Date 11 June 2019
Area About 20kms west of Nelspruit
Hectares under mac 60 hectares: 20 hectares @ 14 years old, 20 hectares @ 4 years old, 20 hectares seedlings
Soils Complete range of soils.
Rainfall About 800mm annually (This last year was drier though)
Altitude 840m
Temperature range Up to 40’. Coldest about -1’ (end June, beginning July)
Varieties Beaumont, A4, 849
Other crops None


I love visiting farmers and I especially love hearing their personal stories; how they found their way into the best occupation on the planet etc etc … so, although we have cut back on the ‘personal stuff’ in TropicalBytes’ interviews, a little background on this particular JAFF is relevant for two reasons:

  1. Although he is no stranger to agriculture, having started off as a maize farmer in his youth, he spent considerable time in construction-related entrepreneurship in order to make is way back into farming. The business acumen, as well as his agricultural passion, nurtured during this detour make him someone worth listening to, and learning from ie: this is a valuable read – don’t miss it!
  2. His international travels, including a recent trip to Australia, to study mac farming in other places, has given him insight and exposure that we can all benefit from.

Jaff is a hard-working man; a leader rather than a follower, a questioner rather than an admirer. The time he spent in commerce, building the capital to re-enter agriculture, honed his finance and logic skills – his insights into what’s lead to his success are valuable.

Equally fascinating are his Australian learnings – I didn’t realise that most Aussie mac farms are smaller than ours, averaging around 20 hectares with a typical annual production of between 80 and 100 tonnes. Something we have in common though, is the trend away from sugar – I also didn’t know that this was an international trend. So, there are similarities between the two countries – things we can capitalise on, and some profound differences … time to get down to the details of Jaff’s success.

Just in case you need another reason to keep reading, know that Jaff’s trees produced an average of 8 tonnes/hectare this past season …


Before anything else, test the soil. Macs are incredibly efficient phosphate miners but an overly phosphate-rich environment has proven detrimental to their development. Old avo orchards are usually always high in P so Jaff warns about using these for macs.

This young tree has almost no hope of surviving. If it was one of Jaff’s, he’d cut his losses and remove it now. His guess is that this is a classic case of phosphorous poisoning although the thin stem and yellowing leaves can be mistaken for iron-deficiency.

There is a definite trend towards ridging ALL mac orchards – Jaff advises that, if you don’t have to do ridges (ie: you have sufficient soil depth), then don’t. It would be an unnecessary expense and may increase costs down the line as ridges limit mechanisation options.

In Australia, land prep involves ripping the rows and then putting down 1m wide x 450mm deep compost on top of the ripped rows. A zinc and boron spray is applied to the compost and a grader comes through and pushes about 100mm of soil on top of the compost. Planting then happens into this soft and organically rich ‘mound’ which subsides as soil settles and compost is consumed. The remaining rise is manageable for all mechanisation.

Drainage is another supremely important part of land prep. Jaff has learnt a hard lesson in this regard and had to retro-fit an orchard with drainage when it just wasn’t producing to full potential. In the picture below, you can see, by the white soil, how water had sucked all life from this field. There are about 10 drains, like the one pictured, and all of them run with water 365 days a year, even in the driest times. Since he invested in draining this orchard, the trees have bounced back and delivered well.

A final word on land prep is that proper planning is essential; plan for heavy downpours, plan for mechanisation, plan to survive the future.


Once the fields are prepped, it comes time to plant. Although Jaff has his own nursery, stocked with about 3500 young trees about to be grafted with A4, he does not use this stock when establishing his own new orchards … why not? “Those are your money factories for the next 30 to 40 years. There’s absolutely no point in saving a few rand by doing it yourself,” says Jaff, who prefers to buy his young trees from a SAMAC Certified professional, from whom he can get the best possible quality and hold responsible should anything go array. Trees cost between R55 and R75 each – saving R20 or even R30 per tree by doing it yourself is not worth it.

Jaff’s stresses the fact that farmers need to slow down when selecting their trees; ask for advice from local successful farmers – where did they buy their trees, what varieties are producing well, what are the production figures for the parent wood stock? And when it comes to taking delivery, ensure that there is uniformity, roots are not escaping the bags and that the trees are not too small. Jaff has 2 year old trees that are bigger than 5 year old trees in the area. Jaff believes that the fact that the other trees were planted when they were too small is the over-riding reason for this. Bottom line: slow down. This is THE most critical phase of your operation. Get it wrong and you’ll pay the price for the next 40 years. Get it right and you’ll reap the benefits for the next 40 years.

Jaff sells his nursery stock and uses it to fill gaps in his orchards.

Another point Jaff has strong advice on is staking young trees – he is vehemently opposed to the idea. He explains that all staking does is encourage a heavy canopy with a weak stem which is not conducive to long term productivity and wind-resistance. Instead, Jaff removes the stake and prunes his little trees back the day he plants them. This forces a root flush which provides excellent foundational establishment in the soil. Most farmers will balk at this idea because you feel like you are cutting back time, but you aren’t. After a good pruning the canopy will grow back well, and the roots will be firm. He learnt this principle in Australia where the flat, open fields are subject to devastating gales. The Aussies have learnt that staking ultimately cripples the trees, leaving them inherently weak and susceptible to high winds as soon as the stakes are removed. There, they prune young trees every 6 months, for about 2 years with the only purpose being strengthening. Thereafter the pruning objectives change to conventional tactics like light access etc.

Another tip when handling young trees is to not plant them too deep. Make sure that the soil level when the tree is in the ground is the same as when it was in the bag. Don’t put water on the stem and, if you use compost, don’t let it touch the stem because, when it gets wet and starts to rot, this will hold moisture against the stem, creating an ideal environment to host bacteria like phytophthora.


When Jaff bought the first farm, it had Beaumonts and a smattering of Nelmak 2. They deliver good yields but he wanted to increase kernel recovery. A new farm and much consideration later, he added A4 and a few 849s to the basket. He now has a good balance of predominantly Beaumonts and A4s and, although he is not convinced that this mix is absolutely optimal, he’s happy with the current results.

Having heard good things about 849 I was interested to hear that Jaff regrets planting this variety – his are about 4 years old now and he’s struggling patience with this very late bearer. He chose them because they bear so well (yield and crack out) and maybe they’ll win back his favour when they come into production and deliver on their promises. Jaff was impressed with their parent’s resumé when he placed an order for young trees – the nurseries farm macs as well as create seedlings so, if you ask for the yield results from their different varieties, you’ll know which ones have produced well. 849’s were in a class of their own.

A last word of guidance in cultivar selection is to factor in your own farm’s micro-climate/s which will affect the varieties you choose. Look, in YOUR area, at what is growing well. Talk to the IMMEDIATE neighbours about their results, victories and regrets.


Jaff has not concerned himself with cross-pollination because he believes that the science needs more research. All varieties have strong and weak aspects – how do you know which ones you’ll be promulgating through cross-pollentation. But, his own logic says that, if you are going to plant with this discipline in mind, you need to involve the right cultivars and plant the cross varieties within the rows, not in separate rows.

Jaff does hire in beehives (about 50 hives per 20 hectares) during flowering and these are raised off the ground because this area has honey badgers. Beehive hire is big business now and has become quite expensive.


When Jaff bought his farms, the ‘clever guys’ warned against it as the soils are awful. But Jaff smiles and says, “macs don’t mind bad soils. Sure, they would do better in better soils but poor soils are not a reason to walk away. What you do need to do is pay extra attention to water management.”

This Ou Klip soil is what the ‘slim mense’ had in mind when they recommended Jaff walk away from this farm.

Although Irrigation is a ‘nice to have’, it is also not a deal-breaker in the mac game. There are some unirrigated farms in this area – they use a water cart for the first few years and then go dry-land. When assessing viability, the calculation they did took into account how much more expensive it is to buy irrigated property and / or how much it costs to put in irrigation and maintain it and compared that cost to the cost of lower yields. As they were still producing 4t/h they concluded that they were better off with the dry land choice.

These kind of assessments appeal to Jaff – reinforcing his resistance to the ‘sheep syndrome’.  But he warns that results would not be the same if a previously irrigated farm had water withdrawn. The dry-land strategy works best when trees have never known water.

Considering the water situation in this area, perhaps more farmers, entering the market, should consider this option carefully. Previously Nelspruit was surrounded by summer crops, mostly tobacco and veg. It rains in summer so irrigation was only required for “top up” purposes. Now that tree crops have become so popular, water is required all year around, placing a strain on an already stretched source and there just isn’t going to be enough to go around. The local river that feeds Jaff’s farm now runs dry every Sept / Oct and it never used to do that. As the city of Nelspruit grows so do the water requirements and there is no dam – all water is drawn from the Krokodil Rivier. But Jaff explains that macs don’t need as much water as we think they do.

Evidence of the ongoing experimentation on Jaff’s farm

Three years ago, two local scientists began a trial on Jaff’s farm. They set up three areas of trees; one received no water (tarpaulins were draped to ensure that the trees didn’t even get rain water.) The next area got half of what was thought to be required and the last area was left to the ‘normal’ irrigation allowances. Results: yields in the NO WATER trees were highest!!

Last year, they set about establishing WHEN trees need water, focussing on three specific stress periods: 1. flower initiation in March, April, May 2. Flowering time in August, September or 3. Nut setting time, in September, October. We cannot share results yet as they are continuing to run the trial this year, to verify data, but the aim of the experiment is actually the important part and you can implement your own trials to make sure that you know, should water become even more scarce, when your trees need it most.

Ultimately, we are over-irrigating which is neither environmentally sustainable nor does it optimise production. Nutrients are being leeched from the soil and root diseases are running rampant. Knowing that we are going to have less, but we also need less is therefore a good thing.

Something I learnt from one of these scientists was about irrigating millimetres instead of millilitres. I was sure I had discussed this in an earlier article but cannot locate the reference. It will be a point of focus when I publish an article dedicated to irrigation, later in the year but, for now, I’ll leave you with the food for thought that reach (distance – hence millimetres as a unit of measure) is more important than the quantity (millilitres) of water as it takes into account soil characteristics and root accessibility.

Australians face similar water challenges and therefore do extensive water management studies before planting an orchard. One of the focus areas is water flow and because the country is so flat they have to create flow in many instances. They do this by building contours. These contours do not dictate the direction of rows. While on this topic, Jaff emphasises that ridges should never be used as a way to manage water or to ‘raise’ trees out of wet soils – that won’t work and you will end up drowning the macs. Ridges are meant for building soil depth only.

And now down to a facet of water management (it’s a much bigger topic than we think): irrigation. Jaff has chosen to continue with what was on the farm when he bought it – microjets. Although he knows that drip is a great way to irrigate macs, he prefers the visual comfort of a working jet. He uses Aquacheck and Chameleon probes in tandem, to verify the reading and action to be taken.

Jaff has a number of dams on the farm including a small 50-cube dam that serves only as a safety for the pump. The pump draws 50 cubes per hour so this dam gives them one hour to address any pump issues.

The buckled walls of this dam are courtesy of a roaming hippo who came back three nights in a row to have a drink and cause further damage.

The pump house with fertigation-ready tank. Although Jaff doesn’t fertigate yet, he does supplement with micro-elements and some phytophthora medicine.

Jaff will start to fertigate when he is happy with how to monitor and regulate the flow of fertiliser to the specific orchards. He does not want to rush and risk burning, or under-feeding, the macs. Fertigating through micro-jets is very different to drip, which is much easier to regulate.

The hippo used to live in this dam but greener pastures lured him into the orchards below.


I always hear that you shouldn’t fertilise baby mac trees and Jaff explains that it is probably just because the nursery seedling bags have a lot of slow release fertiliser in them already. Even so, he chooses to plant with an organic fertiliser – the main ingredient of which is chicken manure. He mixes the soil that comes out the hole with this fertiliser and uses that to plant back around the new tree.

The first application of chemical fertiliser comes 4 months after planting when a granular, multi-coat product is applied in a similar fashion to what was explained in Jaff 2’s article. – scroll about ¾ way through the article to the section on Fertilising and Mulching. Although this coated fertiliser is very expensive, Jaff 3 applies it annually, for the first three years and says it has worked well. When the trees are 3 years old, he does soil samples (the first since land prep) and begins a tailored fertiliser programme, addressing deficiencies that have arisen since establishment. From here on, he will have both the soil and leaves analysed as they tell you different things eg: the soil may say it has sufficient nitrogen but some varieties (like 816, 849) use more than others and therefore the leaves may say the trees require further nitrogen.

Although Jaff could buy a spreader, which costs anything from R60 to R150k for a smallish one, to do this job, he has run the numbers … and, because it takes 3 men just 2 days to do 20 hectares, the equipment is just not cost-effective on this size farm. This is a great reminder to always check the figures rather than rush out to do what everyone else does.

The purpose of this fertiliser application (normal LAN, at a rate of 100g per tree), straight after harvest, was to initiate a flush so he can apply foliar feed. This will be zinc, boron and kelpak which is a good stress relievant for trees, akin to a good G&T for mac trees. 😊 The leaf loss you see was a lingering result of the ethapon used before harvest.

These trees are showing a healthy flush that would absorb foliar feed well


Like many of the top farmers I interview, Jaff is also becoming convinced that mulching works to retain moisture and provide a healthy environment for micro-organisms that will generate essential nutrients to feed the small surface roots of the mac trees. He leaves husks to decay for a year and then puts them around the trees. He also mulches pruned cuttings in the rows and has now bought a side-discharge slasher to move the mulch from the row centre to underneath the trees.

The belly plate on the tractor protects it from the branches (pruned) that the tractor mulches. It is made from rubber matting, rather than steel plate, which is cheaper, lighter and easier to remove for services etc.

Freshly mulched prunings


I was interested to learn that the highest bearing wood in a mac tree is under 3 years and that is one of the main reasons why you must continuously prune; to keep “bearing wood” under 3 years old. If you subscribe to this, it puts a whole new objective to your pruning outcomes and strategies.

In an effort to keep the staff compliment small, Jaff uses a contractor to prune. He can then use his 6 men and 2 women to manage water and nutrients.

He focuses on three things when it comes to pruning:

  1. Height

Note the poor soils in this picture – a positive is that these orchards require less pruning because the trees grow slower.

These orchard rows are planted 8m apart. Working with the recommendation that tree height should be 80% of row width would mean a maximum height of 6,4m. Erring on the side of caution, Jaff’s trees never exceed 6m in height.

  1. Alternate years – Jaff gives a more severe pruning every second year. This involves removing major branches to allow sunlight in and open rows. The result is that, the next year, there will be many water shoots, which he will then need to address.
  2. Skirting – Jaff doesn’t believe in skirting too high because the shade saves some soil moisture. By the time harvesting comes, the branches get very low and pickers generally have to get on their hands and knees.


Stink bugs, nut borer, thrips … it’s an Entomology Extravaganza intent on sabotaging the score cards of mac farmers across the region. If you think about it, insects have no respect for fences and pest-management on every farm is different, therefore there is always somewhere for the critters to hide. Eradicating the scourge of mac-loving insects would take a unified strategy and we all know that humans are not good at unifying. So, it’s each farmer for himself … how does Jaff wage war in his environment?

He does a clean-up spray in July. This cleans the orchards before the flowers start in spring. Usually, another application is required in summer but this is dependent on what scouting finds. He believes that scouting is of utmost importance and he makes sure it is done early every Friday morning, regardless of when his last spray was. He puts white sheets down, sprays and comes back an hour later. He is keen to find juveniles rather than adult bugs; finding adults would mean he’s too late.

Jaff used pheromones, for the first time, to deal with nut borer this year. The devices are quite labour intensive to install and have to go on every third tree. He also used traps but now realises that this was not ideal because the moths are already disoriented and won’t be attracted to the traps, making the contents thereof misleading. He is undecided as to which strategy is best and is torn between using traps and spraying if the count is too high and sticking with the pheromones but having no indicator of insect count. This season’s ‘score card’ showed no nut borer and it was his highest yield in 10 years so maybe the current strategy worked. These good yields may also just be the result of an ongoing maturity of the orchards and a recovery from the 2016 drought.

Of utmost concern to Jaff is how many farmers, throughout the country, are spraying according to a calendar-based programme and using cheap chemicals repeatedly, rather than scouting. Nelspruit farmers have learnt the errors of the former strategy the hard way. They used to use cypermythrin continuously and, when the bugs developed an immunity, it caused widespread damage. They now use a range of chemicals, including more expensive organophosphates.

Farmers are also killing the soil micro-organisms through over application (either in over-dosing or over applying) in their attempt to MAKE SURE that their macs are unblemished. By doing this, they cause invisible damage to the soils that will cost dearly in the long run.

Thrips is another challenge and last year, in Levubu, thrips made the orchards look like there had been a mammoth hail storm. They feed on new leaf growth and nut husks.


Phytophthora is the greatest threat and Jaff applies stem paint twice a year throughout a tree’s life. The active ingredients of this are a phosphorous acid equivalent and potassium phosphite. It can be mixed with PVA although Jaff doesn’t go this route.


All trees, bar Nelmak 2s (being less dense and easier to get into), receive a dose of ethapon 2 weeks before harvest. By this time, 80% of the nuts have dropped. Teams of two then go in and harvest – generally a man knocks any stubborn nuts from the trees and a lady collects all the nuts.

Jaff has an interesting way of measuring each picker’s harvest; instead of using crates which are expensive, prone to breaking and open up debates about how full is full, he uses old fertiliser bags that are hung on a scale which is on the back of the tip trailer, in field. It not only measures the current bag but it also adds up that picker’s daily total because each picker has a unique tag that she uses when weighing each bag. She can see this total and knows when she’s reached her target. This has eliminated the need for manual capture of data as the scale then downloads to the office computer.

Jaff is more comfortable that his harvesting cost is now a fixed amount rather than fluctuating number depending on how full a crate was. He also no longer has to worry about the logistics of getting all crates in at night and back out the following morning.

The scale is leased (R1500 per month that it is used) and the software purchased (R4000 per annum) which Jaff has found to be far cheaper than using the crate system. He never has to worry about running out of crates. All bags are burnt at the end of the season and there are no broken crates left lying around.


The tip trailer offloads into the bin which feeds the dehusker. Husks are collected outside and used to make compost.

Shells, collected from the local processor, are used to fire up the boiler. This pushes hot water through a radiator inside the drying area which adds enough heat to the drying bins to reduce humidity and accelerate the drying process.

The environment is kept at about 32’C and 35% humidity. Jaff is careful to monitor temperature as too much heat will cause condensation and ‘rain’ inside the drying plant.

4 tonnes of nuts will leave 800kgs lighter once moisture has reduced from 20% to 2%. Coming from a sugar background, it took me a while to understand the payment system and why a lighter load was not a problem; with macs, you get paid on the dry weight, whether you dry the nuts or the processor dries them. But, if they dry them, you are charged for that service AND you’ve incurred the additional transport cost for transporting water to the processor. Jaff has saved about R100 000 this last season by installing this boiler system and drying his own nuts. It only takes between 1 ½ to 2 bags of shells per week to fuel the boiler. He has now also avoided building a larger storage facility because he can move nuts through his current set-up faster. As the industry grows and all the thousands of young macs come into production, processors may not be able to dry and store the vast quantities. It is therefore advisable that farmers plan to be able to store their own dry nuts in anticipation of this becoming the norm.

When planning your processing facility, Jaff advises that you go and look at what other farmers have, and learn from their mistakes. Bring a specialist to your property and co-operatively decide what will work for you.

Jaff does not use a water bath as he prefers to avoid the added moisture, especially when it is all over the processing plant floor. He finds that problem nuts are often blown out by the dehusker, which achieves much the same as what the bath does. His quality has been good despite the lack of a bath.

A4’s can create a sticky mess of the dehusker and everything thereafter – Jaff tackles this challenge with his best weapon – time. “Leave them on the ground for 2 weeks after harvest, then try to dehusk. If they’re still too sticky, leave them longer,” is his advice. Last season he also learnt that leaving them too long is also not a good idea as that ‘glue’ turns rock hard and that’s a whole new problem for dehusking.

Jaff sorts twice; once before drying and again after. He does this because he believes that the second one is where imperfections are picked up a lot easier; when the nuts are dry, they are lighter in colour and you can easily detect little holes, cracks, etc.


Information, used wisely, empowers knowledgeable decisions. Without the data (information), everything is guess-work. And that is why Jaff keeps accurate records. He uses them to prove or disprove theories and decide on what action to take going forward. Eg: Jaff has employed results to conclude that using straights in his fertiliser programme has produced the best results. He now has a defence against salespeople trying to sell him ‘specialised’ (expensive) cocktails.


There were a couple of interesting topics that Jaff and I discussed, many of them centred around the lucrative returns of macs currently and the consequences of that …

  • Theft – an area of considerable concern in Nelspruit currently. It is no longer subsistence-based. Syndicates are now running a fairly organised operation that targets farm storage facilities (picking nuts up off the floor is way too much like hard work for these sophisticated thieves). SAMAC is apparently on to this issue and are monitoring all cases of theft to try and establish a pattern that will eventually trip the criminals up and lead them to justice. (We can hope, anyway)
  • The security precautions are also having an effect on the wildlife – farmers are frantically putting up fences without much consideration for wildlife habitats, predation patterns, water-access or breeding pools.
  • Macadamias are currently living in a wonderful world of questioning – there are new ideas and new discoveries daily. Whilst this is exciting, Jaff warns that, because the industry is lucrative, there are many magic potions out there. You have to be astute and curious at the same time. Do your own trials, experiment but keep your wits about you – evaluate the costs vs the returns … good old R.O.I assessments.
  • As the industry grows, it also evolves – the high returns macs are enjoying have meant land prices are creating a barrier for new entrants to the industry, those with Rands in their wallets anyway. But, for foreign investors (who may not even be interested in ever visiting their farm) it’s an attractive option, especially as SA mac farms are even more profitable than Australian ones – although security is a concern, costs are lower.
  • Is the money blinding us to the ‘snake oils’? Jaff told me about a farmer he met who has spent an extra 1,5 mill on foliar sprays and fertilisers in one season. Jaff asked him if it was worth it but this farmer hadn’t done the calculation and therein lies the danger – the industry is so lucrative that there is always someone out there (trying to get a piece of the action) who is telling you how you can do better, without considering whether it is a good return on your investment. Making R1 mill more isn’t worth it if it cost you R1,5 mill to achieve. Is it a case of good judgement being put aside when there is no financial pressure? This happens in many industries where participants are comfortable. Hunger sharpens our senses and forces us into a more discerning frame of mind.

After spending this time with Jaff, in his wonderfully successful but nowhere near full potential operation, I leave, grateful to have met him and to be able to share his experience and expertise with you. Thank you, ‘Jaff’, I know you have sparked many farmers to consider how they can implement and improve, based on your input.