itsapparent some resistance to blight . Growth is vigorous in suitability to the Tehama County area . young trees ; regular pruning is required to pre - vent overbearing and lower quality nuts . Forde Tulare ( 67 - 1 1 ) came from a Tehama x Serr cross mentions that they came closeto discardingvina in 1966 by Forde . Tulare was patented and re - because of the overbearing . Vina is now consid - leased by the University of California in 1993 ered the best of the 1968 releases . ( US Plant Patent Number 8,268 ) . Tulare leafs out University of California numbered selections seal are good , the kernel weight is 54 % of nut 49 - 46 ( + ) is from one of the early crosses be - weight , and the kernel has good quality . Forde Hartleyand Payne . It is afairly good catkin tween considers 59 - 1 24 better than Serr since there is producer , but as it ages it produces fewer and apparently no problem with pistillate flower ab - fewer catkins . It leafs out a week later than Payne scission . Forde said that it was one of the better is harvested about the same time as Payne but seedlings , but they did not make crosses or re - and is highly fruitful on lateral buds . The nut Modesto , California , lease it . The Driver family , resemblesHartley in beingflat on the bottom but considers it a potential replacement for Serr . the seal , kernel weight , and color are only fair . is the only potentially Forde notes that 49 - 46 59 - 165 was selected by Serr and Forde from usefulderivativefrom crosseswith Hartley . Prog - x Ehrhorn cross . seedlings of a 1958 Waterloo eny of certain crosses with 49 - 46 have an un - ( Ehrhorn is a chance seedling possibly from a usual compressed growth habit and russeted x Concord cross ; it occurred in Mountain - Payne nuts , similar to the traits found in selfed Payne view , California and was selected by Adolph seedlings . Ehrhorn from the orchard of Peter Lusich about is fruitful on 1938 . ) 59 - 1 65 leafs at midseason , is a seedling selected from a Payne x 53 - 128 lateral buds , and is harvested at the same time as Early Ehrhardt cross made by Serr and Forde in Hartley . The nut has a fair seal , good percent 1953 . It leafs out early and is protogynous , flow - kernel , and a moderate percentage of light col - is highly ering seven days earlier than Payne . It is a parent of a group of super - late ored kernels . It fruitful on lateral buds . The shell seal is good , seedlings . In 1967 Gene Serr commented on the kernel weight is 58 % of nut weight , but the vigor of a six - year - old tree , " I think it has a very is poor . With a low chilling require - kernel color good bearing potential . " ment , 53 - 1 28 is suitable for southern California . It is not in the Walnut Germplasm Collection but 61 - 25 was selected by Serr and Forde from a is retained in the US National Germplasm Re - cross between 49 - 46 and 53 - 57 ( Conway pository - Davis . Mayette x PI 18256 ) . It is a midseason cultivar , laterally fruitful , and it resemblesthe new French ( + ) is a seedling from a Sharkey x 56 - 224 cultivar Lara . The kernel weight is 53 % of nut Marchetti cross made by Serr and Forde in 1955 . light - weight and nuts have a high percentage of is fruitful on lateral It leafs out shortlyafter Payne , colored kernels . is harvesteda week later buds , protogynous , and than Payne . The nut is large but has a weak shell . 63 - 378 was selected from a cross between Vina is the occurrence of holes in One serious defect and Scharsch Franquette made by Serr and Forde the shell . Gene Serr planted about one acre with in 1962 . ( Because63 - 378 is protogynous , it has 56 - 224 in his orchard near Auburn , California been suggested that it may have been from a and the nuts did not perforate at this elevation of x Sharkey cross made that same year . ) Marchetti 2,500 feet above sea level . However , the selec - 63 - 378 is early to midseason leafing , pro - tion was not suited to the frost conditions there . togynous , and laterally fruitful . Yield is good , but Serr and Forde made quite a few crosses with the nuts are poorly sealed with a moderate per - 56 - 224 , including the cross with Pedro which centage of light colored kernels . The kernel resulted in 35 progeny , two of which becamethe weight is about 55 % of nut weight . cultivars Chandler and Howard . 64 - 57 was selected from a Serr and Forde cross 59 - 1 24 is a seedling selected by Serr and Forde made in 1951 between 52 - 48 ( Payne x Water - in 1958 from a cross between Payne and loo ) and 56 - 224 . It is early to midseason leafing , PI 159568 . This is a sibling of Serr and some laterally fruitful , and protogynous . - the kernel growers think that it is much better . It is early is 55 % of nut weight , nuts are variable in weight leafing and laterally fruitful . The nut shell and color , and seal is poor . 64 - 57 has been planted 76 - 80 is from a cross between Chandler and midsea - in San Benito County , and is especially popular 61 - 25 made by Forde in 1975.76 - 80 is son leafing , precocious , and somewhat fruitful there with grower Al Bonturi . Farm advisor Bill 53 % of the on lateral buds . The kernel weight is Coates noted 64 - 57 suffered less winter freeze nut weight . Its nuts have a very high percentage damage than other cultivars in the 1990 freeze . of light - colored kernels , similar to its parent 67 - 13 was selected from a Tehama x Serr cross Chandler . The nut may have a seal problem and is early and is a sibling of Tulare . This selection the shell is weak . Yields are average to good . is leafing , high yielding , and laterally fruitful and 76 - 98 and 76 - 112 These two seedling selec - harvestedearly . It is nearly homogamous inflow - x 61 - 25 made tions are from the cross Howard ering and produces large numbers of catkins . is generally excellent , but varies by Forde in 1975 . Both selections are retained Kernel quality for their late leafing ( 23 to 26 days after Payne ) from poor to outstanding . Kernel percent of nut is consistently high . 67 - 1 3 does well in hedge - and dichogamy traits ( protandrous with no over - row plantings and as a pollenizer for Chico . It lap of staminate and pistillate flowers ) . They are " Yolo " until P.B . was going to be released as both laterally fruitful and have average to good Catlin determined that it has the problem of yields and a high percentage of light kernels , pistillate flower abscission like Serr . however , 76 - 1 12 has small nuts with low per - cent kernel . 68 - 104 is a seedling selected by Serr and Forde 68 - 77 - 12 is from a cross between Howard and from a 1967 cross between Vina and Serr . 104 is a midseason leafing , laterally fruitful se - is a pro - 64 - 57 made by Forde in 1976 . It lection with high yield . The kernel is light togynous , short - season selection which leafs out colored and weighs 18 days after Payneand 55 % of the nut weight . It is is harvested earlier than is a very low percent - Payne . The kernel weight retained because it shows some tendency to bear nuts in shaded parts of the tree . This selection is age of the nut weight . Nuts have poor seal . It was never released because the nuts are too retained for the short - season trait . The kernels small , even though that is not obvious from the havevariable color and may havean unusual oil evaluation data . composition with a high percentage of unsatu - rated fatty acids . 73 - 16 is a seedling from the cross 59 - 165 x Pedro made by Forde in 1972 . 73 - 1 6 is a super - 78 - 10 resulted from a cross between 53 - 153 late , leafing out two months after Payne with a ( Hartley x PI 18256 ) and Chandler made by peak pistillate bloom at the end of May to early Forde in 1977 . It is similar to Cisco in phenology is harvestedonly a month after Payneand June . It is laterally fruitful , with excellent kernel and is laterally fruitful . The percent kernel is low , but quality and average to good yield . It is being is light . kernel color retained as a potential pollenizer of Chandler , Howard , and Hartley . 74 - 245 , 74 - 256 , 74 - 258 , 74 - 259 , 74 - 266 AII of these selections are from the cross 61 - 12 78 - 189 is from a cross between Chandler and ( 49 - 46 x Scharsch - Franquette ) x 59 - 165 made 64 - 436 ( Marchetti x Sharkey ) made by Forde in is a family of plants saved is protogynous , nearly homogamous , by Forde in 1973 . This 1977 . It in the collection for their super - late phenology . and laterally fruitful with average yield . Nut size Their peak pistillate flowering is in late May to is a potential is small but kernel quality is good . It early June . 74 - 259 is the mostfruitful on laterals ; pollenizer for Chandler , Howard , and Hartley . It Hartley or up to aweek later . Forde 74 - 258 has the biggest nuts . Percent kernel var - leafsout with described 78 - 1 89 as " one of my last children , " ies from 37 % ( 74 - 256 ) to 49 % ( 74 - 259 ) . The kernel weight is low , from 4.8 g ( 74 - 256 ) to 6.9 i.e . , one of the lastcrosses made in the SerrIForde is suprisingly good . walnut breeding program . g ( 74 - 258 ) . Kernel color Paradox and black walnuts in the collection Paradox ' Burbank ' is a hybrid between a Califor - 40 % Paradox seedlings if 1 . regia gives 20 to is available . Other selectionsof California pollen 1 . hindsii or 1 . californica nia black walnut ( either black walnuts give upto 9O0lOParadox seeds , but S . Wats . ) and the English or Persian walnut ( I . produce comparatively fewer nuts . In a letter to regia ) . Paradox types are noted for their vigorous Kelseyville , California in 1964 , Mr . Cliff Gonyo , growth and are widely used as rootstock . In the Forde mentions , " In the case of Rawlins seed , we 1890s , Luther Burbank reported that he made found when they germinate , that part of the this cross and named the resulting hybrid , Para - sprout shows some pink color on the base of the ( Whitson et al . 1914 ) . He mentions the dox " enormously enhanced capacity for growth " be - young root . The ones with the pink color pro - yond that of either parent , with " leaves of ex - duced nearly all Paradox while the pure white traordinary length " and foliage that has " a ones turned out to be all black . " The original Burbank recog - delicious apple - like fragrance . " source of ' Rawlins ' was from Hubert T . Rawlins nized the characteristics of hybrid vigor from in Glen County , California . wide crosses , noting , " The tendency to surpass J . nigra ' Student Orchard'was obtained from the is a characteristic that is very their parents in size Pomology Orchard where students practiced commonly manifested when plants of different grafting . Students had grafted some early - leafing species are hybridized . " The Paradox ' Burbank ' black walnuts which Dr . Davey obtained from in the Walnut Germplasm Collection was ob - the Tennessee Valley Authority and two of these Burbank gar - tained by Serr and Forde from the is the source of this grafts took . One of them den at his home in Santa Rosa , California . germplasm . These ' Student Orchard ' Eastern Paradox ' Bowman Kuhn ' is a selection of Para - black walnuts cross readily with California black dox which is rootable from cuttings and shows walnuts . The hybrids , known as Royals , can be some resistance to nematodes ( Lownsbery et al . ' The hybrids are large seedlings picked out easily . 1974 ) . Forde recalls getting suckers from Para - like the Northern California black walnut instead dox trees in the orchard of Bowman Kuhn , a of small seedlings like those of the Eastern black grower who hada high incidenceof lesion nema - walnuts . Forde commented that it was " too bad tode in hisorchard . The Paradox ' Bowman Kuhn ' that somebody did not try the compatible ' Stu - x 1 . hindsii hybrids as rootstocks . " obtained by Forde was the better , more resistant dent Orchard ' Paradox in that orchard . J . nigra ' Thomas ' is a well - known cultivar from ' O'Farrell ' is a tree on the property of Paradox Pennsylvania which was discovered in 1881 Eileen O'Farrell in Davis , California . It was used ( Jaynes1979 ) . ' Thomas ' bears early , cracks eas - in several studies aimed at selecting vigorous ily , and has a large kernel . " Thomas ' does not Paradox x 1 . regia seedlings and was found to perform consistently from year to year and the yield superior seedlings . Several of its offspring nutsdo notfill well . It is inthecollection because have been selected as clonal rootstock . it has been the standard grafted Eastern black lightcolored walnut for over a century . Italso has 1 . hindsii ' Rawlins ' is a selection of northern kernels with a rich black walnut flavor . California black walnut which yields well and Publications of Eugene F . Serr and Harold I . Forde 1959 Serr , E.F . Walnut varieties . Diamond Wal - 1940 Serr , E.F . and H . Day . Lesion nematode nut News , March . injury to California fruit and nut trees and comparativetolerance of various 1959 Serr , E.F . and H.I . Forde . Blackline , a de - Proc . Amer . species of Juglandaceae . layed failure at the union of Juglans re - Soc . Hort . Sci . 53 : 134 - 140 . gia trees propagated on other Juglans species.Proc . Amer . Soc . Hort . Sci . 1945 Batchelor , L.D . , O.L . Braucher , and E.F . 74 : 220 - 230 . Serr . Walnut production in California . Univ . of Calif . Ag . Exp . Sta . Circ . 364 . 1960 Serr , E.F . and H.I . Forde . Data concern - ing walnut varieties . Diamond Walnut 1945 Forde , H.I . and E.L . Proebsting . Utiliza - News , January . tion of ammonia supplied to peaches and prunes at different seasons.Hil - 1961 Serr , E.F . Early bearing new walnut va - gardia 16 : 411425 . rieties . Diamond Walnut News , August . 1946 Serr , E.F . Trainingyoung walnut trees . 1961 Serr , E.F . and J.H.Foott . Report on Adequate spacing of main branches es - whitewash cover sprays . Diamond Wal - Diamond Walnut News , March . sential . News , April . nut 1951 Serr , E.F . and H.I . Forde . Comparison 1962 Serr , E.F . Combination plantings of old of size and performance of mature Per - and new walnut varieties . Ag . Exp . Sta . , sian walnut trees on Paradox hybrid Univ . of California , Davis , Leaflet 143 . J . hindsii seedlingrootstock . Proc . and Serr , E.F . Selectingsuitablewalnut va - 1962 Amer . Soc . Hort . Sci . 57398 - 202 . rieties . Div . Ag . Sci . Univ . of California , 1953 Brown , J.G.and E.F . Serr . Copper defi - August . ciency : one cause of shriveled kernels . 1962 Serr , E.F . and J.H.Foott . Whitewashing : Diamond Walnut News , May . cover sprays in test orchardsbring 1953 Sen ; E.F . Nursery runts not worth graft - yields and quality above average . Dia - ing . Diamond Walnut News , February . News , June . mond Walnut 1954 Serr , E.F . Trainingyoung walnut trees . 1962 Serr , E.F . and H.I . Forde . Effects of new Intelligent early pruning gives well - and old world varieties . Diamond Wal - shaped productive trees . Diamond Wal - News , February . nut nut News , March . 1962 Serr , E.F . and H.I . Forde . Report on vari - 1955 Serr , E.F . New varieties on the horizon . Diamond Walnut News , Feb - ety testing . Comparativetests show much promise . ruary . Diamond Walnut Nezus , July . 1963 Forde , H.I . and E.F . Serr . Comparison 1956 Serr , E.F . and H.I . Forde . Walnut Breed - and crack tests . Diamond Walnut Nezus , Proc . Amer . Soc . Hort . Sci . 68 : 184 - ing . February . 194 . 1963 Lownsbery , B.F . and E.F . Serr . Fruit and Serr , E.F . A pruning program for ma - 1957 nut tree rootstocks as hosts for a root le - ture trees . Renewing fruitingwood im - Proc . Am . Soc . Hort . Sci . sion nematode . proves yield and quality . Diamond 82 : 250 - 254 . Walnut Nezus , January . 1963 Serr , E.F . and J.H.Foott . Effects of white - 1957 Serr , E.F . Progress report on new wal - wash cover sprays on Persian walnuts . nut varieties . Desirable characteristics Proc . Arner . Soc . Hort . Sci . 82 : 243 - 249 . explained and compared . Diamond Wal - News , March . nut 1964 Serr , E.F . The nut crop of Turkey . Proc . 1969 Martin , G.C . , M.R . Mason , and H.I . Nut Growers Society of'Oregon and Wash - in endogenousgrowth Forde . Changes 50 : ll - 22 . in the embryos of Juglans re - ington substances gia during stratification.J . Amer . Soc . 1964 Serr , E.F . and A.D . Rizzi . Walnut root - Hort . Sci . 94 : 13 - 17 . stocks . Ag . Ext . , Univ . of California 1969 Serr , E.F . Persian walnuts in the western P ~ blA . XT - 120 . A . ( ed . ) states.p . 240 - 263 In : Jaynes , R . 1965 Sen ; E.F . Dwarfing the Persian walnut Handbook of North American nut by use of interstocks.Northern Nut trees . Humphrey Press , NY . Ann . Rept . p . 106 - Growers Assoc . 56th 1970 Forde , H.I . and P.E . Hansche . 1969com - 111 . parison and crack test . Diamond Walnut Sen ; E.F . The case for cross pollination . 1965 News , February . Diamond Walnut News , April . 1971 Forde , H.I . Pollen data brought up to 1965 Serr , E.F . and H.I . Forde . Comparison date . Diamond Walnut News , April . and crack tests . Diamond Walnut News , 1971 Forde , H.I . and P.E . Hansche . 1970com - February . parison and crack test . Diamond Walnut 1966 Forde , H.I . , E.F . Serr , and P.E . Hansche . News , February . 1965comparisonand crack tests . Dia - 1972 Forde , H.I . and W.H . Griggs.Pollina - mond Walnut News , February . tion and blooming habits of walnuts . 1967 Forde , H.I . , E.F . Serr , and P.E . Hansche . Ag . Exp . Sta . , Univ . California Leaflet 1966comparison and crack tests . Dia - 2753 , AXT - N24 . mond Walnut News , February . 1972 Forde , H.I . and P.E . Hansche . 1971com - 1967 Serr , E.F . New varietal plantings show parison and crack test . Diamond Walnut need for updating the pollination News , February . charts . Diamond Walnut News , April . 1972 Hansche , P.E . , V . Beres , and H.I . Forde . 1968 Forde , H.I . and P.E . Hansche . Compari - Estimates of quantitativegenetic prop - son and crack test . Diamond Walnut erties of walnut and their implications News , December . for cultivar improvement . J . Amer . Soc . 1968 Forde , H.I . , E.F . Serr , and P.E . Hansche . Hort . Sci . 97279 - 285 . 1967walnut variety comparisonand 1972 Rizzi , A.D . and H.I . Forde . Selecting crack test report . Diamond Walnut News , new walnut varieties . Ag . Ext . , Univ . of February . California AXT - 360 . 1968 Serr , E.F . Dwarfing interstocks for Per - 1973 Forde , H.I . and P.E . Hansche . 1972com - sian walnut . Plant Propagator 14 : lO - 13 . parison and crack test . Diamond Walnuf 1968 Sen ; E.F . and H.I . Forde . Ten new wal - News , February . Cal . Ag . 22 : 8 - 9 . nut varieties released . 1974 Forde , H.I . and P.E . Hansche . Varieties . 1969 Forde , H.I . Gradual removal of tempo - Diamond Walnut News , February . rary trees from a closed orchard . Dia - 1974 Lownsbery , B.F . , G.C . Martin , H.I . mond Walnut News , April . Forde , and E.H . Moody . Comparative 1969 Martin , G.C . , H.I . Forde , and E.F . Serr . tolerance of walnut species , walnut hy - Yield performance of ( Juglans regia ) brids , and wingnut to the root - lesion ' Payne ' on seedlings of Northern Cali - nematode , Pratylenchus vulnus . Plant fornia black walnut ( Juglanshindsii ) Disease Reporter 58 : 630433 . rootstock at three planting distances . HortScience 4 : 130 - 131 . 1975 Forde , H.I . Varieties . Diamond Walnut D.E . ( ed ) Walnut orchard management . February . Univ . of California , Berkeley . News , H.I . Walnuts . p . 429 - 455 In : H.I . Forde . Rela - 1975 Forde , 1985 McGranahan , G . and tionship between clone age and selec - Janick , J . and J.M Moore ( eds . ) Ad - tion trait expressionin mature walnuts . vances in fruit breeding . Purdue Univ . Press . J . Amer . Soc . Hort . Sci . 110 : 692496 . H.I . Forde . Incidence 1975 Martin , G.C . and 1987 Hendricks , L.C . , G.H.McGranahan , D.E . of blackline in Juglans regia L . propa - Ramos , B . Iwakiri , and H.I . Forde . Se - gated on various rootstock species . J . lection of varieties.Walnut Orchard Amer . Soc . Hort . Sci . 100 : 246 - 249 . Management . Publ . 21410 Cooperative Ext . , Univ . of California . 1976 Forde , H.I . Varieties old and new . Dia - 1990 McGranahan , G . , mond Walnut News , February . D . Ramos , H.I . Forde , and R.G . Snyder . ' Cisco ' Persian wal - H.I . Persian walnut in the west - 1979 Forde , HortScience 25 : 371 - 372 . nut . ern United States.p . 84 - 97 In : Jaynes , R.A . ( ed . ) Nut tree culture in North 1992 McGranahan , G . H.I . Forde , R.G . Sny - W . Reil , J . Hasey , and America . Northern Nut Growers Assoc . der , G.S . Sibbett , Hamden , CT . D.E . Ramos . ' Tulare ' Persian walnut . HortScience 27 ( 2 ) : 186 - 187 . H.I . Forde . Ge - 1985 McGranahan , G.H . and netic improvement . p . 8 - 12 In : Ramos , Literature cited Jaynes , R.A . ( ed . ) 1979 . Nut tree culture in Batchelor , L.D . 1924 . Walnut culture in Cali - North America . Northern Nut Growers fornia . Univ . of California Bull . 379 . Association , Hamden , CT . Batchelor , L.D . , O.L . Braucher , and E.F . Serr . H . 1 Forde , and Lownsbery , B.F . , G.C . Martin , 1945 . Walnut production in California . E.H . Moody . 1974 . Comparativetoler - 364 . Univ . Cal . Ag . Exp . Sta . Circ . ance of walnut species , walnut hybrids , Brown , D.S . , L.L . Claypool , and C.O.Hesse . and wingnut to the root - lesion nema - 1969 . Eugene Frank Serr , Jr . , 1898 - 1968 , tode , Pratylenchus vulnus . Plant Disease Lecturer in Pomology and Pomologist 58 : 630433 . Reporter in the AgricultureExperimentStation , McGranahan , G.H . and P.B . Catlin . 1987 . Emeritus . In : In Memoriam . Univ . of Juglansrootstocks.p . 411450 In : Rom , California , May . R.C . and R.F . Carlson ( eds . ) . Rootstocks Brown , D.S . 1990 . The Pomology Depart - Wiley , NY . for fruit crops . ment , University of California , Davis . 11 . The Con - McGranahan , G . and C . Leslie . 1990 . Walnuts Vol I . The Early Years . Vol . ( Juglans ) . p . 906 - 951 In : Moore , J.N.and temporary Years 1945 - 1981 . J.R.Ballington ( eds . ) Genetic resources California Department of Food and Agricul - 2 . of temperate fruit and nut crop . Vol . ture . 1993 . California agriculturestatisti - International Society for Horticultural cal review 1992 . Calif . Dept . of Food Science.Wageningen , The Netherlands . and Agriculture.Sacramento , CA . Smith , R.E . , G.O . Smith , and H.J.Ramsey . Coppock , R . 1994 . Maintaining the competi - 1912 . Walnut culture in California . Wal - tive edge in California's walnut indus - nut Blight . Univ . of Calif . Agric . Ext . try . University of California Bull . 231 , Univ . of California , Berkeley . Agricultural Issues Center , Davis , CA . Webber , W.T . and W.E . Goodspeed . 1919 . Forde , H.I . 1975Walnuts . p . 429 - 455 In : The California walnut . California Wal - Janick , J . and J.M Moore ( eds . ) Ad - nut Growers , Los Angeles . vances in fruit breeding . Purdue Univ . Press . Whitson , J . , R . John , and H.S . Williams . 1914 . His methods and discoveriesand their Forde , H.I . 1979Persian walnut in the west - Burbank practical applications . Luther In : Jaynes , ern United States.p . 84 - 97 Press , NY . R.A . ( ed . ) Nut tree culture in North America . Northern Nut Growers Assoc . Hamden , CT . Sunland 66 - 4 Tulare 67 - 1 1 Midland Cisco 66 - 1 78 Chandler 64 - 1 72 Howard 64 - 1 82 56 - 206 Initialparent - - connects parentsof a cross cultivars 0 Selectionslcultivars - indicatesprogeny of a cross - - - - - - - - - - indicates speculation Appendix 1 . Pedigreediagramfor cultivars releasedfrom the SerrlFordeWalnut Breeding Program Appendix 2 . Germplasm evaluation data Although this table represents actual data collected , it should be considered only as an approximation of a cultivar's performance because many of the traits vary with tree age and environment . In California , Payne is considered the standard by which other cultivars can be judged , therefore , the leafing , pollen - shed , and bloom data are expressed in date form as well as in days after Payne's leafing date ( DAPL ) ; harvest data are expressed as date and days after Payne's harvest date ( DAPH ) . Kernel % Color Fruitful % Leafing First pollen shed Last pollen shed Peak female bloom Harvest laterals Weight of nut Cultivar [ ID number ] Date DAPL Date DAPL Date DAPL Date DAPL Date DAPH % n weight linhts Old cultivars and introductions Adams [ 28 ] 3128 Ashley [ 4 ] 3120 Carmello [ 29 ] 3122 Cascade [ 87 - 181 414 Concha [ 5 ] 3115 Early Ehrhardt [ 6 ] 319 Eureka [ 7 ] 3126 Scharsch Franquette [ 3 ] 4114 Graves Franquette [ 32 ] 4117 Hartley [ 2 ] 413 Howe [ 34 ] 411 Idaho [ 35 ] 3117 Marchetti [ 41 ] 3125 ConwayMayette [ 31 ] 4117 XXX Mayette [ 58 ] 4116 Meylan [ 42 ] 4111 Payne [ I ] 3119 Placentia [ 51 ] 3116 PI 125249 [ 47 ] 3118 PI 159568 [ 48 ] 3118 PI 18256 [ 49 ] 3119 - 1 Olmo 13 - 1048 [ 24 ] 3116 0 W 4 Olmo 20 - 1072 [ 25 ] 3117 0 Olmo 38 - 1207 [ 26 ] 3130 13 Olmo 70 - 1307 [ 27 ] 3128 10 Appendix 2 . Germplasm evaluation data ( cont . ) fa Kernel . . - - Fruitful % Color Leafing First pollen shed Last pollen shed Peak female bloom Harvest laterals Weight of nut % Cultivar Date DAPL Date DAPL Date DAPL Date DAPL Date DAPH % a weiaht liahts Old cultivars and introductions ( cont . ) 4R 16 4121 Poe [ 52 ] 3118 0 4110 Sharkey [ 53 ] Sinensis [ 54 ] 3122 5 417 3123 4 413 Trinta [ 55 ] Waterloo [ 56 ] 413 16 4112 3120 0 419 Westside [ 57 ] Cultivars released by the Universityof California Arnigo [ 56 - 2261 3 / 31 12 4118 Chandler [ 64 - 1721 414 17 417 Chico [ 56 - 2061 3122 3 4114 Cisco [ 66 - 1781 4117 30 4120 Gustine [ 52 - 611 3119 0 3127 Howard [ 64 - 1821 414 16 419 Lompoc 152 - 46 ) 3119 0 411 Midland [ 49 - 47 ] 3 / 30 11 415 412 15 417 Pedro [ 53 - 1131 Pioneer [ 51 - 1701 3128 9 414 Serr [ 59 - 1291 3120 1 3128 Sunland [ 66 - 4 ] 3 / 20 1 3 / 27 Tehama [ 58 - 1 I ] 411 13 4111 414 17 4110 Tulare [ 67 - 1 I ] Vina [ 49 - 491 3126 8 416 Universityof California numbered selections Selection [ 49 - 46 ] 3126 7 416 Selection [ 53 - 1281 3113 - 3 3126 Selection [ 56 - 2241 3123 4 4116 Selection [ 59 - 1241 3116 - 2 3126 Selection [ 59 - 1651 413 16 4111 Appendix 2 . Germplasm evaluation data ( cont . ) Kernel % - Color Fruitful - - Leafing First pollen shed Last pollen shed Peak female bloom Harvest % laterals Weight of nut Date DAPL Cultivar Date DAPL Date DAPL YO a weiaht liahts Date DAPL Date DAPH University of California numberedselections ( cont . ) Selection [ 61 - 251 413 15 418 21 Selection [ 63 - 3781 3129 10 4116 28 Selection [ 64 - 571 3125 6 4114 26 Selection [ 67 - 131 3124 6 411 14 Selection [ 68 - 1041 3130 12 416 19 Selection [ 73 - 161 5114 57 5116 58 Selection [ 74 - 2451 5117 60 5121 64 [ 74 - 2561 5115 58 Selection 5110 57 5113 56 - - [ 74 - 2581 Selection Selection [ 74 - 2591 5111 54 5112 56 5115 59 - - [ 74 - 2661 Selection Selection [ 76 - 801 3129 13 414 20 [ 76 - 981 Selection 419 26 4110 27 Selection [ 76 - 1121 417 23 4114 31 [ 77 - 121 Selection 411 18 4111 28 Selection [ 78 - 101 417 25 419 27 Selection [ 78 - 1891 3130 16 419 26 Paradox and black walnuts 3119 11 - - Paradox ' Burbank ' [ 45 ] Paradox'Bowman Kuhn ' [ 44 ] 3120 12 - - - - - - Paradox'O'Farrell ' [ 46 ] J . hindsii ' Rawlins ' [ 36 ] 3124 4 4130 41 J.nigra ' Student Orchard ' [ 37 ] 412 17 513 48 J , nigra ' Thomas ' [ 38 ] 4117 28 5112 53