Grant Information
| Knowledge Area | Subject of Investigation | Field of Science | Percent |
|---|---|---|---|
| 503 - Quality Maintenance in Storing and Marketing Food Products | 910 - Grapefruit | 1020 - Physiology | 60% |
| 503 - Quality Maintenance in Storing and Marketing Food Products | 920 - Orange | 1020 - Physiology | 20% |
| 503 - Quality Maintenance in Storing and Marketing Food Products | 999 - Citrus, general/other | 1020 - Physiology | 20% |
This project is intended to improve fresh Florida citrus quality and marketability. Fresh citrus is a major contributor to the economic prosperity of the State of Florida and at the national level. Florida is the number one producer of grapefruit, tangerines, and oranges in the nation, although most oranges are produced for the juice market. During the 2009-10 season, while fresh shipments declined more than 5% compared to the previous season to 32.5 million cartons (4/5 bu), revenues increased more than 19% to over $433 million. Of this fresh production, approximately 54% was grapefruit, 28% oranges, and the remaining 19% tangerines and tangelos. Various defects in citrus fruit appearance can change the marketable value of fruit even though internal quality is unaffected. Of the citrus harvested for the fresh market, about half possess external blemishes that are unacceptable for the fresh market and must be graded out at the packinghouse and diverted to the less profitable juice market. Therefore preharvest cultural and harvest practices and/or treatments that increase the percentage of marketable fruit have direct economic returns to the industry. Furthermore, distant export markets are of critical importance to Florida's fresh citrus growers. For example, only 35% of the 2009-10 fresh grapefruit was shipped to domestic markets, while the rest was exported. Transit times to these more lucrative, distant markets may take up to 28 days. Thus, existing and new fresh citrus cultivars must be of maximum quality and handled after harvest in such a way that maintains excellent quality throughout extended marketing chains. This project will conduct collaborative, multi-disciplinary research to develop and evaluate new preharvest treatments and technologies to improve the quality and postharvest quality retention of existing and new fresh citrus cultivars. Studies will evaluate preharvest environmental factors such as cultural practices, effects of different plant growth regulators, preharvest fungicides, and other chemical treatments. Postharvest treatments will include physical (e.g., washing methods), chemical (e.g., fungicides), and grading procedures. This project will help provide current and new citrus cultivars with excellent postharvest keeping quality, minimize receiver claims due to quality defects, and improve overall arrival quality of fresh citrus at destination markets. We will develop and disseminate production and postharvest handling recommendations to maintain and extend quality of fresh citrus. Results will be published in refereed, scientific journals and extension publications will be published in accessible form via the EDIS system of the Florida Cooperative Extension Service (http://edis.ufl.edu). The information will also be disseminated through extension workshops, such as the annual Packinghouse Day and Indian River Postharvest Workshop, and other events as needed.
Improve fresh Florida citrus quality and marketability
Expected Outputs: The collaborative research will help provide current and new cultivars with excellent postharvest keeping quality, minimize receiver claims due to quality defects, and improve overall arrival quality of fresh citrus at destination markets. For example, postharvest peel disorders (i.e., pitting, necrotic areas, discoloration, etc.) have often resulted in large economic losses of fresh citrus arriving at important export markets such as the European Union and Japan. Recent research in our program demonstrated that preharvest application of a foliar nutrient (potassium or magnesium) or antitranspirant spray greatly reduced a common type of peel breakdown. Subsequent postharvest studies demonstrated additional ways to reduce this breakdown. Some growers who experienced tens of thousands of dollars in losses due to such breakdown learned of our research, began applying similar treatments and reported reduced losses due to such disorders. This systems approach to postharvest quality will be taken to increase grower and shipper returns by improving overall fruit quality of existing and new fresh citrus cultivars and reducing losses due to diseases or physiological disorders. It will also be used to ensure removal of all fruit with disease symptoms of quarantine significance, such as citrus canker and citrus black spot, when domestic and/or export markets establish quarantines for such diseases. This maintains important markets open to Florida's fresh citrus and improves the industry's reputation when negotiating potential quarantine requirements. All issues will be evaluated using a multi-disciplinary approach involving plant pathologists, microbiologists, agricultural engineers, breeders, horticulturists, economists, Extension agents, and commercial producers and packers to develop results that thoroughly evaluate these issues from multiple perspectives.
Collaborative experiments with UF and USDA plant pathologists, physiologists, soil scientists and industry representatives will be established in the fields of growers in the Indian River region, but also with those throughout the state to test preharvest environmental factors, cultural practices, effects of different plant growth regulators (e.g., gibberellins, auxins, abscisic acid, etc.), preharvest fungicides, and other chemical treatments. Spray materials will be applied to runoff using a handgun or backpack air-blast sprayer. Preharvest treatments will use a randomized complete block (RCB) design. Fruit will be harvested and transported to the postharvest facilities at the Indian River Research and Education Center (IRREC) and processed (e.g., in some cases washed and waxed). The fruit will be stored in temperature-controlled rooms and evaluated as described below. For postharvest experiments, fruit will be collected from commercial groves or packinghouses within the Indian River region, or obtained from the UF/IFAS citrus fruit improvement program at the Citrus Research and Education Center, in Lake Alfred. Postharvest treatments will include physical (i.e., washing methods, holding temperatures and heat treatments, exposure to different relative humidities, etc.), chemical (i.e., experimental fungicides, plant growth regulator, sanitizers, etc.), and grading procedures (i.e., using different lighting, conveyer speeds, background roller colors, etc.). For grading experiments, we will collaborate with a UF Agricultural Engineer. Postharvest experiments will use either a RCB or completely randomized design (CRD). Fruit will be evaluated for initial quality and maturity, treated, stored at various temperatures, and evaluated for decay and the development of physiological disorders at regular intervals to determine storage/shelf life. In addition, changes in peel or flesh color, peel integrity, fruit respiration, ethylene production, internal quality parameters may be measured periodically. Data will be analyzed using Analysis of Variance, with Duncan's Multiple Range Test for means separation in treatments with significant differences (SAS Version 9.0; SAS Institute, Inc., Cary NC). Collaboration with UF Economists will evaluate the economic impact(s) of commercial implementation of procedures suggested by the research results. Information obtained from the above research will be submitted to refereed, scientific journals of international reputation and extension publications will be developed and published in accessible form via the EDIS system of the Florida Cooperative Extension Service (http://edis.ufl.edu). The information will also be disseminated through extension workshops, such as the annual Packinghouse Day and Indian River Postharvest Workshop, and other events as needed. Related PowerPoint presentations will be created and made available to growers, county extension agents and support industry representatives. Most publications will be written in English, although extension publication may also be translated into Spanish and Haitian Creole.
Target Audience
The primary audiences for this information have been growers, harvesters, packers, and shippers of fresh citrus. Fellow researchers are also an audience to spur scientific discussion and the development of future experiments.
Changes / Problems
Nothing Reported
Training & Professional Development
Conferences attended: MRL Harmonization Workshop, June 2014, San Francisco, CA. Florida State Horticultural Society Annual Meetings, June 2014, Orlando, FL. American Society for Horticultural Sciences annual meetings, July 2014, Orlando, FL
Dissemination Streams
Presentations: Postharvest Degreening and Ripening Practices and Technology. June-July 2014 (separate presentations at the following universities) China Agriculture University, Beijing, China Beijing Technology and Business University, Beijing, China Southwest University Chongqing, China Fujian Agriculture and Forestry University, Fuzhou, China Non-Anticipated Impacts of Residue Tolerances. 2014 MRL Harmonization Workshop, June 2014, San Francisco, CA. Field and Packing Facility Sanitation. Part of the workshop, "Developing & Implementing a Hazard Analysis, Risk-Based Preventive Control (HARPC) Safety Plan for Fresh Produce", February 2014, Athens, GA. Sanitation During Transportation. Part of the workshop, "Developing & Implementing a Hazard Analysis, Risk-Based Preventive Control (HARPC) Safety Plan for Fresh Produce", February 2014, Athens, GA. Temperature & Relative Humidity Conditions During Transport of Gift Fruit Citrus Shipments. Florida Gift Fruit Shippers Association Annual Meeting, Sept. 19, 2014, Melbourne, FL. Update on Fruit Quality Issues, Peel Breakdown, and Decay Control. Fifty-Third Annual Citrus Packinghouse Day, Aug. 21, 2014, Fort Pierce, FL. Preliminary Report on Temperature & Relative Humidity Conditions During Transport of Gift Fruit Citrus Shipments. Florida Gift Fruit Shippers Association Board Meeting, May 13, 2014, Orlando, FL. Pre- and Postharvest Practices to Maximize Quality and Minimize Postharvest Decay and Disorders of Fruits and Vegetables. New Technology for Commercial Vegetable and Fruit Production (II). February 2014, Gainesville, FL (& via Polycom throughout the state). Temperature and Relative Humidity Conditions During Transport of Commercial Gift Fruit Citrus Shipments. Florida State Horticultural Society Annual Meetings, June 2014, Orlando, FL. Agricultural Challenges and Issues for Martin County. Martin County Board of County Commissioners Public Meeting. Sept. 23, 2014, Stuart, FL. Grade lowering Defects on Fresh Fruit. Florida Citrus Show, January 2014, Ft. Pierce, FL. Correct Identification of Citrus Fruit Diseases. Presented to 3 different industry groups within the state. Principles of Good Food Safety/Hygiene. Presented to 12 different industry groups within the state. OSHA Standard Changes Resulting from the Globally Harmonized System. Presented to 4 different industry groups within the state. The presentations on correct identification of citrus disease was as part of team of UF/IFAS research and Extension faculty and was part of 12 workshops conducted during the current reporting period throughout different citrus growing regions of Florida, training approximately 1,089 workers from 33 different companies. In all, approximately 4000 laminated sheets, posters and other visual aids illustrating and contrasting symptoms of citrus canker and citrus black spot with various defects and diseases that are not of quarantine significance. These workshops have become an annual program and are an important contributor to preventing infected fruit from being shipped to restrictive export markets. Such markets have never reported finding citrus canker or black spot on fresh citrus from Florida. Often during the same training program, we also gave presentations on good food safety/hygiene and personal hygiene. During the current reporting period, more than 33 different companies/businesses participated, resulting in 1,327 documented and trained employees in Food Safety.
Next Reporting Steps
Evaluate and develop ways to control citrus black spot symptom development on harvest fruit. Research will continue evaluating in vitro effects of essential oils, heat, fungicides, and systemic acquired resistance inducing compounds, but will also combine treatments (e.g., heated fungicides) and will evaluate treatments on symptomatic and asymptomatic fruit from blocks with citrus black spot. In addition to potassium phosphite, I will expand work with heated fungicide solutions to control a broader range of postharvest decays in fresh Florida citrus. Postharvest evaluations of new fresh fruit selections will continue and factors that influence fruit peelability will be expanded to more varieties and how peelability changes during maturation.