Progress 09/01/08 to 08/31/11
Outputs
OUTPUTS: Current registered fungicides are ineffective in controlling diseases of tropical fruits in the high rainfall, tropical climate. Therefore, additional disease management approaches, including genetic resistance and more effective fungicides, are needed to produce high quality fruits. Although current industry practice is to use similar packaging materials for both rambutans and longans, our studies showed that the optimal package differed for different fruits. Quality and shelf-life were best when fruit are stored at 10 degree Celsius. Precise temperature control during all phases of postharvest handling (packing, transportation, retail display) was critical for quality assurance. However, if temperatures exceeded 10 degree Celsius during postharvest handling, then clamshell containers were a practical choice for packaging of longans. For rambutans, modified atmosphere packaging with Peakfresh provided the best postharvest quality under constant or fluctuating temperature regimes. In postharvest studies, optimum storage temperatures and packaging systems were established. Fruit quality and shelf life were greatest when stored at 10 degree Celsius. For lychee, studies were also conducted to determine the threshold temperature for inducing flowering on Kaimana lychee. In addition, studies on market analysis and taste testing were conducted to determine consumer preference between imported and locally grown avocadoes. For market analysis, 55 avocado growers were interviewed. Majority of the growers were from Kona, Hawaii, but there were a few growers in other areas. Farm related information and marketing information were collected. Taste panel surveys were developed and administered to collect data from chefs and consumers. A total of 36 chefs participated in the surveys and 292 consumers were interviewed at the Kapiolani Community College farmers' market. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Moisture accumulation in longan fruits is greatest during the twelfth to twenty fourth week, and nutrient accumulation increases in developing fruits from week 15 to 24. Growers should periodically evaluate quality to insure that fruits are harvested at peak quality. Based on temperature and flowering data from field studies near Hilo, Hawaii, threshold winter night temperature for induction of Kaimana lychee flowering was about 15 degree Celsius. Dry weather enhanced flowering but could not substitute for low temperatures. Trunk girdling in autumn was able to enhance flowering. When selecting potential production sites for Kaimana lychee, producers should identify sites where average minimum winter temperatures between December to February are 15 degree Celsius or lower, but warmer temperatures during fruit development. After harvest and pruning, foliar fertilizer can be used instead of ground applied granular fertilizer to provide consistent levels of nutrients to lychee trees, reduce reliance on fertilizer availability dependent upon rainfall, and limit the amount of residual fertilizer held in the soil. Utilizing pruning and foliar fertilizer to synchronize and condition Kaimana lychee trees encourages more consistent production. For avocadoes, results of the market analysis showed that almost half of Hawaii avocado production was wasted without even reaching the market, the Hawaii avocado industry was not able to meet year round demand, and the growers were stallholder farmers. The data on the taste panel surveys showed that consumers and chefs preferred local cultivars to the imported Hass, and that not all local cultivars were the same.
Publications
- Keith, L.M., Nishijima, K.A., Wall, M.M., and Nagao M. 2011. Field Survey and Fungicide Screening of Fungal Aathogens of Rambutan (Nephelium lappaceum) Fruit Rot in Hawaii. HortScience 46: (in press).
- Wall, M.M., Nishijima, K.A., Keith, L.M., and Nagao, M. 2011. Influence of Packaging on Quality Retention of Longans (Dimocarpus longan) Under Constant and Fluctuating Postharvest Temperatures. HortScience 46: (in press).
- Wall, M.M., Sivakumar, D., and Korsten L. 2011. Rambutans (Nephelium lappaceum L.). In: E. Yahia (ed.), Postharvest Biology and Technology of Tropical and Sub-Tropical Fruits. Woodhead, Publishing, United Kingdom, pp. 312-333.
- Wall, M.M., Nishijima, K.A., Keith, L.M., and Nagao, M. 2010. Postharvest Practices for Managing the Quality of Longans and Rambutans. Acta Hort. (ISHS) 880:473-480.
- Krishnakumar, J., Chan-Halbrendt, C., Radovich, T., Sullivan, P., and Love, K. 2009. Supply Demand Integrated Management Model for Effective Farmer Buyer Coordination: Case of the Hawaii Avocado Industry. Journal of Chain and Network Science 9(1):17-23.
- Wall, M.M., Nishijima, K.A., Keith, L.M., and Nagao, M. 2009. Postharvest Practices for Managing the Quality of Longans and Rambutans. Australian Postharvest Conference and the Fifth International Symposium on Managing Quality in Chains, Napier, New Zealand.
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Progress 09/01/09 to 08/31/10
Outputs
OUTPUTS: Biew Kiew is the most important commercial longan cultivar grown in Hawaii due to its ability to flower after potassium chlorate application and due to its high fruit quality. Data on Biew Kiew longan fruit growth, patterns of moisture and nutrient accumulation during fruit development, and the nutrient composition of leaves are being monitored at 2 locations to develop nutrient management information and guidelines suited for this crop. A study has been initiated to synchronize the vegetative growth of the longan trees after fruit harvest to determine if the number of flushes prior to chlorate treatments will affect the flowering response. We are currently evaluating flowering of Kaimana lychee trees using a management rotation consisting of non-pruned untreated trees, non-pruned trees treated with foliar fertilizer and pruned trees to reduce canopy size with consistent lychee fruit production in Kona, Waiakea, and Hamakua. Environmental data and flowering data collected from each location will be used to determine the temperatures used to determine the cold requirement conditions for flowering of Kaimana in the growth chamber experiments. Laboratory studies with registered fungicides have been completed and the main pathogens found on rambutan and longan, Lasmenia, Pestalotiopsis, Colletotrichum and Phomopsis, have been identified. Since Serenade (a patented strain of Bacillus subtilis) showed the most promise in the laboratory and was one hundred percent effective at all test concentrations, it is being further tested in field trials and the treated fruits included in postharvest studies. In the 2008 postharvest tests for longans, fruit packaged in microperforated bags, clamshells, or Peakfresh film had the best visual quality and longest shelf-life (3 weeks) when compared to boxes or Lifespan packages. Therefore, longans harvested from the Serenade field trial in January 2009 were packaged in the three best packages (microperforated bags, clamshells, or Peakfresh film) and evaluated for visual and compositional quality, disease incidence, and shelf-life. Also, sensory analysis was conducted to further define the quality of packaged fruit. Information obtained from these studies will be shared with the Hawaii Tropical Fruit Growers association and its members at their Nineteenth Annual Conference in October 2009, and through meetings coordinated by the extension service. Also, scientific articles describing the results of the postharvest research will be prepared for publication, and a web-based extension publication will be developed and published that describes the common diseases that growers encounter when growing longan, lychee and rambutan in Hawaii. The overall goal is to recommend an integrated system of preharvest and postharvest practices that improve postharvest quality and shelf-life of rambutans and longans. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Moisture accumulation in Biew Kiew longan fruits is greatest during the 12 to 24 week and accounted for seventy-seven percent of the final weight of mature fruits, and accumulation of N, P, K, Ca and Mg in fruits increases in the developing fruit from week 15 to 24. To obtain optimum fruit growth and to maintain the vegetative health of producing trees, growers should provide adequate irrigation and fertilizer nutrients at 12 to 24 weeks after fruit set. Since fruit development occurs over 24 weeks, multiple fertilizer applications should be made during fruit growth to supply trees with adequate amounts of nutrients. Information on the influence of preharvest practices on postharvest quality and on postharvest treatments to maintain fruit quality during transportation and marketing are imperative for export of high quality longan and rambutan from Hawaii. By integrating preharvest and postharvest practices, tropical fruit growers can better manage diseases, improve fruit quality, extend shelf-life, and expand markets for their high-value crops. The postharvest and sensory quality of longan was maintained, overall disease incidence minimized, and shelf-life extended (over 14 days) when microperforated packages or clamshell containers were used in conjunction with storage at ten degrees Celsius. Adoption of an appropriate packaging system will extend shelf-life and provide a market advantage to Hawaii's longan producers and shippers. Rambutans stored in Peakfresh packages had the best overall external quality ratings and lowest disease incidence, but sensory analysis revealed adverse affects on fruit flavor. The experiment will be repeated, and the ratio between fruit weight and package surface area will be varied to achieve more ideal gas concentrations inside the Peakfresh bags. The goal is to maintain the superior visual quality and reduced disease incidence without compromising sensory quality. Adoption of a better packaging system for rambutan will not require a change in field practices but will reduce postharvest quality problems which have been major constraints during export and marketing.
Publications
- Keith, Lisa (2009). Longan Fungicide Field Trials and Laurel Wilt Update. Annual International Tropical Fruit Conference, Kona, Hawaii, September, 2009.
- Wall, Marisa (2009). Maintaining Postharvest Quality of Longans and Rambutans. Annual International Tropical Fruit Conference, Kona, Hawaii, September, 2009.
- Nagao, Mike (2009). Flowering and Fruit Set in the Sapindaceous Fruits. Annual International Tropical Fruit Conference, Kona, Hawaii, September, 2009.
- Matsumoto, Tracie (2009). Lychee and Longan Production Managmenet Update. Annual International Tropical Fruit Conference, Kona, Hawaii, September, 2009.
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Progress 09/01/08 to 08/31/09
Outputs
OUTPUTS: Laboratory studies with registered fungicides have been completed and the main pathogens found on rambutan and longan, Lasmenia, Pestalotiopsis, Colletotrichum and Phomopsis, have been identified. Longans were harvested from a commercial orchard at which trees were sprayed at the flowering and fruit set stages (2 to 4 applications) and during the last 6 weeks prior to harvest (2 to 4 applications) with two levels (2 and 6 quarts per acre) of Serenade(R). The preharvest Serenade(R) treatments did not reduce flower and fruit drop during fruit set, or reduce postharvest diseases caused by the fungal pathogens, Phomopsis sp. and Pestalotiopsis sp. Longans packaged in microperforated bags, clamshells, or Peakfresh(R) film had the best visual quality and longest shelf-life (3 weeks) when compared to boxes or Lifespan(R) packages. Fruit packaged in microperforated bags or clamshell containers had higher visual quality and lower disease incidences (14 to 35%) than those in Peakfresh(R) bags (below average quality and over 60% disease incidence) after 14 days storage at 10 C. Among fruit exhibiting disease symptoms, the most frequently isolated fungi were Phomopsis sp. (93 to 97%), Pestalotiopis sp. (17 to 40%), Colletotrichum sp. (C. gloesporiodes and C. acutatum) (3 to 23%), and Fusarium sp. (10 to 17%). The modified atmospheres inside the Peakfresh(R) packages adversely affected the longan flavor. In sensory tests, fruit from the Peakfresh(R) treatment had significantly lower taste scores (mean score = 4.8) when compared to longans placed in microperforated bags (7.4) or clamshells (7.3). PARTICIPANTS: Dr. Mike Nagao, College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa; Mr. Mel Nishina, College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa; Dr. Marisa Wall, USDA-ARS, Pacific Basin Agricultural Research Center; Dr. Lisa Keith, USDA-ARS, Pacific Basin Agricultural Research Center, Ms. Kate Nishijima, USDA-ARS, USDA-ARS, Pacific Basin Agricultural Research Center. Grower cooperators are Onomea Orchards, Plant It Hawaii and Anuenue Farms. TARGET AUDIENCES: Target audiences are the Hawaii Tropical Fruit Growers Association, Hawaii Tropical Fruit Cooperative, and individual tropical fruit growers. These results have been reported to the Annual Meeting of the Hawaii Tropical Fruit Growers Association Annual Meeting. Extension publications are prepared and distributed to growers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Information on the influence of preharvest practices on postharvest quality and on postharvest treatments to maintain fruit quality during transportation and marketing are imperative for export of high quality longan and rambutan from Hawaii. By integrating preharvest and postharvest practices, tropical fruit growers can better manage diseases, improve fruit quality, extend shelf-life, and expand markets for their high-value crops. The postharvest and sensory quality of longan was maintained, overall disease incidence minimized, and shelf-life extended (over 14 days) when microperforated packages or clamshell containers were used in conjunction with storage at 10 C. Adoption of an appropriate packaging system will extend shelf-life and provide a market advantage to Hawaii's longan producers and shippers. Rambutans stored in Peakfresh packages had the best overall external quality ratings and lowest disease incidence, but sensory analysis revealed adverse affects on fruit flavor. Adoption of a better packaging system for rambutan will not require a change in field practices but will reduce postharvest quality problems which have been major constraints during export and marketing.
Publications
- Follett, P.A., Weinert, E.D. 2009. Comparative radiation dose mapping of single fruit type and mixed tropical fruit boxes for export from Hawaii. Journal of Food Processing and Preservation. 33: 231-244
- Matsumoto, T.K., F. Zee, M. Nagao, M. Nishina, V. Easton-Smith. 2007. Management of flowering and fruiting of `Kaimana' lychee in Hawaii. 17th International Tropical Fruit Conference Proceedings (CD-ROM). Hilo, HI pp. 67-78.
- T.K. Matsumoto, M.A. Nagao and B. Mackey. 2007. Off-season flower induction of longan with potassium chlorate, sodium chlorite and sodium hypochlorite. HortTechnology 17(3): 296-300.
- Matsumoto Brower, T.K., Tsumura, T., Zee, F.T. 2007. Exploring the mechanism of potassium chlorate induced flowering in dimocarpus longan. Acta Horticulturae 738 pg. 451 - 457.
- Zee, F.T., Matsumoto Brower, T.K., Keith, L.M., Nagao, M., Nishina, M. 2007. From Germplasm Collection to Kaimana Lychee Production Management. Keith,L. 2007. Tropical Fruit Diseases. 16th Annual International Tropical Fruit Conference. [CD-ROM]. Hilo, HI. Hawaii Tropical Fruit Growers. www.hawaiitropicalfruitgrowers.org
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