PRODUCTION AND DELIVERY OF HIGH QUALITY STONE FRUIT

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: TERMINATED
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 0153966
• Project No.: CA-D-PLS-5366-H
• Project Start Date: Oct 1, 2009
• Project End Date: Sep 30, 2014

Project Director
Crisosto, C.

Recipient Organization
UNIVERSITY OF CALIFORNIA, DAVIS
410 MRAK HALL
DAVIS,CA 95616-8671

Performing Department
Plant Sciences

Non Technical Summary
The California peach, nectarine, and plum industry has seen demand increasing in the domestic as well as overseas markets for flavorful fresh fruit. Thus, the production and marketing of fresh stone fruits has increased rapidly. However, despite all of the information on the health benefits of eating fruits and vegetables, consumption is low for peaches, nectarines and plums at approximately 2.0, 4.5, and 2.5 pounds of fruit per capita, and has even been decreasing in the last decade. This has led us to evaluate the potential for improving the consumer quality by selecting new flavorful cultivars, advancing the maturity, and developing postharvest technologies to express consumer quality and/or protect flavor during handling of fruits packed in large volume operations. During our last 12 years, we learned that the loss of flavor quality due to ?off flavor? development and changes in texture due to chilling injury during postharvest handling are very important in explaining the low consumer acceptance. Due to globalization, high local production, and a slow market, ?sensory damaged? fruit which reduce consumption are available in the market and compete with sound commodities. A recent intensive consumer quality survey (1,552 consumers) indicated that lack of taste (?sensory damaged?), softening, and spoilage are the main barriers restricting California peach, nectarine and plum purchasing in the USA market (Sterling-Rice Group, 2006). Since major sensory quality problems (softening and unfavorable taste or lack of taste) occur during postharvest handling, the production and delivery of flavorful fruit, and prevention of these postharvest quality losses during the cold chain, could be an approach to improve tree fruit consumption. Traditionally, postharvest physiologists have focused on harvest maturity as their starting point; many ?orchard factors? profoundly influence the postharvest performance of the fruit. For these reasons, our research also included investigating how orchard factors influence stone fruit postharvest quality, storage and handling performance, and consumer preferences.

Animal Health Component

(N/A)

Research Effort Categories

Basic

(N/A)

Applied

(N/A)

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
201	1199	1020	15%
204	1219	1060	25%
503	1199	1080	50%
504	1060	3090	10%

Knowledge Area
504 - Home and Commercial Food Service; 204 - Plant Product Quality and Utility (Preharvest); 503 - Quality Maintenance in Storing and Marketing Food Products; 201 - Plant Genome, Genetics, and Genetic Mechanisms;

Subject Of Investigation
1199 - Deciduous and small fruits, general/other; 1219 - Edible tree nuts, general/other; 1060 - Kiwi;

Field Of Science
1080 - Genetics; 3090 - Sensory science (human senses); 1020 - Physiology; 1060 - Biology (whole systems);

Keywords

fruit consumption

consumer preferences

consumption barriers

consumer quality

preharvest factors

sensory tools

genotypes

postharvest treatment

Goals / Objectives
-Establish a sensory evaluation tool to evaluate pre and postharvest technology on consumer perception. -Select cultivars based on the consumer perception of their organoleptic attributes. -Identify new stone fruit cultivars that produce tasty fruit with high shipping life potential. -Understand orchard factors such as rootstock, canopy management, fertilization, and irrigation. -Test performance of new postharvest innovation technologies and their impact on consumer preference at the retail level.

Project Methods
-Establish a sensory evaluation tool to evaluate pre and postharvest technology on consumer perception. The creation of a trained panel for testing postharvest technology changes will be established according to current standards. Descriptive analysis will be used to describe sensory damaged fruit such as soft, mealy, 'off flavor' or texture changes in fruit treated and untreated during postharvest handling. At the same time, 'in store' and in home consumer panels will be carried out according to our previous work. The sensory data will be analyzed using preference mapping (descriptive and consumer panels) to characterize the impact of these sensory attributes on consumer consumption. In addition, to determine the impact of these sensory attributes on consumer perception, a relationship between the trained panel and consumer acceptance will be tested. In this way, in the future our trained panel can be used to screen out preliminary pre-postharvest treatments prior to a full consumer evaluation and/or economic impact at the market place. As a final step, evaluation of the economic impact of these innovative postharvest treatments on current 'sensory damaged' commodities and fruit consumption during the cold chain will be carried out. These two sensory techniques will be used to evaluate the impact of these sensory damaged attributes on consumer acceptance and preferences. -Identify new stone fruit cultivars that produce tasty fruit with high shipping life potential. Approximately 15 cultivars chosen for their different genotype source and sensory characteristics will be used to determine the sensory attributes ('loss of flavor') during postharvest handling that are related to consumer acceptance/rejection. A market life concept will be derived from the appearance of sensory defects during cold storage handling. Then, fruit will be exposed to real world postharvest handling conditions that will be selected based on our previous domestic and overseas cold chain evaluations. -Understand orchard factors such as rootstock, canopy management, fertilization, and irrigation. We will be taking advantage of well established research plots led by Dr. Ted DeJong at the Kearney Agricultural Center. Right now, we are evaluating storage performance of fruit from the low potassium, low nitrogen, low phosphorous and untreated treatment from the fertilization sand tank project. Evaluation of physiological potential and antioxidant capacity are being evaluated during cold storage. -Test performance of new postharvest innovation technologies and their impact on consumer preference at the retail level. We will evaluate innovation postharvest techniques to improve tree fruit condition at arrival and shelf-life performance. Novel approaches would include the use of 1-MCP, improved temperature management during transportation, modified atmosphere packaging, abscisic acid (ABA) and methyl jasmine (MJ). Barriers to adoption of these innovative postharvest techniques will be documented throughout the produce supply chain including growers/shippers, distributors, and retailers.

Progress 10/01/09 to 09/30/14

Outputs
Target Audience: My target audiences include our stakeholders, California fresh fruit growers, packers, shippers commission organizations, packers, shippers, handlers, peers, transportation personnel, importers, exporters, the produce industry, breeders, retail chains, food service outlets, restaurants and consumers. Because of the knowledge developed during the execution of this program, my clientele was extended to out of state and international working on at any step of the fresh & nuts postharvest handling. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? During the project we trained master students, undergrad students, visitors and industry cooperators. How have the results been disseminated to communities of interest? In cooperation to my postharvest peers our information has been disseminated in our outreach classes such as: Fruit Ripening & Retail Handling Workshop, Postharvest Technology of Horticultural Crops Short Course, and Postharvest Technology of Horticultural Crops Short Course In cooperation to my pomologist peers our information has been included in the following outreach programs: Advances in Pistachio Production Course, Advances in Walnit Production Course, Advances in Almond Production Course and Principles of Fruit & Nut Tree Growth Cropping & Management What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Publications in referee journals and extension publications posted in web sites and newsletters are being distributed. Information has been extended in several growers, retails, and academic meetings. We are creating join ventures with selected companies to demonstrate in a commercial scale the benefits of our findings next season, will be able to document the impact of our work. One of our project results is being illustrated by UC as an example of our impact in the CA industry (dhttp://ucdavis.edu/one/california/#news).

Publications

• Type: Journal Articles Status: Published Year Published: 2010 Citation: Iezzoni A, Peace C, Weebadde C, Luby J, Yue CY, Bassil N, Bink M, Brown S, Byrne D, Clark J, Crisosto, C, Davis T, Evans K, Fazio G, Finn C, Gallardo K, Gasic K, Gradziel T, Hancock J, Jussaume R, Luby J, Main D, McCracken V, Oraguzie N, Reighard G, Stone A, Taylor M, van de Weg E, Wang D, and Xu K. 2010. RosBREED: Enabling marker-assisted breeding in Rosaceae. Acta Horticulturae 859: 389-394.
• Type: Journal Articles Status: Published Year Published: 2011 Citation: Martinez-Gomez, P., C.H. Crisosto, C. Bonghi, and M. Rubio. 2011. New approaches to Prunus transcriptome analysis. Genetica. Doi:10.1007/s10709-011-9580-2.
• Type: Journal Articles Status: Published Year Published: 2011 Citation: Dagar, A., H. Friedman, S. Lurie, C.H. Crisosto, C.M. Ibanez, C.P. Puig, and A. Granell. Utilization of ChillPeach Microarray Platform for Comparing Chilling Injury-Susceptible `Hermoza' and Chilling Injury-Resistant `Oded' Peaches. Acta Hort.) 945:337-343
• Type: Journal Articles Status: Published Year Published: 2010 Citation: Karabulut, O.A., J.L. Smilanick, C.H. Crisosto and L. Palou. 2010. Control of brown rot of stone fruits by brief heated water immersion treatments. Crop Protect. 29:903-906.
• Type: Journal Articles Status: Published Year Published: 2011 Citation: Crisosto, C.H., L. Ferguson, V. Bremer, E. Stover, and G. Colelli. 2011. Fig (Ficus carica L.). In: Postharvest biology and technology of tropical and subtropical fruits, Vol 3: Cocona to mango. (ed.) Elhadi M. Yahia. Woodhead Pub., Cambridge. Pp. 134-158.
• Type: Books Status: Published Year Published: 2011 Citation: Ahmad, R., D. Parfitt, J. Fass, E. Ogundiwin, A. Dhingra, T. Gradziel, D. Lin, N. Joshi, PJ Mart�nez-Garc�a, C. Crisosto. Whole genome sequencing of peach (Prunus persica L.) for SNP identification and selection. 2011. BMC Genomics 2011, 12:569. DOI: 10.1186/1471-2164-12-569.
• Type: Journal Articles Status: Published Year Published: 2011 Citation: Martinelli, Federico, C.H. Crisosto, and A. Dandekar. 2011. Genomics of Fruit Quality and Disorders. Chapter 8. Omics Technologies: Tools for Food Science. K11677_C008.indd.
• Type: Journal Articles Status: Published Year Published: 2012 Citation: Martinez-Garcia, PJ, D. Parfitt, E. Ogundiwin, J. Fass, H. Chan, R. Ahmad, S. Lurie, A. Dandekar, T. Gradziel, C. Crisosto. 2012. High Density SNP Mapping and QTL Analysis for Fruit Quality Characteristics in Peach (Prunus persica L.). Tree Genetics and Genomes. DOI 10.1007/s11295-012-0522-7.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Mart�nez-Garc�a, P.J., J. Fresnedo-Ram�rez, D.E. Parfitt, T.M. Gradziel, C.H. Crisosto. 2013. Effect prediction of identified SNPs linked to fruit quality and chilling injury in peach [Prunus persica (L.) Batsch]. Plant Mol. Biol. 81:161-174.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Mart�nez-Garc�a, P.J., D.E. Parfitt, E.A. Ogundiwin, J. Fass, H.M. Chan, R. Ahmad, S. Lurie, A. Dandekar, T.M. Gradziel, and C.H. Crisosto. 2013. High density SNP mapping and QTL analysis for fruit quality characteristics in peach (Prunus persica L.). Tree Genetics & Genomes 9:19-36.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Dhanapal, A.P. and C.H. Crisosto. 2013. Association genetics of chilling injury susceptibility in peach [Prunus persica (L.) Batsch] across multiple years. 3 Biotech.
• Type: Journal Articles Status: Published Year Published: 2009 Citation: Palou, L., J.L. Smilanick, and C.H. Crisosto.� 2009.� Evaluation of food additives as alternative or complementary chemicals to conventional fungicides for the control of major postharvest diseases of stone fruit.� Journal of Food Protection 72:1037-1046.
• Type: Books Status: Published Year Published: 2009 Citation: Ogundiwin, E.A., C.P. Peace, T.M. Gradziel, D.E. Parfitt, F.A. Bliss, and C.H. Crisosto. 2009. A fruit quality gene map of Prunus. BMC Genomics. 10:587. doi:10.1186/1471-2164-10-587.
• Type: Journal Articles Status: Published Year Published: 2010 Citation: Crisosto, C. H., V. Bremer, M. Norton, L. Ferguson and T. Einhorn. 2010. Preharvest Ethephon Eliminates First Crop Figs. HortTechnology 20(1), Jan.-Mar.

Progress 01/01/13 to 09/30/13

Outputs
Target Audience: My target audiences include our stakeholders, California fresh fruit growers, packers, shippers commission organizations, packers, shippers, handlers, peers, transportation personnel, importers, exporters, the produce industry, breeders, retail chains, food service outlets, restaurants and consumers. Because of the knowledge developed during the execution of this program, my clientele was extended to out of state and international working on at any step of the fresh & nuts postharvest handling. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Eight master and two PhD students completed their thesis research as part of the project's activities with two additional PhD students are scheduled to complete their programs in 2014. Three theses have been published and journal articles have also been published and submitted. The students had opportunities to present their research to our stakeholder group and professional meetings and have gained experience in technical writing. How have the results been disseminated to communities of interest? In addition to our active outreach program, our information generated from this project contributes to the creation and delivery of our UC Davis Produce Professional Certificate. The Postharvest Technology Center is pleased to introduce the Produce Professional Certificate Program. This first-of-its-kind certificate offers a combination of in-person and online educational components in an a-la-carte system that allows participants to focus on areas of interest. The following courses that I have been actively involved are part of this new program: Emerging Postharvest Technologies Workshop, 1st Annual. This compact and interactive workshop will be held on the UC Davis campus. Fruit Ripening & Retail Handling Workshop 19th Annual. This workshop will be held in on the UC Davis campus. Postharvest Technology Short Course 35th Annual. This course will be held on the UC Davis campus, and includes lectures, labs and field trips. Principles of Fruit & Nut Tree Growth, Cropping & Management Short Course (First, Second and Third) This short course is focused on fruit & nut tree biology, and how it relates to orchard management.. Understanding the fundamentals of tree biology is essential to making sound orchard management and business decisions in the tree fruit and nut industry. However, access to educational courses on basic fruit and nut tree biology, and how it relates to agronomic practices, is limited. Our course incorporates lecture, lab exercises, and field demonstrations to provide information on all aspects of basic plant biology and the relationship between plant biology and orchard management. Our course includes nine full days of instruction. The first five days will be held on the UC Davis campus and include lecture, laboratory exercises, and field demonstrations. The following week we will embark upon a four-day field trip throughout fruit and nut tree growing regions of Northern and Central California. Web Sites: http:www.plantsciences.ucdavis.edu/PlantSciences_Faculty/crisosto http://fruitsandnuts.ucdavis.edu/ http://postharvest.ucdavis.edu/ What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Under this project umbrella, we partnered with fresh fruit industry innovators to introduce new systems or technology. For example our peach preconditioning delivery system became standard way to handle tree fruit for our industry and worldwide. A recent article claims that 80% of our industry is using this UC Davis new peach delivery system. (http://westernfarmpress.com/orchard-crops/warmerdam-family-embraces-peach-ripening-program). As acknowledgment for my long time activities, I was selected for the California Peach Flavor Innovation Award as a special recognition for my novel postharvest work and constant efforts to educate growers, shippers and retailers to deliver juicier, flavorful and riper California Peaches, Nectarines and Plums to consumers. Ripening protocols for Kiwifruit, stone fruits. Minimum Quality Standards Selection of high quality fresh fig cultivars Registration of GRAS fungicides for figs and pomegranates Development of organic alternatives to fungicides

Publications

• Type: Journal Articles Status: Published Year Published: 2012 Citation: Palou, Ll., J.L. Smilanick, C.H. Crisosto. 2012. Evaluation of Food Additives and Low-Toxicity Compounds as Non-polluting Means to Control the Main Postharvest Diseases of California Peaches. Acta. Hort. 962, ISHS 2012.
• Type: Journal Articles Status: Awaiting Publication Year Published: 2013 Citation: Slaughter, D.C. C.H. Crisosto, G.Tiwari. 2013. Nondestructive determination of flesh color in clingstone peaches. Journal of Food Engineering. doi:10.1016/j.jfoodeng.2013.01.007. (in-press).
• Type: Journal Articles Status: Published Year Published: 2012 Citation: Frett, T.J., K. Gasic, J.R. Clark, D. Bryne, T. Gradziel, and C. Crisosto. 2012. Standardized phenotyping for fruit quality in peach [Prunus persica (L.) Batsch]. Journal of American Pomological Society 66:214-219.
• Type: Journal Articles Status: Published Year Published: 2012 Citation: Ferguson, L. K. Glozer, C. Crisosto, U.A. Rosa, S. Castro-Garcia, E.J.Fichtner, J.X. Guinard, S.M. Lee, W.H. Krueger, J.A. Miles, J.K Burns. 2012. Publications 14. Improving canopy contact olive harvester efficiency with mechanical pruning. Acta Horticulturae 965:83-88.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Cano-Salazar, J., M.L L�pez, C.H. Crisosto, G. Echeverr�a. 2013. Volatile compound emissions and sensory attributes of 'Big Top' nectarine and 'Early Rich' peach fruit in response to a pre-storage treatment before cold storage and subsequent shelf-life. Postharvest Biology and Technology 76:152-162.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Haug, M.T., E.S. King, H. Heymann, and Carlos H. Crisosto. 2013. Sensory profiles for dried fig (Ficus carica L.) cultivars commercially grown and processed in California. J. Food Sci. 78: S1273-S1281.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Kong, M., B. Lampinen, K. Shackel, and C.H. Crisosto. 2013. Fruit skin side cracking and ostiole-end splitting shorten postharvest life in fresh figs (Ficus carica L.), but are reduced by deficit irrigation. Journal of Food Engineering 154-161. 85.View this Article
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Minas, I.S., G.M. Crisosto, D. Holcroft, M. Vasilakakis, C.H. Crisosto.2013. Postharvest handling of plums (Prunus salicina Lindl.) at 10�C to save energy and preserve fruit quality using an innovative application system of 1-MCP. Postharvest Biology and Technology 76:1-9.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Slaughter, D.C. C.H. Crisosto, G.Tiwari. Nondestructive determination of flesh color in clingstone peaches. Journal of Food Engineering 116:920-925.139. 2013 Dagar, A., C. Pons Puig, C. Marti Ibanez, F. Ziliotto, C. Bonghi, C.H. Crisosto, H. Friedman, S. Lurie, A. Granell. Comparative transcript profiling of a peach and its nectarine mutant at harvest reveals differences in gene expression related to storability. Tree Genetics & Genomes 9:223-235.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Delgado, C., G.M. Crisosto, H. Heymann, and C.H. Crisosto. 2013. Determiningthe primary drivers of liking to predict consumers' acceptance of fresh nectarines and peaches. J. Food Sci. 78: S605-S614.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Salazar, J.A., D. Ruiz, J.A. Campoy, R. S�nchez-P�rez, C.H. Crisosto, P.J. Mart�nez-Garc�a, A. Blenda, S. Jung, D. Main, P. Mart�nez-G�mez and M Rubio. Quantitative Trait Loci (QTL) and Mendelian Trait Loci (MTL) Analysis in Prunus: A breeding perspective and beyond. Plant Molecular Biology Reporter.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Minas, I.S., G.M. Crisosto, K.R. Day and C.H. Crisosto. 2013. Forced-air cooling reduces 1-MCP application duration on plums (Prunus salicina Lindl.) without reducing effectiveness. Acta. Hort. 985:257-259.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Cano-Salazar, J. L. Lopez, C.H. Crisosto, G. Echeverria. 2013. Cold storage of six nectarine cultivars: consequences for volatile compounds emissions, physiochemical parameters, and consumer acceptance. European Food Research and Technology, 237: 571-589.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Johnson, R.S., A. Olivos, Q. XiaoQiong, C. Crisosto and T. Michilaides. 2013. Proper nectarine nutrition improves fruit quality. Better Crops with Plant Food 97(3):11-13. Better Crops with Plant Food.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Teles, Cesar., Benedetti, C. FD. Gubler and C. H. Crisosto. Prestorage application of high carbon dioxide combined with controlled atmosphere storage as a dual approach to control Botrytis cinerea in organic 'Flame Seedless' and 'Crimson Seedless' table grapes 2013.Postharvest Biology and Technology S0925-5214(13)00314-110.1016/ j.postharvbio.2013.11.001.
• Type: Book Chapters Status: Published Year Published: 2009 Citation: 2009 Vicente, A.R., G.A. Manganaris, G.O. Sozzi and C.H. Crisosto: Nutritional quality of fruits and vegetables, Chapter 5, pp. 57-106. In: Florkowski, Shewfelt, Brueckner and Prussia (eds.) Postharvest Handling: A Systems Approach, Second Edition. Oxford: Academic Press, Elsevier.
• Type: Book Chapters Status: Published Year Published: 2011 Citation: 2011 Aked, J., C. Chervin, and C.H. Crisosto: Grapes, Chapter 9, pp. 187-211. In: Wiley Blackwells (ed.), Volume 3: Perishables Crop Post-harvest: Science and Technology.
• Type: Book Chapters Status: Published Year Published: 2011 Citation: 2011 Crisosto, C.H., L. Ferguson, V. Bremer, E. Stover, and G. Colelli: Fig (Ficus carica L.), In: Postharvest biology and technology of tropical and subtropical fruits, Vol 3: Cocona to mango. (ed.) Elhadi M. Yahia. Woodhead Pub., Cambridge. Pp. 134-158.
• Type: Book Chapters Status: Published Year Published: 2011 Citation: 2011 Crisosto, C.H., L. Ferguson, and G. Nanos: Olive (Olea europeaea L.), In: Postharvest biology and technology of tropical and subtropical fruits, Vol 4: Mangosteen to white sapote. (ed.) Elhadi M. Yahia. Woodhead Pub., Cambridge. Pp.63-84.
• Type: Book Chapters Status: Published Year Published: 2011 Citation: 2011 Crisosto, C.H. and K.R. Day: Stone Fruit, Chapter 10, pp. 212-225. In: Wiley Blackwells (ed.), Volume 3: Perishables Crop Post-harvest: Science and Technology.
• Type: Book Chapters Status: Published Year Published: 2011 Citation: 2011 Martinelli, Federico, C.H. Crisosto, and A. Dandekar: Genomics of Fruit Quality and Disorders, Chapter 8. Omics Technologies: Tools for Food Science. K11677_C008.indd.
• Type: Book Chapters Status: Published Year Published: 2012 Citation: 2012 Hummer K.E., Pomper, K.W., Postman, J.D., Graham, C.J., Stover, E., Mercure, E.W., Aradhya, M., Crisosto, C.H., Ferguson, L., Thompson, M.M., Byers, P., and F. Zee: Emerging Fruit Crops, Chapter 4, pp.97-147. In: (M. L. Badenes and D.H. Byrne, eds.). Fruit Breeding. Springer, NY, NY. 875 pp.
• Type: Book Chapters Status: Awaiting Publication Year Published: 2014 Citation: Vicente, A.R., GA Manganaris, CM Ortiz, GO Sozzi, CH Crisosto: Nutritional Quality of Fruit and Vegetables. 2014. Chapter 5, pp 57-106. In:Florkowski, Shewfeit, Brueckner and Prussia (eds.) Postharvest Handling: A Systems Approach, Second Edition. Oxford: Academic Press, Elsevier.

Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: A generic descriptive analysis using 11 judges provided 16 sensory attributes that described the aroma, flavor, and texture characteristics of seven nectarine and peach cultivars selected for their predominant sensory attributes. Simultaneously, the 'in-store' acceptability of these cultivars was evaluated by 120 consumers from northern California. The relationships among instrumental measurements (flesh firmness, ripe soluble solids concentration (RSSC), and ripe titratable acidity (RTA)), sensory panel descriptors, and consumer hedonic responses were studied. In these cultivars, RSSC was the only instrumental measurement significantly related to overall liking. Cultivars with medium acidity and/or flavor-aroma were liked "very much", and consumer willingness to pay more was correlated with overall liking without regard to cultivar. External preference mapping revealed three clusters that were associated with ethnicity and consumer preferences within each cluster. Sweetness was the main driver of liking for two consumer clusters; however, for the third cluster, the perception of fruit aromas described as grassy/green fruit and pit aromas were the main drivers of liking. There was a high correlation between instrumental measurements and their sensory perception; however, the sensory attribute measurements explained cultivar characteristics better than instrumental measurements alone. Sweetness correlated positively with overall liking and consumer acceptance. In an approach to protect fruit quality during postharvest handling, 1-Methylcyclopropene (1-MCP) inhibits softening in plums, making it a candidate for a postharvest strategy of storing fruit at higher than normal storage temperatures to avoid chilling injury (CI) while providing energy and cost savings. This hypothesis was tested by exposing different Japanese plum cultivars to 0.5 _L L−1 1-MCP at 0 ◦C for 24 h. Following 1-MCP treatment, fruit were stored at 0 or 10 ◦C for 10, 20, or 30 d, respectively. A new application technology was tested by applying 1-MCP during forced-air cooling (FAC), reducing the application duration from 24 to 6 h without affecting treatment performance. This new 1-MCP application system is compatible with current postharvest handling, rendering it easily adopted by the tree fruit industry. 1-MCP had no detrimental effect on consumer acceptance of low-acid plums ripened properly prior to consumption, but it reduced the acceptance of high acidity plums. Thus, 1-MCP use on plums should avoid cultivars with high acidity and/or plums picked early when fruit have titratable acidity of 0.9% or more. 1-MCP-FAC treatment followed by storage at 10 ◦C is a promising new methodology to avoid chilling temperatures and provide considerable energy savings without reducing postharvest life and consumer quality of low-acid plums. Our results encourage testing this new technology at commercial scale to accurately quantify energy savings and consumer reactions for specific operations and markets. PARTICIPANTS: Dr. Claudia Delgado and Ms. Gayle Crisosto (Plant Sciences Department, University of California, Davis) were coordinating our sensory work. Dr. Hildegar Heyman at the Enology and Viticulture Department was advising on all aspects of descriptors sensory work. Training. Ms. Megan Haug, Ms. Jenifer Orsi, and Mr. Andres Olivos obtained their master degrees working and contributing to our program and Mr. Ioannis Minas his PhD degree. Dr. Jorge Zegbe spent their sabbatical period working on our kiwifruit quality project. TARGET AUDIENCES: Information from our program is being disseminated to all segments of the academia and produce industry through our current UC Davis postharvest and Kearney Agricultural programs. Our outreach to consumers will make use of existing programs, task forces, and interagency working groups that our project collaborators are already associated with such as California Tree Fruit organizations, etc. Our UC postharvest group will conduct a series of hands-on, audience specific, targeted extension education activities, which will include workshops, distance education and associated written materials. Referee papers, outreach materials and summary articles developed will be disseminated via existing academic meetings, well-known industry, webinars, and public websites and trade publications. These educational outreach activities will also include participation by undergraduate and graduate students to gain experience in understanding challenges and opportunities facing the specialty crops industry as well as in-depth understanding of cutting edge technologies to assist in problem solving. We propose to involve students (under faculty supervision) and visitors in the demonstration aspects of these courses. These educational outreach activities will be updated and refined as data from the project subsequently becomes available. The first set of general courses will be offered late in year one and early in year two on the UC Davis and CSU Fresno campuses. PROJECT MODIFICATIONS: As we detected that the low consumption problem is related to flavor loss perception after a short marketing period, rather than the "complex peach flavor characteristics" at harvest, we changed our program focus to flavor loss (taste and volatiles) during marketing.

Impacts
Development of drivers of liking for fresh peaches and nectarines in order to understand consumer preferences for these fruits. This information can be used by postharvest researchers to evaluate the potential of new postharvest technologies and consumer acceptance and for plant breeders to develop new cultivars with desirable sensory attributes driven by the consumer. Considerable energy can be saved by cooling and storing 1-MCP-treated plums at 10 ◦C, without reducing postharvest life or fruit quality. The proposed 1-MCP application protocol during the forced-air cooling operation reduced the application duration to 6 h without affecting postharvest performance of plums or interrupting handling operations. Thus, this novel 1-MCP-FAC application method can replace the currently recommended 24 h application and would be easily adopted by the tree fruit industry. 1-MCP treatment had no detrimental effect on consumer acceptance of properly ripened, low-acid plums, but significantly reduced acceptance of high-acid or early-harvested plums. Our results are sufficiently encouraging to justify large-scale commercial testing to accurately quantify energy savings and consumer reactions for specific operations and markets.

Publications

• Aked, J., C. Chervin, and C.H. Crisosto. 2011. Grapes. Chapter 9, pp. 187-211. In: Wiley Blackwells (ed.), Volume 3: Perishables Crop Post-harvest: Science and Technology.
• Crisosto, C.H., L. Ferguson, and G. Nanos. 2011. Olive (Olea europeaea L.). In: Postharvest biology and technology of tropical and subtropical fruits, Vol 4: Mangosteen to white sapote. (ed.) Elhadi M. Yahia. Woodhead Pub., Cambridge. Pp.63-84.
• Crisosto, C.H. and K.R. Day. 2011. Stone Fruit. Chapter 10, pp. 212-225. In: Wiley Blackwells (ed.), Volume 3: Perishables Crop Post-harvest: Science and Technology.
• Hummer K.E., Pomper, K.W., Postman, J.D., Graham, C.J., Stover, E., Mercure, E.W., Aradhya, M., Crisosto, C.H., Ferguson, L., Thompson, M.M., Byers, P., and F. Zee. 2012. Emerging Fruit Crops. Chapter 4, pp.97-147. In: (M. L. Badenes and D.H. Byrne, eds.) Fruit Breeding. Springer, NY, NY. 875 pp.
• Olivos, A., S. Johnson, Q. Xiaoqiong, and C.H. Crisosto. 2012. Fruit Phosphorous and Nitrogen Deficiencies Affect 'Grand Pearl' Nectarine Flesh Browning. HortScience 47(3):391-394.
• Cantin, C.M., I.S. Minas, V. Goulas, M. Jimenez, G.A. Manganaris, T.J. Michailides, C.H. Crisosto. 2012. Sulfur dioxide fumigation alone or in combination with CO2-enriched atmosphere extends the market life of highbush blueberry fruit. Postharvest Biology and Technology 67:84-91.
• Crisosto, G., J.K. Hasey, J.A. Zegbe, C.H. Crisosto. 2012. New quality index based on dry matter and acidity proposed for Hayward kiwifruit. California Agriculture 66(2):70-75. DOI: 10.3733/ca.v066n02p70. April-June 2012.
• Minas, I.S., G.M. Crisosto, D. Holcroft, M. Vasilakakis, C.H. Crisosto. 2013. Postharvest handling of plums (Prunus salicina Lindl.) at 10 C to save energy and preserve fruit quality using an innovative application system of 1-MCP. Postharvest Biology and Technology. 76:(2013)1-9.
• King, E.S., H. Hopfer, M.T. Haug, J.D. Orsi, H. Heymann, G.M. Crisosto, and C.H. Crisosto. 2012. Describing the Appearance and Flavor Profiles of Fresh Fig (Ficus carica L.) Cultivars. Journal of Food Science. Vol. 77, Nr. 12, 2012. doi:10.1111/j.1750-3841.2012.02994.x.

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: We made progress in 2areas of work within this project scope: Determining the primary drivers of liking to predict consumer acceptance of fresh nectarines and peaches. A generic descriptive analysis using 11 judges provided 16 sensory attributes that described the aroma, flavor, and texture characteristics of 7 nectarine and peach cultivars selected for their predominant sensory attributes. Simultaneously, the 'in-store' acceptability of these cultivars was evaluated by 120 consumers from Nor. Calif. The relationships among instrumental measurements (flesh firmness, RSSC, and RTA), sensory panel descriptors, and consumer hedonic responses were studied. In these cultivars, RSSC was the only instrumental measurement significantly related to overall liking. Cultivars with medium acidity and/or flavor-aroma were liked "very much", and consumer willingness to pay more was correlated with overall liking without regard to cultivar. External preference mapping revealed 3 clusters that were associated with ethnicity and consumer preferences within each cluster. Sweetness was the main driver of liking for two consumer clusters; however, for the 3rd cluster, the perception of fruit aromas described as grassy/green fruit and pit aromas were the main drivers of liking. There was a high correlation between instrumental measurements and their sensory perception; however, the sensory attribute measurements explained cultivar characteristics better than instrumental measurements alone. Sweetness correlated positively with overall liking and consumer acceptance. Postharvest handling of plums (Prunus salicina L.) at 10 oC to save energy and avoid cold storage disorders using a novel application of 1-MCP 1-Methylcyclopropene (1-MCP) inhibits softening in plums, making it a candidate for a postharvest strategy of storing fruit at higher than normal storage temperatures to avoid chilling injury temperatures while providing energy and cost savings. This hypothesis was tested by exposing different Japanese plum (Prunus salicina L.) cultivars to 0.5 L L-1 1-MCP for 24 h at 0 oC. Following 1-MCP treatments, fruit were stored at 0 or 10 C for 10, 20, and 30 days. A new application technology was tested by applying 1-MCP during forced-air cooling (FAC), reducing the application time from 24 h to 6 h without affecting treatment performance. This new 1-MCP application system is compatible with current postharvest handling, making it easily adopted by the tree fruit industry. 1-MCP had no detrimental effect on consumer acceptance of low acidity plums ripened properly prior to consumption, but it reduced the acceptance of high acidity plums significantly. Thus, 1-MCP use on plum should avoid cultivars with high acidity and/or plums picked early when fruit have titratable acidity of 0.9% or more. For low-acid plums, 1-MCP-FAC treatment followed by storage at 10 C is a promising new methodology to avoid chilling temperatures and provide considerable energy saving without reducing postharvest life and consumer quality. Results encourage testing new technology at commercial scale to accurately quantify energy savings and consumer reactions for specific operations and markets. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Publications in referee journals and extension publications posted in web sites and newsletters are being prepared. For now, information has been extended in several growers, retails, and academic meetings. We are creating join ventures with selected companies to demonstrate in a commercial scale the benefits of our findings next season, will be able to document the impact of our work.

Publications

• Dagar, A., A. Weksler, H. Friedman, E.A. Ogundiwin, C.H. Crisosto, R. Ahmad and S. Lurie. 2011. Comparing ripening and storage characteristics of 'Oded' peach and its nectarine mutant 'Yuval'. Postharvest Biology and Technology 60:1-6. Doi:10.1016/j.postharvbio.2010.11.002.
• Crisosto, C. H., V. Bremer, M. Norton, L. Ferguson and T. Einhorn. 2010. Preharvest Ethephon Eliminates First Crop Figs. HortTechnology 20(1), Jan.-Mar.
• Crisosto, C.H., V. Bremer, L. Ferguson and G.M. Crisosto. 2010. Evaluating Quality Attributes of Four Fresh Fig (Ficus carica L.) Cultivars Harvested at Two Maturity Stages. Hortscience 45:707-710.
• Cantin, C.M., C.H. Crisosto, E.A. Ogundiwin, T. Gradziel, J. Torrents, M.A. Moreno and Y. Gogorcena. 2010. Chilling injury susceptibility in an intra-specific peach [Prunus persica (L.) Batsch] progeny. Postharvest Biology and Technology 58:79-87. Doi:10.1016/j.postharvbio.2010.06.002.
• Karabulut, O.A., J.L. Smilanick, C.H. Crisosto and L. Palou. 2010. Control of brown rot of stone fruits by brief heated water immersion treatments. Crop Protect. 29:903-906.
• Cantin, C.M., V. Bremer, A.L. Ferreira, T. Michailides, L. Palou, C. H. Crisosto. 2011. Evaluation of the use of sulfur dioxide (SO2) to reduce postharvest losses on dark and green figs. Postharvest Biology and Technology 59:150-158. Doi:10.1016/j.postharvbio.2010.09.016.
• Crisosto, C.H., J. Zegbe, J. Hasey, and G.M. Crisosto. 2011. Is Dry Matter a Reliable Quality Index for 'Hayward' Kiwifruit Acta Hort.913: 531-534.
• Cantin, C.M., D. Holcroft, and C.H. Crisosto. 2011. Postharvest Application of 1-Methylcyclopropene (1-MCP) Extends Shelf Life of Kiwifruit. Acta Hort. 913: 621-626.
• Cantin, C.M., A. Soto, G.M. Crisosto, and C.H. Crisosto. 2011. Evaluation of a Non-Destructive Dry matter Sensor for Kiwifruit. Acta Hort. 913: 627-632.
• Karabulut, O.A., J.L. Smilanick, C.H. Crisosto and L. Palou. 2010. Control of brown rot of stone fruits by brief heated water immersion treatments. Crop Protection 29:903-906.
• Leida, C., G. Rios, J.M. Soriano, B. Perez, G. Llacer, C.H. Crisosto, and M.L. Badenes. 2011. Identification and genetic characterization of an ethylene-dependent polygalacturonase from apricot fruit. Postharvest Biology and Technology. Doi:10.1016/j.postharvbio.2011.04.003.
• Martinez-Garcia, P.J., C.P. Peace, D.E. Parfitt, E.A. Ogundiwin, J. Fresnedo-Ramirez, A.M. Dandekar, T.M. Gradziel, and C.H. Crisosto. 2011. Influence of year and genetic factors on chilling injury susceptibility in peach (Prunus persica (L.) Batsch). Euphytica. DOI 10.1007/s10681-011-0572-1.
• Vicente, A.R., G. Manganaris, L. Cisneros-Zevallos, and C.H. Crisosto. 2011. Prunus. Chapter 13, pp. 238-259. In: Terry (ed.), Health-promoting Properties of Fruits and Vegetables.
• Cantin, C.M., L. Tian, Q. Xiaoqiong and C.H. Crisosto. 2011. Copigmentation triggers the development of skin burning disorder on peach and nectarine fruit [Prunus persica (L.) Batsch]. Journal of Agricultural and Food Chemistry. dx.doi.org/10.1021/jf104497s.
• Cantin, C.M., V. Bremer, A.L. Ferreira, T. Michailides, L. Palou, and C. H. Crisosto. 2011. Evaluation of the use of sulfur dioxide (SO2) to reduce postharvest losses on dark and green figs. Postharvest Biology and Technology 59:150-158. Doi:10.1016/j.postharvbio.2010.09.016.
• Cano-Salazar, J.A., G. Echeverria, C. Crisosto, and L. Lopez. 2011. Cold storage potential of four yellow-fleshed peach cultivars defined by their volatile compound emissions, standard quality parameters, and consumer acceptance. Journal of Agricultural and Food Chemistry. Doi:10.1021/jf204126m..

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: Due to globalization, high domestic production, and a slow market, "sensory damaged" fruit which reduce consumption are available in the market and compete with sound commodities. In peaches, the main loss of flavor quality occurs during postharvest handling due to "off flavor" development and changes in texture due to chilling injury and is very important in explaining the low consumer acceptance. Genotypes and other orchard factors (including environmental) profoundly influence the "loss of flavor". This has led us to evaluate the potential for improving the consumer quality by selecting new flavorful cultivars (non-susceptible to chilling injury) using marker assistant selection (MAS), and developing postharvest technologies to express consumer quality and/or protect flavor losses during handling of fruits packed in large volume operations. PARTICIPANTS: Other products/ outcomes: Collaborations: Dr. Marisa Badenes Ms. Gayle Crisosto Dr. Tony Granell Dr. Susan Lurie and Haya Friedman, Department of Postharvest Science, Volcani Center, ARO, POB 6, Bet Dagan 50250 Dr. Hildegar Heyman Mr. Kevin Scott Training: Dr. Claudia Delgado Dr. Arun Prabhu Dhanapal ([e-mail]), Postdoctoral Associate, UC Davis, is coordinating this project's activities, Dr. Naratraj is executing linkage mapping and QTL analysis, and Dr. Dandekar ([e-mail]), Professor, UC Davis, is advising on all aspects of peach genomics. Dr. Celia Cantin ([e-mail]), a visiting scholar from Zaragoza, Spain, was trained in the area of postharvest physiology. Dr. Joseph Fass of the Bioinformatics Unit of UC Davis Genome Center worked on SNP characterization. Dr. Charlie Nicolet, Genome Center, Core Services Facilities, University of California, Davis, is helping in SNP genotyping using Illumina Golden Gate platform. TARGET AUDIENCES: Information from our program is being disseminated to all segments of the academia and produce industry through our current UC Davis postharvest and Kearney Agricultural programs. Our outreach to consumers will make use of existing programs, task forces, and interagency working groups that our project collaborators are already associated with such as California Tree Fruit Agreement, etc. Our UC postharvest group will conduct a series of hands-on, audience specific, targeted extension education activities, which will include workshops, distance education and associated written materials. Referee papers, outreach materials and summary articles developed will be disseminated via existing academic meetings, well-known industry, webinars, and public websites and trade publications. These educational outreach activities will also include participation by undergraduate and graduate students to gain experience in understanding challenges and opportunities facing the specialty crops industry as well as in-depth understanding of cutting edge technologies to assist in problem solving. We propose to involve students (under faculty supervision) and visitors in the demonstration aspects of these courses. These educational outreach activities will be updated and refined as data from the project subsequently becomes available. The first set of general courses will be offered late in year one and early in year two on the UC Davis and CSU Fresno campuses. PROJECT MODIFICATIONS: As we detected that the low consumption problem is related to flavor loss perception after a short marketing period, rather than the 'complex peach flavor characteristics' at harvest, we changed our program focus to flavor loss during marketing.

Impacts
Microarray analysis and qRTPCR analysis for validation of expressed genes was conducted in our selected progenies. These transcriptomic analysis results illustrated the clear picture of ripening genes, non ripening genes, cell wall related genes and non cell wall related genes and their relationship in mealiness susceptibility, a form of chilling injury. We integrated the information from phenotypic, biochemical and gene expression studies and proposed possible candidate genes that are involved in reducing mealiness susceptibility. Currently we are analyzing the 43 candidate genes obtained from the integrated result of phenotypic, biochemical and gene expression analysis. The gene specific primers were designed and tested in two parents 'Dr. Davis' and 'Georgia Belle' and are being analyzed in 100 progenies of Pop-DG freestone melting flesh (FMF) types. Candidate genes are located on the Pop-DG linkage map by obtaining segregation data for 100 FMF progeny and QTL analysis is being conducted. These proposed possible 43 candidate genes will be mapped using primers developed on them and the genes bin-mapped on to TxE bin set to bin map gene sequences. A 100 Free Melting Flesh (FMF) progeny of Pop-DG will be examined for mealiness. QTL analysis will be performed on this phenotypic data using the existing genetic map of Pop-DG. Genomic locations of the identified QTLs will be compared with that of previous mealiness QTLs, to verify their locations and uncover new QTLs. We will develop high density SNP maps for Pop-DG peach populations with full marker information that will accelerate marker discovery for other traits of interest in Prunus.

Publications

• Cantin, C.M., Crisosto, C.H., Ogundiwin, E.A., Gradziel, T., Torrents J., Moreno, M.A. and Gogorcena, Y. 2010. Chilling injury susceptibility in an intra-specific peach (Prunus persica (L.) Batsch] progeny. Postharvest Biology and Technology 58: 79-87.
• Dagar, A., Weksler, A., Friedman, H., Ogundiwin, E.A., Crisosto, C.H., Ahmad, R. and Lurie S. 2011. Comparing ripening and storage characteristics of 'Oded' peach and its nectarine mutant 'Yuval'. Postharvest Biology and Technology (in press) doi:10.1016/j.postharvbio.2010.11.002.
• Manganaris, G.A., Crisosto, C.H., Bremer, V. and Holcroft, D. 2008. Novel 1-methylcyclopropene immersion formulation extends shelf life of advanced maturity 'Joanna Red' plums (Prunus salicina Lindell). Postharvest Biology and Technology 47: 429-433.
• Peace, C.P., Callahan, A.M., Potter, D., Ogundiwin, E.A., Crisosto, C.H. and Gradziel, T.M. 2010. The EndoPG gene in Prunus: Evolution and domestication of a fruit texture locus. Plant & Animal Genomes XVII Conference January 9-14. Town & Country Convention Center, San Diego, CA. http://www.intl-pag.org.
• Ogundiwin, E.A., Gradziel, T.M., Parfitt, D.E. ,Nicole, C.M., Dhingra, A., Lin, D., Slaughter, D.C., Jasieniuk, M.A. and Crisosto, C.H. 2009. Towards SNP and QTL discovery of peach fruit quality genes. Plant & Animal Genomes XVII Conference January 10-14, 2009 Town & Country Convention Center, San Diego, CA. http://www.intl-pag.org.
• Iezzoni, A., Peace, C., Main, D., Bassil, N., Luby, J., Yue, C., van de Weg, E., Weebadde, C., Fazio, G., Bink, M., Brown, S., Byrne, D., Clark, J., Crisosto, C., Davis, T., Evans, K., Finn, C., Gallardo, K., Gasic, K., Gradziel, T., Hancock, J., Jussaume, R., McCracken, V., Oraguzie, N., Reighard, G., Stone, A., Taylor, M., Wang, D. and Xu, K. 2010. RosBREED: Enabling marker-assisted breeding in Rosaceae. Plant & Animal Genomes XVII Conference January 9-13. Town & Country Convention Center, San Diego, CA. http://www.intl-pag.org.
• Peace, C.P., Callahan, A.M., Potter, D., Ogundiwin, E.A., Crisosto, C.H. and Gradziel, T.M. 2009. The EndoPG gene in Prunus: Evolution and domestication of a fruit texture locus. Plant & Animal Genomes XVII Conference January 9-14. Town & Country Convention Center, San Diego, CA. http://www.intl-pag.org.
• Ogundiwin, E.A. Granell, A. Gradziel, T.M. and Crisosto, C.H. 2008. Unraveling peach fruit mealiness and cold storage browning with genomic tools. Proceedings of the 35th Annual Meeting of the Plant Growth Regulation Society of America, San Francisco, California, USA, 3-7 August, 2008.
• Ogundiwin, E.A., Peace, C.P., Nicolet, C.M., Rashbrook, V.K., Gradziel, T.M., Bliss, F.A., Parfitt, D. and Crisosto, C.H. 2008. Leucoanthocyanidin diosygenase gene (PpLDOX): a potential functional market for cold storage browning in peach. Tree Genetics & Genomes 4:543-554.
• Ogundiwin, E.A., Gradziel, T.M., Day, K.R. and Crisosto, C.H. 2008. Deploying functional genomic tools to address chilling injury problem in peach fruit. International Fruit Tree Association, 14-18 February 2008, Visalia, CA p. 26-27.

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: The susceptibility to chilling injury (CI) was evaluated for peach, nectarine, and plum cultivars from different breeding sources. Cultivars were segregated into 3 categories (A,B,C) according to susceptibility to CI based on visual symptoms when exposed to 0oC or 5oC storage temperatures up to 5 wks. Cultivars in Cat.A did not develop any symptoms of CI after 5 wks of storage at either temperature. Cultivars in Cat.B developed symptoms only when stored at 5oC within 5 weeks of storage. Cultivars were classified as Cat.C when fruit developed CI symptoms at both storage temps. within 5 wks of storage. Approximately 60% of peach, 50% of nectarine, and 40% of plum cultivars tested developed CI symptoms when stored at 5 oC (Cats. B&C). However, these %'s were reduced to 35% for peach, 30% for nectarine, and 14% for plum cultivars when stored to 0oC during postharvest handling. Thus, the importance of proper temp. management, and the application of preconditioning or other reliable treatments to extend market life during postharvest handling is well demonstrated. This information provides guidance for shippers and handlers in selecting cultivars for long distance marketing. The UCD preconditioning treatment, a thermal treatment that consists in maintaining stone fruits immediately after harvest and prior to cold storage at 20 deg.C for 24-48 h protect flavor loss better than untreated fruit in storage. Acceptability of preconditioned fruit was higher than control fruit during this 40-d cold storage period. Preconditioned and control fruit were segregated into two clusters by PCA analysis; preconditioned fruit clustered together, show association to acceptability, sweetness, and juiciness. While the second cluster was associated with flesh texture, acidity and aroma, suggesting positive effect of preconditioning on final fruit quality. Preconditioned fruit maintained their sensory characteristics longer than control fruit during this 40-d cold storage period. To develop chilling injury candidate genes, the ChillPeach database was created to facilitate identification of genes controlling chilling injury (CI), a global-scale post-harvest physiological disorder in peach. It contained 7,862 high-quality ESTs (comprising4,468 unigenes) obtained from mesocarp tissues of two fullsib progeny contrasting for CI, about 48 and 13% of which are unique to Prunus and Arabidopsis, respectively. All ESTs are in the Gateway_ vector to facilitate functional assessment of the genes. The data set contained several putative SNPs and 184 unigenes with high quality SSRs, of which 42% were novel to Prunus. Microarray slides containing 4,261 ChillPeach unigenes were printed and used in a pilot experiment to identify differentially expressed genes in cold-treated compared to control mesocarp tissues, and in vegetative compared to mesocarp tissues. Quantitative RTPCR (qRT-PCR) confirmed microarray results for all 13 genes tested. The microarray and qRT-PCR analyses indicated that ChillPeach is rich in putative fruit-specific and novel cold-induced genes. Website (http://bioinfo.ibmcp.upv.es/genomics/ChillPeachDB) was created holding detailed info on the ChillPeach database. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
We have identified several genetic markers, candidate genes and cold-responsive genes for peach fruit internal breakdown traits (flesh mealiness, browning and bleeding). We have also expanded our segregating population for the purpose of validating the association between the markers and the traits. Eventually, breeders can use markers such as these to select fruit with a low susceptibility to internal breakdown symptoms. The cell wall degrading enzyme endopolygalacturonase (endoPG) has been implicated in the physiological development of mealiness. Our research has helped pinpoint the role of endoPG in mealiness. We have also discovered that leucoanthocyanidin dioxygenase gene is associated with flesh browning. These evolving markers can be used by peach and nectarine breeders and germplasm curators for marker-assisted breeding and genetic diversity studies. The ChillPeach database has been completed and a microarray platform established for detail genomics analysis of internal breakdown and other physiological characteristics in peach fruit. We have just generated a partial genome sequence of 'Dr. Davis' and 'F8, 1-42' and bioinformatics analysis of the data is ongoing.

Publications

• Manganaris, G.A., A.R. Vicente, C.H. Crisosto, J.M. Labavitch. 2008. Cell wall modifications in chilling-injured plum fruit (Prunus salicina). Postharvest Biology and Technology 48:77-83.
• Crisosto, C.H. and G. Costa. 2008. Preharvest factors affecting peach quality. Chapter 20, pp. 536-549. In: Layne and Bassi (eds.), The Peach: Botany, Production and Uses. CAB International.
• Manganaris, G.A., A.R. Vicente and C.H. Crisosto. 2008. Effect of pre-harvest and post-harvest conditions and treatments on plum fruit quality. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources 3(9), 10 pp. doi:10.1079/PAVSNNR20083009.
• Crisosto, C.H., S. Lurie and J. Retamales. 2009. Stone fruit. Chapter 13, pp. 287-315. In: Yahia (ed.), Modified and Controlled Atmospheres for the Storage, Transportation, and Packaging of Horticultural Commodities.
• Infante, R., C. Meneses, and C.H. Crisosto. 2009. Preconditioning treatment maintains taste characteristic perception of ripe 'September Sun' peach following cold storage. International Journal of Food Science and Technology 44:1011-1016.
• Terry, L.A., C.H. Crisosto and C.F. Forney. 2009. Small fruit and berries. Chapter 15, pp. 363-395. In: Yahia (ed.), Modified and Controlled Atmospheres for the Storage, Transportation, and Packaging of Horticultural Commodities.
• Vicente, A.R., G.A. Manganaris, G.O. Sozzi and C.H. Crisosto. 2009. Nutritional quality of fruits and vegetables. Chapter 5, pp. 57-106. In: Florkowski, Shewfelt, Brueckner and Prussia (eds.), Postharvest Handling: A Systems Approach, Second Edition. Oxford: Academic Press.
• Manganaris, G.A., A.R. Vicente, C.H. Crisosto, and J.M. Labavitch. 2008. Cell wall modifications in chilling injured plum fruit Prunus salicina. Postharvest Biology and Technology 48: 77-83. doi:10.1016/j.postharvbio.2007.09.017
• Ogundiwin, E.A., C. Marti, J. Forment, C. Pons, A. Granell, T.M. Gradziel, C.P. Peace, and C.H. Crisosto. 2008. Development of ChillPeach genomic tools and identification of cold-responsive genes in peach fruit. Plant Molecular Biology. Published online: 27 July 2008. doi:10.1007/s11103-008-9378-5
• Crisosto, C.H. and D. Valero. 2008. Harvesting and postharvest handling of peaches for the fresh market. Chapter 22, pp. 575-596. In: Layne and Bassi (eds.), The Peach: Botany, Production and Uses. CAB International.
• Manganaris, G.A., A.R. Vicente, C.H. Crisosto, and J.M. Labavitch. 2008. Effect of delayed storage and continuous ethylene exposure on flesh reddening of 'Royal Diamond' plums. Journal of the Science of Food and Agriculture. 88:2180-2185.
• Cantin, C.M., C.H. Crisosto, and K.R. Day. 2008. Evaluation of the effect of different modified atmosphere packaging box liners on the quality and shelf life of 'Friar' plums. HortTechnology 18:261-265.
• Crisosto, C.H., G.M. Crisosto, and K.R. Day. 2008. Market life update for peach, nectarine, and plum cultivars grown in California. Adv. Hort. Sci., 22(3)201-204.

Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: We began segregating plum and pluot cultivars based on the sensory perception of their organoleptic characteristics using a trained panel. Data from 12 plum and four pluot cultivars was evaluated by principal component analysis. The perception of the four sensory attributes (sweetness, sourness, plum flavor intensity, plum aroma intensity) was reduced to three principal components, which accounted for 98.6 percent of the variation in the sensory attributes of the tested cultivars. Using the Ward separation method and PCA analysis (PC1 equals 49.8 percent and PC2 equals 25.6 percent), plum and pluot cultivars were segregated into groups (tart, plum aroma, and sweet/plum flavor) with similar sensory attributes. Fruit source significantly affected cultivar ripe soluble solids concentration (RSSC) and ripe titratable acidity (RTA), but it did not significantly affect sensory perception of plum flavor intensity, sourness, sweetness, and plum aroma intensity by the trained panel on fruit harvested above their physiological maturity. Therfore, we recommend that validation of these organoleptic groups should be conducted using in store consumer tests prior to development of a minimum quality index within each organoleptic group based on ripe soluble solids concentration (RSSC). This organoleptic cultivar classification will help to match consumer preferences and enhance current promotion and marketing programs. Genetics and Internal Breakdown. We expanded the progeny size of one of the segregating populations being used for genetic analysis of internal breakdown. A second set of progenies of 'Dr. Davis' x 'Georgia Belle' consisting of over 250 progeny was raised and named Pop-DG2. To increase the statistical power of QTL detection, about 106 individuals were selected from Pop-DG2 and evaluated for internal breakdown along with 51 progeny of Pop-DG in the summer of 2007. Out of the selected 106 Pop-DG2 individuals 81 were free-stone melting flesh (FMF). There were 29 FMF individuals in Pop-DG, bringing the total of FMF individuals to 100. This was necessary to further search for QTLs that control mealiness as mealiness is observed only among the FMF genotypes. Data analysis is underway. In addition, a peach progeny population developed in Zaragoza, Spain, from the cross 'Venus' x 'Big Top' is being used to validate and further search for internal breakdown controlling genes. This population consists of 70 individuals, all melting flesh genotypes. Another major achievement was the completion of the ChillPeach database and the development of microarray slides consisting of over 4,200 genes. This microarray has been used in a pilot study to identify cold responsive genes in peach mesocarp tissue. Extensive microarray analysis of mealiness resistance/susceptibility is underway. Some ChillPeach genes have been mapped either directly to the Pop-DG linkage map or indirectly through bin mapping using the TxE Prunus reference map. This include 77 new Prunus EST SSRs and 60 candidate genes. Finally, the association of a peach gene encoding leucoanthocyanidin dioxygenase (PpLDOX) to the major QTL controlling internal breakdown flesh browning was validated. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
Our fruit sensory program has developed information that encourages the industry to deliver stone fruit to the consumer within its effective market life in order to provide a consistently satisfying product. It also encourages innovation within the industry with respect to fruit flavor and quality by helping companies market their fruits unique organoleptic characteristics and target specific groups of consumers based upon their preferences. The flavor and quality information we develop allows growers to investigate a fruit's flavor quality and market life (storage and shipping potential) before planting. We have identified several genetic markers and candidate genes for peach fruit internal breakdown traits (flesh mealiness, browning and bleeding). We have also expanded our segregating population for the purpose of validating the association between the markers and the traits. Eventually, breeders can use markers such as these to select fruit with a low susceptibility to internal breakdown symptoms. The cell wall degrading enzyme endopolygalacturonase (endoPG) has been implicated in the physiological development of mealiness for decades. Our research has helped pinpoint the role of endoPG in mealiness. We have also discovered that leucoanthocyanidin dioxygenase gene is associated with flesh browning. These evolving markers can be used by peach and nectarine breeders and germplasm curators for marker-assisted breeding and genetic diversity studies. The CHILLPEACH database has been completed and a microarray platform established for detailed genomics analysis of internal breakdown and other physiological characteristics in peach fruit

Publications

• Ogundiwin, E.A., C. Marti, J. Forment, C. Pons, A. Granell, T.M. Gradziel, C.P. Peace, and C.H. Crisosto. 2008. Development of ChillPeach genomic tools and identification of cold-responsive genes in peach fruit. Plant Molecular Biology. Published online: 27 July 2008. doi:10.1007/s11103-008-9378-5
• Crisosto, C.H. and G. Costa. 2008. Preharvest factors affecting peach quality. Chapter 20, pages 536-549. In: Layne and Bassi (eds.), The Peach: Botany, Production and Uses. CAB International. (In Press)
• Crisosto, C.H. and D. Valero. Harvesting and postharvest handling of peaches for the fresh market. 2008. Chapter 22, pages 575-596. In: Layne and Bassi (eds.), The Peach: Botany, Production and Uses. CAB International. (In Press)
• Infante, R., C. Meneses, and C.H. Crisosto. 2008. Preconditioning treatment maintains taste characteristic perception of ripe 'September Sun' peach following cold storage. International Journal of Food Science and Technology. (In Press)
• Badenes, M.L., G. Llacer, and C.H. Crisosto. 2007. Mejora de la calidad de frutales de hueso. In: G. Llacer, J.J. Diez, J.M. Carrillo, and M.L. Badenes (eds.), Mejora genetica de la calidad en Frutales De Hueso.
• Valero, C., C.H. Crisosto, D. Slaughter. 2007. Relationship between nondestructive firmness measurements and commercially important ripening fruit stages for peaches, nectarines and plums. Postharvest Biology and Technology 44: 248-253.

Progress 01/01/07 to 12/31/07

Outputs
We began segregating plum and pluot cultivars based on the sensory perception of their organoleptic characteristics using a trained panel. Data from 12 plum and four pluot cultivars was evaluated by principal component analysis. The perception of the four sensory attributes (sweetness, sourness, plum flavor intensity, plum aroma intensity) was reduced to three principal components, which accounted for 98.6 percent of the variation in the sensory attributes of the tested cultivars. Using the Ward separation method and PCA analysis (PC1 equals 49.8 percent and PC2 equals 25.6 percent), plum and pluot cultivars were segregated into groups (tart, plum aroma, and sweet/plum flavor) with similar sensory attributes. Fruit source significantly affected cultivar ripe soluble solids concentration (RSSC) and ripe titratable acidity (RTA), but it did not significantly affect sensory perception of plum flavor intensity, sourness, sweetness, and plum aroma intensity by the trained panel on fruit harvested above their physiological maturity. Therfore, we recommend that validation of these organoleptic groups should be conducted using in store consumer tests prior to development of a minimum quality index within each organoleptic group based on ripe soluble solids concentration (RSSC). This organoleptic cultivar classification will help to match consumer preferences and enhance current promotion and marketing programs. Genetics and Internal Breakdown. We expanded the progeny size of one of the segregating populations being used for genetic analysis of internal breakdown. A second set of progenies of 'Dr. Davis' x 'Georgia Belle' consisting of over 250 progeny was raised and named Pop-DG2. To increase the statistical power of QTL detection, about 106 individuals were selected from Pop-DG2 and evaluated for internal breakdown along with 51 progeny of Pop-DG in the summer of 2007. Out of the selected 106 Pop-DG2 individuals 81 were free-stone melting flesh (FMF). There were 29 FMF individuals in Pop-DG, bringing the total of FMF individuals to 100. This was necessary to further search for QTLs that control mealiness as mealiness is observed only among the FMF genotypes. Data analysis is underway. In addition, a peach progeny population developed in Zaragoza, Spain, from the cross 'Venus' x 'Big Top' is being used to validate and further search for internal breakdown controlling genes. This population consists of 70 individuals, all melting flesh genotypes. Another major achievement was the completion of the ChillPeach database and the development of microarray slides consisting of over 4,200 genes. This microarray has been used in a pilot study to identify cold responsive genes in peach mesocarp tissue. Extensive microarray analysis of mealiness resistance/susceptibility is underway. Some ChillPeach genes have been mapped either directly to the Pop-DG linkage map or indirectly through bin mapping using the TxE Prunus reference map. This include 77 new Prunus EST SSRs and 60 candidate genes. Finally, the association of a peach gene encoding leucoanthocyanidin dioxygenase (PpLDOX) to the major QTL controlling internal breakdown flesh browning was validated.

Impacts
Our fruit sensory program has developed information that encourages the industry to deliver stone fruit to the consumer within its effective market life in order to provide a consistently satisfying product. It also encourages innovation within the industry with respect to fruit flavor and quality by helping companies market their fruits unique organoleptic characteristics and target specific groups of consumers based upon their preferences. The flavor and quality information we develop allows growers to investigate a fruit's flavor quality and market life (storage and shipping potential) before planting. We have identified several genetic markers and candidate genes for peach fruit internal breakdown traits (flesh mealiness, browning and bleeding). We have also expanded our segregating population for the purpose of validating the association between the markers and the traits. Eventually, breeders can use markers such as these to select fruit with a low susceptibility to internal breakdown symptoms. The cell wall degrading enzyme endopolygalacturonase (endoPG) has been implicated in the physiological development of mealiness for decades. Our research has helped pinpoint the role of endoPG in mealiness. We have also discovered that leucoanthocyanidin dioxygenase gene is associated with flesh browning. These evolving markers can be used by peach and nectarine breeders and germplasm curators for marker-assisted breeding and genetic diversity studies. The CHILLPEACH database has been completed and a microarray platform established for detailed genomics analysis of internal breakdown and other physiological characteristics in peach fruit

Publications

• Peace, C.P., C.H. Crisosto, and T.M. Gradziel. 2005. Endopolygalacturonase: a candidate gene for Freestone and Melting flesh in peach. Molecular Breeding 16:21-31.
• Granell, A., Pons, C., Marti, C., Forment, J., Royo, C., Gradziel, T.M., Peace, C.P., Ogundiwin, E. and Crisosto, C.H. (2007). Genomic approaches- innovative tools to improve quality of fresh cut produce. Acta Hort. 746:203-212
• C.P. Peace, A.M. Callahan, E.A. Ogundiwin, D. Potter, T. M. Gradziel, F.A. Bliss, and C.H. Crisosto (2007). Endopolygalacturonase variation in Prunus. Acta Horticulturae 738:639-646.
• Peace, C. and C. Crisosto. 2006. Revealing the genetic control of internal breakdown in peach. Summerfruit, Australia Quarterly 8(2):20-21.

Progress 01/01/06 to 12/31/06

Outputs
Fruit Quality and Market Life. In 2006 we began segregating plum and pluot cultivars based on the sensory perception of their organoleptic characteristics using a trained panel. Data from 12 plum and four pluot cultivars was evaluated by principal component analysis. The perception of the four sensory attributes (sweetness, sourness, plum flavor intensity, plum aroma intensity) was reduced to three principal components, which accounted for 98.6 percent of the variation in the sensory attributes of the tested cultivars. Using the Ward separation method and PCA analysis (PC1 equals 49.8 percent and PC2 equals 25.6 percent), plum and pluot cultivars were segregated into groups (tart, plum aroma, and sweet/plum flavor) with similar sensory attributes. Fruit source significantly affected cultivar ripe soluble solids concentration (RSSC) and ripe titratable acidity (RTA), but it did not significantly affect sensory perception of plum flavor intensity, sourness, sweetness, and plum aroma intensity by the trained panel on fruit harvested above their physiological maturity. Based on this information, we recommend that validation of these organoleptic groups should be conducted using in store consumer tests prior to development of a minimum quality index within each organoleptic group based on ripe soluble solids concentration (RSSC). This organoleptic cultivar classification will help to match consumer preferences and enhance current promotion and marketing programs. Genetics and Internal Breakdown. We continued to make improvements to our Pop-DG peach genetic linkage map with particular emphasis on locating genes that control symptoms of internal breakdown (mealiness, browning and bleeding) in peach and nectarine. Last year (2005) we discovered that the gene for endopolygalacturonase (endoPG), controlling the freestone and melting flesh trait, corresponded with a large QTL for mealiness and bleeding. This year, approximately 50 additional candidate genes for fruit softening and internal breakdown have been fine-mapped onto the Pop-DG peach and/or bin-mapped onto the Prunus genetic map. These candidate genes represent cell wall hydrolyzing enzymes primarily affecting pectin, enzymes involved in ethylene synthesis and signaling, and enzymes associated with the carotenoid and anthocyanin biosynthesis pathways. One of these, the gene that codes for leucoanthocyanidin dioxygenase (LAD), mapped very close to the major QTL for browning. This major QTL controls about 40 percent of the variation observed for browning. We have also developed an extensive database of expressed genes during mealiness development known as CHILLPEACH. Fruit tissue was obtained from two progenies of Pop-DG with contrasting susceptibility to mealiness and internal browning, subjected to various cold storage durations and ripening regimes. From this tissue, the CHILLPEACH EST library of cold-stored ripening peach fruit was constructed. This EST library is an ideal genomic resource for identifying genes involved in mealiness.

Impacts
Our fruit sensory program has developes information that encourages the industry to deliver stone fruit to the consumer within its effective market life in order to provide a consistently satisfying product. It also encourages innovation within the industry with respect to fruit flavor and quality by helping companies market their fruits unique organoleptic characteristics and target specific groups of consumers based upon their preferences. The flavor and quality information we develop allows growers to investigate a fruit's flavor quality and market life (storage and shipping potential) before planting. We have identified several genetic markers and candidate genes for peach fruit internal breakdown traits (flesh mealiness, browning and bleeding). Eventually, breeders can use markers such as these to select fruit with a low susceptibility to internal breakdown symptoms. The cell wall degrading enzyme endopolygalacturonase (endoPG) has been implicated in the physiological development of mealiness for decades. Our research has helped pinpoint the role of endoPG in mealiness. We have also discovered that leucoanthocyanidin dioxygenase gene is associated with flesh browning. These evolving markers can be used by peach and nectarine breeders and germplasm curators for marker-assisted breeding and genetic diversity studies. The CHILLPEACH database is a great resource for future identification of markers controlling internal breakdown and other fruit softening characteristics.

Publications

• Williamson J, Peace C, Bliss FA, Garner D, and Crisosto CH. 2006. Evidence for a single locus controlling flesh color, senescent leaf color, and hypanthium color in peach. Journal Of The American Society for Horticultural Science 131 (2): 256-260.
• Crisosto C.H., Crisosto G.M., Echeverria G. and Puy J. 2006. Segregation of peach and nectarine (Prunus persica (L.) Batsch) cultivars according to their organoleptic characteristics. Postharvest Biology and Technology 39: 10-18.

Progress 01/01/05 to 12/31/05

Outputs
Fruit flavor quality potential of peach and nectarine cultivars was investigated in the 2005 season, leading to the segregation of cultivars according to their organoleptic characteristics. Cultivar segregation according to the sensory perception of fruit organoleptic characteristics was attempted by using trained panel data evaluated by principal component analysis of four sources per cultivar of 23 peach and 26 nectarine cultivars. Fruit source significantly affected cultivar ripe soluble solids concentration (RSSC) and ripe titratable acidity (RTA), but it did not significantly affect sensory perception of peach or nectarine flavor intensity, sourness or aroma by the trained panel. The perception of the four sensory attributes (sweetness, sourness, peach or nectarine flavor intensity, peach or nectarine aroma intensity) was analyzed by using the three principal components, which accounted for 92 and 94% of the variation in the sensory attributes of the tested cultivars for peach and nectarine, respectively. Season did not significantly affect the classification of one cultivar that was evaluated during these two seasons. By plotting organoleptic characteristics in PC1 and PC2 for peach and nectarine, cultivars were segregated into groups (balanced, tart, sweet, peach or nectarine aroma and/or peach or nectarine flavor intensity) with similar sensory attributes; nectarines were classified into five groups and peaches into four groups. On the genetics side of the project, the previous partial genetic map of our main segregating population, Pop-DG, was expanded with approximately 70 additional SSR and RAF markers. This expanded map covers an estimated 90% of the peach genome, with direct correspondence to two-thirds of the international Prunus reference map. QTL analysis was performed on the genetic map, using phenotypic data collected for three seasons. QTLs for flesh mealiness, browning, and bleeding were located, confirming the stability of certain previously-identified QTLs over a third season of data. Candidate gene analysis verified that the peach gene for endopolygalacturonase (endoPG), controlling the freestone and melting flesh traits, corresponded to a large QTL for mealiness and bleeding. Further investigation pointed to the cause of mealiness being the result of partial endoPG enzyme activity during cold storage followed by gradual softening during subsequent ripening with negligible endoPG activity. In the genetic populations studied, only freestone melting flesh trees were susceptible to mealiness. In contrast, bleeding susceptibility was confined to clingstone non-melting flesh trees.

Impacts
Based on the investigations into fruit flavor quality potential, we recommend that cultivars should be classified in organoleptic groups and development of a minimum quality index should be attempted within each organoleptic group. This organoleptic cultivar classification will help to match ethnic preferences and enhance current promotion and marketing programs. In the stone fruit industry, one of the most frequent complaints by consumers and wholesalers is the internal breakdown (IB), also called chilling injury, which appears during prolonged cold storage and/or after subsequent ripening. Eventually, markers such as these can be used by breeders to select fruit with a low susceptibility to internal breakdown symptoms. Our research has helped pinpoint the role of endoPG in mealiness. Researchers can now examine other ripening enzymes, and their controlling genes, in perspective. Peach and nectarine breeders can use the DNA test developed for the freestone and melting flesh traits to verify the underlying genotype of any variety or seedling, and also consider susceptibility to internal breakdown in perspective.

Publications

• Peace, C.P., Crisosto, C.H. and Gradziel, T.M. 2005. Endopolygalacturonase: a candidate gene for Freestone and Melting flesh in peach. Molecular Breeding 16: 21-31.
• Peace C.P., Ahmad, R., Gradziel, T.M., Dandekar, A.M. and Crisosto, C.H. 2005. The use of molecular genetics to improve peach and nectarine post-storage quality. Acta Horticulturae 682: 403-410.
• Crisosto C.H., Crisosto, G.M., Echeverria, G. and Puy, J. 2006. Segregation of peach and nectarine (Prunus persica (L.) Batsch) cultivars according to their organoleptic characteristics. Postharvest Biology and Technology 39: 10-18.
• Crisosto, C.H. and Crisosto, G.M. 2006. Relationship between ripe soluble solids concentration (RSSC) and consumer acceptance of high and low acid melting flesh peach and nectarine (Prunus persica (L.) Batsch) cultivars. Postharvest Biology and Technology (in press).

Progress 01/01/04 to 12/31/04

Outputs
During the 2004 growing season, we evaluated the organoleptic quality (SSC, TA, flavor and aroma) and market life of 10 new nectarine, 10 new peach and 5 new plum cultivars. For the evaluation of organoleptic quality, we used a panel of 10 sensory judges to describe fruit sweetness, sourness, flavor intensity and aroma and then associated these measures with the fruits SSC and TA. Cultivars were segregated into clusters according to their organoleptic characteristics using principal component analysis (SIMCA, P7.01, UMETRI). Among fruit characteristics the relationship between sweetness and sourness accounted for almost 88 percent of the variation between judges perception and the fruits physical properties. Using these two principal components, cultivars were segregated into five groups named balanced, sour, aromatic, sweet, and flavorful. In general, traditional yellow flesh high acidity cultivars such as Elegant Lady and O Henry peaches, and Spring Bright nectarine and Fortune plum were segregated into the balanced organoleptic group. Japanese plums such as Blackamber, Purple Majesty, Earliqueen, etc. were classified into the sour group. White flesh and low acidity yellow flesh nectarines and peaches were classified into the sweet or aromatic groups. Within the group of cultivars evaluated, none was classified into the flavorful group. Each of the 25 new stone fruit cultivars was screened for susceptibility to internal breakdown (IB) at two storage temperatures 32F (0C) and 41F (5C). Each week, fruit were ripened and evaluated for symptoms of internal breakdown. Market life was defined as the number of weeks each cultivar can be stored at 32 or 41F with less than 20 percent incidence of internal breakdown symptoms. According to their market life potential at each storage temperature, the cultivars were classified into one of three categories: (A) IB non-susceptible at either temperature; (B) IB non-susceptible at 32F, but susceptible at 41F; (C) IB susceptible at both storage temperatures. Of the 25 stone fruit cultivars evaluated for this study, 13 (7 nectarine, 3 peach and 3 plum) were Category A. With their long postharvest life potential and high tolerance of poor temperature management, these cultivars are good candidates for shipment to distant markets (export). Four of the new cultivars evaluated (1 nectarine, 2 peach and 1 plum) were Category B. For these cultivars it is important for shippers to enforce good temperature management practices to avoid poor arrivals. In addition, shippers may test the benefits of preconditioning treatments or other techniques on these cultivars in order to prolong their postharvest life. The remaining eight new cultivars evaluated were Category C. It is recommended that shippers investigate preconditioning these cultivars or other techniques and/or only market them locally and rapidly.

Impacts
During the 2004 growing season, we evaluated the organoleptic quality (SSC, TA, flavor and aroma) and market life (internal breakdown susceptibility) of 10 new nectarine, 10 new peach and 5 new plum cultivars. The organoleptic data generated will help our industry better target product to demand and increase overall consumption (domestic and export markets). The market life data will be used in the short term to plan new plantings and develop shipping and retail postharvest handling strategies. In the long term, geneticists and breeders will use this information to understand the genetic inheritance of IB, locate the genes related to this disorder, and develop stone fruit cultivars free of IB. In addition, this new information is important for plant physiologists in order to design fundamental studies to improve the basic understanding of the IB problem.

Publications

• Crisosto, C.H., Garner, D., Andris, H.L. and Day, K.R. 2004. Controlled delayed cooling extends peach market life. HortTechnology 14:99-104.
• Crisosto, C.H., Garner, D., Crisosto, G.M. and Bowerman, E. 2004. Increasing Blackamber plum consumer acceptance. Postharvest Biology and Technology 34(3):237-244.

Progress 01/01/03 to 12/31/03

Outputs
Predicting susceptibility of new stone fruit cultivars to internal breakdown. Consumer acceptance of peach fruit depends entirely on the optimum combination of fruit organoleptic traits (FOTs) associated with flavor, texture, appearance, and nutritionally important factors. Among these traits, fruit mealiness and development of off flavors are the main consumer concerns. Low temperature during storage and/or shipping extends fruit market life; however, fruit from some cultivars develop a mealy texture, off flavor, brownish flesh color, fail to ripen and lose flavor during or after cold storage. These symptoms are collectively known as internal breakdown (IB) or chilling injury (CI). We are using a genetic approach to understanding important peach FOTs. Developing molecular tags for these important genes will provide increased efficiency when breeding for greater productivity. To accomplish this, two peach populations segregating for the traits of interest were created one population self rooted and the other on a rootstock. FOT data has been collected for the populations since the 2000 season. These ongoing evaluations over several years have allowed a focused and efficient evaluation protocol to develop. Analysis of the 2002 season data led to several conclusions: significant genetic variation does exist in the populations for all FOTs measured, with particularly high heritability for mealiness, ripening date, and titratable acidity; rootstock effects are minimal except on fruit weight, skin color, and perhaps internal browning; and mealiness is at least partially controlled by the M locus. In the last year (2002-2003), several marker systems were tested for polymorphism amongst the parent cultivars and progeny. Microsatellites were deemed to be the most useful for mapping of Pop DG and Pop G, as they are robust and transferable between laboratories, codominant, are highly polymorphic, and many have already been placed on the consensus peach genetic map. Using microsatellite markers, heterozygosity levels were estimated for the two parent cultivars. A high level of heterozygosity in at least one parent is required for effective linkage analysis when F1 populations are used. This is a particular concern for peach, where self fertility and the practice of breeding within a narrow genetic base have typically resulted in low heterozygosity. However, heterozygosity for Georgia Belle was determined to be sufficiently high (42 percent across 76 microsatellite loci), with heterozygosity for Dr. Davis only half as much (21 percent across the same loci). These results confirm the assumptions that Pop DG should function effectively as a testcross population and Pop G effectively as an F2 population. Preliminary linkage analysis with Pop DG confirmed that previously established linkage relationships for peach are applicable to our mapping populations, verifying that comparative mapping is a useful tool for this project objective. Several major QTLs for mealiness, browning, and bleeding have been located in the Georgia Belle and Dr. Davis genome. These results demonstrate the soundness of the strategies used thus far.

Impacts
Internal breakdown of stone fruit is the basis of most consumer complaints. Our experiments with peach and nectarine cultivars and progeny populations indicate that there is considerable genetic control of mealiness. In fact, the pattern of inheritance suggests that as few as two major genes may be responsible. We are working to identify those genes and develop DNA tests for mealiness so the disorder can be eliminated from future breeding programs.

Publications

• Palou, L., Crisosto, C.H., Smilanick, J.L., Adaskaveg, J.E. and Zoffoli, J.P. 2002. Effects of continuous 0.3 ppm ozone exposure on decay development and physiological responses of peaches and table grapes in cold storage. Postharvest Biology and Technology 24:39-48.
• Palou, L., Crisosto, C.H., Garner, D. and Basinal, L.M. 2003. Effect of continuous exposure to exogenous ethylene during cold storage on postharvest decay development and quality attributes of stone fruits and table grapes. Postharvest Biology and Technology 27:243-254.
• Obenland, D.M., Crisosto, C.H. and Rose, J.K.C. 2003. Expansion protein levels decline with the development of mealiness in peaches. Postharvest Biology and Technology. 29(1):11-18.

Progress 01/01/02 to 12/31/02

Outputs
Predicting cling peach bruising. During the 2000 season, many fruit were damaged during mechanical pitting operations. It was thought that this damage could be attributed to soft fruits. Preliminary data collected in 2001 supported this hypothesis. This season, we repeated the mechanical pitter threshold evaluation. Using a destructive firmness device (UCP), the percentage of Andross, Carson, and Ross fruit with pitting damage increased as fruit cheek firmness fell below 4.0 lbf. for two growing seasons. Regression analysis between the UCP and a nondestructive firmness device reveal high variability in measurements obtained with the nondestructive firmness device. In addition, regression relationships were influenced by cultivar and growing season for the nondestructive firmness device. In addition, the relationship between flesh hue angle and firmness measured both destructively and nondestructively was explored using data obtained in the 2001 and 2002 seasons. Skin hue angle did not predict flesh hue angle. The relationship between fruit flesh hue angle and fruit flesh firmness measured at the cheek with the UC penetrometer was poor for Andross, Carson and Ross fruit during two growing seasons. Predicting susceptibility of new stone fruit cultivars to internal breakdown. Consumer acceptance of peach fruit depends entirely on the optimum combination of fruit organoleptic traits (FOTs) associated with flavor, texture, appearance, and nutritionally important factors. Among these traits, fruit mealiness and development of off flavors are the main consumer concerns. Low temperature during storage and/or shipping extends fruit market life; however, fruit from some cultivars develop a mealy texture, off flavor, brownish flesh color, fail to ripen and lose flavor during or after cold storage. These symptoms are collectively known as internal breakdown (IB) or chilling injury (CI). We are using a genetic approach to understanding important peach FOTs. Developing molecular tags for these important genes will provide increased efficiency when breeding for greater productivity. To accomplish this, two peach populations segregating for the traits of interest were created, one population sel rooted and the other on a rootstock. Variation in FOTs within the replicated populations was measured at harvest and after storage in the 2002 season, with preliminary data also gathered in the previous two years. For quantitative traits, most variation appears to be between genotypes, with less variation between years or rootstocks, a useful result for further genetic analysis.

Impacts
Internal breakdown of stone fruit is the basis of most consumer complaints. We are working to isolate the genetic basis for this disorder so it can be eliminated from future breeding programs. Elimination of this problem may increase stone fruit consumption, which would be healthful for consumers and profitable for the supplier

Publications

• Metheney, P.D., C.H. Crisosto, and D. Garner. 2002. Developing canning peach critical bruising thresholds. Journal American Pomological Society. 56(2):75-78.
• Crisosto, C.H.and J.M. Labavitch. 2002. Developing a quantitative method to evaluate peach (Prunus persica) flesh mealiness. Postharvest Biology and Technology. 25:151-158.

Progress 01/01/01 to 12/31/01

Outputs
'Dr. Davis' and 'Belle of Georgia' peaches were crossed in 1996. Fruit quality of the progeny was evaluated for the second time this season. Of the 196 progeny, approximately half were found to have fruit susceptible to internal breakdown. Genomic DNA was extracted from each selection in the population for development of a molecular marker profile. We will use information from the Prunus molecular marker-based map that we have developed to screen for segregation of as many of the mapped loci as possible. The long-term goal of this line of research is to isolate the genetic basis for internal breakdown and eliminate it from future breeding programs. During the 2000 season, unusually high numbers of canning peaches were damaged during mechanical pit removal. Once mechanical causes were ruled out, it was believed that this damage could be attributed to soft fruits. We investigated potential mechanical pitting damage that may occur over a range of firmness for several cultivars of clingstone peach. For this evaluation we used both a prototype non-destructive firmness tester and the traditional penetrometer. Using the non-destructive firmness device, the percentage of 'Andross', 'Carson', and 'Ross' fruit with pitting damage increased rapidly as firmness index values fell below 7.0. Using the destructive penetrometer, the percentage of 'Andross', 'Carson', and 'Ross' fruit with pitting damage increased as fruit cheek firmness fell below 4.0 lbf. Our results will help processors better estimate processing losses. Additionally, automated systems of non-destructive firmness measurement may allow processors to quickly quantify the firmness of large amounts of fruit. Information about the firmness distribution of fruit samples at the receiving area could be useful for predicting potential problems during processing. Bruising development during cling harvest reduces the quality and quantity of processed clingstone peaches. We investigated how fruit temperature (morning harvest versus afternoon harvest) influences preprocessing bruise development. Also, bruise development of fruit stored postharvest at 0C (32F), 5C (41F), 10C (50F), or outside ambient temperature was observed during a 24-hour period. Fruit harvested in the afternoon had darker bruises than fruit harvested in the morning after 24 hours incubation. Bruise incidence, bruise intensity and bruise color on 'Ross' fruit was not significantly affected by postharvest storage temperature.

Impacts
Internal breakdown of stone fruit is the basis of most consumer complaints. We are working to isolate the genetic basis for this disorder so it can be eliminated from future breeding programs. Elimination of this problem may increase stone fruit consumption, which would be healthful for consumers and profitable for the supplier.

Publications

• Garner, D., C.H. Crisosto and E. Otieza. 2001. Controlled atmosphere storage and aminoethoxyvinylglycine postharvest dip delay post cold storage softening of 'Snow King' peach. 2001. HortTechnology 22:205-213.
• Crisosto, C.H., D. Slaughter, D. Garner and J. Boyd. 2001. Stone fruit critical bruising thresholds. Journal American Pomological Society 55(2):76-81.

Progress 01/01/00 to 12/31/00

Outputs
'Dr. Davis' and 'Belle of Georgia' peaches were crossed in 1996. Fruit quality of the selections was evaluated for the first time this season. Of the progeny, 188 were peaches and 9 were nectarines; 89 were clingstone and 108 freestone; 95 were white flesh and 102 were yellow flesh. After storage 55%, of the peach selections developed internal breakdown (IB). Genetic testing will be conducted to isolate the basis for internal breakdown and help eliminate it from future breeding programs. We evaluated the influence of controlled delayed cooling treatments four peach, seven plum and three nectarine cultivars. Delayed cooling periods of 0, 24, and 48 hours at 68F were used. After pre-conditioning, fruit were held at either 41 or 32F for four to sixteen weeks depending on storage temperature and species/cultivar. Fruit from all cultivars softened during the pre-conditioning treatments. For some cultivars, this softening limited their ability to withstand vibration and impact injury occurring during transportation. In general, delayed cooling at 68F was more effective than immediate cooling in maintaining flavor, and reducing flesh browning and mealiness after a subsequent storage period. This technique to reduce IB has been adopted by several commercial fruit packers in California.

Impacts
My research has focused on understanding stone fruit internal breakdown (IB), and developing a commercial preconditioning treatment to delay its expression. IB of stone fruit is the basis of most consumer complaints. Elimination of this problem may increase stone fruit consumption, which would be healthful for the consumer and profitable for the supplier.

Publications

• Crisosto, C. H., G. M. Crisosto, D. Garner, and K. R. Day. 2000. Quality attributes of white flesh peaches and nectarines growing under California conditions. Journal of American Pomological Society. In press.
• Crisosto, C. H., K. R. Day, R. S. Johnson, and D. Garner. 2000. Influence of inseason foliar calcium sprays on fruit quality and surface discoloration incidence of peaches and nectarines. Journal of American Pomological Society 54(3):118-122.

Progress 01/01/99 to 12/31/99

Outputs
Sensory evaluation studies with the goal of defining high quality stone fruit were carried out for early and late table grapes, sweet cherries, and kiwifruit. Consumer preference tests have indicated an important interaction between SSC, acidity, consumer background, and taste acceptance. The susceptibility to flesh browning and mealiness, internal breakdown (IB), was evaluated in a large population of peach, nectarine and plum cultivars from different genetic sources. IB was not related to the melting, non-melting, cling, or free stone fruit characteristics. The relationship between fruit ripening "ON" and "OFF" the tree and IB incidence was studied in Flavorcrest, Elegant Lady and OHenry peaches. IB was delayed in fruit harvested at different physiological maturities and exposed to "OFF" the tree delayed-cooling treatments. In commercial trials, these treatments delayed flesh browning, mealiness and off-flavor development in the peaches, nectarines, and plums evaluated. Only by attention to all aspects of production and postharvest handling can high quality be achieved and protected in fresh stone fruits.

Impacts
My research has focused on two main areas with the overall goal of increasing fresh fruit consumption. First, we have studied consumer acceptance of stone fruit, table grapes, sweet cherries, and kiwifruit in order to understand our markets. Second, we have worked to understand stone fruit internal breakdown (IB) and develop a commercial preconditioning treatment to delay its expression. IB of stone fruit is the basis of most consumer complaints.

Publications

• Crisosto, C.H., Mitchell, F.G., and Ju, Z. 1999. Susceptibility to chilling injury of peach, nectarine, and plum cultivars grown in California. HortScience 34(6):1116-1118.
• Crisosto, C.H., Garner, D., Palou, L., Metheney, P., Smilanick, J., Luvisi, D., Armson, D. and Corey, D. 1999. Assuring good arrivals of California table grapes in export markets. 1999-2000 Research Report for California Table Grape Commission. 20 pages.
• Crisosto, G., Crisosto, C.H., Garner, D., Metheney, P. and Dokoozlian, N. 1999. Understanding consumer acceptance of 'Redglobe' table grapes. Special Report to the California Table Grape Commission. 16 pages.
• Crisosto G., Crisosto, C.H., Garner, D. and Metheney, P. 1999. Understanding Consumer Acceptance of Early 'Bing' Cherry. Report to the California Cherry Commission. 15 pages.
• Crisosto, C.H., Crisosto, G. and Garner, D. 1999. Evaluation of the maturity index for 'Sugrathirteen' (Midnight BeautyTM) table grapes grown in California. Report to Sunworld International. 13 pages.
• Mitchell, F.G., Thompson, J.F., Crisosto, C.H., and Kasmire, R.F. 1998. The commodity, p. 1-7, In: James F. Thompson, F. Gordon Mitchell, Tom R. Rumsey, Robert F. Kasmire, and Carlos H. Crisosto (eds), Commercial Cooling of Fruits, Vegetables, and Flowers. Publication 21567, Division of Agriculture and Natural Resources.
• Ritenour, M.A., Crisosto, C.H., Garner, D.T., Cheng, G.W., Zoffoli, J.P. 1999. Temperature, length of cold storage and maturity influence the ripening rate of ethylene-preconditioned kiwifruit. Postharvest Biology and Technology 15:107-115.
• Slaughter, D.C. and Crisosto, C.H. 1998. Nondestructive internal quality assessment of kiwifruit using near-infrared spectroscopy. Seminars in Food Analysis 3:131-140.

Progress 01/01/98 to 12/31/98

Outputs
Sensory evaluation studies with the goal of defining high quality stone fruit are being carried out on sweet cherries, yellow flesh nectarines and peaches, and white flesh nectarines and peaches. Consumer acceptance tests have indicated an important interaction between SSC, acidity, consumer background, and taste acceptance. The susceptibility to flesh browning and mealiness, internal breakdown (IB), was evaluated in a large population of peach, nectarine and plum cultivars from different genetic sources. Changes in susceptibility to chilling injury (IB) during 'ontogeny' and 'growth' are being studied in peach and nectarine tissues. If susceptibility to IB does not change during 'ontogeny', young leaves or tips could be used to predict fruit susceptibility to IB and segregate materials early in a plant-breeding program. Data suggests that membrane leakage is the most promising test to measure chilling injury in young tissues. 'Summer Lady' peaches treated with GA3 at pit hardening were juicier and developed less flesh browning after two weeks storage at 5C than control fruit. The relationship between fruit ripening "OFF" the tree and IB incidence was studied in 'Elegant Lady' and 'O'Henry' peaches. IB was delayed in fruit exposed to "OFF" the tree delayed-cooling treatments.

Impacts
(N/A)

Publications

• CRISOSTO, C.H., SEGUEL, X., AND MICHAILIDES, T. 1998. Comparing pulsated ultraviolet light and postharvest fungicide for peach fruit decay control. In: E.R. Monet (ed), Proceedings of the Fourth International Peach Symposium. Acta Hort. 465:471-479.

Progress 01/01/97 to 12/01/97

Outputs
Sensory evaluation studies with the goal of defining high quality stone fruit are being carried out on sweet cherries, yellow flesh nectarines and peaches, and white flesh nectarines and peaches. Trained panel and consumer preference tests have indicated an important interaction between SSC, acidity, consumer background, and taste acceptance. Different non-destructive fruit quality/maturity sensors--a fluorimeter, firmness testers, color meters, and a diode array spectrophotometer (DAS)--were evaluated. The DAS technology was the most promising for detecting physical and chemical changes during stone fruit maturation and ripening. The susceptibility to flesh browning and mealiness, internal breakdown (IB), was evaluated in a large population of peach, nectarine and plum cultivars from different genetic sources. IB was not related to the melting, non-melting, cling, or free stone fruit characteristics. The relationship between fruit ripening "ON" and "OFF" the tree and IB incidence was studied in 'Elegant Lady' and 'O'Henry' peaches. IB was delayed in fruit harvested at different physiological maturities and exposed to "OFF" the tree delayed-cooling treatments. In semi-commercial trials, these treatments delayed flesh browning, mealiness and off-flavor development in the 11 peach, two nectarines, and one plum evaluated. Only by attention to all aspects of production and postharvest handling can high quality be achieved and protected in fresh stone fruits.

Impacts
(N/A)

Publications

• CRISOSTO, C.H., JOHNSON, R.S., DEJONG, T.M., AND DAY, K.R. 1997. Orchard factors affecting postharvest stone fruit quality.
• CHENG, G.W. AND CRISOSTO, C.H. 1997. Iron-polyphenol complex formation and skin discoloration in peaches and nectarines. J. Amer.
• CRISOSTO, C.H., GARNER, D.T., AND CID, L. 1997. Predicting market life for 'O'Henry' and 'Elegant Lady' peaches under controlled atmosphere conditions. CA-97 Seventh International Controlled Atmosphere Research Conference, July 13-18, UC Da
• Crisosto, G.M., CRISOSTO, C.H., AND WATKINS, M. 1997. Chemical and organoleptic description of white flesh nectarines and peaches. International Society of Horticultural Science Fourth International Peach Symposium, June 22-26, Bordeaux, Fr
• WILEY, P., CRISOSTO, C.H., JOHNSON, R.S., AND ANDRIS, H. 1997. Postharvest performance of 'Elegant Lady' peach grown with different nitrogen sources. HortScience 32(3):434.
• CRISOSTO, C.H., SLAUGHTER, D., JOHNSON, R.S., CID, L., AND GARNER, D. 1997. Determination of maximum maturity for stone fruit. HortScience
• CRISOSTO, C.H., JOHNSON, R.S., CRISOSTO, G.M., LABAVITCH, J., AND GARNER, D. 1997. Avoiding internal breakdown of stone fruit by an "off" the tree pre-ripening treatment. HortScience 32(3):497.
• CRISOSTO, C.H. 1996. Stone fruit maturity indices. Perishables

Progress 01/01/96 to 12/30/96

Outputs
Sensory evaluation studies with the goal of defining high quality stone fruit are being carried out on sweet cherries, yellow flesh nectarines and peaches, and white flesh nectarines and peaches. Trained panel and consumer preference tests are being used to accomplish this goal. Large variability in taste and market life potential was determined among stone fruit cultivars. Crop load (number of fruit per tree) is the most effective way to improve fruit taste among cultural practices such as mineral nutrition, irrigation, tree training, and pruning. Delaying harvest also contributed to increase taste quality for some of the stone fruit cultivars. Determination of maximum maturity, however, has to be done carefully for each cultivar to avoid postharvest deterioration problems. Fruit deterioration such as pathological decay, water loss, mechanical bruising and physiological disorders, will adversely impact quality in the market. The use of the critical bruising thresholds will allow maximum quality without increased deterioration. The ideal postharvest temperature management is being developed for different stone fruit cultivars. Only by attention to all aspects of production and postharvest handling can high quality be achieved and protected in fresh stone fruits.

Impacts
(N/A)

Publications

• CHENG, G.W. and CRISOSTO, C.H. Browning potential, phenolic composition, and polyphenoloxidase activity of buffer extracts of peach and nectarine skin tissue. J. Amer. Soc. Hort. Sci. 120(5):835-838.
• CRISOSTO, C.H., DAY, K.R., JOHNSON, R. S., and GARNER, D. 1996. In-season foliar calcim sprays for peaches and nectarines. Tree Fruit 5(3):6-9, 11.
• SLAUGHTER, D.C. and CRISOSTO, C.H. 1996. Nondestructive internal quality assessment of kiwifruit using near infrared spectroscopy. 8th International Diffuse Reflectance Conference, Chambersburg, PA, August 11-16, 1996.
• DAANE, K.M., JOHNSON, R.S., MICHAILIDES, T., CRISOSTO, C.H., DLOTT, J.W., RAMIREZ, H.T., YOKOTA, G. Y., and MORGAN, D.P. 1995. Excess nitrogen raises nectarine susceptibility to disease and insects. California Agriculture 49(4):13-18.
• CRISOSTO, C.H., MITCHELL, F. G., and JOHNSON, S. 1995. Factors in fresh market stone fruit quality. Postharvest News and Information 6(2):17-21.
• MITCHELL, F.G., CRISOSTO, C. H., and JOHNSON, R.S. 1995. Postharvest quality in fresh market stone fruits. 1995 Proceedings 136th Annual Meeting, Hershey Lodge and Convention Center, January 31, February 1&2, 1995. Pennsylvania Fruit News 75 ZOFFOLI, J.P. and CRISOSTO, C.H. 1995. Que es y como reducir el "inking" o entintado en frutos de duraznos y nectarines. Aconex 49, pp. 10-13.

Progress 01/01/95 to 12/30/95

Outputs
There is large variability among stone fruit cultivars in their ability to accumulate SSC and their rate of softening during maturation. Critical bruising thresholds also varied among stone fruit cultivars. Fruit position is an important factor in the calculation of these critical bruising thresholds. In general, plums tolerate more physical abuse than yellow flesh peach, nectarine and white flesh peach cultivars. Development of maximum maturity indices for different peach, plum, and nectarine cultivars based on critical bruising indices as well as eating quality is being carried out. Development of a practical protocol to determine fruit firmness in order to predict bruising susceptibility and maximum maturity looks promising. A survey of different packing protocol to determine fruit firmness in order to predict bruising susceptibility and maximum maturity looks promising. A survey of different packinghouses revealed that bruising potentials varied from 21 to 206 G's. In California's "unusual" 1995 season, delaying harvest beyond CA Well-Mature for 10 nectarine, 12 yellow flesh peach, 5 white flesh peach, and 4 plum cultivars increased fruit size and fruit red color. In most of these cultivars, delaying harvest did not increase SSC significantly compared with the risk of handling soft fruit. Manipulating cultural practices such as crop load and irrigation have been very effective in increasing fruit quality (SSC or SSC/TA).

Impacts
(N/A)

Publications

• CRISOSTO, C. H. 1994. Stone fruit maturity indices: a descriptive review. Postharvest News and Information 5(6):65N-68N.
• CRISOSTO, C. H., MITCHELL, F. G., and JOHNSON, R. S. 1995. Factors in fresh market stone fruit quality. Postharvest News and Information 6(2):17N-21N.

Progress 01/01/94 to 12/30/94

Outputs
Preharvest factors affected fruit quality, internal browning (IB) and mealiness incidence differently. Based on our first season's work, the erratic and unreliable benefit of the controlled atmosphere (CA) technique in delaying IB symptoms appears to be related to preharvest factors. Maximization of the CA benefits and fruit quality may be accomplished by using outer canopy fruit. Optimum fruit quality expression for each cultivar can be achieved by understanding the influences of preharvest factors and harvest time. We are developing a maximum maturity index for selected cultivars using bruising susceptibility measurements based on fruit firmness at the weakest point on the fruit. These bruising susceptibility measurements are being done at different levels of fruit firmness and expressed as g (acceleration). This index will predict how much physical abuse fruit will tolerate at different firmness levels during the harvesting and packinghouse operations. The comparison of fruit g. and packingline g. will help to decide how late fruit can be harvested and packed without causing bruising for each specific case.

Impacts
(N/A)

Publications

• CHENG, G.W. AND CRISOSTO, C. 1994. Development of dark skin discoloration on peach and nectarine fruit in response to exogenous contaminations. J. Amer. Soc. Hort. Sci. 119(3):529-533.
• DAANE, K.M., JOHNSON, R.S., MICHAILIDES, T.J., CRISOSTO, C.H., ET. AL. 1994. Nitrogen fertilization affects nectarines fruit yield, storage qualities, and susceptibility to brown rot and insect damage. Calif. Agric. in-press.
• CRISOSTO, C.H., JOHNSON, R.S., LUZA, J.G., AND CRISOSTO, G.M. 1994. Irrigation regimes affect fruit soluble solids content and the rate of water loss of O'Henry peaches. HortScience 29:1169-1171.
• CRISOSTO, C.H., JOHNSON, R.S., AND LUZA, J. 1993. Incidence of physical damage on peach and nectarine skin discoloration development: anatomical studies. J. Amer. Soc. Hort. Sci. 118(6):796-800.
• CRISOSTO, C.H., GARNER, D., DOYLE, J., AND DAY, K.R. 1993. Relationship between fruit respiration, bruising susceptibility, and temperatures in sweet cherries. HortScience 28(2):132-135.
• CRISOSTO, C.H., JOHNSON, S., ET AL. 1993. Skin discoloration on peach and nectarine fruit. 1993 Research Reports for Calif. Peaches and Nectarines, Calif. Tree Fruit Agreement, Sacramento, CA, 15 pp.
• DAY, K.R., ET AL. 1992. Comparison of high density training systems and summer pruning techniques and timing. 1992 Research Reports for Calif. Peaches and Nec.

Progress 01/01/93 to 12/30/93

Outputs
Fruit red color development decreased as nitrogen increased from 2.09 to 3.48% leaf or from 1.12-1.71% skin. Nitrogen levels did not affect postharvest fruit quality on fruit from 20-year-old 'Fantasia' picked at the same ground color. However, rate of weight loss for fruit from the highest nitrogen treatment was greater than for fruit from the lower nitrogen treatments. Fruit from the lowest nitrogen treatment had significantly denser cuticles (13.5 ug/mm2) than middle (10.7 ug/mm2) or highest (9.5 ug/mm2). Dirty nylon bags and dirty canvas bags induced higher bruising and inking development than clean canvas bags and olive picking buckets on 'September Red' nectarine. Individual pickers affected fruit bruising incidence. Fruit picked early in the day (7:00 a.m.) had more bruising and less abrasion damage than fruit picked later (9:00 a.m.) Decay incidence was higher on fruit harvested during the late pick, except when a dirty container was used in which case decay was high at both picking times.

Impacts
(N/A)

Publications

• CRISOSTO, C.H., RETZLAFF, W.A., WILLIAMS, L.E., DEJONG, T.M., and ZOFFOLI, J.P. 1993. Postharvest performance evaluation of plum (PRUNUS SALICINA Lindel., 'Casselman') fruit grown under three ozone concentrations. J. Amer. Soc. Hort. Sci.
• CRISOSTO, C.H., GARNER, D., CRISOSTO, G.M., SIBBETT, S., and DAY, K.R. 1994. Delayed harvest induces internal browning in 'Ya Li' and 'Seuri' Chinese pears. California Agriculture (in-press).
• CRISOSTO, C.H., GARNER, D., CRISOSTO, G.M., SIBBETT, S., and DAY, K.R. 1994. Late harvest and delayed cooling induce internal browning of 'Ya Li' and 'Seuri' Chinese pears PYRUS PYRIFOLIA x PYRUS USSURIENSIS (Max.)
• CRISOSTO, C.H., ANDRIS, H., DAY, K.R., and GARNER, D. 1994. Flesh temperature influences pitting and bruising susceptibility in 'Brooks' sweet cherry (PRUNUS AVIUM L.) cultivar. California Agriculture (In Press).

Progress 01/01/92 to 12/30/92

Outputs
INFLUENCE OF IRRIGATION REGIMES ON PEACH QUALITY AND STORAGE PERFORMANCE. Postharvest life was not reduced by any of the three irrigation treatments. Scanning and light microscope observations indicated a modification of cuticle and epidermal characteristics by the three irrigation treatments. These differences in exodermis structure may explain the lower percentage of water loss on fruit from the under irrigated (50 percent ET) compared to well irrigated (100 percent ET) and over irrigated (150 percent ET) treatments during the 1990, 1992 and 1993 seasons. INFLUENCE OF DIFFERENT OZONE PARTIAL PRESSURES ON `CASSELMAN' PLUM FRUIT QUALITY AND STORAGE PERFORMANCE. `Casselman' plum fruit quality and internal breakdown incidence measured at harvest and after 2, 4, and 6 weeks of storage at 0 C were not affected by any of the three ozone level treatments. The rate of fruit softening, water loss, ethylene production, and CO2 evolution was greater for plums harvested from the ambient air + ozone treatment compared to those from the charcoal filtered treatment. Anatomical studies of mature plums indicated differences in wax deposition and cuticle thickness between fruit from the ambient air + ozone, ambient air, and charcoal filtered air treatments. INFLUENCES OF PREHARVEST SPRAYS ON PEACH AND NECTARINE INKING DEVELOPMENT.

Impacts
(N/A)

Publications

• CRISOSTO, C.H., RETZLAFF, W.A., WILLIAMS, L.E., DE JONG, T.M. and ZOFFOLI, J.P. 1993. Postharvest performance evaluation of plum (PRUNUS SALICINA Lindel., cv. Casselman) fruit grown under three ozone partial pressures. J. Amer. Soc. Hort.

Progress 01/01/91 to 12/30/91

Outputs
Influence of irrigation regimes on peach quality and storage performance. Waterdeficit treatment (50% ET) induced a high soluble solids content in the fruit without affecting storage performance. Anatomical observations indicated modifications of fruit cuticle characteristics by 50% ET irrigated treatments. Influence of different ozone partial pressures on 'Casselman' plum fruit quality and storage performance. High ozone level during 'Casselman' plum tree growth did not reduce fruit quality and storage performance but enhanced fruit water loss and altered fruit cuticle and ripening pattern characteristics. Influences of preharvest sprays on peach and nectarine inking development. A preharvest Fe-S-chelate spray induced high inking on 'Elegant Lady'. Chelate and Ca-chelate sprays did not increase the incidence of inking on 'Elegant Lady' and 'O'Henry'.

Impacts
(N/A)

Publications

• CRISOSTO, C.H. 1991. Sweet cherry harvesting, postharvest handling and storage. Perishables Handling 71(5):2-6.
• CRISOSTO, C.H. 1991. Peach and nectarine surface staining. Perishables Handling 71(5):6-9.
• SHINKJ, K. and CRISOSTO, C.H. 1991. Flesh spot decay (FSD). Perishables Handling 72(11)3-4.
• SHINJI, K. and CRISOSTO, C.H. 1991. Bagging fruit. Perishables Handling 72(11):1-3.
• CRISOSTO, C.H. and MICHAILIDES, T. 1991. A possible new role of calcium in postharvest technology. Perishables Handling 72(11):10-11.