SCREENING MALUS GERMPLASM TO IDENTIFY THE HARD CIDER APPLES OF THE FUTURE

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1014042
• Project Start Date: Oct 1, 2017
• Project End Date: Sep 30, 2020
• Program Code: [(N/A)]- (N/A)

Recipient Organization
CORNELL UNIVERSITY
(N/A)
ITHACA,NY 14853

Performing Department
Horticulture

Non Technical Summary
Worldwide, and identified as such in this proposal, hard cider is referred to as "cider". Similar to wine and beer, there is a broad range of cider styles, which appeal to a growing group of cider consumers. Recent data suggests that nearly a million Americans drink cider on any given day (Statista, 2016). Many of these new cider consumers previously purchased light beer and are likely to continue purchasing cider now that it is available through most retailers (Petrillo, 2016). Containing between 0.5-8.5% alcohol by volume, cider is made from apples (either culinary cultivars or specialty cider cultivars specifically selected for their juice quality), bulk apple juice, and/or apple juice concentrate. Recent surveys show that cider producers would prefer to make ciders from specialty cider apple cultivars (Peck and Miles, 2015). In order to help sustain this emerging industry, there is a vital need to identify specialized cider apple cultivars that are adaptable to modern orchard production systems and that meet the juice and cider quality expectations of cider producers and consumers.Specialized cider apples contain quality attributes that provide important and noteworthy characteristics to the finished cider. These attributes include bitterness and astringency (naturally provided through a sub-group of polyphenolic compounds called "tannins"), sharpness (naturally provided through organic acids, predominantly malic acid), sweetness (naturally provided through sugars and sugar-alcohols, such as sorbitol), and flavors (naturally provided through volatile aromatic compounds). All apples contain some level of each of these components, but specialty cider apples are unique in that they may contain exceptionally high levels of one or more of these components. For example, some specialty cider apples contain up to ten times higher polyphenol concentrations than culinary apples (Thompson-Witrick et al., 2014; Valois et al., 2006).While there are dozens of European and American specialized cider cultivars that can be used to make cider, many do not perform as well as common culinary apples in commercial orchard situations. Specifically, many cider cultivars are not responsive to chemical fruit thinning, have an extremely biennial bearing habit, tend to be overly vegetative, and/or are highly susceptible to economically important apple diseases. Additionally, apples destined for cider production can be mechanically harvested and pruned and may require lower pesticide inputs than culinary apples because cosmetic defects and even some superficial damage are acceptable for fruit that will be processed soon after harvest. New York State is the second largest producer of culinary apples in the country, but there is currently very little production of the specialized cider apples desired by cider producers. By systematically evaluating a wide range of germplasm and then selecting material that is superior to currently available cultivars, the proposed project will quickly identify the apple cultivars that will become the future of the NY cider industry.

Animal Health Component

50%

Research Effort Categories

Basic

50%

Applied

50%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
202	1110	1060	100%

Knowledge Area
202 - Plant Genetic Resources;

Subject Of Investigation
1110 - Apple;

Field Of Science
1060 - Biology (whole systems);

Keywords

apple

malus

hard cider

germplasm

polyphenol

tannin

malic acid

Goals / Objectives
The goal of the proposed research is to phenotype (i.e., identify and evaluate the horticultural performance and juice quality) Malus xdomestica cultivars, Malus hybrids, and Malus species for desirable characteristics for commercial cider apple production. We will use accessions in the United States Department of Agriculture Plant Genetic Resources Unit (USDA-PGRU) Malus germplasm collection and replicated field plantings located at the Cornell Orchards in Ithaca, NY. Phenotypic data will be used for a complementary genotyping project that is being conducted by Nathan Wojtyna, a graduate student in my lab. Specifically, we aim to identify genetic markers related to cider specific apples, such as those associated with fruit polyphenol and organic acid metabolism. We hypothesize that highly productive apple cultivars with desired cider quality attributes (i.e., high tannin/polyphenol concentration and composition, acidity, juice yield, and consumer sensory preference) and disease resistance can be identified from existing germplasm.Objective 1: Phenotype accession at the USDA-PGRU to identify potential candidates for hard cider production. These extensive collections and breeding populations offer 1,000's of potential genotypes that may have superior horticultural and cider quality characteristics to currently used cider cultivars.Objective 2: Evaluate European cider cultivars that are currently available in the US and offer the fastest route to identifying bitter cider cultivars that are highly productive, adaptable to high-density orchard systems, contribute desired flavors to ciders, and are well suited for NY's climate.Objective 3: Import and test previously unavailable European cider cultivars. Two separate European cider cultivar importations have already occurred (Spain in 2004 and England in 2015). A third importation from France is slated for 2018.

Project Methods
Objective 1: In 2016, MS/PhD student Nathan Wajtyna (funded through other sources) began screening germplasm at the USDA-PGRU collection. Dr. Thomas Chao (the curator for the Malus collection) has been assisting in the selection of potential germplasm to test. In 2016, we tested 30 unique selections. Our goal for 2017-2020 is to phenotype at least 100 additional accessions per year. The accessions selected for phenotyping will be identified by utilizing the Germplasm Resources Information Network (GRIN) database (https://www.ars-grin.gov), which has phenotypic information on 4,867 Malus accessions. Specifically, we identified accessions with high levels of astringency and acidity--two of the most important quality attributes for cider producers. Additionally, we screened out accessions with a soluble solid concentration below 11º Brix (primarily sugars). This was done because low sugar content apples would produce ciders with too low an alcohol content. The final sorting criteria removed apples that were, on average, less than 50 g. This was done to screen out apples that would be too expensive to harvest by hand and too small to be mechanically harvested with existing equipment.Horticultural assessments will include a visual scoring of tree architecture and vigor, root sucker counts, and yield. Starting at budbreak, trees will be assessed once per week until full bloom (that is, when first petals of the king bloom begin to drop). The relative bloom time of each accession will be categorized as early, mid, or late. Bloom density will be rated from 1 to 5 (1 = sparse to no bloom; 2 = light bloom; 3 = moderate bloom; 4 = abundant bloom; and 5 = saturated bloom).Fruit quality assessments will include fruit weight, size, and shape, peel color, juice yield, sugar content (including, sucrose, fructose, glucose, and sorbitol), total acidity and pH, total polyphenol content, individual polyphenol composition, and yeast assimilable nitrogen concentration (important for yeast metabolism during fermentation).Fruit Sampling: Most accessions in the PGRU are single trees. Forty-five apples, selected at random, from each sample tree will be divided into three groups of 15 apples, to allow for three subsamples. Fruit will be selected from upper, lower, exterior, and interior sectors of each tree to reduce within tree variation. Fruit Storage: Fruit will be stored in standard atmosphere cold storage (1-3°C; >90% relative humidity) for no more than seven days. Fruit Maturity: To evaluate maturity, fruit will be sliced equatorially and the starch-iodine index will be determined by dipping the exposed tissue into a potassium iodide solution (1 g potassium iodide plus 0.25 g iodine in 100 mL water), for comparison to staining patterns on published charts (Blanpied and Silsby, 1992). Fruit will be harvested when less than 20% of the flesh is stained with the potassium iodide solution. Internal ethylene concentration will be determined with a gas chromatograph equipped with a flame ion detector (Series II; Hewlett Packard 5890, Wilmington, DE) using a 1 mL gas sample from the apple's core cavity. Flesh firmness will be measured, after removing part of the peel at two locations along the equator of each apple, with a penetrometer (EPT-1; Lake City Technical Products, Inc., Kelowna, BC, Canada) fitted with a cylindrical 11.1 mm diameter tip. Juice Extraction: Apples will be juiced with a Norwalk 280 Juicer (Bentonville, AR). The extraction efficiency will be calculated using the fruit weight and extracted juice weight. Juice Storage: Samples will be stored at -80 °C and then thawed to 4 °C immediately prior to analysis. Juice Analyses: Soluble solids concentration will be measured using a PAL-1 digital refractometer (Atago U.S.A., Inc., Bellevue, WA) and reported as percent Brix. Reducing sugars (fructose, sucrose, and glucose), sorbitol, ammonia, and primary amino nitrogen will be measured on a SpectraMax Plus 384 microplate reader (Molecular Devices, Sunnyside, CA) using packaged kits purchased from Megazyme (Chicago, IL). Titratable acidity will be measured by titrating a 5 mL juice aliquot against a 0.1 N KOH solution to an end-point of pH 8.1 with an 848 Titrino Plus autotitrator (Herisau, CH) and reported as malic acid equivalents. Total polyphenol content will be measured using the Folin-Ciocalteu assay (Thompson-Witrick et al., 2014) and reported as gallic acid equivalents. High performance liquid chromatography will be used to quantify the concentrations of polyphenols, such as: (-) epicatechin, (+) catechin, procyanidin B2, 5'-O-Caffeoyl-quinic acid, caffeoyl-quinnic acid-3, chlorogenic acid, quercetin glycosides, phloetin-2'-O-glucoside, and phloretin-2'-O-xylosyl-glucoside.Based on these data, rapid phenotyping protocols (i.e., a decision-tree and metrics that most quickly distinguish an apple as having a high potential for cider production) will be developed that can be shared with other researchers and industry stakeholders. In years 2 and 3 of this project, we will propagate and begin testing promising selections in field plots.Objective 2: In 2015, a replicated cultivar trial was established at the Cornell Orchards in Ithaca. Cultivars include: Binet Rouge, Brown Snout, Brown's Apple, Dabinett, Ellis Bitter, Harry Master's Jersey, Porter's Perfection, Tremlett's Bitter (Geneva Tremlett's), and Vilberie, each replicated four times in two-tree sets as a completely randomized block design. The trees are planted 3' between trees and 12' between rows and are trained as a tall spindle (a modern, high-density apple orchard system recommended by Cornell Cooperative Extension pomologists and that lends itself to mechanization). Some of the cultivars are starting to bear fruit in 2017. We will keep careful records of material and labor costs, detailing the time it takes to complete each task, so we can calculate the costs of establishment and of production. More thorough economic analyses will also be calculated as the project progresses through subsequent years, as will orchard productivity, which will be measured by tree trunk growth (TCSA), total yields, yield efficiency (yield/TCSA), and fruit size. Fruit and juice data collection and analysis from this trial will be like those listed for Objective 1.Objective 3: In 2004, 25 elite Spanish cultivars were imported into the U.S. These cultivars are officially designated cider cultivars in Asturias, the largest cider producing region in Spain. Relatively few Spanish cider apple cultivars are currently available in the US. Spanish cider (or sidra) tends to be more acidic and acetic than English and French ciders. Spanish cultivars will allow NY producers to explore new cider styles.In 2016, the first nine Spanish cider cultivars (Blanquina, Collaos, Cristalina, Coloradona, Marialena, Piel de Sapo, Raxao, Sangre de Toro, and Solarina) were released from USDA-APHIS quarantine. The extended quarantine period was due to repeated virus detections resulting in the need to propagate the cultivars from tissue culture. The nine cultivars are currently being propagated by Wafler Nursery (Wolcott, NY) and will be put into a similar replicated test planting as described for Objective 2 and we will follow similar procedures as to those outline in Objective 1 and 2. Additional cultivars will be added as they are released from quarantine.The English cultivars include 17 releases from the Long Ashton Research Station known as "The Girls". These cultivars currently account for about 20% of the cider apple acreage in the UK. Until this importation these cider cultivars were unavailable in the U.S. Other UK imports include cultivars that are possibly not true to type, such as Foxwhelp and Tremlett's Bitter. The English cider cultivars will be available for field testing in 2020. Plantings and data collection will be like those outlined in Objective 2.

Progress 10/01/17 to 09/30/20

Outputs
Target Audience:Commercial apple growers and cider producers are the two primary stakeholder target audiences for this project. We also expect our results to also be utilized by non-commercial producers, such as those interested in growing rare and unusual apple trees. We expect our database to be a useful resource for scientists and extension educators who want to search for specific traits in the wide-range of cider apple cultivars available in the United States (US). In particular, apple breeders and those interested in genetic resources will be able to utilize our phenotypic datasets for selecting breeding parents and/or identifying functional genes. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?These Federal Capacity Funds have provided training for two graduate students and six undergraduate students. Nathan Wojtyna successfully defended his Master's thesis in August 2018. During his studies, Nathan presented his research at professional meetings, such as the American Society for Horticultural Science and at industry meetings, such as CiderCon. Mr. Wojtyna is now employed as a high school science teacher. In July 2018, Mr. Shanthanu Krishna Kumar began his doctoral studies in my lab. Mr. Krishna Kumar earned a Master's degree from Guelph University and plans to study cider apple diversity and genetics in my lab. As part of this work, Mr. Krishna Kumar has overseen the sampling from the USDA's Malus germplasm collection in Geneva, NY that is described in objective 1. This project has also provided six Cornell undergraduate students to participate in the Cornell Orchards Summer Internship. During this three-month internship, the students were involved in all aspects of orchard management from trellis construction to fruit thinning to tree training to harvesting. Many of these students aspire to further their education in graduate school studying subjects such as, horticulture, plant breeding, genetics, and soil science. How have the results been disseminated to communities of interest?My lab group has presented data from the grants funded by these Federal Capacity Funds at the following venues: • Peck, G.M. 2020. Cidermaking in the orchard: elevating apple character before the press. CiderCon. Oakland, CA. 31 Jan. Attendees: 75. • Krishna Kumar, S., D. Zakalik, N. Wojtyna, M. Brown, and G. Peck. 2020. Cider apple germplasm diversity. CiderCon. Oakland, CA. 29-31 Jan. Attendees: 1,029. • Peck, G.M. and A. Karl. 2020. Influence of Nitrogen Fertilization on Tannin Synthesis, Yeast Assimilable Nitrogen, and Fermentation Kinetics. Empire State Producers Expo. Syracuse, NY. 15 Jan. Attendees: 37. • Peck, G.M. 2020. Cidermaking in the orchard: elevating apple character before the press. CiderCon. Oakland, CA. 31 Jan. Attendees: 75. • Peck, G.M. and A. Karl. 2020. Influence of Nitrogen Fertilization on Tannin Synthesis, Yeast Assimilable Nitrogen, and Fermentation Kinetics. Empire State Producers Expo. Syracuse, NY. 15 Jan. Attendees: 37. • Knickerbocker, W. and G. Peck. 2020. Prospects for mechanical harvesting in NY cider orchards. Empire State Producers Expo. Syracuse, NY. 15 Jan. Attendees: 37. • Peck, G.M., N. Wojtyna, S. Krishna Kumar, D. Zakalik, M. Brown, and T. Chao. 2019. Cider apple diversity in the USDA Malus germplasm collection. CiderCon. Chicago, IL. 8 Jan. Attendees: 85. • Peck, G.M. 2019. Orchard planning for hard cider production. Mid-Atlantic Fruit and Vegetable Conference. Hershey, PA. 30 Jan. Attendees: 55. • Peck, G.M. 2019. Cornell Reunion Weekend. Cider science: it's about the apples. Liberty Hyde Bailey Lecture, Cornell University. Attendees: 35; 60 Min, 7 June. • Peck, G.M. 2019. Chemotypic profiling of cider apples in the USDA's Malus germplasm collection. Metabolomics Symposium. Cornell University. 2 May. Attendees: 45. • Peck, G.M. 2019. Cider science: it's about the apples. Cornell University, School of Integrative Plant Science-Horticulture Section Seminar Series. 11 Feb. • Peck, G.M. 2018. Cider apples varieties old and new: The state of cider apple plantings in New York. Heritage Apple Meeting. Finger Lakes Cider House. 13 Sept. • Peck, G.M. 2018. Horticultural research on cider apples in New York State and overview of the NY cider industry. University of Guelph. Simcoe, ON. 27 Aug. Attendees: 75. • Peck, G.M. 2018. Potential Impact of Climate Change in the Orchard. CiderCon. Baltimore, MD. 2 Feb. Attendees: 75. • Peck, G.M. and W. Knickerbocker. 2018. Economic Case Studies of Cider Apple Orchards. Baltimore, MD. 2 Feb. Attendees: 100. • Peck, G.M. and W. Knickerbocker. 2018. Enterprise Budgets for Cider Apple Orchards. New York Cider Association Annual General Meeting. Interlaken, NY. 26 Feb. Attendees: 53. • Peck, G.M. and W. Knickerbocker. 2018. The Economics of Growing Cider Apples. Wisconsin Fruit and Vegetable Conference. Via live video feed. 22 Jan. Attendees: 90. • Peck, G.M. 2018. Reflecting on England's Cider Orchards and How We Grow Cider Apples in NY. Empire State Producers Expo. Syracuse, NY. 18 Jan. Attendees: 51. • Peck, G.M. 2017. The Science of Hard Cider. The West Family Lecture. Invited lecturer. The Cornell Club. New York City, NY. Cumulatively, we have presented data related to these Funds to hundreds of individuals over the past three years. We also published a paper in the Fruit Quarterly trade journal which discusses the economics of growing different cider apple genotypes under different types of orchard systems. This trade journal is read by a large number of industry stakeholders, extension specialists, and academics throughout the northeastern and midwestern US. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective 1: During the course of this project, 442 accessions of interest were identified from the USDA-PGRU. Of those, we phenotyped 371 unique genotypes (71 did not have enough fruit during this project). Fruit quality assessments included fruit weight, size, and shape, peel color, juice yield, sugar content (including, sucrose, fructose, glucose, and sorbitol), total acidity and pH, total polyphenol content, individual polyphenol composition, and yeast assimilable nitrogen concentration. Our sample population included 293 Malus domestica, 35 Malus hybrids, 16 Malus sieversii, and 27 various from Malus species (asiatica, baccata,coronaria, micromalus, orientalis, prunifolia, robusta, sylvestris). Approximately 20% of the accessions came from each the United States, France, and the United Kingdom. Another 6% of the accessions originated in Spain, 9% were of unknown origin, and the remainder were from 22 different countries. We identified 68 bittersharp (high tannin and high acid), 84 bittersweet (high tannin, low acidity), 144 sharp (low tannin, high acidity), and 74 sweet (low tannin, low acidity) accessions. Acidity ranged from 0.7 to 29.5 g malic acid equivalents/L and polyphenol concentration ranged from 0.07 to 8 g/L based on the Folin-Ciocalteu method. Soluble sugar concentration ranged from 4.6 to 26.1 ºBrix. We also measured wide ranges for a number of sugars including, sucrose (0-107 g/L), glucose (3.8-74.4 g/L), fructose (11.5-123.0 g/L) and the sugar-alcohol, sorbitol (0.288-39.0 g/L). In addition, the polyphenol composition of 14 genotypes was measured using ultra high-performance liquid chromatography and indicated that the variation in polyphenol levels measured by the Folin-Ciocalteu assay was largely due to procyanidins and phloretin compounds. While greater diversity is beneficial from the standpoint of maintaining genetic resources and creating unique cider styles, it can be a challenge to new cider producers and apple tree nurseries to identify cultivars with the greatest chance for success in a given region. For this reason, our results should aid in determining genotypes to include in future cultivar evaluations. Objective 2: In 2015, a replicated cultivar trial was established at the Cornell Orchards in Ithaca, New York (NY). Cultivars include: Binet Rouge, Brown Snout, Brown's Apple, Dabinett, Ellis Bitter, Harry Master's Jersey, Porter's Perfection, Tremlett's Bitter (Geneva Tremlett's), and Vilberie, each replicated four times in two-tree sets as a completely randomized block design. The trees are planted 3' between trees and 12' between rows and are trained as a tall spindle (a modern, high-density apple orchard system recommended by Cornell Cooperative Extension pomologists and that lends itself to mechanization). Trunk measurements taken in Fall 2020 were compared with measurements taken at the time of planting (Spring 2015). Porter's Perfection, Brown's Apple, and Brown Snout grew more during over this period. The least amount of tree growth over the six years was found for Dabinett and Tremlett's Bitter (note this cultivar is not true-to-type and is often referred to as Geneva Tremlett's Bitter), with the other cultivars being intermediate in growth and not statistically different from each other. Overall yields in 2020 were lower than expected, perhaps due to the biennial bearing habit for many of these cultivars. Over the six years, cumulative yields were greatest for Harry Master's Jersey and Ellis Bitter which both had greater than 30 kg/tree. Binet Rouge, Brown Snout, Porter's Perfection, and Vilberie had cumulative yields between 20-30 kg/tree, and Brown's Apple, Dabinett, and Tremlett's Bitter (Geneva) had less than 20 kg/tree. Pre-harvest drops were least for Binet Rogue, Brown's Apple, Ellis Bitter, Porter's Perfection, and Tremlett's Bitter (Geneva), and most for Harry Master's Jersey and Vilberie. Overall, Porter's Perfection was one of the best performing cultivars in this trial in terms of tree growth, productivity, and minimal pre-harvest drop. Other cultivars that performed adequately included, Binet Rogue, Brown's Apple, Ellis Bitter, Harry Master's Jersey, and Vilberie. Dabinett did not perform well, most likely due to freeze damage that occurred in the nursery to the trunks. In 2020, the cider apples were allowed to tree-ripen to a Starch Pattern Index of 6, which is greater than fresh market apples, so as to have the greatest sugar content for fermentation. In this trial, Brown Snout had the greatest Soluble Solid Concentration, while Ellis Bitter, Tremlett's Bitter (Geneva), and Vilberie had the lowest. Brown's Apple and Tremlett's Bitter (Geneva) had exceptionally high titratable acidity and along with Brown Snout and Porter's Perfection would be considered "sharp" apples (> 4.5 g/L TA). All of the cultivars in this trial would be considered "bitter" with a polyphenol concentration of greater than 1.25 g/L as measured by the Folin-Ciocalteu assay. Vilberie had an exceptionally high polyphenol concentration of 5.9 g/L. Dabinett, Ellis Bitter, Harry Master's Jersey, and Porter' Perfection had polyphenol concentrations between 2-4 g/L. Brown's Apple, Ellis Bitter, Porter's Perfection, Tremlett's Bitter, and Vilberie all had greater than 70% juice extraction efficiency suggesting that they would provide very high juice yields when milled and pressed. Overall, Porter's Perfection had many of the quality attributes to make a single variety cider. The other cultivars could contribute sugar, acidity, and/or phenolics but not necessarily all three attributes. Vilberie, in particular, should be considered as a cultivar to add in low volume to a blend of fresh market apples to provide polyphenols. Objective 3: In 2018, we established a replicated trial of elite Asturian Spanish cider cultivars to allow NY producers to explore new cider styles. Spanish cider (or sidra) tends to be more acidic and acetic than English and French ciders. Cultivars in this study include: Blanquina, Collaos, Coloradona, Marialena, Piel de Sapo, Raxao, Sangre de Toro, Solarina, and Cristalina. All of these cultivars grew between 400 and almost 800% between spring 2018 and fall 2020. The smallest trees were Blanquina, Collaos, and Solarina, but it is too early in this trial to know if they will be genetically smaller trees at maturity. Similarly, although there were some statistically significant differences in yields, several years of data will be needed to make accurate comparisons and recommendations. Juice quality data were taken from the small number of fruit available in 2020, and like the productivity data should be only considered preliminary at this time. However, it is evident that Piel do Sapo has exceptionally high titratable acidity (19 g/L). The other cultivars ranged from 2 (Sangre de Toro) to 11 g/L (Blanquina). Not all Spanish cider cultivars can be considered "sharp", with Coloradona and Sangre de Toro having a TA below the 4.5 g/L threshold. Among the cultivars in this trial, only Coloradona and Piel de Sapo would be considered "bitter" with a total polyphenol content over 1.25 g/L. The English cultivars include 17 releases from the Long Ashton Research Station known as "The Girls". These cultivars currently account for about 20% of the cider apple acreage in the UK. Until this importation these cider cultivars were unavailable in the U.S. Other UK imports include cultivars that are possibly not true to type, such as Foxwhelp and Tremlett's Bitter. The English cider cultivars will be available for propagation in 2021. Plantings and data collection for these cultivars will be like those outlined in Objective 2. The French importation is currently still underdevelopment as we wait for the Spanish and British cider apple imports to be released from quarantine.

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Karl, A.D., M.G. Brown, S. Ma, A. Sandbrook, A.C. Stewart, L. Cheng, A.K. Mansfield, and G.M. Peck. 2020. Foliar urea applications increase yeast assimilable nitrogen concentration and alcoholic fermentation rate in Red Spy apples used for cider production. HortScience 55(8):13561364. https://doi.org/10.21273/HORTSCI15029-20
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Karl, A.D., M.G. Brown, S. Ma, A. Sandbrook, A.C. Stewart, L. Cheng, A.K. Mansfield, and G.M. Peck. 2020. Soil nitrogen fertilization increases yeast assimilable nitrogen concentrations in Golden Russet and Medaille dOr apples used for cider production. HortScience 55(8):1345-1355. https://doi.org/10.21273/HORTSCI15028-20
• Type: Journal Articles Status: Submitted Year Published: 2021 Citation: Krisha Kumar, S., N.C. Wojtyna, L. Dougherty, K. Xu, and G.M. Peck. ND. Using the Ma1 gene as a principal component for future cider apple classification systems. The Journal of Horticultural Science and Biotechnology. (Submitted)
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Krishna Kumar, S., N.C. Wojtyna, L. Dougherty, K. Xu, and G.M. Peck. 2020. A genetic marker-based classification system for acidity in cider apples. HortScience 55(9):S324-325 (abstr.). (Poster)
• Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: Peck, G.M. 2020. Cidermaking in the orchard: elevating apple character before the press. CiderCon. Oakland, CA. 31 Jan. Attendees: 75.
• Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: Peck, G.M. and A. Karl. 2020. Influence of Nitrogen Fertilization on Tannin Synthesis, Yeast Assimilable Nitrogen, and Fermentation Kinetics. Empire State Producers Expo. Syracuse, NY. 15 Jan. Attendees: 37.
• Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: Knickerbocker, W. and G. Peck. 2020. Prospects for mechanical harvesting in NY cider orchards. Empire State Producers Expo. Syracuse, NY. 15 Jan. Attendees: 37.
• Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: Krishna Kumar, S., D. Zakalik, N. Wojtyna, M. Brown, and G. Peck. 2020. Cider apple germplasm diversity. CiderCon. Oakland, CA. 29-31 Jan. Attendees: 1,029.

Progress 10/01/18 to 09/30/19

Outputs
Target Audience:We expect our database to be a useful resource for scientists and extension educators who want to search for specific traits in the wide-range of cider apple cultivars available in the US. In particular, apple breeders and those interested in genetic resources will be able to utilize our phenotypic datasets for selecting breeding parents and/or identifying functional genes. Commercial apple growers and cider producers are the two primary stakeholder target audiences for this project. We also expect our results to also be utilized by non-commercial producers, such as those interested in growing rare and unusual apple trees. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?In July 2018, Mr. Shanthanu Krishna Kumar began his doctoral studies in my lab. Mr. Krishna Kumar earned a Master's degree from Guelph University and plans to study cider apple diversity and genetics in my lab. As part of this work, Mr. Krishna Kumar over saw the thirdyear (2019) of sampling from the USDA's Malus germplasm collection in Geneva, NY that is described in objective 1. This project has also provided five Cornell undergraduate students to participate in the Cornell Orchards Summer Internship. During this three-month internship, the students were involved in all aspects of orchard management from trellis construction to fruit thinning to tree training to harvesting. Many of these students aspire to further their education in graduate school studying subjects such as, horticulture, plant breeding, genetics, and soil science. How have the results been disseminated to communities of interest?My lab group has presented data from the projects funded by these Federal Capacity Funds at the following venues: Peck, G.M. 2019.Cornell Reunion Weekend. Cider science: it's about the apples. Liberty Hyde Bailey Lecture, Cornell University. Attendees: 35; 60 Min, 7 June. Peck, G.M. 2019. Chemotypic profiling of cider apples in the USDA's Malus germplasm collection. Metabolomics Symposium. Cornell University. 2 May. Attendees: 45. Peck, G.M. 2019. Cider science: it's about the apples. Cornell University, School of Integrative Plant Science-Horticulture Section Seminar Series. 11 Feb. Peck, G.M. 2019. Orchard planning for hard cider production. Mid-Atlantic Fruit and Vegetable Conference. Hershey, PA. 30 Jan. Attendees: 55. Peck, G.M. and S. Krishna Kumar. 2019. Cider Apple Diversity in the USDA Malus Germplasm Collection. Empire State Producers Expo. Syracuse, NY. Attendees: 35. Peck, G.M., N. Wojtyna, S. Krishna Kumar, D. Zakalik, M. Brown, and T. Chao. 2019. Cider apple diversity in the USDAMalusgermplasm collection. CiderCon. Chicago, IL. 8 Jan. Attendees: 85. Zakalik,D.*, M. Brown, C. Kahlke, and G. Peck. 2019. Fruit thinning reduces biennial bearing in hard-cider apple cultivars. CiderCon. Chicago, IL. 8-9 Jan. Attendees: 850. Comiskey, N.*, M. Brown, G. Peck. 2019. Managing pre-harvest drop and fruit maturity in cider apple cultivars for mechanical harvest. CiderCon. Chicago, IL. 8-9 Jan. Attendees: 850. Furthermore, we shared information about cider apple diversity at the "Science After Dark" event at the Ithaca Sciencenter (Ithaca, NY 2; Oct; Attnedees: 150), the Cornell Mann Library "A Celebration of Finger Lakes Cider" (Ithaca, NY; 3 Oct; Attendess: 100), and the Cornell Orchards Cider Week event "Cider Sunday" (Ithaca, NY; 6 Oct; 400 people). What do you plan to do during the next reporting period to accomplish the goals?Over the next 12 months, we plan to focus our attention on completing the juice analyses from Objective 1 and publishing the first peer-reviewed journal article based on this research project. We also plan to do additional metabolomic analyses of the USDA germplasm accessions to identify specific polyphenol compounds that are relevant to the cider industry.

Impacts
What was accomplished under these goals? Objective 1: To gain a greater understanding of the diversity of cider apples available in the United States, we have identified more than 330 genotypes in the United States Department of Agriculture-Plant Genetic Resources Unit (USDA-PGRU) Malus germplasm collection in Geneva, NY. Our goal is to categorize genotypes that have desirable and perhaps unique juice quality, but that are also productive in modern orchard systems. France, the United States, and the United Kingdom each represent about 25% of our sample set with the remaining accessions originating from 21 other countries. As measured by the Folin-Ciocalteu assay, total polyphenols in the apple juice samples from these accessions had a nearly 50-fold difference in concentration (0.1-4.86 g·L-1). Other important juice characteristics ranged greatly among genotypes and between years: soluble solid concentration (average 12.4; range 2.8- 21.5 °Brix), titratable acidity (average 4.79; range 0.26-22.9 g·L-1). Sucrose (32.3; 0-107 g·L-1), glucose (21.0; 3.8-74.4 g·L-1), fructose (63.1; 11.5-123.0 g·L-1) and sorbitol (10.4; .288-39.0 g·L-1). While greater diversity is beneficial from the standpoint of maintaining genetic resources and creating unique cider styles, it can be a challenge to new cider producers and apple tree nurseries to identify cultivars with the greatest chance for success in a given region. For this reason, our results should aid in determining genotypes to include in future cultivar evaluations. Objective 2:In 2018, Binet Rouge, Brown Snout, Ellis Bitter, and Harry Master's Jersey had the greatest yields. Binet Rouge, Brown's Apple, Brown Snout, Dabinett, Porter's Perfection, and Vilberie had the greatest soluble solid concentration. Brown's Apple, Dabinett, Ellis Bitter, Porter's Perfection, Tremlett's Bitter, and Vilberie has the greatest juice extraction. Total polyphenol data is still being analyzed. Taken together, these data suggest that growers will need to balance their desire for high yields with juice quality characteristics when planting new cider apple orchards. 2019 Data wascollected, but has not been analyzed or tabulated. Objective 3:All trees were grafted onto the disease resistant G.935 rootstock. The trees were planted 3 feet between trees and 12 feet between rows and are trained as a tall spindle in the spring of 2018. During 2019, we conducted tree training, fruit thinning, and maintained the trees with appropriate pest, disease, and weed control. Additionally, we recorded bloom dates for these cultivars in order to start a long-term database. We harvested a small amount of fruit from this trial in 2019 and expect to have our first complete harvest of all cultivars in 2020.

Publications

• Type: Journal Articles Status: Published Year Published: 2019 Citation: Ma, S., S. Kim, A.P. Neilson, L.E. Griffin, G.M. Peck, S.F. OKeefe, A.C. Stewart. 2019. Comparison of common analytical methods for the quantification of total polyphenols and flavanols in fruit juices and ciders. Food Science 84(8):2147-2158. https://doi.org/10.1111/1750-3841.14713
• Type: Journal Articles Status: Accepted Year Published: 2020 Citation: Miles, C.A., T.R. Alexander, G. Peck, S.P. Galinato, C. Gottschalk, and S. van Nocker. 2020. Growing apples for hard cider production in the U.S. - trends and research opportunities. HortTechnology
• Type: Conference Papers and Presentations Status: Awaiting Publication Year Published: 2019 Citation: Peck, G.M., D.L. Zakalik, and M.G. Brown. 2019. Cider apple germplasm diversity in the United States. HortScience (abstr.).
• Type: Websites Status: Published Year Published: 2019 Citation: https://hardcider.cals.cornell.edu
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Peck, G.M. 2019. Chemotypic profiling of cider apples in the USDAs Malus germplasm collection. Metabolomics Symposium. Cornell University. 2 May.

Progress 10/01/17 to 09/30/18

Outputs
Target Audience:Commercial apple growers and cider producers are the two primary target audiences for this project. However, we expect our results to also be utilized by non-commercial producers. Additionally, we expect our database to be a useful resource for other scientists and extension educators who want to learn more about the wide-range of cider apple cultivars available in the US. Changes/Problems:Some interruption in staffing has occurred. Mr. Wojtyna had originally planned to pursue his doctoral degree at Cornell but instead opted to complete his Masters and then follow other career options. Fortunately, Mr. Krishna Kumar has been able to continue working on this project. What opportunities for training and professional development has the project provided?These Federal Capacity Funds have provided training for two graduate students and five undergraduate students. Nathan Wojtyna successfully defended his Master's thesis in August 2018. During his studies, Nathan presented his research at professional meetings, such as the American Society for Horticultural Science and at industry meetings, such as CiderCon. Mr. Wojtyna is now employed as a high school science teacher. In July 2018, Mr. Shanthanu Krishna Kumar began his doctoral studies in my lab. Mr. Krishna Kumar earned a Master's degree from Guelph University and plans to study cider apple diversity and genetics in my lab. As part of this work, Mr. Krishna Kumar over saw the second year (2018) of sampling from the USDA's Malus germplasm collection in Geneva, NY that is described in objective 1. This project has also provided five Cornell undergraduate students to participate in the Cornell Orchards Summer Internship. During this three-month internship, the students were involved in all aspects of orchard management from trellis construction to fruit thinning to tree training to harvesting. Many of these students aspire to further their education in graduate school studying subjects such as, horticulture, plant breeding, genetics, and soil science. How have the results been disseminated to communities of interest?My lab group has presented data from the projects funded by these Federal Capacity Funds at the following venues: Peck, G.M. 2018. Cider apples varieties old and new: The state of cider apple plantings in New York. Heritage Apple Meeting. Finger Lakes Cider House. 13 Sept. Peck, G.M. 2018. Horticultural research on cider apples in New York State and overview of the NY cider industry. University of Guelph. Simcoe, ON. 27 Aug. Attendees: 75. Peck, G.M. 2018. Potential Impact of Climate Change in the Orchard. CiderCon. Baltimore, MD. 2 Feb. Attendees: 75. Peck, G.M. and W. Knickerbocker. 2018. Economic Case Studies of Cider Apple Orchards. Baltimore, MD. 2 Feb. Attendees: 100. Peck, G.M. and W. Knickerbocker. 2018. Enterprise Budgets for Cider Apple Orchards. New York Cider Association Annual General Meeting. Interlaken, NY. 26 Feb. Attendees: 53. Peck, G.M. and W. Knickerbocker. 2018. The Economics of Growing Cider Apples. Wisconsin Fruit and Vegetable Conference. Via live video feed. 22 Jan. Attendees: 90. Peck, G.M. 2018. Reflecting on England's Cider Orchards and How We Grow Cider Apples in NY. Empire State Producers Expo. Syracuse, NY. 18 Jan. Attendees: 51. Peck, G.M. 2017. The Science of Hard Cider. The West Family Lecture. Invited lecturer. The Cornell Club. New York City, NY. Cumulatively, we have presented data related to these Funds to more than 400 individuals over the past 12 months. We also published a paper in the Fruit Quarterly trade journal which discusses the economics of growing different cider apple genotypes under different types of orchard systems. This trade journal is read by a large number of industry stakeholders, extension specialists, and academics throughout the northeastern and midwestern US. What do you plan to do during the next reporting period to accomplish the goals?Over the next 12 months, we plan to focus our attention on completing the juice analyses from Objective 1 and publishing the first peer-reviewed journal article based on this research project. We also plan to do additional chromatographic analyses of the USDA germplasm accessions to identify specific polyphenol compounds that are relevant to the cider industry.

Impacts
What was accomplished under these goals? Objective 1: Phenotype accession at the USDA-PGRU to identify potential candidates for hard cider production. These extensive collections and breeding populations offer 1,000's of potential genotypes that may have superior horticultural and cider quality characteristics to currently used cider cultivars. Accomplishments: Nearly 158 accessions from the USDA-PGRU were phenotyped in 2017 and another 200 accessions were phenotyped in 2018. Fruit quality assessments included fruit weight, size, and shape, peel color, juice yield, sugar content (including, sucrose, fructose, glucose, and sorbitol), total acidity and pH, total polyphenol content, individual polyphenol composition, and yeast assimilable nitrogen concentration (important for yeast metabolism during fermentation). Samples from 2017 have been fully analyzed and the data has been analyzed. Fruit analyses have been completed for the 2018 samples, and juice quality analyses are underway. From the 2017 samples, we identified 49 bittersweet and 21 bittersharp genotypes that should be further evaluated for their suitability to perform in commercial orchards. In addition, the polyphenol composition of 14 genotypes was measured using ultra high-performance liquid chromatography and indicated that the variation in polyphenol levels measured by the Folin-Ciocalteu assay was largely due to procyanidins and phloretin compounds. Objective 2: Evaluate European cider cultivars that are currently available in the US and offer the fastest route to identifying bitter cider cultivars that are highly productive, adaptable to high-density orchard systems, contribute desired flavors to ciders, and are well suited for NY's climate. In 2015, a replicated cultivar trial was established at the Cornell Orchards in Ithaca, NY. Cultivars include: Binet Rouge, Brown Snout, Brown's Apple, Dabinett, Ellis Bitter, Harry Master's Jersey, Porter's Perfection, Tremlett's Bitter (Geneva Tremlett's), and Vilberie, each replicated four times in two-tree sets as a completely randomized block design. The trees are planted 3' between trees and 12' between rows and are trained as a tall spindle (a modern, high-density apple orchard system recommended by Cornell Cooperative Extension pomologists and that lends itself to mechanization). Some of the cultivars are started to bear fruit in 2017. We kept records of material and labor costs, detailing the time it takes to complete each task, so we can calculate the costs of establishment and of production. More thorough economic analyses will also be calculated as the project progresses through subsequent years, as will orchard productivity, which will be measured by tree trunk growth (TCSA), total yields, yield efficiency (yield/TCSA), and fruit size. Fruit and juice data collection and analysis from this trial will be like those listed for Objective 1. Objective 3: Import and test previously unavailable European cider cultivars. Two separate European cider cultivar importations have already occurred (Spain in 2004 and England in 2015). A third importation from France is slated for 2018. In 2004, 25 elite Spanish cultivars were imported into the U.S. These cultivars are officially designated cider cultivars in Asturias, the largest cider producing region in Spain. Relatively few Spanish cider apple cultivars are currently available in the US. Spanish cider (or sidra) tends to be more acidic and acetic than English and French ciders. Spanish cultivars will allow NY producers to explore new cider styles.In 2016, the first nine Spanish cider cultivars (Blanquina, Collaos, Cristalina, Coloradona, Marialena, Piel de Sapo, Raxao, Sangre de Toro, and Solarina) were released from USDA-APHIS quarantine. The extended quarantine period was due to repeated virus detections resulting in the need to propagate the cultivars from tissue culture. The nine cultivars were propagated by Wafler Nursery (Wolcott, NY) and, as of May 2018, have been planted in a replicated test planting similar to that described for Objective 2. The trees are expected to start bearing fruit in 2020. Data collection will follow similar procedures as to those outlined in Objective 1 and 2. Additional cultivars will be added as they are released from quarantine. The English cultivars include 17 releases from the Long Ashton Research Station known as "The Girls". These cultivars currently account for about 20% of the cider apple acreage in the UK. Until this importation these cider cultivars were unavailable in the U.S. Other UK imports include cultivars that are possibly not true to type, such as Foxwhelp and Tremlett's Bitter. The English cider cultivars will be available for field testing in 2020. Plantings and data collection for these cultivars will be like those outlined in Objective 2. The French importation is currently still underdevelopment as we wait for the Spanish and British cider apple imports to be released from quarantine.

Publications

• Type: Theses/Dissertations Status: Published Year Published: 20018 Citation: Wojtyna, N. 2018. Characterization of Malus genotypes within the USDA-PGRU Malus germplasm collection for their potential use within the hard cider industry. MS Thesis, Cornell University, Ithaca, NY.
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Peck, G.M. 2018. Hard cider research. Great Lakes Fruit Workers Meeting. Ithaca, NY. 1 pp.
• Type: Conference Papers and Presentations Status: Awaiting Publication Year Published: 2018 Citation: Peck, G.M. 2018. Developing integrated programs for the emerging hard cider industry. HortScience (In Press).
• Type: Conference Papers and Presentations Status: Awaiting Publication Year Published: 2018 Citation: Wojtyna, N.C., M.G. Brown, C.T. Chao, and G.M. Peck. 2018. Characteristics of 180 hard cider apple genotypes in the USDA-PGRU Malus germplasm collection. HortScience (In Press).
• Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: Wojtyna, N. and G.M. Peck. 2018. Phenotyping the USDA-PGRU Malus Germplasm Collection for novel apples to use in hard cider production. CiderCon. Baltimore, MD.
• Type: Other Status: Published Year Published: 2018 Citation: Peck, G.M. and W. Knickerbocker. 2018. Economic case studies of cider apple orchards in New York State. New York Fruit Quarterly 26(3):5-10.