Progress 09/01/09 to 08/31/12
Outputs
OUTPUTS: Results of the project on the Pitanga (Surinam cherry) have heightened the public awareness of its health benefits; as such, fresh Pitanga fruits have been consistently available in natural food stores and in traditional grocery stores on the Big Island. Pitanga fruits, freshly picked and immediately packaged in small clamshells, were almost always sold out at retail stores. An informative label affixed to Pitanga fruit packaging details its nutritional value in antioxidants and vitamin C content has helped to promote the fruit and attracted the interests of the public to purchase it. A local food distributor has successfully provided a constant supply of Pitanga to local high scale restaurants, hotels, and other food service venues. Pitanga fruits are highly delicate and easily perishable, they are processed into several highly value added products, including jams, jellies, fruit juice, popsicles, vinaigrette, and many other food items. Some even used Pitanga in wine brewing or as additive to beer for fruit flavor or for the fermented health beverage Kombucha. Project principal investigators and staff have coordinated with other researchers and extension workers to facilitate the publication and dissemination of results from separate but related projects in order to improve communication and collaboration among faculty and others interested in promoting consumption of locally grown avocados. Results of the avocado and Pitanga projects were presented at the annual meeting of the Hawaii Tropical Fruit Growers Association in 2009, 2010 and 2011, which were attended by over 100 participants each year. Pitanga was also presented to the public through an outreach of farmer and chef presentations at a farmers market on the Big Island, in which, the chef prepared and served dishes using Pitanga as a major culinary ingredient. Recipes of those dishes prepared by the chef were made available to the public and the event was also reported by a local newspaper. PARTICIPANTS: Principal Investigators: Mike Nagao, University of Hawaii, College of Tropical Agriculture and Human Resources (CTAHR). Stuart Nakamoto, University of Hawaii, CTAHR. Ty McDonald, University of Hawaii, CTAHR. Ted Radovich, University of Hawaii, CTAHR. Loren Gautz, University of Hawaii, CTAHR. Mark Wright, University of Hawaii, CTAHR. Partner Organizations: Marisa Wall, USDA, Agricultural Research Service. Lisa Keith, USDA, Agricultural Research Service. Kate Nishijima, USDA, Agricultural Research Service. Tracie Matsumoto, USDA, Agricultural Research Service. Peter Follett, USDA, Agricultural Research Service. Susan Schenk, Hawaii Agriculture Research Center. Mel Jackson, Hawaii Agriculture Research Center. TARGET AUDIENCES: Hawaii Tropical Fruit Growers. Information is disseminated through yearly review meetings which include progress reports presented by the principal investigators listed above. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Approximately 16 grafted avocado trees from selected seedling budwoods have been field planted. Scion wood of 8 selected avocado genotypes has been collected and grated trees are being maintained in the nursery before being transplanted. This project is identifying and preserving unique avocado germplasm with the intended long-term outcome of further increasing the market share of locally grown fruit. Short term outcomes include increased awareness by chefs and consumers of the sensory characteristics of little known varieties and superior seedlings, as well as developing new appreciation for standard varieties such as Sharwil. Improved communication and collaboration among researchers, extension workers, and educators interested in niche and larger commodity marketing of avocado is an additional short term impact. Multiple seedling trees with superior sensory characteristics have been identified, grafted, and established in a field planted collection at the Kainaliu station. This collection will serve as a source of budwood for larger, multiple location trials in the future to evaluate the agronomic performance and general adaptability of the varieties in the collection. Avocado growers are aware of the collection being established and have expressed interests in the germplasm to fill the gaps encountered in the annual supply cycle of local avocados. The project has strengthened collaborations with the USDA Pacific Basin Agricultural Research Center (PBARC) in the study on the avocado maturity and quality indices conducted at PBARC using the data generated under this project. We identified package types for longans and rambutans that maintain the postharvest and sensory quality of fruit, minimize overall disease incidence, and extend shelf-life under ideal storage temperatures. Moderate humidity packaging that minimizes skin dehydration without wetting the fruit seems optimal for longans, and microperforated, clamshell and Peakfresh packages appeared to meet these conditions. The use of clamshells, Peakfresh bags, or microperforated bags retained longan quality under constant ten degree celsius. However, temperature fluctuations are common during the postharvest chain and can impact the effectiveness of packaging. When the packages were tested under fluctuating temperatures typical during shipping and handling, sensory quality declined as compared to ten degree celsius. Longans stored in Peakfresh had the lowest weight loss regardless of temperature, whereas fruit packaged in microperforated bags had the greatest weight loss and the softest arils under fluctuating temperatures. In general, longans packed in clamshells tended to have firmer arils, lower disease incidence, and slightly higher flavor scores under fluctuating postharvest temperatures than fruit in other package types.
Publications
- Wall, M.M., Nishijima, K.A., Keith, L.M., and Nagao, M.A. (2010). Postharvest Practices for Managing the Quality of Longans and Rambutans. Acta Hort. (ISHS) 880:473-480.
- Keith, L.M., Nishijima, K.A., Wall, M.M., and Nagao, M.A. (2011). Field Survey and Fungicide Screening of Fungal Pathogens of Rambutan (Nephelium lappaceum) Fruit Rot in Hawaii. HortScience 46: 730-735.
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Progress 09/01/10 to 08/31/11
Outputs
OUTPUTS: Identification of high quality local avocadoes was conducted and sensory evaluations of over 200 entries of avocadoes have been completed. Approximately 40 entries were identified as superior in eating quality. Collection of scion woods and grafting of superior selections has continued. Grafted seedlings of about 20 named varieties and seedlings have been planted in the field at the Kainaliu Experiment Station in Kona, Hawaii. In collaboration with the USDA ARS, analyses of sensory quality, dry matter content, and oil content of selected avocado genotypes have been conducted. Longan (Dimocarpus longan) and rambutan (Nephelium lappaceum) are two of the most important specialty fruit crops grown in Hawaii. Consumer acceptance of these high value crops requires that fruit arrive at their final destination in excellent condition. However, rapid skin browning and postharvest decay are major limitations to fruit shelf life and export to distant markets. Research was conducted to integrate pre harvest disease control methods with postharvest practices to manage diseases, improve fruit quality, and extend the shelf life of longans and rambutans. Field applications were made at commercial orchards of rambutan and longan with Serenade, the registered fungicide shown to be most effective in laboratory tests on fungi isolated from fruits. Applications were made according to label specifications and to simulate grower practices. Preharvest orchard treatment did not prevent fruit drop, reduce disease incidence, or improve the quality of rambutans, but decreased the amount of fruit blemishes caused by fungal pathogens on longans at harvest. PARTICIPANTS: Principal Investigators: Mike Nagao, University of Hawaii, College of Tropical Agriculture and Human Resources (CTAHR). Stuart Nakamoto, University of Hawaii, CTAHR. Ty McDonald, University of Hawaii, CTAHR. Ted Radovich, University of Hawaii, CTAHR. Loren Gautz, University of Hawaii, CTAHR. Mark Wright, University of Hawaii, CTAHR. Partner Organizations: Marisa Wall, USDA, Agricultural Research Service. Lisa Keith, USDA, Agricultural Research Service. Kate Nishijima, USDA, Agricultural Research Service. Tracie Matsumoto, USDA, Agricultural Research Service. Peter Follett, USDA, Agricultural Research Service. Susan Schenck, Hawaii Agriculture Research Center. Mel Jackson, Hawaii Agriculture Research Center. TARGET AUDIENCES: Hawaii Tropical Fruit Growers. Information is disseminated through yearly review meetings which include progress reports presented by the principal investigators listed above. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Results of the identification of high quality local avocadoes and the analyses of their sensory quality, dry matter content, and oil content were presented at the annual meetings of the Hawaii Tropical Fruit Growers Association in 2009 and 2010, which were attended by over 100 participants each year. Consumer acceptance of longans and rambutans requires that fruit arrive at their final destination in excellent condition. Main fungal pathogens were identified; cultivars evaluated for disease resistance, field applications of registered fungicides studied for disease control, and optimum postharvest temperatures and packaging systems were established. Similar pathogens are found on both rambutan and longan trees, and shows that orchards cultivating both crops simultaneously can have susceptible hosts for these pathogens year-round. The Egami longan cultivar and the R167 rambutan cultivar appear more resistant to fungal infection overall. Current registered fungicides are ineffective at controlling disease in the high rainfall, tropical climate. Therefore additional disease management approaches, including genetic resistance and more effective fungicides are needed to produce high quality fruit. Although current industry practice is to use similar packaging materials for both rambutans and longans, the research showed that the optimal package differs for these fruit. Quality and shelf-life is best when fruit are stored at 10 degree Celsius. Precise temperature control during all phases of postharvest handling (packing, transportation, retail display) is critical for quality assurance.
Publications
- Wall, M.M., Nishijima, K.A., Keith, L.M., and Nagao, M.A. (2011). Influence of Packaging on Quality Retention of Longans (Dimocarpus longan) Under Constant and Fluctuating Postharvest Temperatures. HortScience 46:(in press).
- Zee, F.T., and Matsumoto Brower, T.K. (2010). The Tropical Fruit and Nut Collections and Research Activities at the USDA-ARS Pacific Basin Agricultural Research Center, Tropical Plant Genetic Resources Management Unit. Journal of American Pomological Society 64(1): 2-4.
- Matsumoto, T. (2010). Management of Flowering and Fruit Development Longan and Lychee. Twenty Annual International Tropical Fruit Conference. Wailua, Kauai, September 24-26, 2010.
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Progress 09/01/09 to 08/31/10
Outputs
OUTPUTS: For evaluating the avocado germplasm, more than 200 avocado seeds have been planted with 15 grafting tests of selected varieties being performed by experiment station personnel, Hawaii Tropical Fruit Grower, and American Culinary Federation Kona Kohala Chefs Association members. Three trees have been identified as candidates for the collection based on fruit quality, primarily creaminess, seed size and other characteristics. Identifying high quality cultivars with high oil contents that bear in the summer is a high priority objective of this project. To this end, evaluation protocols were revised in consultation with experienced USDA/ARS staff and American Culinary Federation members to optimize evaluation efficiency and maximize the sensitivity of the evaluation of "summer pears." The efficacy of MDSS treatment method against surface pests has been demonstrated. However, its efficacy against the internal pests such as fruit flies has yet to be tested. Results of the in-vitro study showed that mortality of naked adults and larvae of fruit flies generally increased with increasing number of MSDD repetitions. Mortality of fruit fly larvae was low (1-2%) in the vacuum only treatment and relatively high (up to 99%) in the vacuum plus ethanol injection treatment. Oriental fruit fly larvae were significantly more tolerant against MSDD than Medfly or melon fly larvae. Two fruit growers have expressed an interest in acquiring plant materials of the germplasm of the Surinam cherry maintained at the Hawaii Experiment Station. Also at a recent UH Master Gardener outreach event, over 90% of the visitors attended the event found the fruits to be tasty and unique. The MSDD treatment method was found to be effective against the surface infested pests, such as white peach scale. However, it was not effective in controlling such internally infested pests as Medfly, oriental fruit fly or melon fly. Therefore, the MSDD treatment method may be used in quarantine treatment of surface infested pests. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Preliminary results in fertilizer trials and physiological study on fruit bearing and flowering of Surinam cherry trees have been obtained using the 3-year old dark-fruited type of Surinam cherry. The symbiotic relations found between the white-footed ant and a mealybug elevated the important of controlling the infestation of the white-footed ant in Surinam cherry orchards. Using pest management practices, including bait stations, tangle foot tapes, and removing tree branches touching ground, the ant was placed under good control in orchards. Brix contents of the cherry were tested and the results were varied. Climatic conditions where the cherry trees were grown appeared to have caused the variation in Brix contents in the cherry fruits sampled. The nutritional and anti-oxidant levels of the cherry are being tested by a project collaborator at the University of Tennessee. The results should be soon available. In Papayas, about 50% of the fruit fly pupae treated with MSDD emerged as compared with untreated control. Likewise, 50% of the 1st instars larvae of the Medfly in papayas treated with MSDD eventually pupated, which was the same number of the larvae pupated as that of the untreated control. However, when the white peach scale was subject to the MSDD treatment, 98% of its 2nd instars were killed by MSDD in two replicated trials. In selection of cacao cultivars, the cacao trees planted in Hawaii were identified as Crillo, Amazon Forestero and Trinitario types. Results of the selection of fermentation microorganisms showed that five species of yeasts, two species of lactobacilli and one acetic acid bacteria were isolated. Cacao beans subjected to some of the combinations of these microorganisms at 1 billion viable cells per kg of beans were found to result in sufficient growth of the microorganisms and generate high quality of chocolate as determined by the Guittard Chocolate. The quality of chocolate appeared to be influenced by such factors as cultivars, fermentation process, and environmental factors.
Publications
- No publications reported this period
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