The Macadamia - Autumn 2019

LOWVELD 

ORCHARD 

MANAGERS 

SHINE 

&#$/% 

KZN MAC 

EXPORTS 

ON GROWTH 

PATH 

THE ART OF 

EXPERT TREE 

MANIPULATION 

Autumn 2019 

INSECTICIDES

PRODUCERS OF GUARANTEED HIGH QUALITY MACADAMIA TREES 

GLOBALGAP - SAMAC 

TREES AVAILABLE FOR 2019 SEASON 

CONTACT MOUNTAINVIEW NURSERY 

Kiepersol, Mpumalanga 

orders@mountainviewnursery.co.za 

Stefan (M) 071 608 9151 

From 

the 

Editor 

Gareth Wright 

News coming out of South 

Africa’s macadamia industry 

remains hugely positive. 

Despite a turbulent year predicted for the rand which could 

impact on returns, the increasing global demand for the 

crop has meant the price is predicted to exceed last year’s 

offering according to processors Mayo Macs and the Green 

Farms Nut Company (GFNC) which met with shareholders 

and farmers across the country during scheduled pre-season 

road shows. 

Mayo Macs announced a major partnership with a 

pasteurisation group in the United States in line with their 

growth strategy into the high-end kernel export market and 

hopes to continue to break into niche markets particularly 

in the USA, Europe, Japan and South Korea where 

consumer demand for kernel has grown by 9% since about 

2017. The marketing companies for both Mayo Macs and 

GFNC have warned that the ever-increasing demand for 

South Africa’s macadamia nuts worldwide means farmers 

and processors have to make sure their businesses are 

“ready for the future”. 

In this edition of The Macadamia, you will read about how 

KwaZulu-Natal’s largest macadamia nursery, T&T Agric 

at Ifafa Beach on the South Coast, has more than doubled 

its output of micro-grafted macadamia trees as farmers in 

Zambia, Malawi and northern Mozambique plough out 

their maize and soya crops in favour of the development of 

macadamia orchards. In Zambia where soil is fertile, the 

land flat and water plentiful, farmers are planting up to 

100ha of macadamia orchards at a go, compared with the 

average of about 10ha planted by South African farmers 

at any one time. Colin Rand, the horticulture managing 

partner at T&T Agric is also on a drive to halve the price 

of young macadamia trees to make it easier for sugarcane 

farmers to finance the diversification of their operations as 

the sugar industry outlook remains bleak on the back of the 

increased Health Promotions Levy and the record low sugar 

price on world markets. We also highlight a programme 

developed by Lowveld farmers to train young graduates to 

meet the growing demand for top management skills in the 

sector. The programme - called Recruitagri - has recently 

accepted its second group of interns with learning geared 

towards both practical and theoretical training to make sure 

the youngsters are work-ready once they complete the yearlong 

course. Then there are technical articles covering topics 

such as farming for increased nut quality, precision drainage 

in the orchard and the issue of iron deficiency in the soil. 

Mpumalanga expert and consultant, Kobus van Niekerk 

outlines how tree growth can be manipulated to prevent 

structural weaknesses and breakages once the tree matures 

and starts to yield. 

At the start of the new season our hope for all those 

involved in the industry is that the current positivity 

continues and grows into the years ahead. We hope 

our readers enjoy this edition as much as we have 

putting it together. 

WWW.MOUNTAINVIEWNURSERY.CO.ZA

Colleen Dardagan 

Contributing Author 

34 

Contents 

04 Innovation Leads to 

Substantial Growth 

of Macadamia Tree 

Exports to Zambia 

Lindi Botha 


Editor 

Gareth Wright 

072 223 3498 

gareth@blockmedia.co.za 

04 

10 Mbombela Fabrication Plant 

Sets The Quality Bar 

12 Take Cover: 

Protect Your Resources 

With Cover Crops 

16 Mayo Macs 

Breaks New Ground 

With US Partnership 

JP Hughes 


Laura Myers 

Advertising 

Advertising 

Laura Myers 

083 271 5243 

laura@macadamiasa.co.za 

www.themacadamia.co.za 

Cover Image 

T&T Agric nursery manager, 

Mhlengi Sibiya holds a micrografted 

macadamia tree which is 

destined for export to Zambia. 

Image: Colleen Dardagan 

This publication is 

protected by copyright law. 

No part of this publication 

may be reproduced in any way 

without the permission and 

acknowledgement of Block 

Media. Opinions expressed 

do not necessarily represent 

the views of Block Media 

or the publishers. 

Published By 

Block Media 

Po Box 1501 

Simbithi, Ballito 

4390 

Printed By 

12 

10 

28 

20 Combatting Iron 

Deficiencies In 

Macadamia Orchards: 

Solutions For A 

Complex Phenomena 

24 Practical Training 

Grows Mac Farm 

Manager Skills 

28 Get The Most Bang 

For Your Buck 

With Higher Crackouts 

30 Reduce Waterlogging Through 

Subsurface Drainage 

And Increase Tree Health & Yield 

34 Misunderstanding 

Sapling Manipulation 

Puts Mature Mac Trees At Risk 

Elizabeth-Ann Bradley 

Design & Layout 

a Novus 

Holdings 

Company 

30 

20 

38 Nuts & Bolts 

GFNC Price Offer 

Up By 20% in 2019 

2 THE MACADAMIA

Innovation 

Leads To 

Substantial 

Growth 

Of Macadamia Tree 

Exports To Zambia 

A prediction a year ago by nurseryman 

Colin Rand that the demand for 

South African-grown macadamia trees 

would take off in the SA Development 

Countries region has become a reality, 

evidenced by thousands of trees from his 

business in Ifafa Beach on the KwaZulu- 

Natal South Coast already growing on 

the banks of Zambia’s Kafue River. 

Article & Images 

Colleen Dardagan 

With more than 30 000 macadamia nut trees delivered 

to Zambia and another 90 000 ordered between now 

and the end of the year, managing partner at T&T Agric 

Colin Rand says opportunities in regions to the north of 

South Africa are “infinite”. Rand said exporting trees to 

Zambia, Malawi and northern Mozambique offered new 

opportunities for South Africa’s burgeoning macadamia 

sector, particularly in the export of trees and making SA 

technical expertise available to the new growers in the 

Southern African Development Countries (SADC). Rand 

added that offering macadamia trees at a more affordable 

price for potential farmers in South Africa was a priority for 

him between now and next year. “My ultimate vision is to 

supply macadamia tree nurseries in this country with micrografted 

trees to grow out. Our trees cost R30 for a micrografted 

tree and R60 for a ready-to-plant unit. What I really 

want is for the cost per tree to come down - so I want to 

halve the price of the trees, and I am hoping to achieve that 

goal over the next 18 months,” he said. 

4 

THE MACADAMIA 

AUTUMN 2019 

5

The main motivation behind this plan was not only to 

make high quality micro-grafted trees available to sugarcane 

growers in the province who were yet to make the change to 

the nut crop due to the high orchard start-up costs, but to 

increase the number of trees for export to the SADC region. 

“The problem with the sugar industry in KwaZulu-Natal 

is everyone wants to convert to macadamias,” said Rand. 

“What we must do is reduce our costs per unit and have 

trees available at such a lucrative price it won’t deter cane 

growers who haven’t got macs in the ground yet to be able 

to fund and finance their conversion.” 

EXPORT OPPORTUNITIES 

Rand, who took over the running of the nursery just 18 

months ago, has grown the operation from 240 000 trees 

under cover to more than 500 000, with plans to more 

than double that number by next year. “The Zambia pie on 

its own is huge. We have farmers there planting 100ha at 

a time compared with here, where growers are putting in 

macadamias at 10ha at a time,” he said. 

Climatic conditions in Zambia are not as ideal as along 

the coast, but most of the farms planting the T&T Agric 

trees are along the Kafue River, where the soils are rich and 

fertile. “The quality of the nuts is affected by altitude. They 

have a more intensive growing season and milder winters, 

but their biggest challenge is a very dry spring. That is the 

hottest time of the year there - September, October and 

November - so that will affect the late flowering varieties, 

like the Beaumonts and A4s, to a point. But what they do 

have is a lot of water for irrigation from the Kafue River.” 

The trees are transported to Zambia in refrigerated trucks 

and can take anything from a week to nine days to arrive on 

the farms. “The problem with putting them into a normal 

truck is if the driver parks the truck or the vehicle breaks 

down, the trees will cook. For example, during this last 

trip the load was delayed at the Livingstone border post for 

three days. Without the refrigerated truck we would have 

had to make a plan to water the trees. Instead, condensation 

was happening by itself inside the reefer. In fact, the bags 

were wet when they arrived in Zambia. I think seven trees 

died in-field, so not one was affected by the trip,” 

Rand said. 

Right T&T Horticulture 

managing partner Colin 

Rand shows vigorous 

root growth on a young 

macadamia tree. 

Below Left Colin Rand 

discusses operations at 

KwaZulu-Natal’s largest 

macadamia nursery with its 

manager, Mhlengi Sibiya. 

Below Middle Nurseryman 

Colin Rand shows the paper 

bags used for the young 

macadamia trees once they 

have been micro-grafted. 

Below Right 

A young macadamia 

tree rooted using the 

tip of a new shoot. 

Maximising the load, while at the same time avoiding 

overloading, had resulted in a unique innovation developed 

at the nursery. “We fabricated special tables to maximise 

our load space in the truck. The tables, which we have 

called maxi-plan pallets, allow us to double the available 

floor space. And because we have used paper bags for the 

micro-grafted trees – which are about 40cm tall when they 

travel, or eight months old from seed - and our specially 

formulated lightweight substrate, we have brought the 

weight of the load right down. Also sending young trees 

that have been in bags for a shorter space of time means 

they are able to grow with juvenile vigour once they are 

planted, because the units are not pot-bound, and they 

haven’t developed the bonsai effect.” 

6 

THE MACADAMIA 


7

Above Nursery staffer Nogeziwe Qoze 

works on a micro-grafted tree. 

Above Right Thousands of young macadamia trees in the T&T 

Agric nursery at Ifafa Beach on the KwaZulu-Natal South Coast. 

HIGH STANDARDS 

The paperwork linked to the export process starts with 

the customers in Zambia first acquiring an import permit 

from the Zambian Department of Agriculture. On receipt 

of the import permit number, South Africa’s Department 

of Agriculture will visit the Ifafa Beach nursery to inspect 

the load before issuing the necessary transit paper work. 

Officials check for root pathogens, noxious weeds and the 

presence of specific insects. “We are accredited with the 

Seedling Growers’ Association of South Africa (SGASA) 

and the South African Macadamia Growers’ Association 

(SAMAC), so the process is not so bad for us. Accreditation 

means we keep our standards very high. We conform to the 

stipulated criteria linked to phyto-sanitary requirements 

set down by SGASA. Our water growing medium is also 

sent regularly to the Quality Management Services (QMS) 

laboratory as prescribed by the accreditation audit,” he 

said. The growing medium used by the nursery is coco 

coir. “The way we are propagating trees allows us to cut 

our turnaround time by at least half while being able to 

supply robust and healthy units,” said Rand. But there 

are challenges, he added. “Compared with local clients, 

especially those in our area, where we can send the units 

that are ready and then wait before sending the rest, for 

export, the entire load of 10 000 trees has to be up to 

specification all at the same time. We are new exporters, this 

last load was only our third, and it really was very stressful. 

Also, it takes an entire day, from 6am to 7pm, to load the 

truck using my whole labour force of 45 people. It is a slow 

and laborious process as each tree has to be packed nicely so 

it isn’t damaged. We are also the only commercial nursery 

exporting micro-grafted trees grown out in substrate. What 

this has allowed us to do, though, is greatly reduce the 

timeline and to be able to transport a far lighter product.” 

REFINING SYSTEMS 

The father of three, who spends time in his vegetable 

garden to relieve the stress of his working day, believes the 

macadamia industry will be the saving grace for KwaZulu- 

Natal’s agriculture economy. 

“My order book is more than full. I am 

getting calls from all over every day for trees. 

The challenge in the nursery now is to refine 

our systems because we want to expand 

again. We are doubling our labour force 

and looking to halve the price of the trees. 

There are a lot of balls in the air and I 

cannot afford to drop one, because if I do, 

then my customers lose money and time. 

We are working on computer systems to 

guide us in relation to timelines because 

ultimately, I want to be in a position that 

when a farmer phones me for trees, 

I have stock available on the floor in the 

nursery immediately for him. There is just 

no room for error now.” - Colin Rand 

8 

THE MACADAMIA 


9

Mbombela 

Fabrication Plant 

Sets The Quality Bar 

With his experience reaching as far 

back as his school days, Vincent Allan, 

who is the founder and owner of the 

Mpumalanga-based MacMachines, says 

the demand for high quality and madeto-spec 

plant for macadamia processing 

operations has resulted in deliveries as 

far afield as northern Mozambique with 

countries such as Malawi and Zambia 

looking to place orders. 

Article Colleen Dardagan 

Image Supplied 

As South Africa’s macadamia industry is set to more than 

double its production over the next five years and farmers 

across the country’s sugarcane growing regions continue 

to replace the crop with macadamia orchards, demand 

for high-quality machining is now at a premium. Vincent 

Allan who first opened his own steel-fabrication business 

in Tzaneen in 2004 said he started to feel the demand for 

macadamia processing equipment in about 2008. As a 

result, he had moved his business to Mbombela in 2015 to 

be closer to his main customers. “Most of my orders are still 

coming in from the Mpumalanga region but orders have 

definitely increased from farmers in KwaZulu-Natal. We 

are also seeing interest starting to grow from macadamia 

operations in Mozambique, Malawi and Zambia,” Allan 

said. One of his biggest challenges, he said, was two years 

ago when his business was commissioned to build a 660-ton 

drying facility in Mpumalanga. “The area made available 

for the facility was in a basement with lots of pillars. 

That meant we had to fit 66x10 ton drying bins with 23 

conveyors into a very unusual floor space. That was quite 

a challenge because everything had to work seamlessly 

and without interruption to the flow of the nuts through 

the processing plant. I think we must have had about 25 

meetings with the farmer during the design process,” 

he said. 

With a staff complement of 21 people, all of them highly 

skilled and trained, Allan said there was now virtually 

nothing he couldn’t build for processing macadamia nuts. 

“I do all the drawings myself using a computer aided design 

system. Once the drawings are completed and approved by 

the customer I will then sit with my staff and discuss the 

build. I have three teams filled with very experienced people 

- some of whom have worked with me from the beginning - 

to those who are being trained on the job. If the design 

is something new or unusual I will work very closely with 

the teams on the project however, the fact is my work force 

is very capable,” he added. Allan, who started designing 

and making “all types” of steel work when he was still at 

school said he believed very strongly in supporting South 

African businesses. 

Above A de-husking plant delivered to 

a Malawi macadamia processing plant. 

“All the steel we use we get from local 

suppliers. I am sure we could get it cheaper 

somewhere else, but I believe in supporting my 

neighbouring businesses because not only does 

that make sure we have a vibrant economy, 

but they support me in return,” said Allan. 

10 

THE MACADAMIA

Above Right Cover crops, like grasses planted between tree rows, vastly aid in moisture retention and soil health. 

Above Left Bare ridges can’t absorb rainwater and have low soil moisture retention. 

Take 

Cover: 

Protect 

Your 

Resources 

With Cover Crops 


Lindi Botha 

Planting cover crops in macadamia orchards 

has innumerable benefits, including water 

savings, improved soil health, and trees that 

are less prone to stress - ultimately resulting in 

greater yields and profitability. 

Pristine orchards that are swept clean, without a weed in 

sight, might seem like the perfect farm. But dry, exposed 

soils and a lack of biodiversity hinder optimal production, 

resulting in higher water and pesticide usage. Planting 

grasses and legumes between tree rows is a solution to these 

problems and comes with a host of other benefits. 

Freddie Steyn, an agent for Barenbrug, said cover crops can 

be used to improve soil moisture retention and stabilise soil 

temperatures, which results in trees that are less stressed. 

“Cover crops that produce flowers also attract bees and 

will keep pollinators on the farm throughout the year. 

Since cover crops aid in developing biological life in the 

soil, soil health improves and fertiliser requirements drop.” 

He explained that if micro-organisms in the soil flourish, 

then much of the work in getting the soil to its optimum 

level is done for you. “Since many of the nutrients in 

the soil are not in a form that is available to the tree, the 

organisms are needed to help break it down into one that is 

easily absorbed. “It is therefore important to nurture these 

organisms that create a healthier soil. Soil analysis can tell 

you what nutrients are lacking but you can’t necessarily see 

what the biological life is - I think many farmers would get 

a fright if they saw how low it was, as a result of constant 

chemical applications from pesticides to fertilisers.” 

12 

Above Cover crops that produce flowers are ideal to keep bees in the orchards. 

THE MACADAMIA 

AUTUMN 2019 13

CHOOSING THE RIGHT COVER 

Steyn said different cover crops serve different purposes 

and farmers should consider their ultimate goal before 

choosing which to plant. “If your aim is to increase soil 

moisture retention then you need plants that produce a lot 

of mulching material, like lucerne or any summer grasses. 

However, since the trees will eventually grow to a point 

where there will be little sun beneath the trees, grasses 

that grow in shade must be considered.” While Australian 

farmers favour LM grass, as it is ideal not only for its 

shade tolerance but its compatibility with mechanised 

harvesting operations, Steyn said the cost of planting this 

grass in an orchard is significant. A budget-friendly option 

is Paspalum Notatum, as it is also shade tolerant and won’t 

affect tree growth. This grass can be cut and left under the 

trees to form a thick mulch layer. For farmers requiring 

assistance with nitrogen corrections in the soil, cover crops 

like legumes and clover should be planted. Steyn said 

macadamia roots are very deep, but the 80% that takes up 

nutrients is in the top 20cm layer of soil. “So you want 

your nutrients that are deeper to be brought to the surface. 

This is where legumes are beneficial: with their deep root 

system, they assist in accessing nutrients deep in the soil 

and bring them to the surface for the tree to use. “Lucerne 

also draws nutrients out of the soil, but is not removed 

from the field when it is cut; instead, being rather left as a 

mulch layer so the nutrients are still available in the soil.” 

He added that with macadamia land preparation, the soils 

are only ripped once so there is only one opportunity to 

loosen the soils. “With cover crops that have deep roots you 

have a continual opportunity to improve your soil structure 

and reduce compaction. Perennial grasses and chicory are 

ideal for this.” While cover crops aid in weed suppression, 

there is still work to be done to maintain a balance between 

allowing cover crops to flourish and eliminating problematic 

weeds. Steyn added that while certain weeds can be left in 

the orchard, anything that interferes with macadamia tree 

growth should be removed, like climbers or anything using 

a lot of water. “This is when farmers need brush cutters 

to keep the weeds at bay. Unfortunately it requires more 

effort, but is necessary to get the benefits of the cover crops. 

There are challenges with this system, but the benefits far 

outweigh the problems.” During the harvesting season, said 

Steyn, the cover crops need to be kept as short as possible 

to allow for nut collection. “In March, before harvest starts, 

the area will need to be mowed. Any new growth emerging 

after that needs to be sprayed with a soft chemical that just 

burns the tips, without completely killing the plant. After 

the harvesting season, the cover crops will grow out again.” 

WATER SAVINGS 

Reduced water availability has been a reality for many 

farmers over the past few years as the drought has taken 

its toll on available water for irrigation, and soil moisture 

levels. Steyn said that by using cover crops, the effects of 

climate change can be mitigated. “With water restrictions 

and the increase in demand as more trees come into 

production, farmers might end up halving their yield if the 

trees do not get sufficient water. But through mulching, you 

can quarter the amount of irrigation needed for a crop. 

The cover crops do draw moisture as well, but the cover 

is still better for soil moisture retention than having a 

bare piece of soil.” He noted that for every 1% of organic 

material added to the soil, an additional 17mm of rain is 

retained in the soil. This equates to 170 000 litre of water 

per hectare. “Additionally, through the increase in water 

retention, soil temperatures are kept more stable, which is 

crucial to reduce stress in the trees. During high summer 

temperatures they take a lot of strain, which results in the 

November flower drop. This has a big impact on the yield, 

so if the drop can be prevented it will have a big effect on 

your bottom line. “November flower drop is one of the 

biggest challenges we face, so the less stress your trees are 

under during that time of year, the better.” Steyn said that 

because of climate change, the eastern part of the country 

will not get less rain, but it will fall within shorter periods, 

so the soil needs to be able to handle downpours and the 

farm must be geared to make the best of it - not have 

it wash away all your soil and with it, the money spent 

on nutrients for topsoil. For this reason, bare ridges are 

problematic as they are completely exposed to the rain. 

“Each drop that falls on the ground is like a hammer that 

hardens the soil, making it even less likely to absorb the 

water. The water just runs down the sides and doesn’t reach 

the shallow roots contained in the ridges. This is why cover 

crops are needed to ‘soften the blow’ of the rain, and ensure 

it is absorbed.” 

BIODIVERSITY 

In areas where macadamia farming is conducive, the crop 

has dominated the landscape, creating a monoculture 

and reducing biodiversity. Steyn said cover crops 

provide a partial solution to the problem, which, if 

planted throughout the orchards, can drastically increase 

biodiversity. 

“By planting a variety of cover crops you 

create a biodiverse environment where 

numerous insects - many of which prey on 

insects that are harmful for macadamias - 

can flourish. So to a large extent the insect 

problem within the orchards sorts itself out 

and you don’t require excessive amounts 

of insecticides, which ultimately kill the 

harmful and beneficial insects,” said Steyn. 

Bees, and thereby pollination and fruit set, also benefit 

from cover crops as there is more food for them to forage 

throughout the year. Steyn said specific cover crops can 

be planted in the orchards to provide food for bees. In 

addition, herbs like lavender can be planted adjacent to 

orchards to provide ample flowers for them. Planting cover 

crops is a long term plan that requires additional effort, 

he concluded. However, it is a solution to the problems 

farmers are already facing in terms of water supply, insect 

load, pollination problems and November flower drop. “It 

is not a quick fix and farmers should consider starting with 

one block at a time to get the management routine in place 

and compare the outcomes with other blocks to see firsthand 

the benefits in cover crops.” 

14 

THE MACADAMIA

Mayo Macs 

Breaks New 

Ground 

With US Partnership 

Mayo Macs has announced a landmark 

joint venture partnership with a United 

States-based nut pasteurisation company 

as the South African processor looks to 

extend its reputation for top quality 

kernel exports able to meet stringent 

international food safety regulations. 

Article Colleen Dardagan 

Images Colleen Dardagan & Supplied 

Above The Mayo Macs team following the recent shareholder 

meeting held at the Chantilly Resort outside Darnall on the 

KwaZulu-Natal north coast. From left back, John Osborn, 

Johan Smit, Sarah-Jane Stewart, Myles Osborn, Jaap van 

Oenen, Stuart Gregory. From left front, David McIlrath, 

Cobus Venter, PJ Venter, Andrew Sheard, Rohan Orford 

Top The pasteurisation processing plant in Houston Texas 

where all the kernel exported by South Africa’s Mayo Macs 

will be processed to meet stringent food safety standards before 

being delivered to clients across the globe. 

A salmonella outbreak linked to almonds processed in 

California in the early 2000s reportedly led to a discovery 

that the risk of pathogens on tree nuts was much higher 

than previously believed. With the increased focus on food 

safety, there is a growing demand for nuts pasteurised at a 

log 5 reduction of salmonella strains in the US market. 

Since its inception the South African processor Mayo Macs 

has focused extensively on the export of top quality kernel, 

and with the predicted growth of the domestic nut-in-shell 

market in China, the grower-shareholder group has bedded 

down a partnership which will not only increase its kernel 

export reach into the US and European Union markets, 

but is also expected to break new ground in countries such 

as Japan, South Korea and Taiwan. Mayo Macs CEO, PJ 

Venter told shareholders at a recent meeting outside Darnall 

on the KwaZulu-Natal North Coast that what was just a 

pipe dream 12 months ago, had not only become a reality, 

but had extensively widened their marketing options. “We 

are now the only South African processor with a validated 

log 5 kill step. For us food safety is a non-negotiable. We 

looked at various kill step providers before we settled on 

a particular provider and subsequently formed a joint 

venture situated outside Houston, Texas,” he said. As 

explained in the online Quality Assurance and Food Safety 

magazine, “kill-step validation is a pre-emptive scientific 

evaluation that provides documentary evidence that a 

particular process (e.g. cooking, frying, chemical treatment, 

extrusion, etc.) is capable of consistently delivering a 

product that meets predetermined specifications. In other 

words, it is a collection of evidence that a particular process 

involving chemical or physical inputs/parameters in a food 

establishment are consistently delivering a desired effect to 

ensure the destruction of pathogenic micro-organisms often 

expressed as ‘log reduction’.” 

While Venter said he would prefer for the pasteurisation 

company not to be named due to the competitive nature of 

the macadamia industry in South Africa, he said the group 

was more than satisfied the pasteurisation plant was number 

one in the world when measured on its installed state-of-the 

art technology and pasteurisation methodology. “They use 

a “dark process”, in other words the entire pasteurisation 

process is fully automated, from when the kernels are placed 

onto the conveyor through to packaging and labelling.” 

During pasteurisation the kernel is heated in two phases to 

over 200°F (about 100°C) before being cooled down across 

three phases. The last unit which dries the kernel can also be 

used for roasting if requested by customers. The automated 

packing system also includes a metal detector. “So, in the 

morning workers put down the plastics and the cardboard 

boxes behind the machine and that’s all, the whole process 

is then computer run.” Venter said. 

All the kernel from the Mayo Macs factories in Paddock 

on the KwaZulu-Natal South Coast and Rietvallei in 

Mpumalanga from this season will be exported to the 

States. Venter said the group viewed the joint venture deal 

not as a cost to the company, but rather as a profit centre as 

the 3-tons-an-hour plant was geared for processing all types 

of nuts. “Our products will probably take up about two 

hours out of their 24-hour schedule. 

16 THE MACADAMIA 


17

BUMPER CROP 

PREDICTED FOR 2019 

Mayo Macs has 240 grower shareholders and 

110 non-shareholder growers delivering to their 

factories in Paddock on the KwaZulu-Natal 

South Coast and Rietvallei in Mpumalanga. The 

group’s shareholder member-orchards total over 

9 500 ha of which 45% are bearing and 55% 

are non-bearing. The high percentage of nonbearing 

orchards indicates exponential growth in 

production for the company over the next few 

years. This is also the first season that growers in 

the KwaZulu-Natal Midlands will start to supply a 

crop to the Paddock plant. 

The rest of the time other nut-types are pasteurised which 

means the unit is fully utilised and we make a return on it 

as well. Also we have streamlined our operation meaning 

that once the nuts are pasteurised they are not then 

returned to South Africa for packaging and distribution but 

go directly from the Texas plant to our customers.” he said. 

Another plus he said was customers previously buying 

unpasteurised kernel directly out of South Africa were now 

able to eliminate the cost and the burden of processing 

the product themselves before being able to use it. “At 

the moment it is only in the US that the log 5 kill step is 

regulated, but there is no doubt in our minds that the EU 

will soon follow suit as well as countries such as Japan. 

South Korea, Japan and Taiwan are new markets - they 

consume about 9% of the global supply of kernel - and we 

see these as markets with huge potential for growth. Being 

able to offer them a product that meets stringent food 

safety requirements is going to be a huge plus,” he said. 

“Our focus has always been on supplying sound kernel to 

high-end customers in the market. That is why we focus so 

heavily on the value of our on-farm extension services from 

the time a farmer starts planning to plant the trees. We now 

have 5 technical advisors, covering all our major production 

areas, to ensure we meet all our growers production needs. 

To meet the growing international demand for macadamias 

we have to be ready, but we are not going to compromise 

our brand in any way in the process. We will continue to 

concentrate on producing high sound kernel, as well as nutin-shell 

to markets such as those in China,” Venter said. 

Following on the drought in 2015/2016 the 

crop growth in 2018 increased by 34% from 

the 2016 season. A bumper tonnage of nut-inshell 

is forecasted for the 2019 season. Growershareholders 

at the meeting heard about the 

completion of extensive capital investments 

including a new state-of-the art centralised 

laboratory for sample testing, and an oil extraction 

plant at the Mayo Macs Rietvallei plant in 

Mpumalanga. At the factory in Paddock, upgrades 

include a 60-ton delivery point designed to allow 

trucks to deliver their loads directly to the new 

additional 650-ton drying facility. The Paddock 

sorting room floor size has been increased and 

the area for loading containers was heightened 

for ease of packing on trucks destined for the 

Durban port. Further announcements included the 

installation of a new cracker able to process small 

nuts of less than 18mm which were previously not 

accepted, and the contracting of a second transport 

company to ensure the bumper crop expected in 

the forthcoming season is delivered timeously and 

without delays to the factories. 

The Mayo Macs crop outstripped the rest of the 

country with a shareholder sound kernel of 38% 

versus 31.1% as an industry-wide average (2017 

season) and just 1.9% unsound kernel against a 

3.0% industry-wide average. 

The Paddock factory started their processing for 

the 2019 harvest on 1 April while processing at 

the Rietvallei plant is expected to get underway 

on 1 May. 

18 

THE MACADAMIA

Combatting Iron 

Deficiencies 

In Macadamia 

Orchards: 

Solutions For a Complex Phenomena 

Iron deficiencies in macadamia orchards are characterised by yellow 

leaves and, eventually, die-back in branches, resulting in lower yields. 

While rectifying iron levels can be a lengthy and costly exercise, 

orchard preparation at the start can prevent future problems. 

Without iron, chlorophyll cannot be formed in a plant. 

It is therefore crucial to ensure that this micronutrient is 

in perfect balance to make respiration, photosynthesis and 

the mobilising of oxygen and sulphur in the plant system 

possible. Nico Claassens, business development manager 

of plant nutrition at Laeveld Agrochem, explained that 

the yellowing of the intervein areas of a leaf is a typical 

symptom of iron shortages. “If this is not corrected, dieback 

of the leave tips and branches will occur and even 

total die-back of the branch or tree. The yield and nut 

quality of affected trees will decline because no energy is 

available to set a crop or to effectively transform water to 

oil in the kernel.” 

UNDERSTANDING IRON DEFICIENCIES 

Claassens said the following factors 

cause iron deficiency in macadamias: 

Incorrect Soil pH: Iron is most effectively absorbed 

in the tree at a soil pH level of 5 to 6.5. At a pH above 

7.0, iron will bond with minerals such as calcium and 

magnesium, making it insoluble. 

Chemical Imbalances: Elements in abundance, such as 

phosphate, calcium, magnesium, zinc, manganese, sodium 

and carbonates, all have a negative effect on the availability 

of iron to the plant roots. 

Low Soil Temperatures: At soil temperatures below 

13°C, root activity starts to decline rapidly: below 5°C, 

iron uptake will stop completely. This is why new growth 

occurring after a very cold winter will often show iron 

deficiency symptoms. 


Lindi Botha 

Lack of Oxygen in the Soil: This is mainly caused by 

wet and cold soil conditions, which enhance the mobility 

of minerals like manganese, preventing the uptake of iron 

because of manganese’s superior mobility in the soil. A lack 

of oxygen also causes soils to compact, having a negative 

effect on available soil oxygen around the root area. 

Soil Compaction: Insufficient soil preparation before 

planting and lack of organic components in the soil causes 

fine sandy soils and high clay soils to become compacted 

easily. But iron deficiency can occur in any soil type so land 

preparation must be done effectively before planting. The 

soil must also be continuously maintained to ensure proper 

root development and health in the coming years. Older 

orchards in general suffer from compaction, and rectifying 

the problem is expensive and takes time, so prevention is 

better than cure. 

Low Microbial Activity: Bacillus Ferrooxidans is a 

soil-borne bacterium responsible for making elements in 

the soil, such as iron, available to the plant. In leached and 

sandy soils and those that have been vigorously fumigated 

with products like ethylene dibromide (EDB), the microbial 

activity will be very low or non-existent. 

Root Diseases: Diseases such as phytophthora will have 

a negative effect on new root development, which is very 

important for the uptake of iron, because iron is only 

absorbed by newly active, growing roots. 

20 

THE MACADAMIA 


21

Above Iron deficiencies will eventually result 

in lower yields and die-back of branches. 

22 

PROACTIVE PREVENTION 

Claassens advised that the development of new orchards 

be carefully considered to prevent future iron deficiency 

problems in macadamias. “Choose well-drained soils that 

are above the frost line and which are rich in organic 

matter. The richer the soil is in minerals and organic 

matter, the better the trees will perform. Unfortunately, 

macadamia trees don’t have the ability to grow in very 

substandard soils. It is therefore important to ensure that 

the minimum standards for root development and health 

are adhered to.” He said proper soil classification and 

preparation would prevent poor performance of the trees 

due to iron deficiencies or other shortfalls. “Planting trees 

on ridges ensures good drainage and good aeration, which 

results in healthy, active roots. The height of the ridge will 

be determined by the soil depth and physical condition.” 

Claassens cautioned against using organic fertilisers high in 

phosphates, such as chicken litter. “This could result in a 

build-up of phosphates in the soil to the extent where iron 

fixation can take place. “Old tobacco soils were known to 

be annually fumigated with EDB, which had a detrimental 

effect on the soil microbes. Trees to be grown in these 

soils should be treated with beneficial microbes when they 

are planted. Using good organic mulch, organic acids 

and other soil microbe nutrients will help establish and 

maintain a healthy macadamia orchard.” To prevent surface 

compaction Claassens recommended oxygen-enriched 

water, which also assists with creating an oxygen-rich root 

zone beneficial for iron uptake by the trees. 

“A healthy, well developed root system 

guarantees a successful macadamia orchard. 

Farmers should also plant trees from 

reputable nurseries,” said Claasens. 

Above Iron deficiencies are characterised by yellowing of the leaves. 

APPLICATION OF IRON PRODUCTS 

When iron applications are necessary, Claassens said only 

chelated products should be applied, according to the soil 

pH: chelating agent EDTA (15%) for soil pH lower than 

6.0, chelating agent DTPA (11%) for soil pH lower than 

7.0, and chelating agent EDDHA (6%) for a soil pH higher 

than 7.0. 

When iron or any other cation micronutrient is applied to 

the soil in non-chelated form, it has little effect, because the 

mineral becomes attached to the soil particles, which then 

become negatively charged, very quickly. It is also restricted 

by other soil minerals competing for position in the 

rhizosphere of the roots. While low iron levels are common 

in macadamia orchards, Claassens said although excess iron 

can produce symptoms of stunted growth and discoloured, 

bronzing foliage, it is unlikely to happen in tree crops like 

macadamias because they can withstand high iron levels. 

“Over supply can cause a short term toxicity effect due to 

the sudden increase of iron in the root zone. This can either 

cause root burn or an imbalance with other essential plant 

nutrients like zinc, copper, calcium or magnesium. It is 

crucial to continuously measure iron levels and ensure the 

tree is receiving the correct amounts to flourish,” he added. 

THE MACADAMIA 

Multicote® Agri (8) Juvenile: 

The solution for growing new orchards 

A single application of Multicote® Agri controlled-release fertilizer provides your 

young trees with a balanced nutrition over months, supporting establishment and 

enhancing growth. 

1. Moisture penetrates 

the polymer capsule 

2. The moisture 

dissolvesthe 

nutrients in the capsule 

Reg. Nr. K 8834 (Act 36 of 1947) 

3. Nutrients are released 

into the soil by diffusion. 

Soil temperature controls 

the rate of release. 

Nutrition matches growth needs ● Better nutrient use efficiency 

Labor saving ● Nutrient availability independent of irrigation 

 

 

Pioneering the Future 

Haifa South Africa 

PO Box 1409, Brackenfell, 7561, South Africa | Tel: 021 982 0309 | Fax: 021 981 7637 | www.haifa-group.com

Practical Training 

Grows Mac Farm Manager Skills 

A commercial grower training programme to 

shore up the ever widening skills gap in South 

Africa’s macadamia industry has successfully 

completed its first year, with a second group of 

youngsters signed up and busy learning how to 

manage the country’s orchards. 

Article Peter Hughes 

Images Supplied 

A training programme set up by seasoned Lowveld 

macadamia farmers Guy More, Duncan Macgregor and 

Kasper van Rooyen has been met with enthusiasm by the 

region’s farmers, who snapped up the first four recruits as 

soon as they graduated towards the end of last year. 

Macgregor, who farms at Lochaber Estates in South Africa’s 

Lowveld, said as co-founder of Recruitagri, he was not 

only delighted with the project’s progress since it started in 

May last year, but also with the calibre of the first batch of 

students. “We’d like to see steady growth in the number of 

graduates we turn out, without in any way compromising 

on the quality of the training. We are also keen to involve 

other interested farmers and agricultural organisations 

in Recruitagri. It will help us broaden the internship 

experience we can give our trainees and assist in covering 

the costs,” Macgregor said. The vision, he added, was to 

develop an internship programme aimed at turning out 

quality graduates. As a result, those applying to participate 

in the course require a degree or diploma from a recognised 

tertiary institution if they are to be accepted. 

King Dlamini, who is now employed as an assistant farm 

manager on a 200ha property in the Barberton Valley, 

said he landed the job because of his interaction with 

agricultural experts and seasoned managers during the 

course. “I keep learning every day, and I am so grateful 

for the solid platform that Recruitagri gave me,” he said. 

Similarly, BSc graduate Ronnie Mamba, who always 

dreamed of a career in agriculture, said the year at 

Recruitagri had provided a “wonderful bridging year” for 

him. Mamba is now employed as a junior farm manager 

on a nearby kiwi fruit and macadamia-producing operation. 

This year six students were selected from more than 

300 applications. Jenny More, a BSc graduate with majors 

in psychology and genetics from Wits University, has taken 

on the task of managing the non-profit company established 

to drive Recruitagri. She said she was not only thrilled to be 

heading up the initiative but reports received from the 

farmers who employed the first group of graduates had 

filled her with confidence. 

“Their response shows us 

that we are on the right track 

and that we are meeting the 

great need for agricultural 

graduates,” said More. 

While the course is yet to be accredited, More said the 

content was designed with a good balance of both theory 

and practical studies in mind. 

Above Learning how to 

sample soils are, from 

left, Cyril Maseko, 

Khethukuthula Maseko, 

Sabelo Fankomo, 

Xolani Msithini and 

Zwakele Silubane. 

Right Jenny More 

Far Right Roy Porritt, 

who was commissioned to 

develop the course content, 

discusses water infiltration 

with Cyril Maseko, left, 

and Xolani Msithini. 

24 

THE MACADAMIA 


25

Former farmer, agriculture expert and consultant 

Roy Porritt (right) was commissioned by Recruitagri 

to develop the curriculum and to oversee the day-to-day 

teaching responsibilities. The course includes the theory of 

managing soil types, irrigation, tree nutrition and diseases. 

The students get involved in fire protection, they learn how 

to drive a tractor, calibrate irrigation equipment, maintain 

machines and tools, and how to handle chemicals safely. 

Benchmarking protocol GlobalGap as well as safety, healthy, 

environment and quality or SHEQ are dealt with, along 

with the legal requirements of farming and responsible 

management of the environment. More said apart from the 

theory of dealing with soils, water and irrigation, nutrition, 

pests and diseases, the interns were also taught the basic 

principles of economic systems, finance, sales, marketing, 

entrepreneurship, innovation and human resources 

management and motivation. “Between the monthly lecture 

sessions, the interns work on a rotational basis with existing 

farm managers. They also participate in a structured reportback 

and discussion session, complete with written and oral 

tests,” she said. 

For further information on the 

programme contact Jenny More at 

jenny@more-ct.co.za or Ruline Pieters 

at admin@recruitagri.com 

Above Cyril Maseko, who was accepted into the class of 2019 

at Recruitagri, gets hands-on experience in a pumphouse. 

Left Discussing soil profiling are, from left, Xolani Msithini, 

Sabelo Fankomo, Zwakele Silubane, Cyril Maseko and 

Khethukuthula Maseko. 

26 

THE MACADAMIA 


27

Get The Most Bang 

For Your Buck 

There is considerable potential for increasing profit by 

improving the whole kernel percentage and limiting kernel 

discolouration in macadamia crops. As such, a study was 

conducted in the Lowveld region by Alwyn du Preez 

(above), an independent technical consultant for the 

macadamia industry, to determine factors that influence nut 

quality and mitigation practices that can be implemented 

to reduce this discolouration. Du Preez noted that kernel 

recovery is determined by the nut size, shell thickness and 

therefore weight of kernel and shell. “This means that with 

a higher kernel recovery, fewer nuts will be cracked for the 

same amount of kernel, reducing processing costs, and more 

kernels are sellable per unit of nut-in-shell (NIS).” The same 

cultivar can produce nuts that differ in kernel recovery, 

whole kernel recovery and kernel discolouration. 

To develop optimal management strategies to maximise 

productivity and profitability of macadamias, factors that 

influence kernel recovery must be considered. Du Preez said 

the fruit structures are formed during the first 90 days after 

flowering, and the fruit continues to grow until 12 to 15 

weeks, until the shell hardens. Climate, soil moisture, crosspollination 

and nutrition all influence this process, during 

which the shell thickness and kernel size is determined, and 

thereby the kernel recovery. 

HIGHER YIELDS, BIGGER NUTS 

For the study a large set of historical data from different 

regions was used to establish and isolate possible factors 

involved in kernel recovery and discolouration. Although 

With Higher Crackouts 

Article & Images Lindi Botha 

Higher kernel recovery 

and unblemished whole 

nuts means more profit 

in your pocket. But 

with various factors that 

ultimately influence 

crackout, farmers need 

to manage on-farm 

practices carefully to 

reap the full reward 

from the harvest. 

these differed between the six regions over two seasons, it 

was found that relative humidity and vapour pressure deficit 

had an influence on both kernel recovery and whole kernel 

recovery. Whole kernel recovery was determined by the 

method of curing NIS and was improved by faster delivery 

and harvesting time. “We established that whole kernel 

recovery correlated with kernel recovery. This means growers 

can benefit from increased prices and lower production cost 

by increasing kernel recovery and whole kernel recovery 

at the same time.” Du Preez found that high whole kernel 

recovery was associated with high kernel recovery, early 

season harvesting and processing of NIS, the Bungay curing 

system of NIS compared with ambient air, low vapour 

pressure deficit during the nut maturation period from 

middle January to harvest, elevated leaf boron and copper 

concentrations, and low manganese leaf concentrations in 

November. High crop load, no cross pollination, low leaf 

nitrogen and zinc and high leaf potassium concentrations 

in November were linked to low kernel discolouration. The 

study found that high kernel recovery was associated with 

high orchard altitude, good cross pollination, high yield, 

early season harvesting and processing of NIS, high leaf 

boron concentrations in November, water management 

using deficit irrigation, and low daily maximum relative 

humidity during the nut growth stage, which is from 

October to middle January. Du Preez said slope and row 

orientation of the orchard influences light interception 

and is an important factor that will influence the yield 

of macadamia trees. “Solar radiation interception is at its 

optimum when rows are planted perpendicular to east and 

west slopes, and parallel to north and south slopes.” 

IRRIGATION AND KAOLIN INFLUENCESCE 

Because extreme temperatures of 35°C during the later 

stages of nut development have adverse effects on oil 

accumulation and nut growth, resulting in poor kernel 

quality, moderate temperatures were therefore required in 

February during the early oil accumulation period to ensure 

a high kernel recovery. “Previous studies have shown that 

high temperatures of more than 30°C could be regulated 

by evaporative cooling and the use of reflecting substances 

like kaolin clay,” said Du Preez. “The research included two 

irrigation trials and one kaolin trial, to develop possible 

orchard practices that increase kernel recovery, whole kernel 

recovery and decrease kernel discolouration.” 

In the two irrigation trials, water stress was induced 

over two growing seasons by applying different levels of 

irrigation at different phenological stages. Kernel recovery 

was not affected by any of the treatments; however, 

Du Preez added that water stress could not be applied 

continuously because of frequent high rainfall during the 

study. Moderate water stress, however, did not influence 

yield. In the kaolin trial, the efficacy of kaolin foliar 

applications was evaluated to reduce heat stress: there 

was no effect on kernel recovery, nut yield or quality. 

“Previous studies have shown that application of kaolin 

could potentially be a practical and economical way of 

regulating heat stress of macadamia trees. Due to the 

season in which our study was conducted not reaching long 

periods with maximum daily temperatures exceeding 30°C, 

the potential impact of kaolin on heat stress reduction 

and kernel recovery and yield could not be fully evaluated. 

We did, however, establish that up to five layers of foliar 

applied kaolin did not significantly reduce individual leaf 

photosynthesis.” 

POLLINATION 

While macadamia trees flower profusely, only about 0,3% 

set as nuts. Since the potential yield of a macadamia tree 

is determined during floral initiation, it is important 

to manage orchards meticulously during this period to 

ensure maximum pollination. Du Preez said his study 

showed that macadamia nut yield and fruit size improved 

with cross pollination. “It increased the percentage of 

macadamia flowers with a pollen tube at the base of the 

style, and resulted in an increase in initial fruit set and 

sometimes the NIS weight, kernel weight and kernel 

recovery. Supplementary pollination increased NIS weight, 

kernel weight and kernel recovery in some cultivars, like 

A4.” The study noted that the Beaumont variety shows an 

increased yield and kernel recovery after cross pollination by 

various cultivars. But unfortunately Beaumonts flower later 

than most of the commercial cultivars, which reduces the 

benefits derived from cross pollination. With an increase 

in the supply of macadamia nuts as more trees come 

into production, and an increasingly quality conscious 

consumer, orchards and harvesting practices must be finetuned 

to ensure high kernel and high whole kernel recovery 

to capitalise on better prices. In addition to commercial 

studies to determine better on-farm practices, farmers 

should conduct their own trials to find the winning recipe 

that delivers high yields at lower costs. 

Top A higher yield has been found to 

correlate with a higher kernel recovery 

Above Although macadamia trees flower 

profusely, only 0,3% set as nuts. 

28 

THE MACADAMIA 


29

Reduce 

Waterlogging 

Through Subsurface 

Drainage 

Optimally drained soils are 

crucial to orchard health, 

ensuring that trees receive 

adequate water, oxygen 

and nutrients. 

We spoke to Johnnie van der 

Walt (below) from Precision 

Drainage about the benefits 

of a subsurface drainage 

system in combatting 

waterlogged orchards. 


Lindi Botha 

And Increase Tree Health & Yield 

For successful macadamia nut farming, optimal irrigation practices must be 

followed, requiring an understanding of how the soil profile will react when 

water is added. If drainage is inadequate, it will result in a lack of oxygen in the 

soil and reduce the plant’s ability to absorb nutrients. This places stress on the 

trees and results in lower yields. Johnnie van der Walt said waterlogged soils also 

increase susceptibility to diseases like phytophthora, which occurs after roots have 

been submerged in water for only four hours, making it difficult to combat in 

areas with poor drainage. “Soil is also negatively affected by poorly drained soils, 

as temporarily anaerobic conditions decrease positive soil biological activities, 

reducing the soil’s overall health.” He said subsurface drainage systems not only 

prevent trees from drowning but also reduce soil salinisation. “In many areas 

the irrigation water salinity is gradually increasing as the upstream catchments 

supplying water become more saline. 

For productive agriculture to continue, adequate leaching and drainage is 

necessary to remove salt left in the root zone.” Elevated water tables result 

in the mobilisation of the stored salt and when this saline water table comes 

close to the soil surface, it results in soil salinisation and waterlogging, with 

detrimental effects on production. “Subsurface drainage will treat waterlogging 

and salinisation resulting from these shallow water tables. It is also required 

where more saline irrigation water is used. With increasing irrigation water 

salinity, the leaching requirement is increased, which often cannot be met by 

natural drainage.” He added that subsurface drainage does not remove available 

water from the soil; it merely removes gravitational water that would drain 

naturally if unimpeded by confining layers in the soil. “The greatest benefits 

of subsurface drainage typically are realised in wet years, but because drainage 

promotes deep root development, crops will have better access to soil moisture in 

dry years.” 

INSTALLING SUBSURFACE DRAINAGE 

It was important, Van der Walt said, for farmers to ensure proper drainage 

systems are in place, otherwise tree health could be negatively affected. In 

overcoming drainage problems, farmers should first identify soil properties 

through a credible expert. “Subsurface drainage requirements are determined by 

the natural soil properties, either physical, chemical or a combination of both. So 

farmers must first do a proper soil analysis before installing a subsurface drainage 

system. A general rule of thumb is that the higher the clay content, the more 

artificial drainage is required, as the permeability of the fine textured soils is 

slower. Soils with shallow restrictive layers can also pose drainage problems as the 

effective root zone does not have the capacity to accommodate excess water.” 

Above Agricultural Drainage 

The top illustration represents agriculture land without 

drainage improvement. The water table is near the soil 

surface and water ponds in surface depressions. The land 

in the bottom illustration is drained by a system subsurface 

plastic tubing or clay tile. The water table is lowered, which 

allows timely field operations and helps increase crop yields. 

GREAT 

POTENTIAL 

FOR IMPROVING 

WATER SAVINGS 

Besides solving waterlogging in orchards, 

subsurface drainage has far greater potential when 

considered as a means to harvest excess water. Van 

der Walt said existing irrigation can benefit from 

irrigation water recycling through underground 

drainage systems that, when combined with the 

rainwater harvesting systems, greatly improve water 

management and availability on the farm. “The 

concepts of rainwater harvesting on a commercial 

scale, drainage water recycling and reuse and 

subsurface irrigation and fertigation, are still new, 

having come to attention due to South Africa’s 

water scarcity and prevalence to extreme droughts. 

“However, through subsurface drainage systems, 

the whole farm can effectively be harnessed as a 

catchment area. Measurements taken through a 

Global Navigation Satellite System (GNSS) provide 

accurate topographical data of the farm, which 

identifies where the runoff and natural waterways 

occur. This can be used to determine where to 

place dams in the lower lying areas of the farm so 

they can receive and store the water that has been 

diverted through the drainage systems.” Van der 

Walt said this concept, however, requires a change 

in mindset from the farmer’s side and a complete 

change in how a farm is managed. 

“We need to move from 

a passive to an active 

solution to climate 

change. In short, the 

technology we use makes 

it possible to change 

the entire farm into an 

active catchment area 

to accommodate and 

store as much rainwater 

as possible.” 

- Johnnie van Der Walt 

30 

THE MACADAMIA 


31

Right Guided by lasers and GPS equipment, modern 

drain ploughs can lay drainage tiles with precision. 

The following important points must be 

considered when installing subsurface drainage: 

Depth and spacing of pipes is determined by soil 

structure and texture properties that need to be 

sampled and analysed beforehand. Drainage pipe depth 

is mainly determined by the depth of the restrictive 

soil layer. Generally, finer textured soils are spaced 

closer than that of coarse soils. Subsurface drainage 

installation can be either via conventional trenched 

drains or modern trenchless drainage, also referred to 

as tiling, depending on soil properties. The former is 

labour intensive and takes some time to install correctly 

as many manual processes are required. On average 

about 300-400 metres per day is possible, while tile 

drainage is mechanised and automated and can install, 

depending on soil condition and type, upwards of 4000 

metres per day. 

The tiling method, which uses GPS technology, is a 

quarter of the cost of a conventional trenched drainage 

system. It requires no labourers or the addition of 

crusher stone as the drainage pipe is ripped into the 

subsurface by a specially designed plough that installs 

the pipe automatically on the correct slope and 

gradient and forms a perfect hole for the pipe. This, 

therefore, does not destroy the soil profile above or 

below the pipe, so does not require the crusher stone 

layer above the pipe. It should be mentioned that 

subsurface drainage works from the bottom up, so the 

water flow enters the pipe from the bottom, not from 

the top, because of capillary action. Drainage amount 

is based on the soil properties and pipe spacing, soil 

stratification, pipe size, slope and depth (a deeper 

drainage pipe takes longer to drain). 

It is important to ensure the drainage system is selfcleaning: 

this is designed to flush out small dead hair 

roots and sedimentation. 

There are three main factors that influence 

the cost of subsurface drainage systems: 

- Size of the problem area: only the problematic area 

needs to be drained, not necessarily the whole field. 

- Soil type: fine textured soils require more pipes per 

hectare to drain effectively. 

- Drainage coefficient: the amount of rainfall and the 

irrigation system is a determining factor in deciding 

on the pipe size. 

The cost of subsurface drainage systems in South 

Africa installed by GPS-controlled drainage ploughs 

ranges from R10 000 per hectare to R25 000 per 

hectare, depending on soil physical properties. The 

return on investment is between one and five seasons. 

PRODUCTION & 

ENVIRONMENTAL 

BENEFITS 

OF SUBSURFACE DRAINAGE 

- Increased yields, visible plant health and vigour. 

- Excess salts from irrigation or rain water causing 

soil salinisation can be leached out of the 

root zone. 

- Plant roots receive enough oxygen to 

mature properly. 

- Plant roots are grown deeper into the soil 

so they can absorb more nutrients. 

- Storm water runoff is absorbed and downstream 

flooding reduced. 

- The chances of water-borne diseases are reduced. 

- Since the soil can absorb and store more 

rainfall, runoff from the soil surface is reduced, 

so soil erosion is reduced. 

- Soil structure is improved. Soil needs to be 

drained to avoid soil compaction and structural 

damage, both of which reduce yields. 

- Soil bearing strength is increased. The bearing 

strength of soil depends on its water content, 

which in turn is affected by the depth of the 

water table. Good soil drainage increases soil 

strength and reduces damage caused by 

farming operations. 

Why do the biggest avocado, macadamia and 

citrus growers and exporters, among others, use 

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Visit our website 

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32 

THE MACADAMIA 

Cell 

082 652 6705 

E-Mail 

helitractor@vodamail.co.za 

Website 

www.helitractor.co.za 

The only operator in 

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guidance technologies

Misunderstanding 

Sapling Manipulation 

Puts Mature Mac Trees At Risk 

In this technical article, macadamia expert, Kobus van Niekerk outlines 

how before a tree is topped it should be planted and well established in the 

orchard to prevent structural weaknesses once it matures and starts to yield. 

Also the breakages result in a loss of growth time and the adjustment of inputs such as fertiliser and water 

to prevent over application to a tree that suddenly requires 45% to 85% less feeding and watering than the 

rest of the orchard. Maintaining full input levels to damaged trees can result in secondary repercussions, 

such as fertiliser burn, over irrigating and the possible introduction of root diseases and pathogens. As 

shown in the third example a lack of proper training and manipulation of a tree in its formative stages can 

result in the loss of an entire tree. That means the time and money spent on the tree have effectively been 

flushed down the drain. Proper training following the correct principles and techniques will prevent losses 

in the future of a newly established orchard. During storms and floods it is not possible to prevent all tree 

damage, but with the timely application and intervention, potential breakages and damage to an orchard 

development can be prevented way in advance. In effect the work done in a macadamia orchard over the 

first 18 to 24 months of its development equals an investment with a lifespan of 35 years or more. 

Example 1 

Side branches 

developed from an 

untrained node 

after planting 

Example 2 

A side branch is torn 

from a tree where no 

shoulder or side base was 

trained to develop. 

Example 3 

Failure to apply proven techniques at 

the time this tree was planted resulted 

in the loss of a four-year investment in 

water, fertilisers and maintenance. 

Many nurseries “top” trees but I have yet to get a clear 

reason or explanation as to why it needs to be done other 

than to prevent the young trees from getting too tall 

because they become too difficult to transport. For the 

sake of easy handling and for deliveries to customers this 

may make sense, and it is true that some cultivars do get 

quite tall after just two growth flushes above where the 

graft comes out of the scion. But when trees are topped by 

the nurseries, care should be taken to follow up with the 

correct training and manipulation to make sure there is 

no threat to the strength of the tree later on. I prefer that 

topping be done when the trees are planted in the orchard 

and well-established, particularly when a healthy vegetative 

flush indicates that the trees are established and a root flush 

has occurred. At this point, and with no side branches 

developed, all the trees can be topped at a height of about 

600mm to 700mm above the level of the ground. No more 

than 25% of the leaves should be removed. Even if the trees 

are much taller than the 600mm, say they are at 800mm or 

in some cultivars they might be taller at 1 800mm, if there 

are no side shoots (which are the future branches), the trees 

can be topped back to the desired height. This is one of the 

very few occasions where I would recommend such a drastic 

cut to the trees. 

In the first example the tree was topped while it was still in 

the nursery or soon after it was planted in the orchard. The 

three shoots which developed from the primary buds on the 

topmost node were left to grow without training. As a result 

the narrow angles between the shoots did not allow for 

the development of a branch base or allow for the proper 

shoulder attachment to each other. The lack of a secure 

base for the shoots is pronounced because a growth leader 

was not selected when the tree was still young. All three 

side branches grew simultaneously and vigorously resulting 

in a lack of lignification or put simply, wood growing in 

each branch base or shoulder, resulting in the bark and 

non-binding bark being caught and squeezed between the 

rapidly thickening branches. It is very clear that without 

lignin (wood) fibre tissue growing inside a branch base 

or shoulder, a poor attachment developed. In such cases 

branch breakages are inevitable. While such a break might 

happen early on in the tree’s lifespan resulting in limited 

vegetative growth loss, if the break happens when the tree 

is much older it can result in increasing degrees of damage 

and loss. It is not a case of if the branch base will break 

if it is insufficiently developed and untrained but rather, 

when it will break. Whether it is at three, five or fifteen 

years, any force exceeding the strength developed within 

the side branch attachment at its base or shoulder means 

that branch will eventually give way, snap, break or tear. If 

the branches had been properly trained, the degree of the 

breakage would have been equal to the amount of attention 

given to training and manipulation when the tree was 

still young. 

Breakages of this nature can be caused by many factors, and 

if the orchard is subjected to high winds or other external 

factors, they heighten the probability of attachment failure. 

Also as trees grow, the weight on an individual branch 

increases creating further pressure on the weak base or 

shoulder joins. The weight of the developing crop after nut 

set adds further pressure, and in most cases breakages don’t 

happen at the first nut set, but rather later on, and the older 

the tree is the more severe the breakages tend to be. 

The incurred losses from breakages include: 

- the loss of vegetative material grown during the whole 

period from planting, 

- the crop set on the branch will fail to fully mature, 

- the cost of extra labour to clean up, chip or prune 

broken branches, and 

- orchard maintenance activities are hampered by the 

fallen limbs. 

Principle Differences Between 

MANIPULATION & PRUNING 

Manipulate g rowth 

Manipulate growth hormones 

Manipulate amino acids 

Influence of light important 

Influence of gravity important 

O r ie ntation of branches dete r mines 

amino acid concentrations 

Stimulates NEW growth 

Additional leaf area 

Additional bearing wood 

Shorten juvenile phase 

No material removed 

Measure light on all sides of the tree 

Remove growth 

Stimulates growth hormones 

Stimulates amino acids 

Influence of light important 

Gravity influence ignored 

No orientation of branches 

Stimulates Re-growth 

Less leaves 

Less bearing wood 

Lengthens juvenility 

All removed material needs to regrow 

Measure light on all sides of the tree 

Kobus van Niekerk heads up his own consultancy business, MACADAMIAS AFRICA. 

Kobus can be contacted on his email at kobusvn@rocketmail.com 

25% reduction of light necessitates 

pruning or manipulation 

25% reduction of light 

necessitates pruning 

34 

THE MACADAMIA 


35

Manipulating Young Macadamia Trees 

The Fundamentals 

1 

Establish a 

strong growing 

2 

central leader 

3 

7 

The numbers of side branches 

on one node must be thinned 

to one less than the number 

of leaves. This is to ensure 

vigorous growth is maintained 

in the central leader and that 

the trees develop upwards 

rather than as bunched 

mop heads. On Beaumont 

(695), “A” cultivars, and the 

Nelmacs, there might be two, 

three, four or five leaves on 

one node. All Hawaiian and 

integrifolia cultivars will 

always have just three leaves 

per node (whorl). 

4 

Left A well-shaped tree 

with side branches at 

regular height intervals 

with ample light on all 

the leaves on the side 

branches and a welldefined 

strong growing 

central leader. 

Below Number of side branches on one node thinned to one less than the number of leaves 

5 

6 

Side branches at regular intervals, knee, hip 

and shoulder height are normally mentioned. 

Where two or three nodes are close to each other on 

developed side branches, more side branches can be 

kept, but still one less than the number of leaves. 

Side branches that originate from primary 

buds grow more upright with smaller angles of 

attachment. These can be removed leaving the 

secondary bud as a side branch with a naturally 

wider angle of attachment to the stem. 

Open the angle of the side branches where they 

grow from the main stem to allow for the growth 

of strong “shoulder” attachments onto the stem. 

Side branches in a horizontal position stimulate amino acids that promote 

growth and extra leaves (more photosynthetic and light intercepting areas). 

Far Left Strong open 

attachment of the side 

branches to the main stem 

Middle Left A side branch 

growing in a narrow angle 

grows bark in the attachment 

resulting in a weak attachment 

Left A wide angled 

attachment grows wood on 

the attachment shoulder and 

thickens strongly at the same 

pace as the main stem. 

8 

Strong 

Depending on the cultivar 

there are three buds 

above each leaf. In most 

cases only the primary 

or topmost bud develops 

followed by both the 

primary and secondary. 

The primary developed 

bud is the most upright 

and suitable as a central 

leader. On a topmost node 

the primary bud should 

be left to develop as the 

central leader. Secondary 

or tertiary buds are 

suitable for strong side 

branches due to their 

natural wider attachment 

angle to the main stem. 

Right Kobus van Niekerk training 

management and employees on the 

manipulation techniques. 

Far Right On bigger trees with hard 

woody side branches, the branches need 

to be bent horizontally and tied with 

sisal string (untreated) for 14 to 21 

days until set in that position. The 

attachment angle would not be opened as 

required but growth on the side branch 

will be stimulated. 

Below Workers tying bigger, woody, side 

branches. String should be completely 

removed once branches has set in position 

to prevent ring barking the tree and 

branch. 

Below Right Rubber bands can 

alternatively be used to tie side branches 

in a horizontal plain. 

growing secondary side branches that grow more vigorously than 

the flush on the central leader should be bent in a horizontal position 

to reduce the vigour and allow the leader to maintain dominance. 

Below Side branches with open 

attachment grow strong woody 

shoulders against the main stem. 

Notice the secondary side branches 

growing on the side branch, these 

should be kept in a horizontal 

plane to reduce vigour and allow 

strong growth on the central leader. 

Right All three buds on this 

node are well developed. 

Stapling young side branches is sufficient to bend 

open the attachment angle and get the side branch in a 

horizontal position. Using an extra leaf prevents over 

bending of the side branch. Important to note is that no 

pruning is recommended during the first three years. 

The aim of manipulation is to change the behaviour of 

light or to cause a red shift. Light does not stimulate 

growth. The only purpose of light is Photosynthesis 

and storing that energy in sugars and carbohydrates. 

Growth hormones and amino acids are synthesized 

with that energy. Only then is growth stimulated by 

the various amino acids. Pruning should only be done 

when light inside the canopy measures 25% less than 

that outside the tree. North/South orientation is less 

important than soil conservation. Photosynthesis 

converts only 0.02 to 0.05% of Photosynthetically 

Available Radiation to sugars. 

Thus gaining 2% of that with North/South rows make no sense at all 

if there is a slight possibility of soil erosion. (North/South orientation 

should be considered only when the land is at less than a 8% slope.) 

36 THE MACADAMIA 


37

Industry 

nuts 

&bolts 

GFNC Price Offer 

Up By 20% in 2019 

Macadamia farmers at the recent Green 

Farms Nuts Company (GFNC) price offer 

meeting heard that the processors were 

gearing up for top prices and a bumper 

harvest, despite a growing preference for 

the Australian nut-in-shell product. 

GFNC CEO Allen Duncan said at the 

Umhlali Country Club meeting on the 

KwaZulu-Natal North Coast that as this 

was an election year, the South African 

currency was likely to fluctuate, which could 

affect returns. However, the growing global 

demand for the crop meant pricing was still 

well above last year’s offering. 

Duncan said the group would consult experts 

on an ongoing basis as was usual to manage 

risk on behalf of the growers and to secure 

the best returns for their crop. 

Left Sabrina Li, key account manager in 

China, and Beatriz Carmargo, sales and 

marketing manager for Latin America, 

are from Green & Gold Macadamias. The 

company is one of the largest marketers of 

processed macadamias in the world. 

Below Left Andrew Waddell, vice 

chairman of the Australian Macadamia 

Society, chats over a cup of tea with KZN 

macadamia farmers Rob Hoatson and 

James Hoatson. 

Below Barry Christie from the Green 

Farms Nut Company with macadamia 

farmer William Davidson at the recent 

price offer meeting in KZN. 

Top Right Macadamia farmers Alex 

Searle, left, and Steve de Ricquebourg. 

Below Left From left, GFNC 

agricultural and technical 

manager Barry Christie; Cairine 

Whyte, GFNC; GFNC executive 

chair Jill Whyte; Alex Whyte, 

sales and marketing manager 

for Europe, Africa and the 

Middle East for Green & Gold 

Macadamias, and GFNC 

CEO Allen Duncan. 

Below Andrew and Graeme 

Johnson with Laurie Brecher at 

the annual price offer meeting. 

Below Frederik Coetzee and Impi Brecher browse through The Macadamia 

ahead of the recent GFNC price offer meeting at the Umhlali Country Club. 

Despite a growing preference for the 

Australian nut-in-shell crop, which Duncan 

attributed to Australia’s 0% import duty 

tariff against South Africa’s 12%, he said 

this country remained an origin of choice 

for high quality macadamias, with the 

in-shell market predicted to improve as 

the season progressed. 

Images Colleen Dardagan 

Above Listening to a presentation by GFNC 

CEO Allen Duncan are Cairine Whyte from 

GFNC and Brian Loader, Green & Gold 

Macadamias CEO and sales and marketing 

manager for America and Australasia. 

Right Macadamia growers Kirsten and 

Philip Dickerson with Shayne McIntyre. 

38 

THE MACADAMIA 


39

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AFRICA DIGEST 

YOUR GUIDE TO THE AFRICAN MACADAMIA NUT INDUSTRY 

Extend your reach into Africa 

Focusing on Africa’s fastest growing agriculture 

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place for companies with an interest in the nut crop. 

CONTENT 

Informed and in-depth editorial 

ranging from growing the 

macadamia tree seedlings, 

to orchard management, 

maintenance and design, tree 

nutrition, irrigation, integrated pest 

management and the harvesting 

process. 

The Macadamia Africa Digest 

makes use of experts to detail best 

practice management and how to 

produce top yields and quality nutin-shell 

for processing. 

The publication also follows 

technical and processing 

developments closely through 

in-depth interviews and 

research-based articles aimed at 

assisting readers to understand 

the intricacies of this valuable 

agriculture product. 

REASONS TO ADVERTISE 

• Distribution is targeted 

• Specialist content on 

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• Commentary from leading 

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• High quality layout and 

presentation 

• High visibility of both the printed 

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• Advertisers who would find 

the publication relevant to 

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include: horticulture sector 

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2020 

DISTRIBUTION 

• 4 500 printed copies 

• Processing and industry marketing 

companies as well as growers and 

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• Governments, embassies and 

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Advertising: Laura Myers 

Email: 

laura@macadamiasa.co.za 

Cell: 083 271 5243 

www.themacadamia.co.za

The Macadamia - Autumn 2019

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