Progress 10/01/03 to 09/30/10
Outputs
OUTPUTS: A reliable and simple on-farm method for evaluating macadamia (Macadamia integrifolia) kernel quality was developed to assess quality. Data were obtained on response of macadamia cultivars (HAES selections 294 (Purvis), 344 (Kau), 741 (Mauka), 788 (Pahala), HAES 835 and HAES 856) to fertilizer, and retention of kernel quality while nuts remained on the ground for extended periods prior to harvest. Studies were conducted on mature 15 year-old trees grown in Kealakekua extremely rocky silty clay loam soil at the Univ. of Hawaii Captain Cook-Kona Station (600 m elevation). To determine whether leaf nutrient concentrations differed between cultivars receiving similar fertilizer inputs, trees were fertilized identically for 2 years prior to analysis; leaf mineral analysis was conducted in spring when nutrient levels were stable. Leaf standards developed by the Univ. of Hawaii for productive trees were used to assess the nutrient status of each cultivar. Freshly fallen in-husk nuts were harvested from the Captain Cook Station and placed in wire cages under trees at the University of Hawaii Waiakea Research Station near Hilo, Hawaii (mean annual rainfall 4572 mm). Cages allowed a single layer of in-husk nuts to remain in contact with the ground and exposed to prevailing weather conditions found in wetter growing environments. Nuts were harvested from the cages at various intervals, cracked and evaluated for kernel quality and defects. New infestations of macadamia felted coccid (Eriococcus ironsidei), were discovered outside of the original infestation in South Kona. Univ. of HI and State of HI Dept. of Agriculture entomologists were enlisted to help survey the infestations. Infestation was heaviest around trees purchased from the orchard with the original infestation. Collaborative research with Dr. Lisa Keith, USDA Plant Pathologist, was completed on the cause of macadamia quick decline (MQD), a problem responsible for the death of a large number of mature trees in Hawaii. Research was conducted with the HAES 333 cultivar on the Univ. of Hawaii Waiakea Agricultural Research Station and focused on identifying the causal agent and determining control strategies for this disease. Tests with Koch's postulates for MQD were completed with organisms isolated from declining trees. Artificial inoculations of field grown trees with prospective pathogens were conducted to duplicate the entire disease syndrome. Observations on the effect of volcanic emissions on macadamia were made to determine whether orchard and nursery trees sustained damage and to document damage symptoms. Flowering, vegetative growth and fruit development on mature durian (Durio zibethinus), dragon fruit (Hylocereus undatus) and mangosteen (Garcinia mangostana), trees were monitored in orchards near Hilo to develop information on crop phenology. Data on flowering and flushing patterns were collected for durian and mangosteen by visually estimating the amount of flowering and vegetative flushing occurring on each tree at monthly intervals. Fruit growth of durian, dragon fruit and mangosteen was monitored at weekly intervals to obtain data on fruit development. PARTICIPANTS: Partnering with the Hawaii Macadamia Nut Association and the Hilo Macadamia Nut Association was necessary to organize educational meetings with macadamia growers and processors regarding new macadamia felted coccid infestations discovered on Hawaii Island. Collaboration with University of Hawaii and State of Hawaii Department of Agriculture entomologists was required to confirm the identification, survey the new infestations, and to identify beneficial predator and parasitoid insects feeding on the coccid. Collaborative research with Dr. Lisa Keith, Plant Pathologist, with the USDA Pacific Basin Agricultural Research Center was required to identify the cause and control strategies for macadamia quick decline. The Pacific Nut Producer magazine was a principal outreach method used to educate producers and marketers of macadamia on the latest information derived from the project research. The Hawaii Department of Agriculture and the Hawaii Farm Bureau Federation are acknowledged for their funding support of the macadamia decline study. The County of Hawaii Department of Research and Development is acknowledged for their funding support of the dragon fruit, mangosteen and durian studies. Industry support from tropical fruit growers was provided thorough use of their orchard for research and outreach activities. Collaboration with the Hawaii Tropical Fruit Growers association and the County of Hawaii, Department of Research and Development provided the opportunity to educate and transfer information to producers through a presentation at the 20th Annual International Tropical Fruit Conference. The annual conference for producers and marketers of Hawaii's specialty tropical fruits was convened to provide this industry with the latest research and extension updates. TARGET AUDIENCES: The target audience consisted of macadamia and specialty tropical fruit producers, processors, nursery operators, the Hawaii Macadamia Nut Association, Hilo Macadamia Nut Association, Hawaii Tropical Fruit Growers association, Hawaii Farm Bureau Federation members, USDA, university and international scientists and extension personnel, processors and marketers of specialty fruit crops. PROJECT MODIFICATIONS: This project was originally scheduled to terminate on September 30, 2013. However, the project was terminated at an earlier date on September 30, 2010 due to retirement of the project leader.
Impacts
A rapid on-farm method for kernel quality evaluation required drying nuts to 1.5% kernel moisture in a food dehydrator at 63 degrees C for 84 hours. Dried nuts were shelled, and kernels immersed in tap water to separate mature kernels (kernels with >72% oil content float) from immature kernels (low oil content kernels sink). Although different macadamia cultivars were similarly fertilized, lower leaf nutrient concentrations were observed in 294 trees. Mean leaf N concentrations in 294 trees were nearly 20% lower than in 344, the most widely grown cultivar. Foliar N, P, K, Ca, Mg and S concentrations in 741 and 856 trees were similar to 344 trees; concentrations in 835 and 788 were between 294 and 344 trees. When 294 was grown along with other cultivars, more fertilizer was required by 294 trees to maintain foliar mineral concentrations at recommended levels. Kernel quality of 788 and 741 were most affected by harvest interval. By 6 weeks after nut drop all cultivars experienced quality deterioration. Greatest reduction in quality occurred with 788 and 741 due to higher percent seed germination. The 344 cultivar and the 835 selection tended to retain better quality over the 10 week trial. Koch's postulates for MQD proved that Phytophthora tropicalis was the causal pathogen. Following inoculation of mature trees with P. tropicalis, early signs of infection such as sap bleeding, Ambrosia beetle infestation and Nectria growth was reproduced after infection with P. tropicalis. A control method was developed with a pressurized injection system to deliver phosphorous acid fungicide into the trunk at or near the infection sites. Chemical injection prolonged life of trees with MQD, and provided the industry with a solution to a long standing problem. Trees in the Kau district displayed volcanic emission damage characterized by large necrotic areas on young leaves and emerging shoot tips. Damage occurred on orchard trees, and on grafted and rootstock plants in nurseries. A monthly macadamia Orchard Tasks column published in the Pacific Nut Producer magazine and distributed free of charge to nut (macadamia, pecan, hazelnut, walnut, almond, pistachio) growers in the western US was the principal educational tool to reach producers and marketers of macadamia. Information on-farm quality analysis, fertilizer use in cultivars, effect of harvesting interval on quality, MFC control, volcanic emissions damage, and MQD control were published. Production of dragon fruit was confined to summer and early fall months; fruits grew rapidly and matured in 7 weeks. Absence of a consistent dry season caused irregular flowering of mangosteen. Flowering occurred during late spring and summer in response to drier periods during January and February and summer. Fruit development took over 20 weeks, and mature fruits weighed between 57 and 180 grams. Durian trees flowered in spring and summer in response to drier weather conditions that preceded flowering. Fruit development took 20 weeks or more depending upon variety. Phenology information was presented to producers and marketers at the 20th Annual Hawaii International Tropical Fruit Growers Conference in September 2010.
Publications
- Nagao, M.A. 2009. Macadamia orchard tasks, September-October 2009. Pacific Nut Producer 15(8): 24-26.
- Nagao, M.A. 2009. Macadamia orchard tasks, December 2009. Pacific Nut Producer 15(10): 15-16.
- Nagao, M.A. 2010. Macadamia orchard tasks, May 2010. Pacific Nut Producer 16(5): 14-15.
- Keith, L., Sugiyama, L. and Nagao, M. 2010. Macadamia quick decline caused by Phytophthora tropicalis is associated with sap bleeding, frass, and Nectria in Hawaii. Plant Disease 94(1): 128.
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Progress 10/01/08 to 09/30/09
Outputs
OUTPUTS: Collaborative research with Dr. Lisa Keith, USDA Plant Pathologist, has been ongoing on the cause of macadamia quick decline (MQD), a problem that has been responsible for the death of a large number of mature macadamia trees in Hawaii. The research has focused on identifying the causal agent and determining control strategies for this disease. The research is being conducted in an orchard planted with the HAES 333 cultivar on the University of Hawaii Waiakea Agricultural Research Station. The work at this site is critical since previous work has shown that this cultivar is highly susceptible to MQD. Tests to complete Koch's postulates for MQD have been ongoing with organisms isolated from declining trees. Artificial inoculations of field grown trees with prospective pathogens are being conducted to duplicate the entire disease syndrome. Volcanic emissions are a concern for agricultural crops including macadamia, because of potential injury caused by high concentrations of hydrogen sulfide and hydrogen chloride in the emissions. These acid-precursor gases can affect plants directly or can acidify rainfall which can affect the soil and injure plants. Significant damage has been reported on a variety of plants from farmers in the downwind path of the northeasterly trades in the Kau district where protea flower growers have sustained heavy damage. Macadamia is in the same family (Proteaceae) and growers have reported that trees may have sustained damage to the foliage when emission concentrations are high. Visitations to orchards in near Pahala and Naalehu in the Kau district were made to determine whether trees in the orchard and in the nursery have sustained any damage and to document damage symptoms. Two new infestations of macadamia felted coccid (Eriococus ironsidei) (MFC) were discovered and were outside of the initial infestation site in south Kona and found in February 2005. The new infestations were detected in Waiohinu and Pahala in the Kau district, the major macadamia growing area along the south eastern coast of Hawaii Island. PARTICIPANTS: Collaborations with a USDA Pacific Basin Agricultural Research Center plant pathologist, and with University of Hawaii and State of Hawaii Department of Agriculture plant entomologists were required to confirm the pathogen responsible for MQD and to confirm the identification of the new coccid infestations, and identify beneficial predator and parasitoid insects feeding on the coccid. TARGET AUDIENCES: The target audience consisted of the Hawaii Macadamia Nut Association and Hilo Macadamia Nut Association members, macadamia growers, processors and nursery operators. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Experiments to test Koch's postulates for Macadamia Quick Decline (MQD) proved that Phytophthora tropicalis was the causal agent for MQD. It showed for the first time through artificial inoculation of 12 year old field grown trees with P. tropicalis, that sap bleeding, Ambrosia beetle infestation and Nectria growth were associated with the disease. Thus all 3 of these early signs that are usually visible on trees suffering from MQD could be reproduced after infection with P. tropicalis. This research also developed a control method for MQD using a pressurized injection system to deliver a phosphorous acid fungicide into the tree trunk at or near the infection sites. The chemical injection application provided a method to prolong the life of macadamia trees with MQD. Injected trees to date lived an additional 700 days which allowed for 2 additional seasons of harvests. The trunk injection control method provided the macadamia industry a solution to a long standing problem and could be used as an application technique for other root or trunk problems in macadamia and other fruit/nut trees. Observations on macadamia trees in the Kau district showed that volcanic emission damage was characterized by development of large necrotic areas on young leaves and emerging shoot tips. Damage occurred on young and mature trees in the orchard, but grafted and rootstock plants in the nursery were more severely impacted by the emissions. An Orchard Tasks article with photos showing damage to macadamia plants was published in the Pacific Nut Producer magazine to enable growers to recognize damage from volcanic emissions. A new online publication (Volcanic Emissions Injury to Plant Foliage. Plant Disease, Aug. 2008, PD-47 ) also discussed effects of volcanic emissions damage to plants in HI and contained images documenting the injury symptoms on macadamia plants. Several management strategies to reduce injury were also provided, and were more applicable to macadamia plants in the nursery rather than large trees in the orchard. Based on the number of macadamia felted coccids on the newly infested trees, the level of branch dieback, and number of trees affected, it appeared that the new infestations was present for some time. A macadamia Orchard Tasks column on the coccid was published in the Pacific Nut Producer magazine to reach producers and marketers of macadamia. The industry was alerted that MFC infestations continued to occur outside of the original infestation site and that all growers should regularly survey orchards, particularly if they received plant material from or share harvesting personnel with an infested orchard. Use of spray oil emulsion was recommended because of its effectiveness against adult coccids. Growers were informed that a new insecticide, Spirotetramat, which targets aphids, mealybugs, whiteflies and scale insects is currently registered for use on macadamia. Good control of scale insects has been reported for several tree fruits, and an orchard that used the pesticide reported that it was effective against the MFC.
Publications
- Nagao, M.A. 2008. Macadamia orchard tasks. Pacific Nut Producer 14 (8): 13-14.
- Nagao, M.A. 2009. Macadamia orchard tasks. Pacific Nut Producer 15 (8): 24-26.
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Progress 10/01/07 to 09/30/08
Outputs
OUTPUTS: In March 2008 infestations of macadamia felted coccid (Eriococcus ironsidei Williams), a potentially devastating pest of macadamia (Macadamia integrifolia Maiden & Betche) were discovered by the project leader (PL) in Paauilo and Wood Valley in Kau on Hawaii Island. Until the new discoveries, the insect was confined to a single orchard in South Kona. Macadamia felted coccid (MFC), a tiny scale-like insect native to Australia, is observed by inspecting undersides of leaves. Univ. of HI and State of HI Dept. of Agriculture entomologists were enlisted to help survey the infestations. The Paauilo infestation was established in a 5 acre orchard for some time, since biological control was occurring with several natural enemies. Beneficial parasites and predators were feeding on adult coccids and up to 50% of the coccids were destroyed by beneficial insects. Emergence holes were observed on the scales caused by a parasitoid wasp, Encarsia lounsburyi, whose larvae feeds on the scale. Predation by ladybird beetles was evident. The infestation appeared to spread from grafted plants that were purchased from a nursery at the original infestation site 3 years earlier. Infestation was heaviest around one of the imported trees and had spread into the orchard and into an adjacent orchard. The grower was advised to make 2 applications of horticultural oil (Saf-T-Side, Brandt Consolidated, Pleasant Plains, Illinois) onto infested trees and avoid using malathion, to reduce the impact on the natural enemies. The Kau infestation was more recent and also occurred on plants recently imported from Honomalino. Infestation was detected at an early stage, and no evidence of parasitism and predation was evident. Since infestation was restricted to the imported trees, the grower was advised to make multiple applications of horticultural oil to eliminate the infestation. To educate growers in the eastern part of Hawaii Island on how to recognize MFC infestations, how the insect is spread, and on control measures, the PL made presentations at meetings in April 2008 (40 participants, organized by Hawaii Macadamia Nut Association) and May 2008 (120 participants, organized by Hilo Macadamia Nut Association). Growers learned that MFC is a pest restricted to macadamia and not found on other species. Growers who received grafted trees from the infested orchard within the past few years were advised to conduct intensive surveys of imported trees and adjacent trees for MFC infestation. Infestations should be reported to the HI Dept. of Agriculture and the Cooperative Extension Service in Hilo. Frozen specimens of macadamia branches with MFC infestation were used to provide growers with first hand experience at recognizing the insect and signs of biological control. Two articles were published in the Pacific Nut Producer (PNP) magazine (April 2008; May 2008) to alert the industry that MFC infestation is no longer confined to South Kona and all growers should begin surveying orchards, particularly if grafted trees came from the infested orchard. A photo of MFC infestation on macadamia leaves was published in the PNP to for growers recognize the insect and damage. PARTICIPANTS: Partnering with the Hawaii Macadamia Nut Association and the Hilo Macadamia Nut Association was necessary to organize two educational meetings with macadamia growers and processors regarding new macadamia felted coccid infestations discovered on the eastern shore of Hawaii Island. Collaboration with University of Hawaii and State of Hawaii Department of Agriculture entomologists was required to confirm the identification, survey the new infestations, and identify beneficial predator and parasitoid insects feeding on the coccid. TARGET AUDIENCES: The target audience consisted of the Hawaii Macadamia Nut Association and Hilo Macadamia Nut Association members, macadamia growers, processors and nursery operators. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Growers learned to recognize MFC infestations, damage caused by the insect and the control tactics available for managing infestations. Two macadamia Orchard Tasks columns on the MFC were published in the Pacific Nut Producer magazine which is the principal educational tool to reach producers and marketers of macadamia nuts in the state of Hawaii and other macadamia growing areas in the US. The Pacific Nut Producer magazine, published by Malcolm Media, Clovis, CA, is distributed without charge to nut (macadamia, pecan, hazelnut, walnut, almond, pistachio) growers in the western US. Macadamia growers understand that the common method for MFC dispersal is through movement of infested plants or grafting material and that regular and close inspection of new macadamia plants brought into an orchard must be undertaken to reduce the spread of the pest. Short term control measures will rely upon horticultural oil sprays in the orchard or pyriproxyfen sprays in the nursery. Macadamia growers will rely upon biological control with the parasitoid wasp, Encarsia lounsburyi, whose larvae feed on the MFC and by predation of the MFC by ladybird beetles. Growers will recognize the feeding patterns of these bio-control agents on the MFC and will take measures to introduce these agents into the orchard if MFC infestations become established. These tactics will reduce the impact of the MFC and help sustain tree health and productivity over the long term.
Publications
- Nagao, M.A. 2008. Macadamia orchard tasks. Pacific Nut Producer 14 (4): 12-13.
- Nagao, M.A. 2008. Macadamia orchard tasks. Pacific Nut Producer 14 (5): 22-23.
- Nagao, M.A. 2008. Macadamia integrifolia: macadamia nut. In: J. Janick and R.E. Paull (eds.), The Encyclopedia of Fruit and Nuts. CABI Wallingford, UK. p. 600-610.
- Nagao, M.A. and R.E. Paull. 2008. Nephelium mutabile: pulasan. In: J. Janick and R.E. Paull (eds.), The Encyclopedia of Fruit and Nuts. CABI Wallingford, UK. p. 816-817.
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Progress 10/01/06 to 09/30/07
Outputs
OUTPUTS: Experiments were initiated to obtain data on the response of macadamia (Macadamia integrifolia) cultivars to fertilizer applications, and on the retention of kernel quality while nuts remain on the ground prior to harvest. Cultivars in the study included Hawaii Agricultural Experiment Station (HAES) selections 294 (Purvis), 344 (Kau), 741 (Mauka), 788 (Pahala), and unnamed selections HAES 835 and HAES 856. To optimize fertilizer use in macadamia trees, an experiment was implemented to determine whether leaf nutrient concentrations differ between cultivars when trees receive similar fertilizer inputs. The study was conducted in an orchard at the University of Hawaii Captain Cook Station in Kona) which is situated at 600 m elevation and consists of mature 15 year-old trees planted in a Kealakekua extremely rocky silty clay loam soil. All trees received identical fertilizer applications for at least 2 years prior to the analysis, and leaf samples were collected for mineral
analysis from the different cultivars in spring (March 2006) when nutrient levels were stable. Leaf tissue standards developed at the University of Hawaii for productive macadamia trees were used to assess the mineral nutrient status of each cultivar. All trees were grafted onto seedling rootstocks; therefore rootstock was not considered a factor in this study. Information was also developed on retention of kernel quality during the period nuts remain on the orchard floor after nut drop. Freshly fallen in-husk nuts were harvested from the Captain Cook Station during the 2006 harvest season and placed in wire cages under trees at the University of Hawaii Waiakea Research Station near Hilo, Hawaii (mean annual rainfall 4572 mm) to protect the nuts from rodents. The cages allowed a single layer of in-husk nuts to remain in contact with the ground and exposed to prevailing weather conditions found in wet growing environments. Beginning at 4 weeks and up to 10 weeks after nut drop, nuts
were harvested from the cages, cracked and evaluated for kernel quality and defects. A monthly macadamia Orchard Tasks column is the principal educational tool to reach producers and marketers of macadamia nuts in the state of Hawaii and other macadamia growing areas. The column is published in the Pacific Nut Producer magazine and distributed free of charge to nut (macadamia, pecan, hazelnut, walnut, almond, pistachio) growers in the western US.
PARTICIPANTS: The Hawaii Department of Agriculture and the Hawaii Farm Bureau Federation are acknowledged for their partial funding support of the project. Industry input for undertaking these studies was obtained through collaboration with Mr. Alan Yamaguchi, horticulturist with M.L. Macadamia Corporation, and the research committee of the Hawaii Macadamia Nut Association. The overall goal was to develop information for more efficient production in terms of nutrient requirements and harvest intervals for various cultivars. This is important for the industry when selecting compatible cultivars to replace weak or dead trees in existing orchards or when deciding upon planting compatible cultivars for new orchards.
TARGET AUDIENCES: The target audience consists of macadamia nut producers, the Hawaii Macadamia Nut Association and its members, processors and marketers of macadamia nut products.
Impacts
Results showed that although trees of each cultivar were fertilized with a similar analysis and amount of fertilizer, lower leaf nutrient concentrations were observed in the 294 (Purvis) cultivar compared to the other cultivars. Mean nitrogen (N) concentrations in 294 trees were 1.14% (dry wt. basis) which was nearly 20% lower than N concentrations (1.42%) in leaves of the 344 (Kau) cultivar which is the most widely grown macadamia cultivar in Hawaii and the world. Phosphorus (P), potassium (K) and calcium (Ca) concentrations in the 294 leaves were 0.04, 0.65 and 0.77%, respectively and were also lower than concentrations in 344 trees (0.05% P, 0.72% K, 0.90% Ca). Foliar N, P, K, Ca, Mg and S concentrations in the 741 (Mauka) and 856 trees were very similar to concentrations in the 344 trees. Leaf nutrient concentrations in the 835 and 788 (Pahala) trees were intermediate between concentrations found in 294 and 344. These results showed that when 294 trees were grown
in an orchard along with other cultivars, a greater amount of fertilizer should be given to the 294 trees to maintain foliar mineral concentrations at recommended levels. Results from the second study showed that the kernel quality of the 788 and 741 cultivars were most affected by the length of the harvest interval. By 6 weeks after nut drop all varieties experienced some deterioration in quality due to decreased recovery of No.1 kernels, increased germination or increased insect damage. Recovery of No.1 kernels was the weight of the Grade 1 kernel as a percentage of the weight of the in-shell nut at 1.5% kernel moisture. Thus a high level of spoilage reduced the percent recovery of usable kernel. The greatest reduction in percentage of recovery of No.1 kernels occurred with 788 and 741 and was due to a higher percentage of seed germination. The 344 cultivar and the 835 selection tended to retain the best quality over the 10 week duration of the trial. The 788 selection was less
affected by stinkbug damage in dry locations, but in wet areas its quality deteriorated due to increased germination. Through this project macadamia growers learned how different varieties responded to fertilizers which enabled producers to fertilize trees more efficiently. We also learned which varieties were most prone to quality defects when kept on the ground for extended periods and required more frequent harvesting to maintain kernel quality.
Publications
- Nagao, M.A. 2007. Orchard Tasks: Macadamias. Pacific Nut Producer, 13 (5): 10, 24.
- Kawabata, A.M., Nagao, M.A.,Tsumura, T., Aoki, D.F., Hara, K.Y and Pena L.K. 2007. Phenology and fruit development of rambutan (Nephelium lappaceum L.) grown in Hawaii. J. Hawaiian Pacific Agric. 14: 31-39.
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Progress 10/01/05 to 09/30/06
Outputs
Macadamia in Hawaii is generally grown between 92 and 610 m elevation with the highest yielding orchards usually found at 305 to 518 m elevation. A study is ongoing at the University of Hawaii Captain Cook Experiment Station in Kona to evaluate the performance of several commercial macadamia varieties and new selections planted at 610 m elevation. Selections under evaluation are HAES 294 (Purvis), 344 (Kau), 741 (Mauka), 788 (Pahala) and the following un-named selections, 816, 835, 856 and 857. Trees were planted in a 4.6 x 9.2 m spacing and were top-worked in May 1988. The plot consisted of 6 trees of each selection planted in 2 replicates. Nut and kernel quality and yield data were obtained during the 2003, 2004 and 2005 seasons (15th, 16th and 17th year after top-working). By 2003 the trees were mature and orchard was fully closed-in. A summary of the quality data over the 3 harvest seasons showed that percent kernel recovery ranged from 36.5 to 44.5% with
selection 816 having the highest kernel recovery. This was due to its large kernel and thinner shell. However the 816 selection also tended to have the lowest percentage of Grade 1 kernels indicating that the kernels tended to be lower in quality compared to the other selections. The highest percent of Grade 1 kernel was obtained with 294, 788, 835, and 856, and the percent recovery of Grade 1 kernel was also highest for the 294, 788, 835, and 856 selections. Based on kernel quality these selections tended to perform better at this location compared to the other selections planted in the test plot. Stinkbug damage and the presence of a darkened area toward the base of the kernel were also least prevalent in the 294, 788 and 856 selections. Although 741 (Mauka) has performed well in other trials at upper elevations, results from this Captain Cook trial showed that 741 did not perform as well as 788. Wet-in-shell (WIS) yield data from the 2003, 2004 and 2005 harvest seasons (15th to
17th year after planting) showed that the highest average wet-in-shell yields over the 3 year period were obtained with 344, 741, 835 and 856 and were 52.4, 41.8, 45.0 and 44.2 kg/tree, respectively. However, the estimated yield of No. 1 kernel which was calculated from the percentage recovery of No. 1 kernel showed that 294, 344, 788, 835 and 856 were better performing selections. The estimated kernel yield was based on the WIS nut yield, and moisture content of the WIS nuts was not determined at the time of harvest. Two of the un-named selections, 816 and 857, produced the lowest yields and exhibited poor kernel quality. The estimated Grade 1 kernel yield of 294, 344, 788, 835 and 856 obtained at Captain Cook were comparable to yields obtained with similarly aged 344 and 508 trees growing in favorable environments at lower elevations.
Impacts
In Hawaii macadamia is generally grown between 92 and 610 m elevation with the highest yielding orchards usually found at 305 to 518 m elevation. In this study at the Univ of HI Captain Cook Station in Kona, the performance of commercial varieties and new selections is being evaluated at 610 m elevation. Quality data from the 15th to 17th year after planting showed that the highest percent of Grade 1 kernel was obtained with 294, 788, 835, and 856, and the percent recovery of Grade 1 kernel was also highest for the 294, 788, 835, and 856 selections. Based on kernel quality these selections performed better at this location compared to the other selections planted in the test plot. Stinkbug damage and presence of a darkened area toward the base of the kernel were also least prevalent in the 294, 788 and 856 selections. Wet-in-shell (WIS) yield data showed that the highest average wet-in-shell yields over the 3 year period were obtained with 344, 741, 835 and 856 and
were 52.4, 41.8, 45.0 and 44.2 kg/tree, respectively. However, the estimated yield of No. 1 kernel which was calculated from the percentage recovery of No. 1 kernel showed that 294, 344, 788, 835 and 856 were better performing selections at this site. The estimated Grade 1 kernel yield of 294, 344, 788, 835 and 856 obtained at Captain Cook were comparable to yields obtained with similarly aged 344 and 508 trees growing in favorable environments at lower elevations. For orchards established at higher elevations in Hawaii, it is recommended that growers consider planting the 294, 344, 788, 835 and 856 selections.
Publications
- Nagao, M.A., Ito, P.J., Meisner, M., and Kawabata, A.M. 2005. Performance of macadamia selections at Captain Cook-Kona. Hawaii Macadamia Nut Association 46th Annual Conference Proceedings. Kailua-Kona, Hawaii. p 26-30.
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Progress 10/01/04 to 09/30/05
Outputs
Yield and quality of kernels are the basis for evaluating cultivar performance and for determining revenues macadamia producers will receive for their crop upon delivery to processors. Crop losses across the Hawaii macadamia industry amount to 10% of the delivered nuts with a total value of $7.1 million. To help producers determine kernel yield and quality at the farm level, a reliable and simple on-farm method for evaluating kernel quality was developed to enable producers to assess their nut quality before processing. The method identifies the percentage of mature good quality kernels, and is based on rapid drying of wet-in-shell nuts at 63 degrees C in a food dehydrator for 84 hours (3.5 days). Wet-in-shell nuts are dried to 1.5% kernel moisture content, cracked, shelled, and floated in tap water to separate mature from immature kernels. Fully mature kernels with oil content greater than 72% will float while immature kernels which have lower oil content will sink.
In the procedure, a representative sample of the harvested nuts is collected randomly from the field or harvest bins, de-husked, and 2.0 kg of in-shell nuts placed onto trays in a food dehydrator that is able to sustain a temperature of 63 degrees C. The dehydrator temperature is set to 63 degrees C, and the nut samples dried for 84 hours. Dried in-shell nuts are weighed and cracked, and the kernels are floated in tap water to separate mature and immature kernels. Mature kernels are examined for quality defects (insect damage, mold, hollow centers, gray kernel) and the good quality kernels weighed. Percent kernel recovery is calculated and is based on the ratio of the weight of mature good quality kernels to the weight of the dry-in-shell nuts. The kernels processed with this method may appear brown, because the rapid drying method does not simulate the commercial drying conditions that produce white kernels.
Impacts
A reliable and simple on-farm method for evaluating macadamia nut and kernel quality was developed to enable producers to assess their nut quality before delivery to processors. The method identifies the percentage of mature, good quality kernels, and is based on rapid drying of wet-in-shell nuts at 63 degrees C in a food dehydrator for 84 hours (3.5 days). Wet-in-shell nuts are dried to 1.5% kernel moisture content, cracked, shelled, and floated in tap water to separate mature from immature kernels. Fully mature kernels with oil content greater than 72% will float while immature kernels which have lower oil content will sink. Kernels processed with this method may appear brown, because the rapid drying method does not simulate the commercial drying conditions that produce white kernels.
Publications
- Gentry,T., Wall, M. and Nagao, M.A. 2005. A rapid method for on-farm quality evaluation of macadamia nuts. Univ. of HI. Coop Ext. Serv. F&N-11a.
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Progress 10/01/03 to 09/30/04
Outputs
An initial consideration in developing a fertilizer program for producing longan trees is to determine the amount of fertilizer nutrients contained in the harvested fruits. Data were collected to document the nutrient content of fruits for two longan cultivars (Biew Khiew and Sri Chompoo) at 3 different locations in East Hawaii on Hawaii Island. Trees were treated with potassium chlorate to stimulate flowering, but tree age and field management practices varied between the growing locations. Results obtained from the two varieties were somewhat similar and showed that P levels for the two varieties were nearly identical but showed some variation between the sampling periods. Fruits contained relatively high amounts of nitrogen and potassium with N exhibiting the largest variation within each variety. Based on the analyses, when 100 kg of Sri Chompoo fruits are harvested, approximately 0.207, 0.042, 0.370, 0.077, 0.037, and 0.018 kg of N, P, K, Ca, Mg, and S
respectively, will be removed from the orchard. When 100 kg of Biew Khiew fruits are harvested, approximately 0.266, 0.042, 0.360, 0.098, 0.036, and 0.023 kg of N, P, K, Ca, Mg, and S respectively, are removed. Previously we reported that potassium chlorate could stimulate flowering of longan trees. To determine if similar responses could be obtained with other closely related oxidizing agents, experiments were conducted to determine whether strong oxidizing compounds containing hypochlorite (sodium hypochlorite, calcium hypochlorite) could elicit a similar flowering response in longan. Experiments were conducted on 3 to 5 year old longan trees planted in East Hawaii in rocky Aa soils commonly found near Hilo and in the Puna district. Experiments were undertaken with Sri Chompoo, Biew Khiew, and Egami. Stimulation of flowering was observed within 2 months on Sri Chompoo and Biew Khiew trees growing in rocky Aa soil when 500 grams of calcium hypochlorite was applied as a drench to the
soil beneath the canopy to an area extending to about 1.5 meters away from the trunk. Application of sodium hypochlorite solution (2.625 %) applied as a 7.5 liter soil drench also stimulated flowering of Biew Khiew, Egami and Sri Chompoo trees within 2 months after application. Application of muriate of potash (potassium chloride) fertilizer with sodium hypochlorite did not affect the drench treatment, indicating that addition of potassium did not enhance the effect of hypochlorite. Although trees appeared uninjured by the treatment, heavy feeding and foliage damage from Chinese rose beetles were often evident in the hypochlorite treated trees just prior to and at the time of flowering. These experiments showed that treatment with strong oxidizing agents such as calcium hypochlorite and sodium hypochlorite could stimulate flowering of longan trees, however, the response was reduced compared to flowering obtained after treatment with potassium chlorate. Preliminary trials with
hypochlorite soil drench treatments to trees growing in deep silty clay loam soils showed that these trees were less responsive compared to trees growing in rocky soils.
Impacts
An initial consideration in the development of a fertilizer nutrient program for producing longan trees is to determine the amount of fertilizer nutrients contained in the harvested fruits. Based on the fruit analyses, when 100 kg of Sri Chompoo fruits are harvested, approximately 0.207, 0.042, 0.370, 0.077, 0.037, and 0.018 kg of N, P, K, Ca, Mg, and S respectively, will be removed from the orchard. When 100 kg of Biew Khiew fruits are harvested, approximately 0.266, 0.042, 0.360, 0.098, 0.036, and 0.023 kg of N, P, K, Ca, Mg, and S respectively, will be removed. The amount of fertilizer to replace these amounts of N, P and K will be dependent upon tree ability to absorb the fertilizer nutrients along with weather and soil factors. Experiments conducted with Sri Chompoo, Biew Khiew, and Egami longan trees showed that strong oxidizing compounds containing hypochlorite (sodium hypochlorite, calcium hypochlorite) could elicit a flowering response in longan. However, the
response was greatly reduced compared to flowering obtained after treatment with potassium chlorate. Preliminary trials with hypochlorite soil drench treatments showed that trees growing in deep silty clay loam soils were less responsive compared to trees growing in rocky soils.
Publications
- Nagao, M.A., Ito, P.J., Tsumura, T. and Kawabata, A.M. 2003. Performance of new macadamia selections in Hawaii. Proceedings Second International Macadamia Symposium 2003. p 76-79.
- Nishina, M.S., Nagao, M.A. and Furutani, S.C. 2004. Optimizing germination of papaya seeds. Univ. of HI. Coop Ext. Serv. F&N-8.
- Nagao, M.A. and Kawabata, A.M. 2004. Sapindaceae production in Hawaii. Proceedings of the 6th National Lychee Conference of the Australian Lychee Growers Association. (In press)
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Progress 10/01/02 to 09/30/03
Outputs
An orchard established at the UH Captain Cook Station in Kona to evaluate production and quality of several macadamia cultivars and some newer selections at this upper elevation site (600 m) is mature and in its fourteenth year of growth. The trial, planted in a 4.6 x 9.1 meter spacing and top-worked in May 1988, consists of selections 294, 344, 741, 788, 816, 835, 856 and 857. Nut and kernel quality data from the 2002 harvest season (14 years after planting) showed that kernel recovery for all selections ranged from 37.1 to 43.8%. Recovery of No. 1 kernel showed that selections 788 (Pahala), 835 and 856 tended to perform better at this location. Although 816 had a high kernel recovery (43.8%), the low amount of No. 1 kernel (67%) led to the low recovery of No. 1 kernel (30%) from in shell nuts. Selection 816 had large kernels, but tended to suffer from stinkbug damage, and had discolored and shriveled kernels. Although 741 (Mauka) has produced well in other trials at
upper elevations, results from this trial showed that 741 did not appear to perform well at this site. Yield data from the fourteenth year after planting showed that higher average wet-in-shell yields were obtained with 816, 856 and 857. However, when the percent No. 1 kernels is considered, the mean net wet-in-shell yields showed that 788, 856 and 857 tended to perform better. The estimated yield of No. 1 kernel, which was calculated from the percentage recovery of No. 1 kernel, indicated that 788 and 856 were better performing selections. The trial will be continued to determine whether similar trends persist in future harvests. To identify new macadamia selections, preliminary quality data were collected from some promising selections established at University of Hawaii Waiakea Experiment Station. Selections 862, 887, 896 and 932 selections had greater than 40% kernel recovery. The 900 selection had the lowest percent kernel (31.3%) due to a thicker shell however, this
characteristic may provide some natural protection against stinkbug and tropical nut borer damage. Selections 887, 896 and 932 had recovery of No. 1 kernel which ranged from 36 to 38% and were comparable to 800 in this regard. Among the distinguishing characteristics of 879 and 932 were their upright growth habits which may allow for closer tree spacing and higher planting densities in the orchard. New trials have been established at the Kainaliu and Waiakea Stations to evaluate these newest selections and to determine their yield potential, kernel quality and over-all performance.
Impacts
Nearly all commercial macadamia orchards in Hawaii have been established at elevations below 610 meters; also most cultivars have been developed and tested at elevations between 90 and 579 m. A trial established at the UH Captain Cook Station in Kona to evaluate the production and quality of several macadamia cultivars and some newer selections at 600 m elevation showed that selections 788 (Pahala), 835 and 856 had the best recovery of No. 1 kernel. Yield data from the fourteenth year after planting showed that higher average wet-in-shell yields were obtained with 816, 856 and 857. However, when the percent recovery of No. 1 kernels is considered, the estimated yield of No. 1 kernel showed that 788 and 856 were better performing selections. Although 741 (Mauka) has produced well in other trials at upper elevations, results from this trial showed that 741 did not appear to perform well at this site. The trial shows that 788 and 856 may be macadamia cultivars that are
suited for higher elevation plantings.
Publications
- Nagao, M.A., Ito, P.J., Tsumura, T. and Kawabata, A.M. 2003. Selection for new macadamia varieties. Hawaii Macadamia. Nut Assoc. 43rd Ann. Proc. (In press).
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Progress 10/01/01 to 09/30/02
Outputs
Longan (Dimocarpus longan (Lour.) Steud.) flowering in Hawaii can be inconsistent and is a major constraint to sustained commercial production of this crop. Experiments were conducted to determine if basal application and foliar sprays of potassium chlorate fertilizer could be effective for inducing flowering of longan in Hawaii. The first study on 7 year-old air-layered longan trees growing in an Olaa silty clay loam near Hilo, Hawaii consisted of evenly broadcasting 0, 250 or 500 g KClO3 fertilizer beneath the canopy of each tree in an area extending to about 1.5 meters away from the trunk. All leaves and loose organic matter were removed from soil surface prior to application, and trees were immediately irrigated to deliver the KClO3 to the root zone. Four longan varieties, 'Kohala', 'Sri Chompoo', 'Biew Kiew', and 'E-Wai', were used in the trial. In a second study 10 year-old air layered 'Kohala' trees growing under similar conditions were treated with a foliar
spray consisting of 0 or 2.0 g/l potassium chlorate applied to run-off. KClO3 was applied to the lower branches on one side of each tree with the opposite side of the tree serving as the control. Panicles were evident on 74% and 86% of the canopy for the 250 and 500 g/l treated trees, at 2 months after treatment. By 3 months after treatment, 91% and 97% of the terminals were flowering with the 250 and 500 g/l KClO3 treatments, respectively. All varieties responded similarly. For the duration of the fruit development period, fruit set was maintained on about 44% of the terminals in the untreated trees as compared to 84% and 86% of the terminals with the 250 and 500 g treatments. Foliar applications containing of 2.0 g/l KClO3 stimulated flowering within 2 months after application. The flowering response was limited to the treated section of the trees as none of the control branches exhibited flowering during this period. At 7 months after treatment significantly greater numbers of
panicles with fruit set were present on d in the treated sections of the trees. No evidence of phytotoxicity was observed on any of the branches receiving the foliar treatments. Three fruit rotting fungi were isolated from rambutan trees in Hawaii. Inoculation studies with Lasmenia sp., Gliocephalotrichum simplex and G. bulbilium showed that all three fungi produced the fruit rot symptoms observed in the field. Field symptoms were characterized by brown to black water soaked lesions on the fruit surface that progressed to blackening and drying of the pericarp, which often split and exposed the aril. In some cultivars green immature fruits were also mummified. Trees with high incidence of fruit rot also exhibited branch dieback. This is the first report of Lasmenia sp. in Hawaii and the first report of Gliocephalotrichum on rambutan in Hawaii.
Impacts
Basal applications of 250 and 500 grams/tree of KClO3 stimulated flowering of longan trees within 2 months after application and resulted in earlier, more profuse and more synchronous flowering, and in a greater amount of fruit set within the tree canopies. The response to KClO3 was not restricted to soil applications since foliar application with 2.0 g/l KClO3 also induced flowering at about 2 months after treatment. This technology will enable growers to stimulate flowering of longan trees and obtain consistent seasonal and off-season production of this crop. Three fruit rotting fungi were isolated from rambutan trees in Hawaii. Lasmenia sp., Gliocephalotrichum simplex and G. bulbilium fungi produced the fruit rot symptoms which were characterized by brown to black water soaked lesions on the fruit surface that progressed to blackening and drying of the pericarp, which often split and exposed the aril.
Publications
- Nishijima, K.A., Follet, P.A., Bushe, B.C. and Nagao, M.A. 2002. First report of Lasmenia sp. and two species of Gliocephalotrichum on rambutan in Hawaii. Plant Dis. 86:71.
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Progress 10/01/00 to 09/30/01
Outputs
Vegetative flushing in late autumn and early winter is associated with irregular flowering of lychee (Litchi chinenesis Sonn) trees during spring and can result in inconsistent yields. Although Kaimana lychee is adapted to Hawaii conditions and has been helpful in overcoming erratic bearing, vegetative flushing in late autumn and early winter can result in irregular spring flowering and inconsistent yields. A study was conducted to determine if tip pruning of vegetative flushes emerging on 'Kaimana' lychee trees in early winter could enhance spring flowering. Results from this study confirmed that a resting period during early winter was conducive to floral initiation in lychee. Results also showed that vegetative flushing occurring during early winter reduced flowering of Kaimana trees and that pruning of young flushes, which emerged during early December, stimulated flowering. Pruning of emerging vegetative flushes significantly increased the number of panicles
developing on trees in February compared to trees on which flushing branches were left unpruned. Pruning also increased the number of panicles developing on each pruned branch by stimulating the production of multiple inflorescences from nodes located immediately below the pruned terminal. Although flowering was increased in the pruning treatments, fruit set was not similarly increased in all pruned trees due to the low rainfall experienced during the fruit set period. Increased flowering may not necessarily result in greater yields, as low soil moisture and low humidity during blooming and fruit set can cause abscission of flowers and fruitlets and reduce yields. Thus it is imperative that sufficient irrigation is available to trees during flowering and fruit set to obtain maximum yield.
Impacts
Continuous vegetative flushing during the winter and the absence of a dormant or resting phase during this period can reduce flowering of Kaimana lychee. By tip pruning vegetative flushes that emerge during the winter rest period, it may be possible to induce flowering and overcome some of the inconsistencies associated with Kaimana trees growing in Hawaii conditions. Tip pruning will only be successful if cool temperature and dry weather conditions continue for several weeks after the tipping procedure. The economics of employing the tip pruning treatment in a commercial setting are not known. However, vegetative flushing during the winter will reduce flowering, while tip pruning of vegetative flushes will offer the possibility for obtaining increased bloom and fruit set.
Publications
- Nagao, M.A., Ho-a, E.B., Nishina, M.S. and Zee, F. 2000. December pruning of vegetative flushes affects flowering of 'Kaimana' lychee in Hawaii. J. Haw. Pac. Agric. 11:17-21.
- Nagao, M.A and Ho-a, E.B. 2000. Stimulating flowering of longan in Hawaii with potassium chlorate. J. Haw. Pac. Agric. 11:23-27.
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Progress 10/01/99 to 09/30/00
Outputs
A new longan cultivar has been selected and named in Hawaii. 'Egami' is a very productive longan (Dimocarpus longan (Lour.) Steud.) cultivar selected at the University of Hawaii CTAHR, Kona Research Station. The selection is an open-pollinated seedling of unknown origin and formerly has been referred to as 'Kona No. 1', 'Mauka' and 'Kainaliu'. 'Egami' consistently bears large clusters of fruits and produces crops more regularly than 'Kohala' longan. When compared with nine other cultivars in the collection at the Kona Research Station, 'Egami' was preferred based on taste and ranked second for flavor and third for pulp crispness. It was also highly acceptable as a dried fruit based on flavor and pulp recovery. 'Egami' trees are vigorous with strong, upright branching. The large, dark green leaves have eight leaflets. The bark is slightly rough and gray-brown. Both grafted and air-layered trees produce fruits in four years and can be pruned to maintain a low stature.
Initially during flowering more male flowers are produced on the panicles, but later flowers are predominantly female, and fruit set is excellent. Flowering can start in late February and continue to the end of March. Fifty or more fruits are usually borne on each panicle; they mature from August to early October. Mature fruits are round and brown-russet with a smooth leathery skin. Fruits are slightly smaller than those of 'Kohala', with a diameter ranging from 1.9 to over 2.5 cm, and they can weigh up to 14 grams. The whitish, translucent edible flesh is about 72-75% of the total fruit weight. The pulp is tender, crisp and sweet with total soluble solids ranging from 18-22%. The small, shiny black seed is only about 10% of the total fruit weight.
Impacts
'Egami' is a new longan (Dimocarpus longan) cultivar available to growers of tropical fruits in Hawaii. Egami' is a very productive cultivar that consistently bears large clusters of high quality fruits and produces crops more regularly than 'Kohala' longan. When compared with nine other cultivars in the collection at the Kona Research Station, 'Egami' was preferred based on taste and ranked second for flavor and third for pulp crispness.
Publications
- Ito, P.J., Zee, F. and Nagao, M.A. 2000. 'Egami', a new longan cultivar from Hawaii. Univ. Hawaii Cooperative Extension Service, New Plants for Hawaii NPH-5.
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Progress 10/01/98 to 09/30/99
Outputs
No progress to report.
Impacts
Fully ripe lychee fruits of the Kaimana cultivar harvested from trees of varying ages from orchards located throughout Hawaii showed that fruit quality was fairly constant. The dark-red to maroon fruits had a mean weight of 24.3 grams, a mean diameter of 37.8 mm, 77.1% edible pulp, 66.5% abortive seeds and 19.5% soluble solids. Fruit quality data of longan cultivars showed that Biew Khiew exhibited good overall quality, because of its large fruit (11.2 g), high % edible pulp (66.4%) and high soluble solids (22.4%).
Publications
- No publications reported this period
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Progress 10/01/97 to 09/30/98
Outputs
A series of meetings were held with various fruit industry groups to obtain input as to future direction.
Impacts
(N/A)
Publications
- No publications reported this period
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Progress 10/01/96 to 09/30/97
Outputs
A longan selection has been identified at the UH-CTAHR Kona experiment station and is being propagated for on-farm evalutions at various cooperator sites throughout the state of Hawaii. Six cooperators have been identified who will be responsible for maintaining trees and collecting yield and phenological data. The principal investigators will be responsible for collecting fruit quality data (% soluble solids, flesh to seed ratio, fruit size). Materials for the trial will be ready for release to the cooperators in June 1998. Inflorescence of mango accessions at the UH-CTAHR Poamoho experiment station were severely damaged by powdery mildew during spring of 1997. Yield and kernel quality data from macadamia plantings at the UH-CTAHR Kona and Waiakea experiment stations are being summarized. Data for new HAES selections (HAES 816, 835, 849 and 856) are being compared to previously released cultivars (HAES 294, 344, 741, 788, and 800).
Impacts
(N/A)
Publications
- No publications reported this period
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Progress 10/01/94 to 09/30/95
Outputs
Due to lack of funds, no one represented Hawaii at the S-9 meeting for the past three years and maintenance on all collection in the state lacking. However, several litchi, longan and rambutan introductions were made from Thailand. A new longan selection was named 'Kainaliu' where it was located. Publications on 'Waiakea' guava and 'Poamoho' pili nut, and 'Kyra' carambola are still pending. Two excellent sapodilla selections are being tested. Four selections of pulasan have been made and being propagated for testing. Rust resistant coffee selections are maintained. All avocado selections will be kept at Captain Cook farm. A 'Fall' mango from China produced fruit late in the season and had good quality. Mild strain T-30 cross protected Mexican lime trees continued to produce good quality limes. This was a good year for litchi, longan, rambutan and pulasan and comparative fruit quality was analyzed and evaluated. 'Sri Chompoo' and 'Kainaliu' longan produced good quality
fruits and so did 'Sri Chompoo' and Ron Rien rambutan, while 'Kaimana' and 'Kwai Mi Pink' were the better quality litchi. As for the pulasan, four selections look promising.
Impacts
(N/A)
Publications
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Progress 10/01/93 to 09/30/94
Outputs
Awaiting publication are new cultivars 'Waiakea' (guava) and 'Poamoho' (pilinut). Two selections of sapodilla are being propagated for testing. Selections of pulasan have been made but due to the disappearance of rootstocks they are not propagated. Only one pilinut selection was made. Eleven coffee selections were made from Catura and Catamor types. Six avocado selections were made, propagated and planted in Kona. A Rambutan trial has been established. Five mango introductions from Southern China have been planted. Lychee and longan cultivars were evaluated and one logan selection made.
Impacts
(N/A)
Publications
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Progress 10/01/92 to 09/30/93
Outputs
Airlayering of pulasan selections gave poor results and rootstocks are being grown for grafting. Rootstocks are also being grown to graft the sapodilla selections. The avocado selections have been propagated and planted at Captain Cook, Kona for evaluation. Release and publications of 'Malama' avocado, 'Exel' mango, 'Kaimana' lychee, 'Sunset' papaya, 'Puma' grapefruit and 'Kary' carambola have been done. The following are waiting publication, 'Poamoho' pili nut, 'Greengold' avocado, 'Waiakea' guava, and 'Rapoza' mango.
Impacts
(N/A)
Publications
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Progress 10/01/91 to 09/30/92
Outputs
Only eleven new introductions were made from Brazil and Chile. All of the cherimoya scionwood was in poor condition an was not successfully propagated. Two pulasan selections at Waiakea produced good quality fruits and are being propagated for testing. At Poamoho two sapodilla selections producing good quality fruits will be propagated for testing and four avocado selections have been propagated. The following have been named, released and sent for publication: aimana', An improved New Lychee Cultivar for Hawaii; xel', A High Quality Dessert Mango;
alama', An Early Fall Avocado;
uma', Grapefruit; ary', An Improved Carambola for Commercial Planting.
Impacts
(N/A)
Publications
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Progress 10/01/90 to 09/30/91
Outputs
Accession book was stolen at the Poamoho experimental farm and valuable and irreplaceable information lost. Some attempt has been made to recover some of the lost information. A total of 34 new introductions from seven genera were made from Thailand, Colombia and Costa Rica. All scionwood brought in were unsuccessful but some seeds germinated. Two of the pulasan selections produced good quality fruits and are considered for release. The cross protected limes in Kona and Poamoho are producing heavily. Two sapodilla selections produced many good quality fruits with good size. Five mango selections from China have been propagated and will be field planted.
Impacts
(N/A)
Publications
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Progress 10/01/89 to 09/30/90
Outputs
Twenty seven new introductions of tropical fruits and nuts were made and collections of rambutan, litchi, longan, durian and lansone from, China and Thailand were made. Two of the pulasan selection produced good quality fruit again this year and are being considered for naming. The crop of litchi was fair with Kaimana doing well. There was a good crop of rambutan at Kona and the cross-protected limes in Kona and Poamoho produced heavily. Mangosteens and durian produce good quality fruits. Mangoes did poorly due to wet weather but 'Rapoza' and 'Excel' produced good quality fruits. Two sapodilla selections having good size and quality were made.
Impacts
(N/A)
Publications
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Progress 10/01/88 to 09/30/89
Outputs
There were only 12 new introduction of tropical fruits and nuts. There was a good crop of pulasan at Waiakea Experimental Farm and three, good yielding selections were made which produced good quality fruits. 'Kaimana' was the only litchi which produce a crop a Poamoho and also, produced well in Kona and other locations.
Impacts
(N/A)
Publications
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Progress 10/01/87 to 09/30/88
Outputs
New introductions from Thailand totalled 37 which included Jack fruit, rambutan,litchi, guava, durian, duku, pepper, papaya, and longan. Due to the harsh treatment with methyl bromide, many of the imported plants died. 'Sunset' papaya, 'Hoku' and 'Kary' carambola, and 'Waiakea' guava and 'Excel' and 'Rapozo' mango has been released for propagation. Despite the poor year for litchi, 'Kaimana' has fruited and has been released to nurseries. Most of the tropical fruits did not bear well this year.
Impacts
(N/A)
Publications
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Progress 10/01/86 to 09/30/87
Outputs
Fifty four new introductions from Australia, Africa, Japan, Mexico, Thailand, and Taiwan were added to the collection. These include seeds of annona, diospyros passion fruit and papaya, and scions of avocado, macadamia and diospyros. 'Kaimana' litchi, 'Excel' and 'Rapoza' mango, 'Hoku' and 'Kary' carambala, 'Waiakea' guava, 'Sunset' papaya, and 'Hess' jak fruit are being propagated for distribution. Since there were good crops of litchi and rambuton, fruits were vapor heat treated and preliminary results were successful. Drought continues to be a problem especially with durian, pulasan, mangosteen and peach palm.
Impacts
(N/A)
Publications
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Progress 10/01/85 to 09/30/86
Outputs
New introductions totalled 49 mainly from Mexico, Thailand,Tanzania and Sri Lanka. Few more types have been added to the Hawaiian banana collection. Rambutan seedlings produced a good crop while litchi cultivars, except 'Kaimana' and 'Gross' yielded poorly. Mango selection R6-T6 has been named 'Rapoza' and consistently produced good quality fruits. Carambola selection 11-1, having good quality and color, will be named. A guava selection WK11-26 has yielded well with good quality fruits for processing and a name 'Waiakea' has been selected for this cultivar. Interest in peach palm seems to be mounting and a thornless selection produces high quality fruits with very little fibers and with a high number of seedless fruit. Drought plagued most fruit and nut crops such as durian, pulasan, mangosteen, peach palm and jaboticaba.
Impacts
(N/A)
Publications
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Progress 01/01/85 to 09/30/85
Outputs
The number of new fruit introductions made was 42. Of great interest was a fruiting cactus that had better quality fruits than Kiwi. The Hawaiian banana collection is yielding well. Litchi cultivars also yielded good crops with 'Kaimana' producing an early crop and 'Groff' a late crop. Rambutan is consistently producing a crop, and so are several Pulasan selections. Mango selection R6-T6 produced an impressive crop of high quality fruits and will be named. Yield of 'Santa Catarina Prata' doubles that of the tall 'Brazilian' banana, while the quality is the same. Carambola selections have produced heavy crops with good quality fruits with selection #11-1 having good color. A thornless peach palm produced high quality seedless fruits and will be propagated for testing both for fruit production and for heart of palm. Pollination seems to plague the durian with very poor fruit-set. No effective pollinating agent may be the cause. A cherimoya selection was made
which had a good crop.
Impacts
(N/A)
Publications
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Progress 01/01/84 to 12/30/84
Outputs
Additional 23 new introductions of fruit were made. The Hawaiian banana collections have been established at Waimanalo. Yield and quality trials indicate that three carambola selections 6-1, 9-4 and 11-1 can be released. Pili nut selection No. 3 from Poamoho produced good quality nut and a new seedling planting has been established. Tabata naval from Kona and Rico No. 2 appear to be cross-protected against Tristeza and produce good quality fruits in Kona. Excellent crop of pulasan was produced at Waiakea. Rambutan was also productive but longan and litchi crops were poor. Pollination is a problem with durian fruit set and seeling durian produce a few fruits but one tree had very good quality fruits. Persimmon collection has been increased and several local selections included. Another bad year for mangoes with some cultivars producing fruit in November and December. A good crop of cloves was produced. Jaboticaba produced four crops during the year with heavy
production in March and November.
Impacts
(N/A)
Publications
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Progress 01/01/83 to 12/30/83
Outputs
Thirty-four new introductions of fruits and nuts were made. Several hundred plants of 'Santa Catarina Prata', a dwarf Brazilian type, have been distributed to growers and yields of 25-38 kg per bunch have been reported. From the 12 carambola selections 3 have shown great promise in tests having good quality. Another pili nut selection has been made having over 25 percent kernel with good production and grafting of this species appears to be feasible. Rico No. 2 is an excellent nucellar navel orange from Puerto rico which appears to be cross protected against severe tristeza virus strain in Hawaii. Excellent crop of good quality lansone was produced. Atemoya cultivars, African Pride and Geffner produced good quality fruits. Persimon trial was planted with several local and Japanese selections. Lychee production was poor but the cultivar Kaimana, originally assigned the name 'Poamoho', yielded well in Kona with excellent quality fruits. Longa crop was fair and
several Rambutan selections produced heavy crops. It was a bad year for mangoes due to the weather conditions.
Impacts
(N/A)
Publications
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Progress 01/01/82 to 12/30/82
Outputs
A total of 36 new introductions of fruits and nuts were added to the plant collection coming from Mexico, Costa Rico and Sri Lanka. The dwarf Brazilian, 'Santa Catarina Prata', is being propagated by meri-culture with the first hundred released to growers and thousands of plantlets being requested. Hawaiian banana collection was established at Waimanalo experimental farm. From the carambola selections made last year, four selections with excellent quality and good appearance and shelf life as well as yield, will be further tested at different locations. Pili nut selections have yielded more than 25% kernel and produced over 45 kilograms of wet, in shell nuts. The lychee selection previously assigned the name 'Poamoho' has been changed to 'Kaimana' in commemoration of the University's 75th anniversary as plants are being propagated for distribution. Hurricane Iwa caused severe damages to all tree crops on the experimental farms on Kauai and Oahu.
Impacts
(N/A)
Publications
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Progress 01/01/81 to 12/30/81
Outputs
Introductions of fruit and nut species totaled 47, mostly from Brasil and Mexico. Banana corms of `Santa Catarina Prata` introduced from Brasil have been distributed to growers who elected to increase plants by meristem culture. Twelve excellent Carambola selections have been made and will be propagated for testing. Sapodilla seedlings from superior plants from Mexico and Brazil have been planted for selections. Tree tomatoes have fruited well at the Volcano experimental station. Two pili nut selections have been further tested for kernel quality and yield. A lychee selection from `Hak Ip` seedlings with large, attractive fruits have been named, `Poamoho`. Two mango selection with excellent quality were named, `Winner` and `Ultra`.
Impacts
(N/A)
Publications
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Progress 01/01/80 to 12/30/80
Outputs
Thirty-seven accessions of named cultivars, unnamed clones and selected seed were received, cataloged and propagated for testing at experiment stations and with private cooperators. It takes several years to produce fruit for evaluation and many older accessions are still being evaluated. It, therefore, seems appropriate to enumerate the best new clones developed under this project and accessions not well enough known to be widely utilized but meriting greater distribution and use.
Impacts
(N/A)
Publications
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Progress 01/01/79 to 12/30/79
Outputs
One hundred nineteen accessions of clones, cultivars and species level seed collections were imported, catalogued and propagated for introduction and testing with private cooperators and at Experiment Station facilities. Included were improved cultivars of banana, avocado, passion fruit and peach palm. The project leader spent the first 6 months of the year in Brazil, Peru and Mexico collecting 113 of the 119 accessions received during the year. Outstanding were 19 Mexican race avocado clones for testing as varieties and hybridization with local clones. Also of considerable potential value were seed of 11 excellent quality, seedless and/or thornless peach palms, 'Guilielma gasipaes', also 'camu camu', Myrciaria paraense, from Peru a fruit with the highest known ascorbic acid content and Santa Caterina Silver banana, a dwarf, wind resistant mutant of the 'Brazilian' (Pome) variety. Ascorbic acid of lychees from Waiakea and Kona was very low ranging from 11-36 mg/100
g. Refractometer readings ranged from 17.0-21.1% TSS. Number of aborted seeds was highest in 'Groff' (88%) and lowest in 'Bengal' (4%).
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Progress 01/01/78 to 12/30/78
Outputs
New accessions from New Zealand included superior strains of papino, New Zealandgrapefruit, tree tomato, guava and an avocado relative (B. tarairi). Other more significant accessions are nutmeg from Puerto Rico, Physalis species from Mexico and a mango relative from Thailand. Overall there were a total of over 40 new introductions which included important tropical crops such as avocados, guavas and papayas. Of the 20 lychee cultivars tests, 'Groff' had the highest percentage of aborted seeds with 88% and No. 15-3 had no aborted seeds. 'Groff' and 'Kwai mi' averaged over 75% flesh, while 'Bengal' had less than 60%. Half ripe lychee fruit had as much sugar as ripe lychee but also higher acid content. Yield of 12-year old cherimoya trees in Kona ranged from 45.4 to 136.2 kg per tree for the cultivar 'McPherson'. 'Thomson' had the highest ascorbic acid content with 12 mg/100 g and 'Deliciosa' 5.2 mg/100 g. Pili nut selection No. 1 and 2 had 65% oil and over 25%
kernel. 'Chandler' pummelo produced fruits with excellent red color and good quality.
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Progress 01/01/77 to 12/30/77
Outputs
During the year 47 accessions of improved cultivars, new clones and seedling selections were introduced, catalogued and propagated for testing at branch experiment station facilities and with private cooperators. Included are promising cultivars of avocado, durian, guava, papaya, pummelo and rambutan. The promising new accessions are presently undergoing testing and evaluation: Druing the 1977 fruiting season the following recent accessions have come into bearing producing furit of good quality for the first time: pili nut, lansone, pulusan, rambutan, champedek, marang and amagosteen.
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Progress 01/01/76 to 12/30/76
Outputs
30 introductions and new accessions of clones, cultivars and species level seed collections were received, cataloged and propagated for testing with private cooperators and at Experiment Station facilities. Included were improved cultivars of avocado, citrus, durian, lychee, papaya and rambutan. 'Berangan" (chestnut)is an outstanding banana accession introduced from Malaysia in 1973. It appears to be a dwarf mutant form of the Philippines 'Lakatan' and has good appearance, excellent quality and outstanding shelf life. Papaya Acc. No. 7905 from El Salvador appears to have field resistance to mites and mildew, the 2 most serious pests of papaya in Hawaii. It is therefore of considerable potential value in breeding programs. The 'Cameron Highlands lemon' imported from Malaysia in 1972 is a prolific, small-fruited, high quality lemon which appears well adapted to growing in Hawaii where most lemon cultivars are not well adapted.
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Progress 01/01/75 to 12/30/75
Outputs
41 new accessions of clonal & seed introductions were received, cataloged & propagated for testing at Branch Station facilities & with private cooperators. Included are improved cultivars of: annona, avocado, carambola, durian, guava, mango & rambutan. HAES 7315 has been named 'Hayes' and introduced as a new late-season commercial avocado cultivar. Two imporved cultivars, 'Pinks mammoth' custard apple & 'Seremban' star fruit were released to nurserymen for introduction and sale to the public.
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Progress 01/01/74 to 12/30/74
Outputs
27 new introductions consisting of 16 selected clones and 11 foreign and domestic seed introductions were introduced, cataloged and propagated for testing at the best available locations on branch stations and with private cooperators. These include promising clonal cultivars of annona, avocado, banana, carambola and mango. Sharwil," which has become the major new cultivar in recent commercial plantings, is the most recent accession to become widely utilized in the State.
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Progress 01/01/73 to 12/30/73
Outputs
Twenty-two accessions consisting of 9 selected clones and 13 foreign and domestic seed introductions were acquired, cataloged and propagated for testing at the most suitable locations available on branch stations and with private cooperators. These include promising clones of banana, annona, carambola, avocado and mango.
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Progress 01/01/72 to 12/30/72
Outputs
Twenty-nine accessions which included 17 selected fruit clones and 12 seed introductions were imported and grafted or planted for testing at appropriate experiment station locations. Promising clones of 6 durians, 4 rambutans, 4 mangos and 3 carambolas grown commerically in Thailand, Malaysia and Indonesia were introduced. The promising 'Amritsagar' banana clone was found susceptible to Panama wilt but the recently imported Poovan variety shows good field resistance to both "Panama Wilt" and "Black leaf-streak" diseases. Sixteen imported avocado cultivars and 8 promising late-winter and spring maturing clones selected in Hawaii have begun to fruit in test plantings on 3 experimental farms. Avocado clones that have fruited for the first time which appear most promising are Semil 43, Sharwill, St. Claire, HAL R1T45 and HAL R3T37. Recommended varieties recently introduced and/or developed in Hawaii include Sharwill, Nishikawa, Fujikawa and HAES 7315.
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Progress 01/01/71 to 12/30/71
Outputs
Thirty-three accessions including 18 selected clones and 15 foreign and domesticseed introductions were acquired, cataloged and propagated for testing at suitable locations in the State. Sixteen imported avocado cultivars and 8 outstanding winter and spring maturing clones from hybrid seedling progenies were topworked on older trees for preliminary testing at the Kona Branch Station. To date no satisfactory summer maturing selection has been found. 'Amritsagar,' a new banana clone from E. Pakistan, fruited for the first time producing high quality bunches averaging 60 lbs. The hands and fingers are equivalent to 'Gros Michel' in size, shape and shelf life while the dessert would be an acceptable substitute for 'Gros Michel' in infested locations. The 5 mos important commercial clones of longan in Thiland have been imported and successfully established for testing at Poamoho Expt. Farm and Kona Branch Station. Nineteen mango cultivars from Hawaii, Florida, Puerto
Rico, Israel andIndonesia, considered to have resistance or tolerance to blossom anthracnose, have been established for testing by topworking on older trees at Poamoho Expt. Farm where conditions are favorable for anthracnose.
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Progress 01/01/70 to 12/30/70
Outputs
Forty-seven accessions including 35 selected clones and 12 foreign and domestic seed introductions were acquired, cataloged and propagated for trial. Fifteen new mango cultivars from Fla. and Puerto Rico bring the No. of varieties now on trial to 73. Nine new avocado cultivars from Fla. and Puerto Rico plus 2 selections made from 1800 hybrid seedlings at Haleakala Expt. Farm have been propagated and established in test orchards on Oahu, Maui and Hawaii. Two out of 49 "Peach Palm" (Guilielma gasipaes) plants from selected seedling progenies have produced completely seedless fruit bunches. One hundred percent seedless fruit bunches have not been previously reported for this palatable fruit, one ofthe worlds richest sources of Vitamin A. 'Heen Naran' and 'Triumph,' both highly resistant to foot rot and gummosis, were tested and shown to be excellentcitrus rootstocks on poorly drained lateritic soils. Fifty-one out of 53 bananavarieties in the trial of native and
exotic cultivars planted at Kauai Branch Station were supplied by the Horticulture Dept. Two of these varieties importedby the University, 'Williams Hybrid' ('Giant Cavendish') and 'Dwarf Bluefields' ('Cocos') have been in heavy demand for commercial planting.
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Progress 01/01/69 to 12/30/69
Outputs
Forth-three new accessions consisting of 24 selected clones and 19 foreign and domestic seed introductions of promising new fruit and nut crops acquired in 1969, were cataloged and propagated for trial at appropriate locations. Of 42 tangerine types, 18 orange varieties and 21 rootstocks tested, "Fremont" was theoutstanding tangerine tested, "Pera" was the most acceptable orange variety and "Heen Naran" (C. crenatifolia, F. lycopersicaeformis) was the outstanding rootstock. HAES 7795 (formerly CR10T2) was the most promising new lychee clonalselected tested. It is a seedling of the variety "Hak Ip." Size, appearance and general fruit quality are outstanding to date. Yield trials will, however, precede naming and release as a new variety. Approximately 935 avocado seedlings of Guatemalan and Mexican race hybrid origin were tested and evaluated. Fruit samples of 30 of the most promising were analyzed. Fourteen outstanding seedlings were propagated for further
testing as clonal varieties inavocado growing areas. The "Gouveia" mango, an exceptionally attractive high quality, new seedling selection under test for several years has proven suitableboth for fresh dessert and freezing purposes. It has been officially named and described to expedite and facilitate introduction to the public.
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Progress 01/01/68 to 12/30/68
Outputs
Thirty-one new accessions including 19 selected clonal varieties of promising fruit and nut crops which were received during 1968, were cataloged and propagated for testing under Hawaiian conditions. 'Cocos' banana, a recently introduced semi-dwarf mutant of 'Gros Michel,' has demonstrated ability to withstand wind better than the parent variety and is being successfully used to replace the wind susceptible 'Gros Michel.' 'Gouveia,' a high quality dessert mango tested under this project, has shown sufficient merit and promise to be officially named and described as a new variety. 'Pera' is proving to be the outstanding of 12 orange varieties on trial, while 'Heen Naran' rootstock has given the most satisfaction tree growth and disease resistance of the 18 citrus rootstocks presently under field tested. To date Guatemalan and Guatemalan X WLrace progenies have produced the best selections for ripening in the period fromOctober to July.
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