Farm Progress

The Jim Trump family of Island Harvest Inc. farm about 700 acres of conventional and organic grown macadamia trees in Kapaau, Hawaii located on the Big Island of Hawaii.Jim Trump says, “We think soil health is key to nutrition, production, and tree health.”The farm is shifting to 100 percent organic using Korean natural farming practices.   

June 17, 2016

7 Min Read
<p><strong>The macadamia team at Island Harvest Inc. at Kapaau, Hawaii includes from left: Chris, Jim, and Nathan Trump, plus Hansen Kapeliela and Gilbert Bigtas. 2016 marks the 25<sup>th</sup> year for the Trump family in the macadamia business on the Big Island coast.</strong></p>

Crashing ocean waves are quickly stilled as they hit the majestic tall rock cliffs protruding like a mountain fortress on the coastline near the community of Kapaau at the northernmost tip of the Big Island of Hawaii.

Just a few miles down the coast line is an amazing 700-acre farm which many decades ago was a sugarcane plantation. In the 1980s, the cane yielded way to plantings of macadamia trees for nuts. Farming the macadamia operation today is the Jim Trump family and their Island Harvest Inc. farm which started in 1991.   

Jim Trump, no relationship to the U.S. presidential candidate, is a first generation grower. The family patriarch previously worked in land management on the Big Island, mostly managing farms growing vegetables, pineapples, herbs, and other crops.

The Trump macadamia nut operation includes Jim’s wife Debbie and their sons Chris and Nathan who are actively involved in the day-to-day operations, plus strategizing the farm’s future.

The farm includes an equal amount of conventionally- and organically-grown trees (350 acres each). The farm’s hilly terrain ranges rises in elevation from 400 to 1,000 feet and has silty clay soils.

“We think soil health is key to nutrition, production, and tree health,” says Jim.

Needed rainfall

Average rainfall on this northern coast parcel is about 60 inches per year. About 40 inches aew needed to grow high quality mac nuts in the Kapaau area.  Less than this amount can create drought stress in trees. Rain is the sole water supply in the macadamia orchards.

“What really matters is the distribution of the rain during the crop cycle,” Jim says. “We especially need good rains during kernel development, especially in May and June during the critical oil accumulation phase of the kernel.”

He says the top threats to the family’s operation are the weather, including possibly too much rain at harvest, and the access to capital. Summer temperatures usually top out in the mid-80s while winter temperatures rarely fall below 60 degrees.

Three bloom periods

For the Trumps, macadamia nut production is year round. Bloom occurs from January into March. Three bloom periods are common in the State of Hawaii. If a tree doesn’t produce a good nut set during the first flowering, it usually produces a better set during the second or third flowerings.

The blooms are naturally pollinated mainly by the wind, along with honeybees and flies. The Trumps manage 30 honeybee hives on their operation.

The kernel development phase runs from March through August. During those months, orchards are pruned, mowed, and fertilized, plus needed equipment repairs take place. Nut harvest occurs from August through January; the peak months are September and October.

Mechanized, hand harvests

On the Trump operation, most of the nuts are mechanically harvested with balance picked up by hand. The Trumps have five mechanical harvesters, including four Australian-made Nabba harvesters and one Monchiero harvester from Italy. The harvesters – mechanical and employees - pick up nuts in each orchard about once per month.

Son Chris says the Nabba harvester resembles a machine picking up balls on a golf course. In the case of macadamias, the harvester wheel runs over a nut, picks it up, and sends it through two augers where the husk is removed. Nut moisture content at harvest averages 20 percent.

Price and yield

Harvested wet in-shell nuts are sent to the processor and fetched about $1 per pound in 2014 and 2015. The dollar rate was based on 20 percent moisture and 30 percent kernel recovery. In 1,000 pounds of wet in-shell nuts, there are about 300 pounds of nut meat.

In the end, the Trumps received about $3.33 per kernel pound for their 2014 crop. The 2015 grower crop price was not finalized at press time.  

Across the farm, the Trumps harvested 1.5 million pounds of mac nuts with average yields of 2,200 pounds per acre in 2014. Production in conventionally-grown orchards was 2,357 pounds per acre. In the organic orchards, yields were about 2,000 pounds per acre.

Jim says nut yields on the farm are a little lower than some other operations, due to missing trees in the orchards.

2016 marks the 25th anniversary of the Trump farm. There are 15 full-time employees and eight seasonal employees, the latter mostly Filipino immigrants.

Employees as leaders

As the family was seated in the farm office, they were asked what they excel at on their mac nut farm. Chris chimed in first, sharing kudos about his father’s leadership.

“My Dad cultivates a team approach on the operation,” Chris explains. “He empowers each employee to draw on their strengths to make good decisions. This approach has led them to become effective leaders on the operation.”


On the varietal side, three varieties of macadamia trees are planted - 344, 246, and 508. Jim describes 344 as a more upright tree than the others which usually produces an earlier crop.

Nathan adds, “The 344 variety is one of the highest yielding varieties on the island. There’s good kernel recovery since it’s thin shelled.” Jim explains, “We really like the 344 and the 246 since the trees lend themselves to mechanical harvesting. They are easy to prune and more resistant to disease.”

It takes macadamia trees about six to eight years to achieve commercial production and about 12 years to reach full production.  A typical macadamia tree grows 30 to 40 feet tall, and can produce a nut crop for about 100 years.

The primary tree rootstock on the Trump farm is Bond 23.

No pesticides

Macadamia trees on the Trump operation face several pest challenges but luckily none are at threshold levels so pesticides are not used. The top insect pest on the operation is the southern green stink bug (Nezara viridula) which causes pitted kernels which can be rejected by processors.

The Trumps combat the pest naturally with beneficial insects in the orchards and surrounding gulches.

On farm management, Nathan says many of the same techniques are shared in the conventional and organic orchards.

A farm tour with Nathan behind the steering wheel included discussions on tree nutrition. He says the farm’s largest nutritional challenge is determining the correct amounts of nitrogen, potassium, and phosphorus to apply, along with solving stubborn micronutrient deficiencies in macadamias.

Nathan says, “If we can better define our boron deficiency addressed it would improve our nut yields.”

Korean natural farming

For the last three years, the Trumps have shifted the management of their organic operation to Korean natural farming (KNF). Now practiced in about 30 countries, KNF is based on using indigenous microorganisms, including fungi, bacteria, protozoa, and nematodes, to boost soil fertility and yields without pesticides.

Chris says science today understands only about 3 percent of what occurs in the soil. He has traveled to South Korea three times to study a farm using KNF and has been amazed by its success.

“The idea is to cultivate microbial activity on a scale with a wild or indigenous forest,” Chris says. “Without a lot of inputs, your wild forest can thrive and mitigate disease.”

'Knocking out diseases'

This is important in macadamias, he notes, since trees are at a higher risk of phytophthora root rot disease which is also a problem on the Trump operation. Chris says trees on the farm which were leafless and dying from the disease are now farmed using KNF.

“We are knocking out root borne diseases which were causing defoliation. We are seeing new branches from the tree’s center and leaf re-foliation. The trees are producing nuts again.”

On his use of KNF, Chris says, “We are reducing our input costs to almost nothing, and increasing yield, drought tolerance, and disease resistance in a holistic, earth-tending, and environmentally conscious way.”

Transition to 100 percent organic 

Starting last fall, the Trump family began to transition the conventionally-grown orchards to organic using KNF.

“We think that the nutrition piece will be primarily addressed through the microorganism foliar applications,” Jim notes.

By eliminating herbicide use, he believes added mowing costs should be offset over the long-term from the benefits of additional organic matter (cut grass) on exposed roots.  

“Now our major challenge is to process and market the organic crop. This story is yet to be written,” says Jim.

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