The Mango Loa Project phase two: Improving Hawaii's mango industry by incorporating high density orchard management systems

Progress report for FW21-375

Project Type: Farmer/Rancher
Funds awarded in 2021: $16,533.00
Projected End Date: 10/01/2023
Host Institution Award ID: G377-21-W8613
Grant Recipient: Umi Martin
Region: Western
State: Hawaii
Principal Investigator:
Umi Martin
Umi Martin
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Project Information


The mango loa project is a continuation of project FW17-034 and will carry on the objectives into the production years.

Hawaii used to have a robust agriculture based economy that has slowly been replaced by tourism.  Even before Covid-19, we the people of Hawaii have been voicing the demand to have a more balanced and diversified economy, by rebuilding and growing our agricultural industries. Tree crops like mangoes, avocados, and citruses have been identified as having great potential.  According to the most recent national agriculture statistics, Hawaii reported producing 270,000 lbs. of mango in 2017, while importing millions of pounds from Central and South America.

The mango loa project’s goal is to improve Hawaii’s mango industry by incorporating two new innovative high density orchard management systems that have been completely changing tropical fruit production around the world.  These systems are the ultra high density plantation and the open Tatura trellis systems.

With the conventional mango orchard, a realistic expectation of production is two to five tons/acre. The two new systems mentioned above have been producing eight to twenty tons/acre.  Aside from that, these systems are a more efficient use of land, natural resources, and inputs; it reduces the demand on labor; and has a quicker time to production.  Utilizing these high density systems have the potential to double Hawaii’s mango production with just 20 acres.

The project will be disseminated through farm field days, farmer to farmer tours, online events, power point presentations, videos, posters, and networking.

Project Objectives:

The objectives of this project is to demonstrate two high density orchard management systems and report on the harvest and production of these systems. another object is to demonstrate harvest and post harvest practices to preserve the quality of the produce.  The educational objectives is to reach Hawaii's tropical fruit farmers and professionals and make them aware of these new innovative techniques that have been improving the yield and quality of tropical fruit production, improving profitability, and improving the quality of life of farmers.


October 2021 start project

November 2021- Hawaii Ag Conference- PowerPoint presentation, poster, and networking  

January 2022- build mango wash station

February 2022- set up the cold storage unit

March 2022- Erect framework for the netting demonstration

April 2022- Field day for the orchard update and new aspects of the project

April 2022- KCC garden fair- poster presentation and networking

June 2022- Document all aspects of the harvest with videos

August 2022- Waipa Mango Festival: networking and poster display.

September 2022- Hawaii Tropical Fruit Growers conference Maui: PowerPoint presentation on project.

November 2022- Post-harvest Pruning video.

April 2023- KCC garden fair: display poster and networking

June 2023- Field day during harvest to update the orchard and demonstrate the different aspects of the project.

August 2023- Waipa Mango Festival: Display poster and network.

September 2023- HTFG Kauai.  Update project, display poster, and networking

October 2023- Final


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  • Emilie Kirke - Technical Advisor


Materials and methods:

The mango loa project is a continuation of project FW17-034: it incorporates two high density mango orchard systems on one acre of land.  The first system is the ultra high density plantation (uhdp) method; this is a standalone orchard with 310 trees on a little more than a half acre field, this field is three years old and a good harvest is expected this summer, 2021.  The second is the open Tatura trellis system that incorporates a unique V-trellis design, and has 300 trees on a half acre field.  The trellised field is nearing two years in the ground and the first full season of production is expected summer, 2022.

The first objective of the mango loa project is to observe, compare, and document the progress of the two different high density orchard systems.  This includes the pruning and training time requirements; the growth cycle, flushing, flowering, fruit development, and harvest; nutrient and pesticide management; and harvest and post-harvest procedures.  Timed observations will utilize a stopwatch, and all other observations will be documented using a notebook, videos, and pictures. Materials needed here will be small tools; pruners, saws, and harvest poles, vinyl tape, trellis clips, wire tensioners, as well as other small miscellaneous tools.

The next objective will focus on protecting the fruit from bird and insect damage.  A beneficial factor of the high density systems and the low bearing trees is the ability to cover the orchard with crop-netting, this provides three benefits; it keeps fruit flies away from the fruit, blocks birds pecking and damaging crops, and provides just a bit of shading to reduce excessive sun exposure. We have four major fruit flies in Hawaii that cause millions of dollars in damage to fruits and vegetable crops.  There are integrated pest management plans to suppress the fruit fly population around your farm and these will be practiced; this includes trapping, baiting, and sanitation in the field.  However, if other farms in the area do not follow the same practices, its’ effectiveness is limited.  Kauai has many fruit loving birds that also adversely affect marketable fruits.  One in particular is the Rose ringed parakeet, a newly established species that is starting to have devastating effects on many tree crops.  Netting the fruit trees may be the only way to truly ensure a high quality crop.  We will use crop netting on two trellised rows and two uhdp rows to demonstrate its effectiveness in mitigating damage caused by birds and insects.  Materials needed for this objective are: crop netting, poles, concrete, and cables, small hardware will be needed to aid in attaching cable to framework.

The another objective is to mitigate the damage caused by sap burn on mangoes during harvest.  Severe sap burn makes the fruit unmarketable, while low level sap burn makes the fruit more susceptible to disease infection and lessens the shelf life of the fruit.  It is essential to neutralize the mango sap with a wash at harvest time to prevent losses due to sap-burn.  There are two ways to de-sap mangoes; first is to pick the mango and immediately neutralize the sap with a mango wash in the field.  This requires a station that will have a tank to hold the wash, a pump and sprayer to facilitate washing, tarps that will be used to guide the washed mangoes into another tank until it is removed and put in crates, ready to go to the packing house.  The other way to reduce sap-burn is to pick the fruit with a couple of inches of stem on, this is above the sap ducts and will not ooze sap.  The fruit is packed in crates and taken to an area where the stems are removed, the sap is neutralized and allowed to de-sap before it is washed and packed for sale.  The mango loa project will build these stations and demonstrate how preventing sap burn.  The materials needed to complete this objective are the materials to build the in-field station mentioned above and the objective will be documented with video and pictures.

The final objective will be to build a simple cold storage unit that will delay the ripening of fruit and allow the farmer to extend its’ shelf life, allowing more time to sell their fruit.  The cold storage unit will be built out of an insulated shipping container, with a window air conditioner, and a Cool Bot external thermostat used to regulate the temperature of the air conditioner.  Mango ripening can be delayed if stores at 50-55 degrees Fahrenheit.  This is important to maximize profitability.  Peak mango season lasts about six weeks and there is usually a surplus of fruit on the market. During heavy cropped years the price plummets forcing farmers to undervalue their crop.  Mangoes can be stored for as long as 6 to 7 weeks, however there will be some diminished fruit quality.  This added time will give farmers the flexibility to delay sales during a surplus time and release their product when the demand increases.  A cold storage unit is also critical to farmers who wish to process their fruits into value added products, giving them the ability to ripen the fruits depending on what they can process.

The ultimate goal of the mango loa project is to improve Hawaii’s mango industry by incorporating new innovative high density orchard management systems that have increased the yield and quality of harvested fruit.  However, increasing production is not enough, equal importance must be placed on proper protection, harvesting and storage of the fruit to maximize profitability and reduce waste.  This is what the mango loa project aims to accomplish.

Participation Summary
1 Producers participating in research

Research Outcomes

No research outcomes

Education and Outreach

2 Consultations
4 Curricula, factsheets or educational tools

Participation Summary:

1 Farmers participated
1 Ag professionals participated
Education and outreach methods and analyses:

This project began in October and due to Covid restrictions all planned outreach activities have been postponed or canceled, however the restrictions have been lifted and we are hopeful we can schedule in person events moving into the summer/ harvest season, where the focus of this project is.  Upcoming, there is a garden fair at the community college in April that I will have a presentation and poster display; There is a field day planned in June; the project will be featured in the University of Hawaii CTAHR newsletter for the summer edition; and the Hawaii Tropical Fruit Growers Conference in November, where I will have a power point presentation

The Mango Loa Project YouTube channel has been the best outreach effort so far, with a total of 78,000 views.  Based on the amount of feedback I have received through emails and messaging, there is real enthusiasm for high density orchard systems. Four new videos were produced with a focus on post-harvest pruning of the two different high density techniques, ultra high density plantation and the open Tatura trellis system, that are demonstrated in this project.  At this point, the four new videos have a total of 1400 views.

Education and Outreach Outcomes

1 Producers reported gaining knowledge, attitude, skills and/or awareness as a result of the project
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.