Written by Nancy L. Sweet, FPS Historian, University of California, Davis - June, 2021 © 2021 Regents of the University of California

 

Harold Olmo

Dr. Harold Olmo was a well-respected viticulturist and geneticist and pursued a broad range of interests related to grapevines. Olmo’s work at U.C. Davis with grape clonal selection, grape breeding and grapevine importation greatly increased the varieties and clones available to the industry in California. His plant exploration travels around the world earned him the nickname the “Indiana Jones of Viticulture”. His support of “clean grapevine material” motivated him to co-found the organization that became the California Grapevine Registration & Certification Program. Olmo was a major influence on the public foundation grapevine collection at Foundation Plant Services.

In the 1920’s, then Chair of the U.C. Division of Viticulture & Fruit Products Frederic Bioletti travelled back and forth between Berkeley and the University Farm at Davis managing the University’s viticulture work. In the early part of the decade, Frederick Flossfeder and Leon Bonnet were stationed permanently at Davis to oversee the daily operations.

In the latter part of the decade, Bioletti found he needed a research assistant at Davis. He hired a young undergraduate who was then studying horticulture and cytogenetics on tobacco plants with Dr. Roy Clauson on the Berkeley campus. That student was Harold Olmo, who ended up transferring to Davis at the end of his sophomore year and beginning his association with grapevines. 1 Harold P. Olmo, Plant Genetics and New Grape Varieties, pp. 5-9, California Wine Industry Oral History Project, Regional Oral History Project, Bancroft Library, University of California, Berkeley, 1976.

Harold Olmo was born and raised in San Francisco. His heritage was Italian, German and Irish. As a youth, he worked with flowers and grew them for sale to local district florists. He was inspired to seek a college education in horticulture and plant breeding by among other things a set of books by Luther Burbank given to him by his mother. 2 Harold P. Olmo, Plant Genetics and New Grape Varieties, pp. 1-2, California Wine Industry Oral History Project, Regional Oral History Project, Bancroft Library, University of California, Berkeley, 1976.

Olmo received his B.S. degree in Horticulture from the University of California in 1931, after which he began his graduate work in Genetics at Berkeley. Olmo took his tobacco cultures to Davis and completed much of the practical research work for his degree there while serving as Bioletti's research assistant.

Olmo described Bioletti as a short, frail man with oversized glasses who had a good sense of humor and “boiled over with energy”. A few years before he retired when Olmo was still a graduate student, Bioletti would visit Davis and the two would leave at 5:00 a.m. in a University car to visit vineyards in Napa or Sonoma. Bioletti entertained Olmo with stories of the times in the early days that Bioletti cycled from the Berkeley campus to St. Helena in Napa County to attend field meetings. On the trips in the car to visit growers, he would keep up “a running conversation” about grape varieties, their characteristics, uses and histories - Olmo later found his detailed notes from those conversations to be invaluable. 3 Harold P. Olmo, Plant Genetics and New Grape Varieties, pp. 8, 9, 20, California Wine Industry Oral History Project, Regional Oral History Project, Bancroft Library, University of California, Berkeley, 1976.

Graduate student Olmo was tasked with cataloguing and maintaining table grape imports from North Africa as well as the University grape variety collection. Olmo credited Bioletti with guiding his early career in viticulture and referred to him as his "mentor on [grape] varieties". 4 Harold P. Olmo, Plant Genetics and New Grape Varieties, pp. 8-20, California Wine Industry Oral History Project, Regional Oral History Project, Bancroft Library, University of California, Berkeley, 1976. Letter to John W. McConnell at Shields Library from H.P. Olmo, dated December 14, 1984, Olmo collection D-280, box 59: 3, Special Collections, Shields Library, UC Davis. Bioletti imported table grapes from Algeria, Morocco, Corsica, Tunis and Turkey between 1931 and 1934; the grapes were planted at UC Davis. Olmo collection, D-280, box 59: 1.

Olmo was awarded a Ph.D. in Genetics at Berkeley in 1934. Bioletti thereafter hired him as a junior viticulturist at Davis in the Division of Viticulture & Fruit Products (later Viticulture & Enology). 5 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction by James F. Guymon, Professor of Enology, page iii, pp. 8-10, 15, 22, California Wine Industry Oral History Project, Regional Oral History Project, Bancroft Library, University of California, Berkeley, 1976. http://senate.universityofcalifornia.edu/inmemoriam/haroldolmo.htm – “In memoriam, Harold P. Olmo”.

Prohibition had been recently repealed and most winegrape vineyards that existed prior to 1919 had been decimated; many winegrape vines in California were misidentified or unidentified. The two men worked together to begin the process of sorting the mess and improving the grapevine germplasm available to the grape and wine industry. Olmo would eventually take the primary role in the identification and improvement of grape varieties in California after Bioletti retired in 1935.

Olmo became an Assistant Professor of Viticulture at Davis in 1938. The interaction with Bioletti planted the seeds for Olmo's own career that was built upon early projects initiated by his mentor at the University. Olmo succeeded Bioletti in the Viticulture program in genetics (including cytogenetics, ampelography, clonal selection, plant exploration) and grape breeding and expended his own inexhaustible energy supply to surpass Bioletti’s legacy. Olmo would later add his own unique imprint on the program in many areas including a collaboration at Davis to ensure that the grape selections available through the University were healthy (virus-tested) and true to type.

James F. Guymon, Professor of Enology, U.C. Davis, provided a glimpse of "Harold Olmo the person" (known to close friends and colleagues as "Jack") in the Preface to Olmo's oral history interview in 1976:

"Dr. Olmo is a rugged energetic person, fiercely independent in many respects, but equally open, friendly and congenial. He tends to live to the hilt, is completely dedicated to his work, but at the same time enjoys parties and social occasions to the fullest. Playing practical jokes to invoke hearty laughs runs in his veins. He likes to deflate the pompous and even at social wine tastings or large dinner parties often insists the wines be tasted blind." Guymon noted that Olmo was keen on pursuing his research and consultations with domestic and foreign experts in viticulture. 6 Harold P. Olmo, Plant Genetics and New Grape Varieties, pp. i-v, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

Dr. Olmo sat for interviews for the California Wine Industry Oral History Project in 1973. His career was so diverse and productive that it is difficult to report it fully in a single chapter of this book. Primary emphasis will be devoted here to the positive ways he impacted the grape industry in California and the grapevine collection amassed at Foundation Plant Services. This chapter can only touch on the highlights of Olmo’s brilliant career at U.C. Davis.

Professor and Geneticist

Olmo taught various courses in Pomology and Viticulture and directed the research of many master and doctoral students at Davis. His expertise and research were devoted to the general topics of "grapevine genetics" and " grape breeding". He was also involved with various general viticultural projects including mechanical harvesting.

Retired U.C. Davis Viticulture Professor and geneticist Carole Meredith joined the Department of Viticulture & Enology in 1980 to fill the genetics position vacated by Olmo - but her expertise was in the field of biotechnology. She would go on to pioneer the use of DNA fingerprinting techniques to determine grapevine varieties and establish their parentage. Meredith explains that "genetics" is a broad field that includes such things as proper identification of plant material (ampelography), cytogenetics, clonal development, breeding and plant exploration. Olmo made substantial contributions in all of these areas while at UC Davis.

The primary projects for which Olmo was responsible were described in annual progress reports to the Chair of the Department of Viticulture & Enology. His principal research work was allotted to six major project areas that were defined by Olmo in a memo including project reports dated September 21, 1971. 7 Project Report Memo, dated September 21, 1971, Olmo collection D-280, box 66: 31, Department of Special Collections, Shields Library, UC Davis. Those six areas were either continuation of projects begun by Bioletti or new projects initiated by Olmo.

AMPELOGRAPHY AND IDENTIFICATION OF GRAPE VARIETIES

Project 3513 (formerly 2397). Title: Ampelography - Description of Grape Varieties. Objectives: to prepare an ampelography of California wine grape varieties and to correctly identify unknown and misnamed varieties.

In those early years when Olmo was first in Davis, Bioletti gave him a great deal of instruction on grape varieties, morphology, their history, and the value and uses of particular varieties. The instruction was necessary because Olmo was a novice when it came to grapevines. He was born in 1910 in the Mission District of San Francisco but neither side of the family was associated with the grape or wine industry. His interest as a youth had been in ornamental horticulture. 8 Harold P. Olmo, Plant Genetics and New Grape Varieties, pp. 1-8. 19-22, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

As educators, scientists and consultants to industry, both Bioletti and Olmo were required to be proficient in the science of "ampelography" to accurately identify grapevine varieties and clones. Bioletti had honed his skills in the field for decades prior to those trips in the University car when he taught Olmo about grape varieties. According to Olmo, planting was often done in the first half of the 20th century in California with little knowledge or concern for varietal identity. 9 Lynn Alley and Deborah A. Golino, “The Origins of the Grape Program at Foundation Plant Materials Service, p. 224, Proceedings of the ASEV 50th Anniversary Meeting, Seattle, Washington, June 19-23, 2000.

The word "ampelography" is derived from ampelos (vine) and graphe (writing) and means the description of vines. In his very detailed Hilgardia paper published in 1938, Bioletti stated that in modern usage the term is usually confined to what may be called the horticultural description of grapes using gross characteristics of the fruit, leaves and growing shoot and mature vine with canes, trunk and root. Bioletti noted that the characteristic form is that recognized as most common where the variety is best known. 10 Frederic T. Bioletti, Outline of Ampelography for the Vinifera Grapes in California, Hilgardia, vol. 11(6): 227-231, June, 1938.

Bioletti wrote: "to one whose experience with vines has made him familiar with their differences and who can distinguish with confidence a considerable number of varieties, [ampelography] is very useful in bringing him to a probably correct decision as to the identification of a variety which is new to him. Certainty of identification of an unfamiliar variety can be attained in most cases, however, even by the expert, only by actual comparison of the variety with a specimen whose genuineness is guaranteed by its origin". 11 Frederic T. Bioletti, Outline of Ampelography for the Vinifera Grapes in California, Hilgardia, vol. 11(6): 227-231, June, 1938; see also, Harold P. Olmo, "California Grape Ameplography", Report to Wine Institute Technical Advisory Committee Meeting, March 3, 1952. In the first half of the 20th century, the use of ampelographic techniques was the exclusive means of identifying a particular grape variety.

Common features of a vine used to identify the variety using these techniques include berry size, color or shape; cluster size or shape; method of detachment of berry and length of pedicel; number and shape of seeds; character of cluster; morphology of shoot tips; shape, size and lobes, sinuses and teeth on leaves; leaf surface; size of the vine and canes. The characteristics such as berry color or leaf shape can fluctuate with environmental conditions. Bioletti and Olmo were both unusual in that they focused on the use of characters of the grape seeds in making their identifications. 12 Frederic T. Bioletti, Outline of Ampelography for the Vinifera Grapes in California, Hilgardia, vol. 11(6): 251-260, June, 1938. Bioletti mentions the number of seeds, the form, size, and weights and measurements.

A drawing discovered in the files in the Harold Olmo collection at Shields Library at UC Davis shows a diagram of seeds prepared by Bioletti for use in the Hilgardia piece:

Documents on file in the Olmo collection show notes on grape seeds written by Bioletti at Berkeley in 1930-31, after examination of seeds of 243 vinifera varieties and 71 American varieties. He observed that grape seeds vary in size and weight according to variety and condition of growth (weather, climate, soil). He found that seeds which sink in water are the normal seeds of the variety and are usually viable. 13 Olmo collection, D-280, box 16: 2, 3, 9, 11-12, Department of Special Collections, UC Davis Library.

Today the files in the Olmo collection still contain actual loose seeds sent to Olmo over the years for grape variety identification. Olmo believed that the seeds were the best by which to identify a grape variety but cautioned that seed characters varied by district of origin. He found it difficult to define the exact technique he used for identifying grapes with seeds but knew the "indescribable characters of the seeds added up together for identification". Some varieties that looked much alike were easily separable once the seed characteristics were known. 14 Harold P. Olmo, Plant Genetics and New Grape Varieties, p. 23, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976. H.P. Olmo, Origin and Domestication of the Vinifera Grape, undated, D-280, box 57: 54; H.P. Olmo, The Use of Seed Characters in the Identification of Grape Varieties, undated, Olmo collection D-280, box 59: 36, Department of Special Collections, Shields Library, UC Davis.

Professor Andy Walker was hired in 1989 to succeed Olmo with the grape breeding activity in the Department of Viticulture & Enology at UC Davis. Walker, who was also Olmo's successor for the expertise in ampelography, relates that Olmo developed a method to identify grape cultivars using only seeds to make the assessment. In Olmo's tenure at UC Davis, samples would arrive at the department all dried out, broken and curled up after two weeks on the delivery truck; the seeds were all that remained intact. He would receive a sample of fruit, gnaw on it and take out the seeds to examine them. The identifying characteristics included size, length, width and scars on the bottom of the seeds. Olmo accumulated a collection of seeds from 1,000 varieties and put them in vials, labelled and catalogued. That collection is now destroyed.

In the Post-Prohibition period of the early 1930's, there were many misnamed and unidentified wine varieties in the commercial vineyards (and some in the UC Davis collection). The situation in the industry was described as "chaotic". 15 Harold P. Olmo, Plant Genetics and New Grape Varieties, pp. iv-v, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

The job of varietal identification at UC Davis fell on (first) Bioletti and then Olmo as his successor. Growers would send unlabelled samples to UC Davis. The Enology professors had a learning curve despite the fact that the University had a wine grape variety collection because wine activity had been suspended at the University during Prohibition. The professors all went on collecting trips for wine tests and brought back duplicates of the same grape that looked different because they were grown in different districts. In an effort to identify the varieties, Olmo spent hours in field observations and laboratory studies of leaves, clusters berries and seeds. 16 Harold P. Olmo, Plant Genetics and New Grape Varieties, pp.19-24, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976. See D-280, box 66: 41, box 76: 53.

Ampelography

Olmo developed a proposal that he described to the Wine Institute Technical Committee (WITS) for production of an Ampelography for important California wine grape varieties. He felt that a history of varieties in California was actually a history of grape growing and winemaking. Olmo began compiling the information for the variety profiles in the library and field beginning in 1936. Original work in the form of interviews, surveys and photographs was collected on a county basis. 17 Harold P. Olmo, California Grape Ampelography, Report to the Wine Institute Technical Advisory Committee, for Meeting March 3, 1952.

Olmo eventually submitted his formal proposal for an Ampelography of 50 important wine grape varieties to the Wine Advisory Board (WAB). The WAB was established by a marketing order in 1938, was administered in part by the Wine Institute (established in 1934) but operated under the authority of the State Department of Agriculture. The purpose of the WAB was to promote the "uses, joys and benefits" of California wine. The WAB helped convert the wine industry from dessert wines to table wines and then ceased operation in 1975. 18 Olmo collection D-280, boxes 49: 9, 78: 35, Department of Special Collections, Shields Library, UC Davis.

The WAB sponsored Olmo's project, designated "Ampelography V-32", from 1938 through 1968. The project was initiated to correctly identify wine grape varieties, to isolate the best types or clones of that variety, to describe the historical role of the variety in world viticulture and publish an accurate description with a full color photograph to aid in identification. 19 Project Report to the Wine Advisory Committee: V-32, Ampelography, October 11, 1971; Olmo collection D-280, box 76: 29 and 78: 35, Special Collections, Shields Library, UC Davis.

Olmo completed the first variety, Chardonnay, in 1966. 20 Olmo collection D-280, box 66: 41, 76: 29, Department of Special Collections, Shields Library, UC Davis. Although he completed three additional manuscripts (Cabernet Sauvignon, Pinot noir and Palomino), Chardonnay was the only variety that was ever published by the WAB, in September, 1971. The publication was advertised for sale at that time. 21 Olmo collection, D-280, box 76: 4. box 68: 64 Department of Special Collections, Shields Library, UC Davis.

The WAB ceased support of the Ampelography project after the “Chardonnay” profile was published, apparently because the financial returns were not satisfactory. 22 Harold P. Olmo, Plant Genetics and New Grape Varieties, p. 90, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976. Olmo collection D280, box 76: 49-50, Department of Special Collections. Olmo had a plan to publish 18 cultivars per year after 1971 but did not pursue the plan in the official Ampelography format after funding was discontinued.

Wines and Vines articles

Wines and Vines magazine was known as California Grape Grower Magazine until 1935. Articles describing the state of the post-Prohibition wine, the table grape industry and grape variety profiles were begun by U.C. staff and industry members in the California Grape Grower in 1932, including a profile of Zinfandel by Bioletti in the September (1932) issue.

Olmo and A.J. Winkler wrote a series of articles profiling grape varieties in Wines and Vines magazine, published in 1937 and 1938. They started their series of articles in January, 1937, with Chasselas doré. 23 A.J. Winkler and H.P. Olmo, “The Chasselas doré”, Wines and Vines, p. 4 (January, 1937). They followed with Sylvaner (Franken Riesling), Sémillon, Refosco (Crabb's Black Burgundy), Cabernet Sauvignon, Saint Macaire, Valdepeñas, Trousseau, Tinta Amarella, Aleatico, Colombard (Sauvignon vert, by error), and Muscadelle in 1937. The articles were written for "popular use" and included a photograph to assist wine grape growers to correctly identify what they were planting in the Post-Repeal years. 24 Olmo collection D-280, box 16: 35; the Wines & Vines magazines from 1935 onward are on the shelves of Shields Library in the Viticulture section, SB 387.W5.

Grape Nomenclature Project with BATF

Olmo also participated in a federal project involving winegrape varietal names. There was concern that the proliferation of synonym names for winegrapes could result in confusion when the names were used on wine labels. The federal Bureau of Alcohol, Tobacco and Firearms (now, Alcohol, Tobacco Tax and Trade Bureau) decided in the 1980’s that it was appropriate and necessary for them to regulate the use of nomenclature for wine labels in the United States. The BATF initiated an advisory committee in the early 1980’s with industry experts to recommend appropriate label names for winegrapes. Harold Olmo was one of those experts on the Committee. 25 Report, The Winegrapes Varietal Names Advisory Committee, September 1984, BATF Wine Grape Nomenclature Committee, accessible in Olmo collection D-280, box 58: 13 and 59: 38.

The Committee developed a “Working List of US Grape Varieties” which they reviewed and discussed periodically. In 1992, the BATF proposed new regulations for using grape variety names on labels of American wines. The proposal involved approval of more than 250 varietal names which could then be used on American wine labels. A final rule effective February 7, 1996, contained a list of approved prime grape variety names which were allowed to designate American wines. The BATF stated that the list of approved names would help standardize wine label terminology and prevent consumer confusion by reducing the large number of synonyms for grape variety names on wine labels. 26 Grape Variety Names for American Wines, Federal Register, volume 61, number 5, January 8, 1996 (27 CFR Part 4, RIN 1512-AA67), copy accessible also in Olmo collection D-280, box 59: 26 and 59: 38, Department of Special Collections, Shields Library. The federal Alcohol, Tobacco, Tax and Trade Bureau (TTB) continues to regulate the approved names for wine labels in 2021.

The sorting of grape identities and grape variety naming was not without controversy in the industry. As noted later in the chapter on Pinot noir, wine industry members (including Leon Adams at the Wine Institute) were concerned that commercially successful wines associated with incorrectly identified grapes would lose their identity when a variety such as Gamay beaujolais was renamed to reflect the correct name of Pinot noir. 27 Letter from Leon D. Adams to the Bureau of Alcohol, Tobacco and Firearms, dated July 17, 1984, Olmo collection, D-280, box 56: 1. Harold P. Olmo, Plant Genetics and New Grape Varieties, p. 24, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

FPS has experienced the grape naming contentiousness in connection with the California Grapevine R&C Program. Varieties in the R&C Program must be “true to type”. That determination was made using only ampelography in Olmo’s day (but is now confirmed with DNA analysis). The same grape variety is frequently known by many different names known around the world as “synonym names”. FPS is tasked with ensuring an accurate name for hundreds of varieties and choosing between multiple synonyms for a “primary name” in connection with identification of its selections. Olmo was the advisor in that process while he was at U.C. Davis.

“THE INDIANA JONES OF VITICULTURE” – PLANT EXPLORATION

Project 3501 (formerly 903). Title: The study, collection and trial of new, rare and promising varieties of grapes. Objectives: to introduce and test new varieties and native species from foreign countries for possible use in California.

Olmo wrote in 1957: varieties introduced from foreign sources established the grape industry in California, and the California Experiment Station played a leading role in that process. 28 H.P. Olmo, Introduction and Testing of Foreign Grape Varieties, Department of Viticulture and Enology, Project 903, page 179, March 8, 1957, Olmo collection D-280, box 58: 41, Department of Special Collections, Shields Library, UC Davis.

Bioletti began a project to collect and study “new, rare and promising grapes” for California in 1930. The formal project was a collaboration between the UC Agricultural Experiment Station and the USDA Bureau of Plant Industry in Washington D.C., who for some time had been interested in plant exploration studies in the Mediterranean region for various crops including grapes. The project cooperators were interested in North African table grapes and apricots. In 1929, the USDA engaged Bioletti as a “grape specialist” cooperator to undertake the search because of his training and experience with the countries, languages employed and familiarity with the horticultural crops. 29 Frederic T. Bioletti, Project No. 903, The Study, Collection and Trial of New Rare and Promising Varieties of Grapes, Agricultural Experiment Station, College of Agriculture, University of California, April 23, 1931, Olmo D-280, box 58: 40., Special Collections, UC Davis Library.

The trip would be Bioletti’s second visit to North Africa in search of table grapes. He had visited the area in 1904 with a USDA permit naming him an “Agricultural Explorer”. In Algeria, he discovered that California’s principal table grape, known as Flame Tokay (origin unknown) was actually the Ahmar bou Ahmar of Kabylia, a mountainous region to the east of Algiers. Bioletti was unable to make any collections on that 1904 trip.

A few years later he visited the Richter Nurseries in Montpellier, France, and examined their collection of “interesting” grape varieties. Although he felt that the names of the vines at Richter were uncertain and incorrect, he studied the fruit and selected 40 or 50 varieties he thought would thrive in California and sent them back to Berkeley. Grapes from this shipment became valuable commercial varieties, including Molinera (erroneously named “Red Malaga” at Richter), Alphonse Lavallee (“Gros Ribier”) and Santa Paula (“Olivette blanche”). The varieties obtained at Richter Nurseries would later be incorporated into the first U.C. variety collection vineyard planted at the University Farm in Davis beginning in 1910.

The agreement for Bioletti to serve as an “Agent” for the USDA on his second trip to North Africa began in February, 1930. Hand drawn maps in the files at Shields Library at UC Davis show the countries Bioletti explored. The large number of table grape varieties he collected was returned to Davis, where his research assistant Harold Olmo organized and maintained them. 30 Olmo collection D-280, box 59: 1, Department of Special Collections, Shields Library, UC Davis. Hundreds of varieties were sent to Davis from North Africa, Turkey, Hungary, Greece, India, and Europe between October, 1931 and May, 1936. 31 The list of those varieties is filed in Olmo D-280, box 57: 28, Department of Special Collections, UC Davis Library.

After Bioletti retired in 1935, Olmo assumed the role of plant explorer and researcher for the University. His research took him to such places as France, Afghanistan, Iran, Yugoslavia, Australia, Mexico, and Venezuela. He served as a consultant in Brazil, Mexico, Malta, Romania, Venezuela, Iran, and India, three of these as an appointee of the United Nations Food and Agricultural Organization (FAO). Olmo gave numerous invited presentations at international symposiums and congresses. 32 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, pp. iv and v, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976. He travelled so frequently and collected so much grape material during his lengthy career, many times under remote and dangerous conditions, that he became known as the Indiana Jones of Viticulture.

Collection of Cultivated Varieties and Clones

Olmo’s explorations abroad resulted in the improvement in the diversity and quality of California grape varieties and clones, primarily related to winemaking. He was motivated in the early days by the fact that there was significant misidentification of grape varieties in California and also by winemakers seeking new and improved varieties and clones. Olmo travelled many times to established wine regions in Europe and elsewhere between 1938 and 1976 in search of cultivated varieties for growers and winemakers.

Olmo catalogued the varieties and clones that came to UC Davis from his collections beginning in 1936 in a document entitled Grape Variety Introductions by Division of Viticulture (H.P. Olmo), a copy of which is on file at FPS. He was proud that he initiated this “catalogue” that systematically assigned a station number to each species or vine newly introduced from the “different grape growing countries”. 33 Harold P. Olmo, Plant Genetics and New Grape Varieties, pp. 88-89, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

Some of the highlights of his collection of cultivated varieties follow.

1938 Europe

Olmo’s first trip abroad for the University was a trip to Europe in 1938. His goal was to study and collect important (mostly wine) grape varieties that might be suitable for California. He preferred to study those varieties at their places of origin to begin the task of sorting the identities of unlabeled and misidentified varieties that were already present in California.

Olmo’s solution to the problem of misidentified grape varieties was to reimport those varieties from the areas in Europe where they gave the most outstanding results. 34 H.P. Olmo, "The California Grape Certification Association", (1955) on file in FPS files. Both Bioletti and Olmo believed that comparison of grapevines from the point of origin with the grapevines in California was essential to make a correct identification. Bioletti had always stressed to Olmo that one should never make a change of a variety name absent a lengthy period of such evaluation. 35 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, p.24, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

Olmo's travel diary shows that his 1938 trip to Europe was productive and educational. His tour was based at the National School of Agriculture at Montpellier in southern France, home of a university with an extensive winegrape collection. Olmo attended lectures, consulted with the experts and studied the variety collection. He selected many wine grape varieties and rootstocks at Montpellier and sent them to Davis. 36 Olmo collection D-280, box 57: 55, Department of Special Collections, Shields Library, UC Davis. Those imports included many of the vinifera “clones” that were tested in the early days of the certification program at FPMS, including selections of Cabernet franc, Durif/Petite Sirah (“Bas plant”), Marsanne, “Pinot blanc Chardonnay”, “Pinot blanc vrai”, Pinot noir, Roussane, and Syrah. 37 The list of the varieties collected by Olmo in Montpellier in 1938 can be found in Olmo D-280, box 57: 55, Department of Special Collections, Shields Library, UC Davis.

Olmo’s visit occurred at a time of much tension in France and Germany ahead of the imminent war in Europe. As he travelled throughout France collecting grape material, he saw troops marching and many anxious French people. On the lighter side, he compared the shows in Paris at the “Casino de Paris, nudes galore and Maurice Chevalier” with the Folies Bergere which was “not as good a show as to ladies”. He attended the International Congress of Wines and Vines in Lisbon, Portugal. In Germany, Olmo arranged with Professor Herman Moog for German varieties to be sent to Davis. While in Germany, Olmo saw a burning synagogue and scattered incidents of violence against Jewish men while travelling around and visiting horticultural stations”. 38 Travel Diary, Trip to France and Portugal, 1938, Olmo collection D-280, box 44: 12, Department of Special Collections, Shields Library, UC Davis.

1951 Europe

Olmo’s trip to Europe in 1951 to collect important wine grape varieties was significant for the FPMS grape collection. As discussed in the chapters of this book on FP(M)S, grape and wine industry members who supported the new clean plant program at Davis at that time were motivated by the desire for new and better grape varieties from Europe. Olmo was dispatched to Europe with the support of the Wine Institute (WAB) in fall 1951 to obtain superior clonal selections, with a particular eye out for Pinot noir, Gamay noir, White Riesling, Chardonnay and Red Traminer.

Olmo visited Spain, France, Italy, Switzerland and Germany, studied vines while they bore fruit and obtained about 48 desirable and superior “strains” (clones) of 24 wine grape varieties. Those selections were imported directly to Davis and were catalogued as Hewitt introductions rather than under Olmo’s own system. See the chapter on the Origin of FPS. Many of those selections were the first to be tested by the new U.C. grape certification program and remain in the FPS collection in 2016. 39 A list of the selections and varieties is on file in the Olmo collection at Shields Library, Olmo D-280, box 66: 67; see also correspondence in D-280, box 49: 41, both at Department of Special Collections, Shields Library, UC Davis; H.P. Olmo, Introduction and Testing of Foreign Grape Varieties, Department of Viticulture and Enology, Project 903, page 179, March 8, 1957, Olmo D-280, box 58: 41.

The importation list compiled by Olmo (Grape Variety Introductions by Division of Viticulture (H.P. Olmo) shows many trips abroad resulting in new varieties and clones for winemakers and grape growers. On his way back from the Middle East in 1949, Olmo stopped in Greece, met with Professor M.B. Krimbas and collected 250 varieties from the collection at the College of Agriculture in Athens; the Greek accessions were later installed at the National Clonal Germplasm Repository in Davis. 40 Olmo collection D-280, box 67: 38, Department of Special Collections, Shields Library, UC Davis; box 67: 44, Letter from H.P. Olmo to Professor M.B. Krimbas, Superior School of Agriculture, Athens, Greece, dated January 12, 1949; Summary of illustrated talk given at a meeting of the Wine Institute Technical Advisory Committee, Alexander Hamilton Hotel, San Francisco, January 14, 1949, in Olmo D-280; box 68: 4.

Olmo collected many port varieties in the Douro region of Portugal in 1939 (including Souzão and Touriga) and 1984; many of those selections remain in the FPS foundation vineyard. He took a sabbatical in 1968-69 and went to renowned vineyards in France and Italy to study more troublesome winegrape varieties that were not correctly identified or of which the University had poor “strains” (clones). 41 Olmo collection D-280, box 66: 41; box 67: 55; box 78: 35, Department of Special Collections, UC Davis Library.

Olmo’s regular and persistent efforts throughout the years resulted in numerous new and improved vinifera and hybrid varieties in the University collection.

Collection of wild vinifera and species vines

Former U.C. Professor of Viticulture Carole Meredith feels that Olmo’s most significant contribution as a plant explorer was bringing wild Vitis and other native species from the Middle East and other areas to California. She was not sure whether Olmo realized at the time how threatened the wild species were by lost habitats in their regions of origin and by encroachment and crosses with cultivated varieties. Meredith cited Olmo’s drive and passion to explore obscure and sometimes dangerous places to discover wild vinifera grapevines. Adventures experienced during those collection trips evoke the adventures of Indiana Jones.

1948 Afghanistan and Persia

Olmo was awarded a Guggenheim Foundation Research Fellowship to study native fruits of the Middle East beginning in April, 1948. It was conventional wisdom that the center of origin of many fruits was in the area around Persia (now Iran) and Afghanistan in the Middle East. Olmo believed that the vinifera grape “seem[ed] to come out of Middle Asia, at least most of these cultivated forms”. 42 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, p. 61, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

In his General Report of Sabbatical Leave Spent in Pakistan, Persia and Afghanistan, April 15 to November 15, 1948, Olmo wrote that, in the opinion of most authorities, the mountainous areas skirting the great and forbidding desert plateau that includes Afghanistan and Persia is the ancestral home of a large number of our most important cultivated fruit and nut varieties, including grape. He wrote that one can find, in the same locality, not only the wild form in thickets or forests, but the transitional forms, culminating in the much larger-fruited and higher quality cultivated varieties. He sought in the Middle East a reservoir of fruit and nut varieties that could supply breeders with new gene combinations that could be used in production of new varieties with more desirable qualities. 43 Olmo collection, D-280, box 82: 42 and box 40: 19, Department of Special Collections, Shields Library, UC Davis.

Despite warnings from the State Department against travel in Afghanistan, Persia, Iraq, Syria, Turkey and maybe Palestine at that tense time, Olmo set out to explore the region in April, 1948. 44 Olmo collection D-280, box 100: 4, Department of Special Collections, Shields Library, UC Davis. His oral history provides a compelling and harrowing account of travel in Pakistan, Afghanistan, and Persia (Iran) in some extremely remote, sparsely populated and primitive areas. 45 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, pp. 60-67, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976; Olmo collection D-280, box 40: 19, Department of Special Collections, UC Davis.

Olmo alternated between travelling alone and with a guide. Travel was accomplished by jeep, horse, burro and dilapidated automobiles. He travelled 7,000 miles by automobile alone. He tells the story of being stranded in a gorge in a very desolate area when the Afghan guide driving the old Chevy station wagon missed a bridge and drove down into a stream, turning the car over. A group of nearby nomads in the desert area turned the car over and made a new road to drag it from the gorge over a period of three days. Olmo was amazed that all the group expected was a “thank you”. 46 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, pp. 67-73, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

Olmo visited the area in southwestern Persia around Shiraz, one of three principal vineyard districts in the country. The major varieties were Askari (seedless light green) and Rish Baba. The region, whose climate he likened to that of the San Joaquin Valley in California, once had a wine industry but was principally table grapes by 1948. He was able to collect a lot of seeds and even some grape cuttings when he was within two to three days of Teheran. The cuttings included some excellent table grape varieties with very firm crisp berries that were used in breeding at UC Davis to create commercially successful varieties for California. 47 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, p. 75, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

The greatest diversity of cultivated fruit species (including grapes) was found in the countryside surrounding Tabriz (the area near Iranian Azerbaijan), in the crossroads between Turkey and Russia. There was a large assortment of grape varieties. Olmo found this northern area of Persia (Azerbaijan) to be very rich in wild and cultivated fruit species. The native ranges of many progenitors of our cultivated grape forms were found to be much greater in that area than expected. 48 Olmo collection D-280, box 82: 42, Department of Special Collections, Shields Library, UC Davis.

One of Olmo’s most valuable finds on this trip was the discovery of a wild vinifera vine in northern Persia on the route to the southern shore of the Caspian Sea. He believed that the vinifera grape originated as a wild vine in the southern Caucasian Mountains. Olmo was travelling through a small, isolated village when he spied a vine that looked like wild grapes on a rocky ledge near a stream. Olmo felt that the moderating temperatures of the Sea kept winter temperatures from going so low as to kill the vinifera plant. The vine had the qualities of cultivated grapes except that the berries were very small. Olmo collected seeds and some leaf samples and brought them back to Davis. The leaf and shoot tip samples were pressed and donated to the herbarium collection at UC Davis. 49 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, p. 77, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

Wild Vitis Shirwandah, collected by Olmo in Persia in September 1948, specimen at Vitis collection at the UC Davis Center for Plant Diversity ("The Herbarium")

Vitis collection at the UC Davis Center for Plant Diversity (“the Herbarium”)

The wild Vitis vine collected in Shirwandah, Persia (Iran) was given the name O30-44 by Olmo. “Sibling vines” O30-51 and O30-53 were collected in Adhai, Afghanistan. Andy Walker states that he had vines of O30-51 growing in his University collection in 2016. He used it in breeding for resistance to fanleaf virus to bring wild resistance genes into new crosses. 50 M.A. Walker and C.P. Meredith (1990), The genetics of resistance to grapevine fanleaf virus in Vitis vinifera, pp. 228-238, Proceedings of the 5th International Symposium on Grape Breeding, 12-16 September 1989, Germany, in Vitis, Special Issue 1990.

Olmo collected a large group (102) of grape varieties in Afghanistan and Persia and sent them to Davis in 1948; he identified over 50 varieties with potential for outstanding wine making. The accessions have been widely used in breeding new varieties at UC Davis. Olmo returned to the area in 1954 to collect an additional 25 vinifera varieties. 51 H.P. Olmo, Introduction and Testing of Foreign Grape Varieties, Department of Viticulture and Enology, Project 903, page 179, March 8, 1957, Olmo D-280, box 58: 41; M.A. Walker, C.P. Meredith, A.C. Goheen (1985), Sources of resistance to grapevine fanleaf virus (GFV) in Vitis species, Vitis 24: 218-228, 224; Olmo collection D-280, box 65: 60., Department of Special Collections, UC Davis Library.

In an illustrated talk given at a meeting of the Wine Institute Technical Advisory Committee (WITS) on January 14, 1949, Olmo described the challenges and findings in his 1948 trip to Afghanistan and Persia. He identified Greece as a source of varieties of interest to California and proceeded to that country on his way home to the United States and collected hundreds of varieties many of which he believed possessed high sugar content and distinctive flavors. Many of those varieties were later incorporated into the FPS foundation grapevine collection. 52 Summary of illustrated talk given at a meeting of the Wine Institute Technical Advisory Committee, Alexander Hamilton Hotel, San Francisco, January 14, 1949, in Olmo D-280; box 68: 4, Department of Special Collections, Shields Library, UC

1961 Mexico

Olmo travelled to other countries in search of native grapevines. He made a collecting trip to northeastern Mexico on a grant from the USDA in 1961 and was pleased to find native grapevines near streams and in high altitudes. They found many variable wild grapevines of interest in these isolated desert areas, offering what Olmo characterized as “a wealth of new material”. 53 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, p. 146, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

Olmo travelled to northeastern Mexico and adjacent areas of Texas in August of 1961, in search of native grapevines and new species for direct use as resistant rootstock and breeding material for resistance. Eighty-five seed and herbarium specimens were obtained. The seeds from the wild grapevines included several species new to UC Davis and were planted and grown out, resulting in 500 seedling plants. Those plants later underwent testing for resistance to phylloxera, root knot nematodes, and common viruses with the goal of providing a resistant or tolerant rootstock to commercial grape growers in arid zones. 54 Project No. 903 - the Study, Collection and Trial of New Rare and Promising Varieties of Grapes, 1956-1964, Report dated January 3, 1962, Olmo D-280, box 58: 41, Department of Special Collections, Shields Library, UC Davis.

National Clonal Germplasm Repository (NCGR), Davis

Over the years, Olmo travelled extensively and collected innumerable grapevine varieties and clones for the grape and wine industry in the United States. Most of the varieties he collected were donated to the National Clonal Germplasm Repository (NCGR) at Davis as well as included in the Department of Viticulture and Enology collection on the Davis campus. Samples of leaves, shoot tips and seeds were donated to the Center for Plant Diversity (also known as the herbarium) on the UC Davis campus.

Service Work

1943-45 World War II in Brazil

Olmo's international service work began during World War II in Brazil. He was "on leave" from the University from May 1943 to July 1945 and employed by the Office of Inter-American Affairs and the Brazilian Ministry of Agriculture as part of a war program in agriculture. The Director of the U.C. Experiment Station, Claude Hutchison, was reluctant to approve the trip and feared for Olmo and his family's safety in Brazil, where "there was nothing but alligators". 55 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, pp. 126-131, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

After the State Department intervened, the Olmos went to Brazil. Olmo was fluent in Portuguese and stationed at Campinas in São Paulo state. His instructions were to help the Brazilians set up agricultural education and work in viticulture. He knew that there was little possibility of establishing a grape and wine industry in Brazil based on pure vinifera varieties. 56 Olmo collection D-280, box 56: 33, Department of Special Collections, Shields Library, UC Davis.

United Nations Food and Agriculture Organization

Some of Olmo’s international travel involved consulting work for the United Nations Food and Agriculture Organization (FAO). The purpose of the FAO consulting agreements was to investigate and recommend solutions to agricultural issues in developing countries, mostly related to grapevine growing and production. Olmo assisted with many FAO projects, including those in Tunisia (1980-85), Egypt (1983-1993), Kenya (1975-81), India (1969-70), Iran (1972), Romania (1965), and Malta (1962). 57 Olmo collection D-280, box 68: 66-70; box 80: 1-3; box 80: 32, 36; box 81: 57; box 82: 5 and 56: 53; box 83: 1-5; box 87: 17-22 and box 53:2 (journals for trips), all available at the Department of Special Collections, Shields Library, UC Davis. He also participated in an ongoing United Nations mission from 1968 to 1997 to create a proposal for a plan that would result in a viticulture industry and marketing program in Afghanistan. 58 UNDP Project, Afghanistan, consulting re viticulture production and marketing, 1968-1997, D-280, box 78: 62 and box 53: 2 (journal of 1972-73).

1955 Fulbright Australia

In 1954, Olmo was awarded a Fulbright Grant for Viticultural Research. He studied at the University of Perth in Australia as a research scholar in 1955. Awards under the Fulbright Act were part of an educational exchange program of the International Exchange Service, Department of State. Olmo investigated a serious decline in viticultural production in the Swan Valley and concluded the fault was a combination of high water table, poor drainage and rootknot nematodes. He recommended South West Australia for wine grape production. 59 Letter to Christian Moueix from H.P. Olmo, dated January 27, 1982, Olmo collection D-280, box 67: 48, box 78: 67; box 53: 2 (journal of trip to Western Australia), all in Department of Special Collections, Shields Library, UC Davis.

These highlights of Olmo's international research, consulting and plant exploration activity can only touch on a portion of his work abroad. His extensive travel schedule is responsible for many accessions that now reside in the NCGR at Davis and in the FPS foundation grapevine collection. His name will appear hundreds of times in later chapters in this book describing the origin of those selections. Olmo's contribution to the grape and wine industry in this respect was enormous.

VARIETY AND CLONAL EVALUATION

Project 3503. Title: Bud mutation and clonal selection in the vinifera grape. Objectives: to further the study of bud mutation in order obtain superior clonal selections; and to do basic research on radiation and chimeras to determine the basic structure of the shoot apex; index new clones for disease status and release through Foundation Plant Materials Service.

Harold Olmo devoted a substantial portion of his research time to variety and clonal evaluation in search of quality winegrapes for the grape and wine industry. He began a clonal selection program at U.C. Davis in the 1930’s in search of superior vinifera clones. One of his stated goals in his research work was to identify and index those superior clones for disease status for use as mother plants for the FPS foundation grapevine collection.

A few words defining “clones” and their genetics and about propagation of winegrapes are appropriate here. The information is taken from a 1989 paper authored by Michael G. Mullins and Carole P. Meredith, two Professors in the Department of Viticulture and Enology at U.C. Davis. 60 Michael G. Mullins, Maynard A. Amerine Professor of Enology and Viticulture and Chair of the Department, and Dr. Carole P. Meredith, then Associate Professor - Grape Genetics and Improvement, “The Nature of Clonal Variation in Winegrapes: A Review”, Proceedings of the Seventh Australian Wine Industry Technical Conference (T. H. Lee, Ed.), Adelaide, Australia, 14-16, August, 1989.

Good quality wine has been closely associated with the winemaking characteristics of a relatively short list of traditional cultivars. The world’s vineyards are planted with traditional grape cultivars which have been perpetuated for centuries by vegetative propagation. The original genotype is preserved for many generations using this type of propagation. Some well-known examples of traditional French cultivars are Cabernet Sauvignon, Pinot noir and Chardonnay. Those French cultivars can be traced back to Roman times.

Viticulture was founded on vegetative propagation and on what are called “clonal cultivars”. A “clone” is a population of plants all members of which are the descendants by vegetative propagation of a single individual. The same genetics are theoretically passed on to descendants through the generations.

In theory, all members of a “clone” are genetically identical, but it is common knowledge that there is variation within clonal cultivars of winegrapes. Mutations are a source of random genetic variation within vegetatively-propagated cultivars. Mutations contribute to clonal variation. Variations within cultivars are frequently caused by an accumulation of what is known as somatic mutations, resulting in “bud sports”. A bud sport often includes progeny with visible difference from the parent vine, such as a color change. 61 Mullins et al., supra at pp. 2-3.

Harold Olmo and Austin Goheen each had a significant impact on the FPS foundation grapevine collection. The two men disagreed on the nature of clonal differences in grapevines. Olmo, a geneticist, subscribed to the belief that clonal variation in grapevines consisted of differences inherent to (within) the vines and were not attributable to pathogens. 62 Handwritten paper in Olmo’s handwriting, undated, Olmo collection D-280, box 66: 39, Department of Special Collections, Shields Library, UC Davis. Although he eventually conceded that viruses could have some impact on variation in grapevine, he maintained that genetics were the primary influence. 63 Personal communication to author by Dr. Carole Meredith, Professor Emeritus, UC Davis, January 14, 2016, Napa, California.

Goheen, the USDA Plant Pathologist (virologist) who developed the heat-treated clones at FPMS in the 1960’s and 1970’s, believed that hereditary genetic differences within cultivars were minimal and clonal variation is attributable primarily to differences in the presence of pathogens. He developed his thermotherapy treatments to inactivate the viruses in the grapevine material. 64 Lynn Alley and Deborah A. Golino, “The Origins of the Grape Program at Foundation Plant Materials Service”, p. 227, Proceedings of the ASEV 50th Anniversary Meeting, Seattle, Washington, June 19-23, 2000.

Clonal selection

A widely used procedure for improvement of wine grapes is “clonal selection”, which is the exploitation of variation within traditional cultivars. 65 Mullins et al., supra at pp. 2-3. Carole Meredith describes the process as looking at the natural variation that exists within a variety and identifying sub-types that have naturally arisen, identifying their potential, and introducing them as special selections. 66 Personal communication to author by Dr. Carole Meredith, Professor Emeritus, UC Davis, January 14, 2016, Napa, California.

In the early 1920’s, Frederic Bioletti did the first clonal selection work at the University with Muscat of Alexandria selections collected at Kearney in the San Joaquin Valley. See discussion in Chapter 1, supra. Bioletti made the selections on the basis of high and low yielding vines. When the selections did not maintain their yield tendencies when propagated into a controlled experiment, he concluded that clonal selection work was of “no use” and he dismissed the idea that there could be variation. 67 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, pp. 91-95, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976; J.A. Wolpert, A.N. Kasimatis, and E. Weber, “Field Performance of Six Chardonnay Clones in the Napa Valley, Am.J.Enol.Vitic., vol. 45(4): 393 (1994). The research was published in Hilgardia in 1926.

Harold Olmo resumed the University clonal selection program with grapevines at U.C. Davis in 1937. 68 Minutes, FPMS Grape Industry Meeting, December 14, 1984, on file in Foundation Plant Services collection AR-050, box 23: 11, Department of Special Collections, Shields Library, UC Davis. He disagreed with what was being taught at Davis at that time, i.e., “nothing could be gained by selecting within a given variety”. 69 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, pp. 91-95, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

Olmo started his own selection program from material collected from the oldest vineyard plantings (70 years) he could find in California. Selections of the following varieties were made: Barbera, Burger, Cabernet Sauvignon, Cardinal, Chardonnay, Folle blanche, Muscat of Alexandria, Palomino, Petite Sirah, Pinot noir, Red Malaga, St. Emilion, Sauvignon vert, Semillon, Thompson Seedless, White Riesling and Zinfandel. 70 Minutes, Meeting of FPMS Grape Industry Committee, December 14, 1984, in the FPS collection AR-050, box 23: 11, Department of Special Collections, Shields Library, UC Davis.

Professor Andy Walker was Olmo’s successor in grape breeding at U.C. Davis. Walker studied Olmo’s work in clonal selection. He indicates that Olmo selected variants in vineyards across the State emphasizing good cluster formation, high yields, fruit quality, and disease-free status. 71 M. Andrew Walker, “UC Davis’ Role in Improving California’s Grape Planting Materials”, Proceedings of the ASEV 50th Anniversary Annual Meeting, page 213, Seattle, Washington, June 19-23, 2000.

Most of the older selections in the program were collected by U.C. Davis scientists over the years both from superior California vineyards and by plant exploration in other countries. 72 Deborah A. Golino and James A. Wolpert, “Vine Selection and Clones”, Wine Grape Varieties in California, p. 9 (University of California, Agriculture and Natural Resources, publication 3419, 2003). Many of the clonal selections developed by Olmo with the assistance of Curtis Alley are industry standards today, such as Chardonnay FPS 04 (Wente) and Cabernet Sauvignon FPS 08 (Concannon). 73 Lynn Alley and Deborah A. Golino, “The Origins of the Grape Program at Foundation Plant Materials Service, p. 227, Proceedings of the ASEV 50th Anniversary Meeting, Seattle, Washington, June 19-23, 2000.

Clonal studies require the comparison of multiple selections on multiple sites. 74 M. Andrew Walker, “UC Davis’ Role in Improving California’s Grape Planting Materials”, Proceedings of the ASEV 50th Anniversary Annual Meeting, page 213, Seattle, Washington, June 19-23, 2000. Olmo collected his selections and installed them in vineyards at U.C. Davis and in Napa.

Olmo often did the initial screenings at private vineyards such as the Louis Martini vineyard on Stanly Lane in Carneros (Chardonnay, Pinot noir) and Larkmead Vineyard (Cabernet Sauvignon). After years of yield and wine tests, the best clones were selected for a closely controlled and replicated test at the University Field Station at Oakville. 75 H.P. Olmo, Early Work on Clonal Selection in California Vineyards, undated paper, Olmo collection D-280, box 49: 35, Department of Special Collections, Shields Library, UC Davis.

Oakville Experimental Vineyard

The major University test plot was at the Oakville Experiment Station in Napa County. The Department of Viticulture and Enology used the vineyard at Oakville for enlarging the variety collection at U.C. Davis, for varietal identification and selection trials. The Oakville vineyards were used for among other things Olmo’s selection work on Chardonnay and Cabernet Sauvignon and to plant wine varieties to evaluate the wines.

The Oakville station consisted of several parcels. U.C. had purchased what was referred to as the “South Vineyard” at Oakville in 1947 from the estate of Martin Snelling. That property consisted of 20 acres on Dwyer Road about a mile south of the Old Federal Vineyard (USDA station). 76 James Lapsley and Daniel Sumner, “We Are Both Hosts”: U.C. Davis, Napa and Wine Quality, p. 185 (Agricultural Issues Center, U.C. Davis, 2014), pdf accessible at aic.ucdavis.edu.

Looking to increase its research acreage in the 1950’s, U.C. acquired the “Old Federal Station” portion of the Oakville property through Act of Congress in 1954. The federal government had used the site for grape rootstock trials around 1903 and it later was abandoned during the Depression. 77 James A. Wolpert, "Oakville Experimental Vineyard: Past, Present and Future," (Prepared for the Pre-Conference Tour of the Society of Wine Educators, Department of Viticulture and Enology, University of California, Davis, August 3, 1998). Correspondence and some collaboration between the USDA and the University of California regarding the station had been going on since the end of Prohibition. John Daniel Jr., of Inglenook Winery, was instrumental in persuading the Wine Institute to introduce a bill in Congress that allowed the university to assume control of the station. The bill was passed on June 28, 1954, and as a result the USDA deeded the "Old Federal Station" to the University of California to establish the UC Davis Oakville.

Olmo replicated trials at Oakville

Yields were taken and wines were made of the best selections. Several varieties were chosen for more extensive research, including Cabernet Sauvignon (Kunde Vineyard, Sonoma County), Chardonnay (McCrea Vineyard, Napa, and Wente Vineyard, Livermore), Pinot noir (19 selections from around the state), St. Emilion, and Thompson Seedless. 78 Minutes, FPMS Grape Industry Meeting, December 14, 1984, accessible in the FPS collection AR-050, box 23: 11, Department of Special Collections, Shields Library, UC Davis. The stories of the selections developed for Cabernet Sauvignon, Chardonnay and Pinot noir are told in the respective chapters in this book containing each of those varieties.

Olmo worked on more obscure (at the time) varieties such as Chardonnay, known as a shy variety. Olmo indicated that the most significant results he obtained with the clonal selection program were with Chardonnay; clonal selection beginning in 1951 raised yield from an average ½ ton to 6 tons per acre without any loss of wine quality. 79 Harold P. Olmo, “Selecting and Breeding new grape varieties”, California Agriculture, vol. 34(7): 22-24 (July, 1980). Olmo’s end product combined high yields with high fruit quality, exemplified by Chardonnay FPS 04 and 05, which have been the best-selling Chardonnay selections in the FPS collection.

The U.C. Davis clonal selection program was not a formal system such as those established in France, Germany, Italy and Spain. FPS has European clones from ENTAV (France), Rauscedo (Italy) and Geisenheim (Germany) in the FPS foundation collection. However, the Olmo program definitely performed comparison analysis by planting out in the industry and comparing the performance of the various selections. Wines were prepared and evaluated. Dr. Meredith opined that the products of the Olmo program could validly be called “clones”.

BREEDING AND CYTOGENETICS

Project 3500 (formerly 819). Title: breeding and selection of the vinifera grape. Cytogenetics of the grapevine. Objectives: by breeding to develop new seedless grapes and earlier and later varieties for table use, wine varieties adapted to both cool and warm growing areas and combining high yield and quality, and improved disease and insect resistance. to study the basic cytogenetics of both natural and cultivated species of the grapevine.

The grape breeding program at the University of California began in 1929 when close friends Professors Ernest B. Babcock (Genetics) and Bioletti (Viticulture) decided that it would be a good idea to develop improved grape varieties. They intended to study the nature and causes of seedlessness and create new seedless table grape varieties. 80 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, p. 12, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976. No thought was given at the time to breeding wine grape varieties because Prohibition was still in effect. 81 Harold P. Olmo, Selecting and Breeding new grape varieties, California Agriculture 34(7): 22, July 1980; Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, p. 15, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

Bioletti hired a geneticist, Dr. Helen Pearson, wife of vegetable crops Professor Oscar Pearson, to implement the new program. The work was performed in a vineyard at Davis at a site on campus occupied in 2016 by the Vet-Med complex. Olmo stated that Dr. Pearson was miserable in the field emasculating flowers with fine forceps and making crosses due to biting black gnats to which she was allergic. She was able to plant out the first population of seedlings but left the program soon thereafter. Olmo took over the breeding work. He characterized Pearson as a “talented plant breeder” from whom he learned a great deal. 82 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, pp. 10-12, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

Only one seedless variety of commercial value was obtained from the 1,000 seedlings fruited in the first planting, all involving varietal combinations of seeded and seedless grapes. That one variety was Canner Seedless, whose berries released easily from the stems and processed in canning better than Thompson Seedless. 83 Harold P. Olmo, Selecting and Breeding new grape varieties, California Agriculture 34(7): 22, July 1980.

Olmo breeding program at UC Davis

After Prohibition was repealed in 1933, public interest developed in improving wine varieties. One method to improve varieties was to breed new ones.

Harold Olmo developed a successful breeding program at UC Davis where he created new table, raisin, wine and juice grapes and worked on many rootstocks. He was working for Bioletti in 1931 when Olmo made his first crosses to produce new grape varieties in the University breeding program. His first recorded cross was Muscat of Alexandria x Black Corinth; he made 76 crosses that year and continued at that pace throughout his career at UC Davis until he retired in 1979. 84 M. Andrew Walker, “UC Davis’ Role in Improving California’s Grape Planting Materials”, p. 212, Proceedings of the ASEV 50th Anniversary Annual Meeting, Seattle, Washington, June 19-23, 2000.

Olmo collected many varieties he used in the breeding program on his trips around the world. Some feel that the most important grapes Olmo brought back to the United States were the wild species from Middle East and Latin America. The habitat of those grapes in places like Afghanistan was threatened. Those grapes offered fertile study for new genes and characteristics.

Olmo managed an active breeding program at the University with various objectives in mind. He produced many selections and released 31 varieties. Dr. Andy Walker authored a paper in 2000 on U.C. Davis’ role in improving California grape varieties. In the paper, he lists the varieties bred by H.P. Olmo at U.C. Davis. He released 31 varieties including 9 winegrape varieties, 18 table/juice/raisin varieties, 2 color/concentrate varieties and 2 rootstocks. 85 M. Andrew Walker, “UC Davis’ Role in Improving California’s Grape Planting Materials”, p. 212, Proceedings of the ASEV 50th Anniversary Annual Meeting, Seattle, Washington, June 19-23, 2000. The article contains a complete list of the 31 varieties as well as parentage information.

The winegrapes in the list in Walker’s paper included: Calzin, Carmine, Carnelian, Centurian, Emerald Riesling, Flora, Helena, Ruby Cabernet, and Symphony. A primary objective in Olmo’s wine grape breeding was to create grapes that produced quality wines suitable for growing in the warm climate of places like California’s Central and San Joaquin Valley. The challenge was to maintain suitable acid levels and color.

Two promising Olmo winegrape varieties, Ruby Cabernet and Emerald Riesling, were in the first group the University introduced in 1946. 86 Leon Adams, Wines of America, p. 35, 4th ed., (1990). California Agricultural Experiment Station, RUBY CABERNET and EMERALD RIESLING, Two New Table-Wine Grape Varieties, Bulletin 704, May, 1948, College of Agriculture, University of California, Berkeley.

Ruby Cabernet is often mentioned as Olmo’s most successful winegrape variety. Ruby Cabernet is a hybrid of Carignane (growth habit) x Cabernet Sauvignon (quality of the fruit). Olmo indicated that he used the “variety long judged to give the best quality in California, i.e., Cabernet Sauvignon”, to improve the quality of several standard red table wines making up the bulk of the wine industry. 87 Harold P. Olmo, “Selecting and Breeding new grape varieties”, California Agriculture, vol. 34(7): 22-24 (July, 1980). University sources concluded that the Ruby Cabernet produces quality wines with good color under optimum conditions, especially at lower crop levels. 88 Paul Verdegaal, “Ruby Cabernet”, Wine Grape Varieties in California, pp. 131-133 (University of California, Agriculture and Natural Resources, Publication 3419, 2003).

Emerald Riesling is a hybrid of Muscadelle (CA) x Riesling and has exhibited high acid. Olmo stated that Ruby Cabernet and Emerald Riesling were widely adaptable to all areas of California, including the warmer inland regions. 89 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, pp. 35-39, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

Rubired (Alicante Ganzin x Tinta Cão) is an Olmo teinturier variety released in 1958. The variety proved successful for concentrates/blending for table and dessert wines due its deep red color and vigor. 90 H.P. Olmo and A. Koyama, Rubired and Royalty, New Grape Varieties for Color, Concentrate and Port Wines, California Agricultural Experiment Station, Division of Agricultural Sciences, Bulletin 789, University of California, August, 1962, accessible in the Olmo collection D-280, box 56: 87, Department of Special Collections, Shields Library, UC Davis.

Olmo’s table grapes were well received particularly the seedless ones. Perlette, Ruby Seedless, Beauty Seedless, Christmas Rose and Redglobe were some of the notable varieties. Perlette was the earliest maturing seedless table grape at the time (1946) and was quite successful around the world. 91 Olmo collection D-280, box 57: 21, Special Collections, UC Davis Library; Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, p. 13, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976. One drawback with Perlette was tight clusters in a heavy set. Cytological studies on mutant vines caused by irradiation suggested to Olmo that looser clusters might be induced. He attempted radiation treatment on Perlette to induce somatic mutations for looser clusters. 92 H.P. Olmo, “Plant Breeding Program aided by Radiation Treatment”, California Agriculture, July 1960. Olmo collection D-280, box 55: 24, 25, Department of Special Collections, Shields Library, UC Davis. Olmo conceded that the “Loose Perlette had not been completely successful”. 93 Harold P. Olmo, “Selecting and Breeding new grape varieties”, California Agriculture, vol. 34(7): 22-24 (July, 1980).

Olmo created rootstocks O39-16 (Vitis vinifera ‘Almeria’ x V. Rotundifolia) and O43-43 for the purpose of phylloxera resistance in 1948. The rootstocks were found to be resistant to phylloxera (Olmo) and fanleaf (Lider) virus in trials completed by 1984. 94 “UC Fanleaf Resistant Rootstock Varieties Ready for Release”, FPMS Newsletter, number 6, November, 1986.

Harold Olmo appeared at the FPMS Industry Advisory Committee meeting on October 27, 1980, and announced that his breeding program would be phased out in two years, even though all his seedlings had not yet been evaluated. The person initially selected to replace Olmo had left U.C. Davis unexpectedly. 95 Minutes, FPMS Industry Advisory Committee Meeting, October 29, 1980, accessible in FPS collection AR-050, box 23: 10, Department of Special Collections, Shields Library, UC Davis.

The Department of Viticulture & Enology hired Dr. Andy Walker in 1989 as a “rootstock breeder”. Walker has had success with new rootstock and scion varieties in his career at UC Davis. The rootstock varieties with the GRN variety name were bred for nematode resistance and released in 2008. 96 FPS Grape Program Newsletter, Foundation Plant Services, page 6, October 2008. Walker developed five Pierce’s Disease Resistant scion varieties with high quality Vitis vinifera lineage that were released in 2019.

Cytogenic studies of the genus Vitis

One subspecialty in Olmo’s research was cytogenetics, the study of the structure of chromosomes; long before DNA technology was perfected, geneticists assigned genetic characteristics to distinctive chromosomes by examining them in individual cells under microscopes. Many decades would pass before scientists such as Carole Meredith or Andy Walker were able to use DNA technology to identify, isolate and sequence genes. Meredith recalls giving a department seminar at Davis in the late 1990’s about her ground-breaking scientific accomplishment of identifying the parents of the Cabernet Sauvignon grape. Olmo and another retired professor attended and appeared skeptical about the new DNA technology.

The “Loose Perlette” research is an example of Olmo’s use of cytogenetics research. He radiated Perlette with compact clusters hoping to induce mutation of certain gene(s) on a chromosome to produce a new subvariety with looser clusters. He was able to induce partial sterility early on in the research but the end result was not as he had hoped. He also attempted radiation to infuse a variety with resistance to powdery mildew. 97 Olmo collection D-280, box 66: 9, Department of Special Collections, Shields Library, UC Davis.

MECHANICAL HARVESTING

Project 3522. Title: Mechanical harvesting. Objective: to develop a system for mechanical harvesting of grapes.

The Post-Repeal interest in improved wine grape varieties fostered interest in mechanical harvesting of grapes. Support for a project on mechanical harvesting of grapes increased rapidly with the first attempt at mechanical harvesting made at UC Davis in 1952. Olmo and Winkler worked on the project. Varieties with long-stemmed clusters adapted to the machine methods were developed. But in the interim, the machine method changed and the new varieties were never introduced. 98 Harold P. Olmo, “Selecting and Breeding new grape varieties”, California Agriculture, vol. 34(7): 22-24 (July, 1980). Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, pp. 100-106, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

REGISTER OF NEW FRUIT AND NUT VARIETIES

Project 3508. Title: Register of New Fruit and Nut Varieties. Objectives: to prepare an annual "Register of New Fruit and Nut Varieties" for the purpose of listing and describing all new fruit and nut varieties introduced commercially in the United States and Canada.

The Register of Fruit & Nut Varieties was originally published at intervals in the Proceedings and HortScience of the American Society for Horticultural Science (ASHS) from 1944 to 1970. The profiles of new fruit and nut varieties were eventually compiled into a book, the first edition of which was published by University of California Press in 1972. Harold Olmo and Reid M. Brooks managed the publication with the assistance of cooperating horticulturists. The 3d edition was published in 1997 and is entitled “The Brooks and Olmo Register of Fruit and Nut Varieties”. 99 Reid M. Brooks and Harold P. Olmo, The Brooks and Olmo Register of Fruit and Nut Varieties, 3rd ed., 1997 (ASHS Press, Alexandria, VA).

GRAPEVINE CERTIFICATION

Olmo's colleague and former student Dr. Andy Walker wrote that "one of Olmo's least appreciated activities was the initiation of the Foundation Plant Materials Service at UC Davis". 100 M. Andrew Walker, "UC Davis' Role in Improving California's Grape Planting Materials", pp. 209-215, Proceedings of the ASEV 50th Anniversary Meeting, Seattle, Washington, June 19-23, 2000. Although he was recognized more for being a plant explorer, plant breeder and ampelographer, Olmo was an instrumental party behind the clean plant program created at the University of California in 1952.

Olmo's experience with the adverse effects of disease in grapevines became personal. Early in his career, he determined that color and sugar deficiencies in the table grape Emperor were probably caused by a virus that was spread by vegetative propagation. 101 Olmo H.P. and A.D. Rizzi. Selection for fruit color in the Emperor grape. Proc. Am. Soc. Hortic. Sci. 42: 395-400 (1943). Years later, Olmo's red wine grape Ruby Cabernet showed disappointing results after being grafted onto poor rootstock vines in Napa vineyards. 102 C.J. Alley, A.C. Goheen, H.P. Olmo and A.T. Koyama, “The Effect of Virus Infections on Vines, Fruit and Wines of Ruby Cabernet”, Presented at the Annual Meeting of the American Society of Enologists, Santa Barbara, California, June 28-30, 1962, accessible in the Olmo collection D-280, Box 28, folder entitled “Ruby Cabernet talk”, Department of Special Collections, Shields Library, UC Davis.

Growers used their weakest rootstock vines for trials of the new Ruby Cabernet variety, which had performed well in the Department vineyards in Davis. The weak vines onto which Ruby Cabernet was grafted did not mature the fruit well, resulting in low production, poor fruit color and aberrant growth. Olmo was "struck by the sorry look of the vineyards and lack of effort to stop the ravages of the various diseases". 103 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, pp. 30-31, 100-106, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976. He wrote that "it seemed unreasonable to spend 15 years in breeding and testing a new variety and then see it contaminated unwittingly after commercial introduction. Some control in the propagation and distribution of new varieties had to be devised". 104 H.P. Olmo, Professor of Viticulture, University of California, Davis, paper presented at First Semana International del Vino, Jerez, Spain, June 2-6, 1975, pp 379-389.

Olmo was further affected by virus damage he observed on his study and plant collection tour in Europe in 1951. The study tour alerted Olmo to the widespread virus contamination of European vineyard soils, called "infectious degeneration". 105 H.P. Olmo, Professor of Viticulture, University of California, Davis, paper presented at First Semana International del Vino, Jerez, Spain, June 2-6, 1975, p. 380. Olmo found similar symptoms and patterns of disease in California vineyards on his return and was inspired to share his observations in industry presentations throughout the state.

William Hewitt

Another early advocate in Davis for implementation of a clean stock program for grapevines was Dr. William B. Hewitt, Department of Plant Pathology. In the 1940's, new knowledge and methods of disease detection made clear to University scientists how widespread virus disease problems were in the state's vineyards.

Hewitt was one of the primary University researchers on grape diseases. He had been hired by the University in 1937 to work on Pierce's disease, which was believed at the time to be a virus. He played a pivotal role in early identification and elimination of virus diseases in California vineyards, including identification of fanleaf virus in 1954 as the cause of vineyard problems in a USDA-bred table grape variety. Hewitt ultimately became known as the father of modern grapevine virology and served as the founding President of the ICVG. 106 Lynn Alley and Deborah A. Golino, “The Origins of the Grape Program at Foundation Plant Materials Service, p. 223, Proceedings of the ASEV 50th Anniversary Meeting, Seattle, Washington, June 19-23, 2000.

Olmo and Hewitt regularly encountered problematic circumstances in their work for the University. The addition of new grapevine varieties had stagnated in California by the early 1950's. Grape varieties were often misnamed, remained unidentified or sometimes referred to a mixture of unrelated varieties.

Federal quarantine regulations for imported grape material were enacted in the early 1950's, requiring that imports be tested for viruses before release. A backlog in release from quarantine of imported varieties and clones exacerbated demand. Many common European grape varieties had been brought to California prior to quarantine control. An increasing number of destructive virus diseases were spreading in young vineyards propagated from diseased stock. Olmo defined the virus problem in simple terms as follows: "Once a vine is infected, no practical way has yet been found of killing the virus without at the same time killing the vine. There is no medicine and no cure". 107 H.P. Olmo, "A Proposed Program for the Introduction, Improvement and Certification of Healthy Grape Varieties", Wines & Vines 32(7): 7-9 (July, 1951). The solution was healthy new grapevine material.

Both Olmo and Hewitt lobbied for a program that would facilitate availability of high quality grapevine material produced in a certification program. University researchers made presentations to the California grape and wine industry in 1950 and 1951 explaining their findings and describing a proposed program centered at UC Davis. 108 Lynn Alley and Deborah A. Golino, “The Origins of the Grape Program at Foundation Plant Materials Service, p. 223, Proceedings of the ASEV 50th Anniversary Meeting, Seattle, Washington, June 19-23, 2000. H.P. Olmo, Professor of Viticulture, University of California, Davis, paper presented at First Semana International del Vino, Jerez, Spain, June 2-6, 1975, pp 379-389. A series of three articles in Wines & Vines magazine in July and August 1951 laid out the justification and support for such a program.

Olmo wrote the first article in the Wines & Vines series in July, 1951. He began by defining the causes of degeneration of grape varieties in California vineyards: viruses and adverse mutations. His proposed plan for better grape materials included testing to ensure freedom from disease (virus), professional identification of varieties as true to type, and a positive clonal selection program such the one for Zinfandel and Cabernet Sauvignon that had operated at UC Davis since 1938. 109 H.P. Olmo, "A Proposed Program for the Introduction, Improvement and Certification of Healthy Grape Varieties", Wines & Vines 32(7): 7-9 (July, 1951).

The administrative structure for the proposed program included an advisory committee to oversee operations and make policy decisions. The six members would represent the grape and wine industry, grape nurserymen, the California Department of Food & Agriculture (CDFA), and UC Davis (Division of Plant Pathology and Division of Viticulture & Enology, both of which are now Departments). CDFA would enforce the program via regulations. Olmo suggested that the whole grape and wine industry would benefit by the service the program would render to grape growers and should take responsibility for financing the program.

Olmo proposed to centralize at U.C. Davis all post-entry quarantine activity for foreign grapevines imported into the United States. The material could be isolated, indexed and evaluated for disease at the University. Varieties would be planted in an isolated foundation vineyard as a permanent mother vine planting once there was a reasonable certainty they were free of diseases.

Nurserymen and growers could then purchase cuttings from the foundation vineyard to grow in isolated plots in each viticultural area in California. The rootstocks onto which foundation material were grafted would also be tested.

The vineyard plantings would be inspected twice yearly by a committee of experts and by qualified pathologists from UC and CDFA. The outlying vineyard plantings would be known as certified vineyards. Vines would be tagged with the accepted variety names. Growers would have the privilege of selling buds or cuttings as certified stock. Nurserymen propagating grafted vines for sale would be supplied with a bi-colored tag indicating that both stock and scions were from certified plants.

Olmo had been wrestling with the issue of misidentified and mislabelled grapevines since he started at U.C. Davis. In his article, Olmo addressed what he characterized as a great concern of the California wine industry, i.e., the mixture and misnaming of varieties. His solution to the problem of degenerated clones or misidentified varieties was to reimport those varieties from the areas in Europe where they gave the most outstanding results. After index testing, those new imports would offer authentic and healthy varieties for wine makers. Olmo also proposed a program of clonal selection to identify valuable heritage clones in California vineyards and validate the identity of existing industry clones. 110 H.P. Olmo, "The California Grape Certification Association", (1955), accessible in the Olmo collection D-280, box 68: 58, Department of Special Collections, Shields Library, UC Davis.

William Hewitt wrote a companion article in Wines & Vines one month later entitled "Virus and Virus-like Grape Diseases". He alerted growers to the serious disease problems that were occurring in California vineyards. Hewitt described the major grapevine virus diseases known or suspected at the time: "White Emperor disease" (leafroll), yellow mosaic (fanleaf), fanleaf, leafroll, and rough bark (later known as corky bark). He also mentioned Pierce's Disease, which was thought to be a virus at the time. Hewitt warned that unless some action was taken to prevent the spread of those vine diseases, great harm would be done to the California grape and wine industry. Hewitt made clear that the use of propagating wood from diseased vines and rootstock was responsible for rapid spread of the virus diseases into new plantings. His solution to the problem was production of certified, healthy vines as a source of cuttings for the growers. Hewitt's article gave a scientific basis for the creation of the program described by Olmo. 111 W.B. Hewitt, "Virus and Virus-like Grape Diseases", Wines & Vines 32(8): 14-15 (August, 1951).

The grape and wine industry responded with support for the proposals. After a presentation at Davis in December, 1950, the Wine Advisory Board’s Viticulture Research Committee led by D.C. Turrentine recommended that its Board of Directors pursue importation of select foreign varieties, reestablish the identification process of California vines, and recommend to U.C. to collect, isolate and propagate choice varieties for industry. 112 Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, p. 98, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

An article in the August, 1951, issue of Wines & Vines alluded to the industry support. "Because of the increased threat to California vineyards from virus and virus-like diseases, proposals by Dr. H.P. Olmo and Dr. William B. Hewitt to control the introduction of new cuttings (both imported and California-bred varieties) into California vineyards are receiving serious consideration by that state's vintners". 113 "Industry Group Gives Consideration to Controlled Cuttings Program", Wines & Vines 32(8), p.9 (August, 1951); Harold P. Olmo, Plant Genetics and New Grape Varieties, Introduction, p. 32, California Wine Industry Oral History Project, Regional Oral History Office, University of California Berkeley, Regents of the University of California, 1976.

In July 1952, the California Grape Certification Association (CGCA) was formed at U.C. Davis to develop, maintain and distribute virus-tested grape stock that was true to the variety name. Olmo's former genetics student Curtis J. Alley was hired as manager of the newly developed grape certification program. In a letter to CDFA Supervising Biologist Jules Rodigou dated November, 1953, Alley wrote: "We are just beginning our program for the development of grape stock and varieties that will be certified as to freedom from known virus diseases and true to variety named. This will require several years before such wood becomes available." 114 Letter from C.J. Alley to Jules Rodigou, Supervising Biologist, Nursery Services, SF, CDFA, dated November 23, 1953, on file in Foundation Plant Services collection AR-050, box 30: 12, Department of Special Collections, Shields Library, UC Davis.

The CGCA program would eventually evolve into the program now known as Foundation Plant Services. That evolution is fully addressed in the following chapters. Olmo continued to advise the grape certification program in subsequent years as a result of his clonal selection efforts and on issues related to proper identification of varieties and clones. His importations, clonal selections, and breeder selections would become a major segment of the FPS foundation grapevine collection.