Progress 09/01/06 to 08/31/09
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 (I & II) to develop nutrient management information and guidelines suited for this crop. Fruit growth followed a sigmoid pattern, with the largest increase in fruit weight occurring between 12 and 24 weeks after fruit set. The increase was primarily due to moisture accumulation which accounted for 77% of the final weight of fruits by week 24. The weight of individual 'Biew Kiew' fruits ranged between 0.48 to 0.54 ounces, with 29 to 33 fruits contained in each pound. Longan fruits matured at about 24 weeks after anthesis when total soluble solids (brix) content reached its maximum (19.2%). Although fruit weight increased slightly after 24 weeks, fruit quality decreased over the nest 3 weeks due to a reduction in soluble solids and increased seed germination. Due to the large amount of fruit set on KClO3 treated longan trees, large amounts of fertilizers are supplied to sustain fruit growth, and can result in high concentrations of fertilizer nutrients remaining in the soil and trees when subsequent KClO3 applications are made. A study has been initiated to determine if the nutritional status of trees at the time of chlorate application affects the response to chlorate. 'Biew Kiew' trees exhibiting high and low nutrient levels were treated with potassium chlorate are being evaluated for their response to KClO3. Observations indicated that trees exhibiting high and low nutrient levels both responded well to KClO3 application, however response in the low nutrient level trees was slightly delayed.Due to the reduction in the budget, the molecular aspects of the research project are being reduced to focus upon studies that will be more immediately applicable to the Hawaii tropical fruit growers. We are working with Dr. Tom Davenport at the University of Florida to clone the FT (Flowering Locus T) genes from lychee and longan. The FT gene has been associated with "Florigen" model in which the "flowering signal" is translocated from the leaves to the meristem to induce flowering in other plant systems. We will monitor these genes along with our growth chamber and field experiments to determine the condition for flowering. The "Egami" longan and "Kaimana" lychee trees have been propagated and established in pots the nursery. Each longan tree was planted adjacent to a lychee tree to encourage intermingling of the root systems and to make it easier to approach graft the 2 trees. Approach grafting between the lychee and longan trees in the nursery to evaluate transmission of a floral stimulus after KClO3 treatment will begin after air layered trees are well established. To test the transmission of the floral stimulus between lychee cultivars, air layers of "Kaimana", "Hak Ip", "No Mai Tsz" and "Salathiel" have been propagated and are currently being established in the greenhouse. PARTICIPANTS: Individuals working on this grant from the College of Tropical Agriculture and Human Resources, University of Hawaii: Dr. Mike Nagao, Department of Plant and Soil Sciences (TPSS); Dr. John Griffis (TPSS); Dr. Kent Fleming (TPSS); Ms. Virginia Smith (TPSS); Mr. Ty McDonald (TPSS); Mr. Mel Nishina (TPSS); Dr. Loren Gautz, Department of Molecular Biosciences and Bioengineering (MBBE); Dr. Catherine Chan-Halbrendt, Department of Natural Resource and Environmental Management (NREM); and Dr. Stuart Nakamoto; Department of Human Nutrition, Food and Animal Sciences (HNFAS). Participants from the USDA ARS Pacific Basin Agricultural Research Center are Dr. Peter Follett, Dr. Tracie Matsumoto; Dr. Marisa Wall; Dr. Lisa Keith, and Ms. Kate Nishijima. From the Hawaii Agricultural Research Center, Dr. Mel Jackson, participated in the project. From the University of Florida, Dr. Thomas Davenport. From the Hawaii Tropical Fruit Growers Association, Mr. Ken Love, Mrs. Gini Choobua and Mrs. Susan Hamilton were individuals who worked on the project. Partner organizations involved were the Hawaii Tropical Fruit Growers Association, the Hawaii Cacao Growers Association, and the Hawaii Avocado Association. This project funded several graduate students. TARGET AUDIENCES: Members of the Hawaii Tropical Fruit Growers Association; other tropical specialty fruit growers in Hawaii; College of Tropical Agriculture and Human Resources Cooperative Extension Service; Hawaii Farm Bureau Federation members and Hawaii farmers at large. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Moisture accumulation in 'Biew Kiew' longan fruits is greatest during the 12th to 24th week and accounted for 77% 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. Based on preliminary studies on the nutrient content of mature 'Biew Kiew' fruits (1.01% N, 0.18% P, 1.72% K, 0.30% Ca and 0.16% Mg), fertilizer ratios such as 10-5-20 w/micronutrients, 15-5-25 w/micro nutrients, or 14-7-28 w/micronutrients are recommended to supply trees with appropriate fertilizer nutrients during fruit development. Since fruit development occurs over 24 weeks, multiple fertilizer applications should be made during fruit growth to supply trees with adequate amounts of nutrients. The large amounts of K found in the fruits also indicate that additional K applications during fruit development will be beneficial. Longan fruits will mature at about 24 weeks after flowering when total soluble solids (brix) content reached its maximum (19.2%). If fruits are not harvested at peak maturity and are left on the tree, fruit weight will increase slightly after 24 weeks, but fruit quality will decrease significantly within 2 weeks due to a reduction in soluble solids and increased seed germination. Growers should periodically evaluate quality as fruits mature to insure that fruits are harvested a peak quality. Based on temperature and flowering data taken from a low elevation (68 m) growing site near Hilo, HI, the threshold winter night temperature for induction of Kaimana lychee flowering appears to be about 15 degrees C. Dry weather enhances flowering but does not substitute for low temperatures, and trunk girdling in autumn can enhance flowering. Therefore when selecting potential production sites for Kaimana lychee producers should identify sites where the average minimum winter temperatures between December to February are 15 degrees C and lower.
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
|
Progress 09/01/07 to 08/31/08
Outputs
OUTPUTS: 1)Integrating Preharvest and Postharvest Practices to Improve Fruit Quality of Rambutan and Longan: In vitro fungicide assays were completed for the fungicides Trilogy(R), Abound(R) and Serenade(R) for the four main pathogens found on rambutan and longan, Lasmenia, Pestalotiopsis, Colletotrichum and Phomopsis. Trilogy(R) was least effective, with % inhibition ranging from 14 to 26% for Pestalotiopsis, Colletotrichum and Phomopsis and 61% for Lasmenia. Abound was a little more effective, with % inhibition ranging from 30 to 52% for Pestalotiopsis, Colletotrichum and Phomopsis and 78% for Lasmenia. Serenade(R) showed the most promise in the laboratory and was 100% effective at all concentrations tested. Serenade(R) was chosen for all future field trials. Postharvest experiments to date suggest that modified atmosphere packaging with Peakfresh(R) or Lifespan(R) films, combined with optimal temperatures (10C), extends rambutan shelf-life when compared to current industry packaging approaches (micro-perforated bags, clamshells, or boxes). Respiring fruit created a modified atmosphere inside the Peakfresh(R) and Lifespan(R) packages, with steady state CO2 concentrations ranging from 4-5%. As a result, fruit packaged in Peakfresh(R) or Lifespan(R) bags had better visual quality and less postharvest disease than rambutans placed in other package types. For longans, fruit 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 packages. 2)Improving Flowering of Longan and Lychee Trees in Hawaii: To provide consistent levels of nutrients to trees, foliar fertilizer was applied immediately after pruning to synchronize and condition Kaimana trees. Trees growing rocky soil at Waiakea and in Kona successfully flowered and set fruit with this strategy. Similar treatments on trees in silty clay loam soil in Hamakua produced vigorous vegetative growth and reduced flowering. 3)Enhancing the Competitiveness of Hawaiian Fruit Producers' Through the Marketing and Branding of Locally Grown Avocado: Two taste panels were conducted - one with chefs in Kailua-Kona and in Honoluu and one with consumers in Honolulu. A total of 36 chefs and 292 consumers participated in the taste panel surveys. Both chefs and consumers rated the top locally grown avocado cultivars compared with imported Hass avocados. The local cultivars are Sharwil, Kahaluu, Malama, Linda and Yamagata. For taste characteristics (flavor and texture),the chefs preferred the local cultivars Kahuluu, Malama and Linda and the Hass was least preferred. Consumers preferred Yamagata over all other cultivars. Seed-to-meat ratio is an important characteristic for consumers because they pay by the pound. The Sharwil was found to have the poorest seed-to-meat ratio, compared with Linda and Malama. PARTICIPANTS: Individuals working on this grant from the College of Tropical Agriculture and Human Resources, University of Hawaii: Dr. Mike Nagao, Department of Plant and Soil Sciences (TPSS); Dr. John Griffis (TPSS); Dr. Kent Fleming (TPSS); Ms. Virginia Smith (TPSS); Mr. Ty McDonald (TPSS); Mr. Mel Nishina (TPSS); Dr. Loren Gautz, Department of Molecular Biosciences and Bioengineering (MBBE); Dr. Catherine Chan-Halbrendt, Department of Natural Resource and Environmental Management (NREM); and Dr. Stuart Nakamoto; Department of Human Nutrition, Food and Animal Sciences (HNFAS). Participants from the USDA ARS Pacific Basin Agricultural Research Center are Dr. Peter Follett, Dr. Tracie Matsumoto; Dr. Marisa Wall; Dr. Lisa Keith, and Ms. Kate Nishijima. From the Hawaii Agricultural Research Center, Dr. Mel Jackson, participated in the project. From the Hawaii Tropical Fruit Growers Association, Mr. Ken Love, Mrs. Gini Choobua and Mrs. Susan Hamilton were individuals who worked on the project. Partner organizations involved were the Hawaii Tropical Fruit Growers Association, the Hawaii Cacao Growers Association, and the Hawaii Avocado Association. This project funded several graduate students. TARGET AUDIENCES: Members of the Hawaii Tropical Fruit Growers Association; other tropical specialty fruit growers in Hawaii; College of Tropical Agriculture and Human Resources Cooperative Extension Service; Hawaii Farm Bureau Federation members and Hawaii farmers at large. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
A major export constraint for longan and rambutan from Hawaii has been lack of information on the influence of preharvest practices on postharvest quality, and the absence of information on postharvest treatments to maintain fruit quality during transportation and marketing. A primary bottleneck in postharvest quality for rambutans and longans is fruit decay from fungal diseases. An integrated system of preharvest and postharvest practices will enable specialty tropical fruit growers to manage diseases, improve fruit quality, extend shelf-life, and expand markets for these high-value crops. Similar pathogens were found on both rambutan and longan fruits, indicating that orchards cultivating both crops simultaneously could have susceptible hosts for these pathogens year-round. Modified atmosphere packaging appears to be a viable alternative to the standard industry packages, although the optimal package will differ for longans and rambutans. Currently the industry practice is to utilize similar packaging materials for both longan and rambutan. Adoption of a new packaging system will extend shelf-life and provide a market advantage to Hawaii's specialty fruit growers and exporters. In Hawaii, consistent lychee production is achieved through management practices that limit high nitrogen content and restrict growth of new vegetative flushes during the time of year when cooler temperatures induce flowering. Recommendations based upon soil condition assists growers in managing their orchards. The locally avocado varieties scored higher among chefs and consumers. These data illustrate that there is a lack of coordination between what farmers grow and what the buyers prefer. The Sharwil variety is the most common locally grown avocado, yet both consumers and chefs prefer other varieties. This information needs to be shared with growers to encourage the growing of other varieties.
Publications
- Keith, L.M. 2008. First report of Pestalotiopsis virgatula causing Pestalotiopsis fruit rot on rambutan in Hawaii. Plant Disease 92(5): 835.
- Krishnakumar, J. 2008. The Willingness and Likelihood of Growers Participation in Fresh Produce Supply Chain Management: Special Focus on the Hawaiian Avocado Industry. M.S. Thesis. Department of Natural Resource and Environmental Management. University of Hawaii at Manoa.
- Barber, S. 2008. Consumer Preferences for Avocados in Honolulu, Hawaii: a Latent Class Analysis of a Conjoint Choice Experiment. M.S. Thesis. Department of Natural Resources and Environmental Management. University of Hawaii at Manoa.
- Keith, L. 2008. Rambutan disease update. Proc. 17th International Tropical Fruit Conf.pp. 62-66.
- Wall, M. 2008. Postharvest practices for longan and rambutan. Proc. 17th International Tropical Fruit Conf. pp. 58-61.
- Chan-Halbrendt, C., J. Krishnakumar, K. Love, P. Sullivan. 2007. Hawaii Avocado Industry Analysis: Part I: Supply Focus. University of Hawaii, College of Tropical Agriculture and Human Resources. CTAHR Cooperative Extension: Economic Issues Nov. 2007, EI-12.
- Barber, S.G., Chan-Halbrendt, C., Radovich, T.J., Love, K. 2008 Hawaii Avocado Industry Analysis: Part 2: Buyer Preference Focus. University of Hawaii, College of Tropical Agriculture and Human Resources. CTAHR Cooperative Extension: Economic Issues July. 2008, EI-15.
|
Progress 09/01/06 to 08/31/07
Outputs
OUTPUTS: The little fire ant, Wasmannia auropunctata (Roger) (Hymenoptera: Formicidae) is an invasive ant that forms supercolonies when it invades new areas. W. auropunctata was first reported in Hawaii in 1999 and has since invaded a variety of agricultural sites including nurseries, tropical fruit farms, macadamia orchards, and pastures. Amdro (hydramethylnon; in bait stations), Esteem (pyriproxyfen; broadcast bait), and Conserve (spinosad; ground spray) were tested for their efficacy against W. auropunctata in a rambutan and mangosteen orchard by making biweekly treatments for 16 weeks. Relative estimates of ant numbers in plots was determined by transect sampling using peanut butter-baited sticks. On weeks 12 and 16, the reduction in ant numbers in the Amdro plots was 65% and 38%, respectively, compared with pre-treatment numbers, and the reduction in ant numbers in the Esteem plots was 44% and 90%. Ant numbers in the untreated control plots increased by 194% and 255% on weeks 12
and 16 compared with pre-treatment counts. No plots for any of the treatments achieved 100% reduction. Homoptera on branch terminals were significantly lower in the Amdro and Esteem treatment on week 16. Many W. auropunctata were found nesting in protected sites in the orchard trees which may have compromised the ground-based control methods. Absolute density estimates from shallow core samples taken from the orchard floor indicated the W. auropunctata supercolony exceeded 244 million ants per hectare. The Hawaii avocado industry analysis was also conducted as a result of this project. The Hawaii Agricultural Statistics Service (2005) indicated a total of 150 avocado farms in Hawaii. For the purpose of conducting our survey, a list of the Hawaii avocado growers was obtained from the Hawaii Avocado Association. We contacted the growers via telephone and e-mail, and 55 growers agreed to participate in the survey. About 75 percent of the surveys were completed in face-to-face interviews,
and the remainder was completed via telephone. Of the farmers who were interviewed, about 90 percent were from Kona, and the remaining growers were spread out over the rest of the islands, with 6 percent from Hilo and about 5 percent from the other islands (2 percent from Kauai, 3 percent from Oahu). The questionnaire was designed to focus on farm-related information such as the farm size, number of years in farming, the nature of land ownership (leased or owned), part-time or full-time farming status, the cost of production, and farm income. The next part focused on marketing information, cultivars grown, quantity produced, quantity sold, selling outlets, and prices received. Background research and survey results indicated that about 150 avocado farms in Hawaii currently produce about 800,000 pounds of avocado that reaches the local market. The survey revealed that about half of the avocados produced do not reach the market. This suggests that the actual current production,
including waste, could be about 1.2 million pounds. The average avocado farm size was about 2 acres, and the total avocado acreage was about 286 acres. Total production per acre is estimated to be 2400 pounds.
PARTICIPANTS: Hawaii Tropical Fruit Growers Association, USDA ARS Pacific Basin Agricultural Research Center, CTAHR Department of Tropical Plant and Soil Sciences, CTAHR Department of Natural Resources Environmental Management.
TARGET AUDIENCES: Hawaii tropical fruit growers, Hawaii avocado growers, macadamia nut growers
Impacts
Little fire ant continues to spread into new areas on the east side of the Big Island. Amdro and Esteem are effective in suppressing ant populations but elimination of populations once they reach high densities is unlikely. Growers can monitor for little fire ant using peanut butter on sticks placed around the perimeter of the area of interest. Ant controls will be most effective against incipient populations. This suggests that the actual current production, including waste, could be about 1.2 million pounds. In 2005-2006, Hawaii imported about 2 million pounds of avocados, which shows that there is considerable demand for the fruit. The avocado farmers should be able to tap into this demand, replace imports, and enhance the industry.
Publications
- Chan-Halbrendt, C.,J. Krishnakumar, K. Love and P. Sullivan. 2007. Hawaii Avocado Industry Analysis, Part 1: Supply Focus. University of Hawaii at Manoa, Cooperative Extension Service, College of Tropical Agriculture and Human Resources, Office of Communication Services, EI-12, 6 pp. Available: http://www.ctahr.hawaii.edu/oc/freepubs/pdf/EI-12.pdf
|
|