EVALUATION OF NEW MACADAMIA NUT SELECTIONS FOR HAWAII PRODUCTION

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1010395
• Project Start Date: Oct 1, 2016
• Project End Date: Jan 10, 2020
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIV OF HAWAII
3190 MAILE WAY
HONOLULU,HI 96822

Performing Department
Tropical Plant & Soil Science

Non Technical Summary
Macadamia nut is one of the most important agricultural commodities in the state of Hawaii. Most orchards in Hawaii were last planted in the 1980s, and there is a need for research into new selections of macadamia nut that have higher quality nuts that will help Hawaii remain competitive on the global macadamia nut market. The purpose of this project is to evaluate new selections of macadamia nut planted at two research stations in Hawaii (Waiakea and Kainaliu) for yield and quality. The first objective will evaluate new selections of macadmia nut compared to the current industry standard for yield and quality. The second objective will evaluate the effects of mulch treatments on soil and tree health. The third objective will evaluate a new tissue sampling method for macadamia.The results from these objectives will be released to the industry and the public when the study is complete and the yield and quality data is analyzed and considered to be stable and representative.

Animal Health Component

50%

Research Effort Categories

Basic

0%

Applied

50%

Developmental

50%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
204	1099	1081	10%
205	1099	1081	75%
701	1099	1081	15%

Knowledge Area
204 - Plant Product Quality and Utility (Preharvest); 205 - Plant Management Systems; 701 - Nutrient Composition of Food;

Subject Of Investigation
1099 - Tropical/subtropical fruit, general/other;

Field Of Science
1081 - Breeding;

Keywords

macadamia

nut

Goals / Objectives
The overall objective of this proposal is to evaluate sustainable macadamia production practices for new macadamia nut selections in Hawaii. Specific objectives include:Evaluation of new macadamia selections for production in Hawaii.Evaluation of six un-named selections compared to two released selections ('344' and '800') for yield and quality at two locations in Hawaii.Evaluation of yield and quality of advanced macadamia nut selections '856' and '835' compared with '800' at Waiakea Research Station.Evaluate the effects of different mulch treatments on macadamia nut production and quality and macadamia orchard soil health.Simplified tissue sampling for macadamia.

Project Methods
Objective 1 (A)Two locations were planted in 2001 with grafted macadamia nut to evaluate advanced selections (Table 1) from Dr. Phil Ito and later Dr. Mike Nagao that were selected based on desirable kernel quality characteristics and tree morphology shape. These locations include the Kainaliu Research Station (elevation 390m) planted in May 2001 and the Waiakea Research Station (elevation 183m) planted in July 2001. At the time of this proposal, the trees are approximately 15 years old.Table 1. List of macadamia nut selections planted at two locations in Hawaii.KainaliuWaiakeaSelectionNo. of trees3446138006148796148626088751389651490053932614Kainaliu Research Station Randomized complete block design with three replications. Each block consisted of a selection with initial planting of 4 trees each. Trees were planted at a 15ft spacing. After 10 years, every other tree was removed to have a 30ft tree spacing. Tissue and soil analysis are conducted annually to help guide fertilization regimes. Please see plot map (Attachment C). The plot allocation for this site has been approved through 10/22/2020 (Plot allocation no. 15HKON041).Waiakea Research StationRandomized complete block design with three replications. Each block consisted of a selection with 5 trees each. However, over time some trees were lost to Macadamia Quick Decline, selection '900' was especially susceptible (Table 1). Trees were planted with 14ft between trees, 25ft between rows, and a 30 ft break between reps. Tissue and soil analysis are taken annually to help guide fertilization regimes. Please see plot map (Attachment D). The plot allocation for this site has been approved through 10/22/2020 (Plot allocation no. 15HWAI107) and will be renewed upon expiration.YieldsYields will be collected on a regular basis beginning in August 2016 and wet in shell weights will be taken per tree. These weights will be adjusted based on the industry standard adjusted to 20% moisture and 30% kernel recovery. Quality AnalysisHarvested macadamia nut will be husked mechanically and 50 nuts will be randomly selected from each selection (1 sub-sample per rep). Wet in shell weights will be taken for the 50 nuts. Nuts will then be dried in an oven at 30C for 7 days, followed by 40C for 7 days, and 70C for 3 days (Wall and Gentry, 2007). Dry weight of the 50 nuts will be taken. Each nut will be weighed and then cracked. Kernel weights will be recorded and kernels will be floated to determine No. 1 grade kernel recovery rate. Floating in tap water indicates a specific gravity less than 1.0 and a 72% or more oil content. Lower recovery of floaters suggests a reduced oil content of the kernels. Sub-samples will be submitted to the USDA-ARS PBARC for evaluation of oil content. Tree Morphology and SusceptibilityIn addition to yield and quality analysis, the susceptibility of these new selections to insects that affect both post-harvest losses, as well as causing tree damage (macadamia felted coccid), will also be recorded for use in evaluation of these selections. Tree morphology will also be described to add information to the selection descriptions for decision making on utilization of these selections.Objective 1 (B)Waiakea Research StationThe experiment will evaluate three advanced selections of macadamia nut, '835', '856' and '800'. The experiment is set up in a randomized complete block design with three replications. The grafted trees were planted in July 2000. Each block consists of 5 trees of each selection with 25ft between trees and 30ft between rows. Tissue and soil analysis will be collected annually to assist with appropriate fertilizer regimes. Please see plot map (Attachment E). The plot allocation for this site has been approved through 10/22/2020 (Plot allocation no. 15HAWAI107) and will be renewed upon expiration.Yields, quality analysis and tree morphology and susceptibility will be collected as described in Objective 1A above.Objective 2This study will be conducted at two locations at Island Harvest (private farmer cooperator) in Kohala, Hawai'i. Mulch treatments include:Macadamia nut husk mulchMacadamia nut husk mulch + macadamia nut shell biocharMacadamia nut husk mulch + EM1Soil profiling: adding soil to exposed roots under treesWood chip mulchControl (no mulch added)The experiment is set up as a randomized complete block design. Two sites were selected based on uniformity in variety ('508'). Four blocks were selected at each site, with plots randomized within each block. Each plot is comprised of four trees with a minimum of two border trees between plots. Mulches will be applied on top of undisturbed soil, by hand, at a depth of 10 cm and to a radius of three meters from the trunk. Treatments will be applied in the spring of 2017.Objective 2(A)Evaluate the effect of different mulch treatments on macadamia yield and nut quality, tissue nutritional levels, SPAD, and proteoid root development.Data to be collected: Objective 2(A)Samples of macadamias will be measured forWet in husk weightWet in shell weightDry in shell weightKernel weightKernel recovery rateOil contentRoot biomass will be collectedSPAD measurements will also be collectedObjective 2(B)Evaluate the effect of different mulch treatments on soil organic matter and nitrogen concentration in macadamia.Data to be collected: Objective 2(B)Percent soil organic matterpH,EC, andNO3- and NH4+ concentrations.Objective 3Current recommendations for tissue sampling of macadamia trees is for the spring, which coincides with the period just before the onset of a major vegetative flush. However, farmers are often interested in the nutrient status of the trees year-round. Tissue analysis is important for accurate record keeping and crop logging in order to make accurate fertilizer applications.We hypothesized that mature leaves collected from flushing branches would not differ from mature leaves collected from branches in a resting state.Tissue samples will be collected in the fall (September to October) and in the spring (April to May) from four locations on Hawaii Island. Table 2 lists the locations, varieties, and number of samples collected from each location.Table 2. List of locations, varieties, and number of reps (trees) for each treatment.LocationVarietyReps (n=trees)Waiakea3443Waiakea8793Kona3443Kona8793Kohala3444Kau3446The treatment is leaf sample method, and treatments are applied to the same trees throughout each location. The first sample is from the current standard recommendation for selection: from a mature branch and the leaf is selected from the second whorl below the terminal bud (which was in a resting stage or just beginning to flush). The second sample is from the mature portion of a flushing branch where the leaf was selected from the second whorl below the end of the flushing terminal bud. Each sample consists of 16 to 20 leaves.Leaf samples will be submitted to the University of Hawaii's Agricultural Diagnostic Service Center (ADSC) for tissue analysis for the Waiakea, Kona, and Kohala locations. Leaf samples from the Kau location will be submitted to Crop Nutrient Solutions, Inc for tissue analysis.

Progress 10/01/17 to 09/30/18

Outputs
Target Audience:The target audience for this project are macadamia producers in Hawaii. This target audience is composed of large and small growers, including large businesses and family-run farms. The target audience was reached primarily through the Hawaii Macadamia Nut Association. The PI (A. Cho) met monthly with the board of the association and presented at the annual grower's meeting in July. The audience was also reached through outreach events at which growers were in attendance. These efforts include, but are not limited to: 1) Monthly attendance at the board meetings of the Hawaii Macadamia Nut Association 2) Presentation of research update at the annual grower's meeting held by the Hawaii Macadamia Nut Association Changes/Problems:While it has not yet caused any major changes in the design, the Kona field has recently been experiencing rapid tree decline and death. I have involved the plant pathologist, Dr. Lisa Keith, from USDA-ARS who has been surveying the field. We have two species of Phytophthora present, which are causing this decline. I have applied Phosphite, and plan another application, to try and reduce the damage from this pathogen. What opportunities for training and professional development has the project provided?While no formal opportunities occurred during the reporting period, there were several students (one undergraduate, one graduate, and one post-doc) working on this project. These students all had opportunities to interact with growers and processors, and participate in ongoing research data collection and presentation of these materials at monthly lab meetings. How have the results been disseminated to communities of interest?In July 2018 the results were disseminated to the attendees of the Hawaii Macadamia Nut Association's annual grower meeting. This meeting had over 50 attendees of growers, processors, researchers, and others involved in the macadamia industry. Many attendees were not aware of the research before the presentation. After the presentation, two growers expressed interest in some of the new selections and ongoing plans for distribution of planting material are currently being coordinated with those interested. The results are continually updated to the Board of the Hawaii Macadamia Nut Association at monthly meetings and informal conversations with growers. What do you plan to do during the next reporting period to accomplish the goals?During the next reporting period, data will continue to be collected on the yield and quality of the selections at the two locations. The efforts for creating and distributing planting material will also be initiated. Rootstock will be established, with hopes of grafting to occur in the 2019 FY. Scion wood will be girdled and prepared for distribution to growers who have their own rootstock available and will be ready for grafting ideally by early 2019. Additional scion wood will be prepared for the grafting efforts for the distribution of planting material at field days that will occur in the Fall of 2019.

Impacts
What was accomplished under these goals? For objective 1, data collection on yield and quality continues at both locations, Hilo and Kona. Data from these fields has been compiled and presented at the Hawaii Macadamia Nut Association annual grower meeting (July 2018). Yields and quality were best in the selections'800', '887', '879', and '900'. Yields at the Kona site were consistently higher than the Hilo location. This is partially due to the environmental conditions, but also related to the maintenance of the fields. Yields at the Kona locationin these 4 high performing selections exceeded 100 lbs of wet-in-shell macadamia per tree, which was higher than the standard selection, '344'. As important, the quality of these selections was also good, with a kernel recovery above 30% for the '800', '879', and '887' selections. Kernel recovery was lower (24%) in the '900' selection, which is primarily a function of the thick shell on this selection. Although the recovery rate is lower, the initial selection of this '900' individual was due to the potential for this selection to have more resistance to pests that infest the nuts while they sit on the orchard floor. This could potentially increase the quality of the kernels in operations that have long harvest intervals. The second objective has still not been initiated due to a lack of staffing at this site.

Publications

• Type: Theses/Dissertations Status: Published Year Published: 2018 Citation: Galanti, R. 2018. The effects of soil amendments on tree growth, yield, and soil properties in mature Macadamia integrifolia orchards. Masters Thesis. University of Hawaii at Manoa.
• Type: Journal Articles Status: Published Year Published: 2018 Citation: Gutierrez-Coarite, R., Mollinedo, J., Cho, A., and Wright, M. 2018. Canopy management of macadamia trees and understory plant diversification to reduce macadamia felted coccid (Erriococcus ironsidei) populations. Crop Protection Journal 113:75-83.
• Type: Other Status: Published Year Published: 2017 Citation: Gutierrez, R., Zarders, D., Pulakkatu-Thodi, I., Mollinedo, J., Yalemar, J., Wright, M.G., and Cho, A. 2017. Macadamia felted coccid Eriococcus ironsidei (Hemiptera: Eriococcidae) description, monitoring and control. University of Hawaii at Manoa, College of Tropical Agriculture and Human Resources. November 2017, IP-43.

Progress 10/01/16 to 09/30/17

Outputs
Target Audience: Nothing Reported Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?One graduate student is being trained in association with this project. However, one additional graduate student, one post-doc, and several (2-3) undergraduate students also participate in data collection, processing and analyses. The graduate student who is helping with this project gave the public presentation at the Hawaii Macadamia Nut Association meeting in July 2017 (the PI was out on vacation), providing the opportunity for professional development for the student. The graduate student is also helping to run a smaller set of training sessions for a sub set of the industry association, the Kohala growers group. Many of these growers are physically separated from other parts of the island and don't get to communicate with other growers often, so he has been providing basic workshops (such as how to collect tissue and soil samples in macadamia) for these growers. How have the results been disseminated to communities of interest?The results are shared on a regular basis (monthly) with the board of the Hawaii Macadamia Nut Association. Results are also shared at scientific conferences and industry meetings. During this project year, the results were shared at the Hawaii Macadamia Nut Association annual meeting in July 2017. What do you plan to do during the next reporting period to accomplish the goals?During the next reporting period, I plan on continuing to collect yield and quality data on objective 1. I also plan to start collecting data on objective 2, permitting technician assistance. I also plan on adding in an analysis on the effect of harvest time on quality of the new selections. Some selections may tolerate longer harvest intervals than others, and this additional data should help growers in choosing selections that will fit into their harvesting time schedules.

Impacts
What was accomplished under these goals? For objective 1, yield and quality data were collected from two locations (Hilo, Kona) where these varieties are planted, during the harvest season of August 2016-March 2017. Harvests for the 2017-18 season has also begun at both sites. Preliminary data suggest that 3-4 selections (3 at the Kona site, 4 at the Hilo site) perform as well or better than the controls for yield and quality. These data suggest that with a few more years of data collection, we may have 3 new selections to release to the public for planting. These results were presented at the Hawaii Macadamia Nut Association annual meeting in July 2017 and several growers are interested in obtaining scion wood to plant some of the new selections and participate in the evaluation trial. This will provide additional data on performance in different environmental conditions. For objective 2, the field has been maintained and data collection will begin soon. A delay has been in place due to the limited time of the agricultural technicians at the research stations to help with harvesting.

Publications

• Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Cho, A. and Galanti, R. 2017. Cho Lab Updates. Hawaii Macadamia Nut Association Annual Meeting. Hilo, Hawaii. Oral Presentation.