Date of visit 9 April 2021
Area George, Western Cape
Soils Saamgestelde soils (compounded) Mostly sandy on a clay underlayer. 50mm to 1500mm deep.
Rainfall 700mm annually
Altitude Below 300m
Distance from the coast 8kms
Temperature range 15° to 25° C
Varieties 18 different cultivars, but most orchards are Hawaiian – 788, 816, 246
Hectares under mac 110 hectares

Total farm 320 hectares – a lot unarable in gorges etc.

Other crops 50 hectares avocados  |  100 head beef cattle.

This my final visit of the Cape expedition. All week I have been hearing about how awesome this particular Jaff is and how much the other farmers admire what he’s achieved and how he operates. So, although I was rather exhausted at this stage, I was very excited to be ending on such a high. To be able to witness who and what was impressing everyone else was a privilege indeed. In fact, there was so much wisdom and experience in this visit that it is the first I will be splitting into two stories. I’m not saying I haven’t met epic mac farmers before but I am listening to my readers more and you’ve been telling me that the TropicalBytes stories can get a bit long … for a single sitting anyway. I hope this two-part solution adds value and enhances your experience. Let me know:

Jaff’s credentials

Jaff has been farming macadamias for over 40 years! That’s longer than a lot of us (myself excluded ) have been alive. Over and above that, he has a real passion for the crop and for our country. He’s travelled and worked internationally, adding global experience to his already impressive CV. I can’t tell you how much respect and gratitude I have that this man opened his farm and knowledge to us. He’s a walking mac encyclopedia, but so humble in the acknowledgement that he still has so much to learn about this “new” crop. Where do I even start in sharing this story! A little background … Jaff was raised in Levubu and lived all his early years there. He always wanted to follow in his Dad’s footsteps and become a farmer.

After military training he fought the pressure to attend university and started farming in 1978, planting his first 250 mac trees in 1979. Jaff’s close association with the pioneers of the mac industry inspired this head start and his Dad’s banana farm provided the perfect platform. Although avos were also a very viable option in Levubu at that time, Jaff had a strong affinity for the macs and, when he married, he pursued this option seriously by establishing a mac-farming partnership with his in-laws.

It’s been anything but an easy ride though, with the market crashing more than once. Jaff’s trees were about 10 years old when the fledgling local industry first came to a stand-still; following the disintegration of the early SAMAC body. Jaff’s father-in-law had planted his first trees in 1968 and, together, they were producing about 80 tonnes, nut in shell (NIS). Providently, the core income stream of the operation was generated by bananas which pulled them through this disaster but Jaff’s own farm, which he had just bought from his father-in-law, only had macs. He had to go back to some of his earlier crops, like sweet potatoes. Even during this time, Jaff continued to expand the macs, showing vision that few of us have. Even the bank, who had just financed the farm purchase, wanted to close him down but, before they could move on the threats, the mac industry took off again and everyone breathed a sigh of relief.

His macs were now marketed through a company called SAPEKO. Jaff became a member of the (reconvened) SAMAC board, taking up the seat of Chairman in the late 1990s. Under his leadership, they started networking more closely with other mac producing countries. Jaff himself visited many of these nations and expanded his knowledge of the whole value chain; farming, processing and marketing.

During this time, Jaff, together with 5 fellow farmers, began a well-known processing company; Royal Macadamia. He was the first chairman. The years spent in the factory, refining equipment and processes added priceless understanding but also extracted a heavy price in the form of extensive hearing loss. It seems nothing is for free.

By now Jaff knew how to farm and process macadamias but marketing them seemed to be an industry challenge. His international travels gave him a global perspective and fresh eyes. He saw that specialist marketers were expensive and often left them with a warehouse full of nuts. Jaff met with a buyer at the International Nut Council and sold the entire Royal stockholding. Upon returning to the factory, he was unanimously appointed Head of Marketing! In grappling with this task he realised that SA can never produce too many macadamias; the only threat to our industry, in terms of sales, is if we don’t work together. It is his advice that internal competition should make way for national cooperation so that international markets can be served in the volumes they require. If we get this right, the sky’s the limit!

Land claims in Levubu drove Jaff out of the area in 2003 … he had to start from scratch …

12-year-old 816

Macadamias in South Africa

But before we get into Jaff’s next chapter, I couldn’t resist the opportunity to capture some insight into the South African macadamia industry’s history. So Jaff indulged with a short synopsis; “When I started, macs were a very young crop and there were no processors around. The co-op did what they could to help by storing nuts in an unused room, and sourcing supplies specific to the crop. Early farmers designed their own processing equipment, based on what they saw being used in Hawaii and sold their nuts any way they could. SA Dried Fruit (SAD) then came on board – which was interesting because they were marketing a product they knew very little about – they didn’t know about wholes and halves etc and had to figure out how to package and present the nuts for an international market.

Then the first crash happened in the late ‘80s. This crash originated in Hawaii which was, at that stage the mac world’s biggest market. As a result, the local industry was hit hard. SAD had been giving the farmers an upfront payment for their produce, recovering that when they sold the stock. When the crash happened, they couldn’t sell the nuts and wanted those upfront payments back. Being such a new crop, the farmers simply weren’t financially well off enough to be able to pay anything back. The immature sector couldn’t cope; SAMAC disintegrated and the industry came to a standstill.”

Jaff continues; “This was just the wakeup call the industry needed – to realise that this is not a fresh-market produce that you can dump on the market and someone else will take care of it. The farmers started to really get involved. There was lots of new innovation and some great companies, both marketers and processors, born.” The recovery was swift, albeit short-lasting. But Jaff believes that it was through these ‘rough patches’ (the next market adjustment happened in the late 90s) that our industry was strengthened.

Taken en route to Jaff’s farm

And on to the Cape

Back to Jaff’s Journey … land claims meant he had to leave Levubu but where to? Emigration wasn’t an option for this patriot (lucky for us!) – his extensive travelling had taught him that nowhere is perfect. He also knew he really wanted to grow macs. Where else could he grow macs in SA? Sedgefield was one of their favourite holiday spots (and was void of claims) so maybe there?

The Stoep, as this area between the Outeniqua mountains and the sea is known, is very interesting. A lot of local people have never left, not even to venture over the Outeniquas, to the Karoo or even to Oudtshoorn. Originally, A great portion of the land between Sedgefield, Mossel Bay and the mountain was owned by only two families but they have sold off most of it by now. He considers himself incredibly lucky to have found this farm as it is very unique. Although it is 150kms away from Sedgefield, where they initially wanted to settle, it is exactly what he needed.

It was the climate that drew Jaff in completely. This Mossel Bay / Plett area has one of the most moderate climates on our planet, second only to Hawaii. One other region that comes close is Vietnam. Not sure about the rest of you but I needed an explanation of ‘moderate’ – and now understand that it a lack of extremes. Jaff says you can count the days in a year, where the temperature goes above 30°C, on one hand. Similarly, it seldom dips under 15°C. This is a starkly different to Levubu where the heat (which typically sears during macadamia flowering season) is something to behold. As are the torrential rains and periods of dry, debilitatingly hot wind. After all that, Jaff was very keen to farm in something more ‘moderate’. Made me wonder why Levubu ever succeeded with macs but they are a hardy tree that thrived in the high humidity typical of Northern Limpopo.

Jaff explains that the close proximity to the sea means that the air is always moist. The dew, still evident on the lawn at midday, is testament to that.

Humidity is important for macadamias. As a part of their ‘wild’ survival skills, they close their stomata and “shut down their factories” if the humidity drops. See this article for more detail:  Although the humidity might be lower here in the Cape, the mist is common and this form of precipitation can encourage the macadamias to keep their stomata open, just like ‘invisible’ humidity. Another element that Jaff says encourages the mature macs to keep operating (open stomata) is the south-easterly wind that blows consistently, during summer, at about 3 to 5m per second. This carries cool, moist ocean air into the orchards.

Other baskets for your eggs

Although Jaff is first and foremost a self-confessed mac man, he entertains diversity when it presents undeniable benefits. The 100 head of cattle are primarily self-funding mowers – the black wattle in this area will blanket your grasslands in the blink of an eye so he keeps the cattle, who will eat wattle seedlings along with the grass.

The avos he planted out of curiosity; to see where in the market they would land, in terms of timing. Fortuitously, it was at the tail end, out of the usual South African season. Harvesting right up until the new year means that he can secure import prices for his crop. And, unlike the Levubu avos, they don’t need fungicides. In fact, Jaff’s Cape avos are completely organic; he does not spray anything. To top it all, the avos are happy in the poorer soils – which was a refreshing change for Jaff and the final decider in keeping about 50 hectares producing. “The macs will always get the best soils on this farm,” smiles Jaff.

Diversity is always wise though, and has saved Jaff multiple times, even after he arrived here in the Cape. He’d just planted 110 hectares of macs here when the market plunged (yet again) in 2004/5. The decision was then made to keep operating the dairy operation on the neighbouring farm he’d just purchased. Thankfully Jaff had grown up with dairy and was fully equipped to keep this going for the next 10 years.

Mac market crashes – Jaff says that we learn more in the tough times than in the good ones – and hopes we remember these lessons in the current prosperity.

Macs are the core

I’ve met sugar farmers who turned to macs when trying to escape plummeting sugar prices. Similarly, I’ve met avo farmers, looking for something easier than the insanely delicate trees that bear the green gold. But I don’t remember too many farmers who had so many options but chose to farm macs anyway … Jaff explains his choices; “Macs are so easy. Avos are hard. All macs want is for you to stick to the basics. Because macs are so new, many people feel they should be being adventurous with them. I know many people who have burnt themselves that way. There’s nothing wrong with risk, that’s different – risk is what brought macs to SA. But don’t make a simple crop difficult with unnecessary complications.”

Snow-capped mountains close to Jaff’s farm

A unique perspective on farming

It took some real exertion to figure out what was so different about this Jaff. I don’t believe I have the capacity to fully capture it but this is my humble attempt:

  • He has a broad knowledge and understanding of agriculture, across almost all sectors (crops, orchards, animals, dairy …) This foundation means he always has perspective and is well equipped to pivot when required. What we can learn from this is to broaden our own exposure across a more diverse scope.
  • His experience in ALL sectors of the mac industry (farming, processing and marketing) both here and abroad give him valuable perspective and insight. When we come from only ONE viewpoint, our opinions are limited and our decisions are compromised. The lesson here is to experience the industry from all aspects and thereby broaden your understanding of where you fit in and where you are going.
  • He has a clear understanding of what HIS goals are. When Jaff initially explained that he is a kernel producer I (ignorantly) thought “aren’t we all?” Then Jaff explained why he believes there is a very important choice to be made between whether you are a nut-in-shell producer or a kernel producer, before you put a single tree in the ground because this choice affects:
    • Cultivar selection – each cultivar delivers unique characteristics in terms of their fruit. Generally, nut-in-shell producers focus on the quantity of nuts produced before any other factor. Kernel producers tend to focus on the style and size as a priority. Therefore, you need to select cultivars that will meet your particular criteria.
    • Management – when chasing quantity, typical of nut-in-shell producers, you will make different decisions on what nutrition to supply or chemicals to spray than if you are trying to optimise quality of the naked kernel.
    • Processor and Marketing channels selected – the type of produce you offer will be better suited to select processors and marketers.

My aha moment came when Jaff was explaining why he has chosen to be a kernel producer. He was visiting a sweet manufacturer in Japan, trying to sell South African macadamias. The confectioner explained why he had very specific requirements (and wasn’t going to buy Jaff’s nuts) by describing the manufacturing process of his chocolate-coated macadamias, backwards. They come in a specific box size, and into that box, he must fit a certain weight. This determines the overall size of the chocolate morsel and subsequently, the thickness of the chocolate and the size of the nut. His tolerance for variance on the macadamia nuts he bought was no more than 0,5mm. If this confectioner was to buy Jaff’s nuts, they had to conform to this specification, roast well and be available in high volumes. Price was secondary to these aspects. That’s when Jaff realised that, to supply someone like this, the decision needs to be made decades earlier.

Right now, while China is taking nut-in-shell in large volumes, there is money to be made in churning out large nuts in big quantities, with less concern on kernel quality. But, Jaff asks, what happens when all the new suppliers start entering the market and we need to start looking for new customers? Some may have more specific requirements and be willing to pay handsomely for suitable product. Jaff believes that farmers should be considering those options, now.

I found this long-term perspective valuable and hope it sparks some stimulating conversations. What kind of farmer are you? Does that align with your future customers’ needs? How will that consciousness affect your farming decisions going forward?

And now it’s time to ZOOM IN on the nitty gritty of what Jaff does on a day-to-day level …

Land prep

Discerning between where to farm and where not to farm can be key to success. Pictured below is an expansive bowl higher up on the farm that used to be an elephant dam. When they roamed free in these parts, this was a stop on their migratory path. They’d stop and dig for water and essential minerals. Planting water-sensitive macs in this ‘dam’ would be suicide.

Wholistic farming and environmental preservation is vital for sustainability so Jaff leaves vast tracts of natural vegetation in the borderline areas, as shown below.

As most of the agricultural areas here were under wheat, there is seldom much bush clearing to do. Anything that might have established itself is uprooted and mulched in place. Jaff feels this is far preferable to burning. Once accessible, the soil acidity is tested and lime with gypsum is used to correct imbalances. Using bulldozers, Jaff rips the earth as deeply as possible. I immediately wondered about the notoriously shallow clay layer typical in the Cape and how, the farmers I had visited, avoid ripping into this layer least it reduce the soil drainage capacity. Jaff explains that, initially, he was also cautious about this layer of clay but, when there is a field that only has 200mm of topsoil above the clay he decided to risk going down to about 800mm and hasn’t regretted it.

A bulldozer preparing an orchard on Jaff’s farm.

He emphasises that using a bulldozer to rip, rather than a tractor implement, makes a big difference because of the width and shoulder shape of the bulldozer spline – this is about 250mm wide and effectively displaces and turns the soil, incorporating the lime and breaking up the layers of clay. Narrower, tractor-drawn splines tend to cut through the soil without turning it. This means that the soil rests back in the same position as soon as the implement has passed through. This ineffectiveness is exacerbated when the soil is wet so Jaff advises that land prep is always done on very dry soil.

In 2009 Jaff had to dig a pipeline through one of the orchards prepared 5 years earlier. He could clearly see the clay layer as well as where the ‘dozer had turned a clear V in the soil. The macadamia roots had used this break to extend their root systems and the orchard was healthy.

When it comes to land prep, he listens to and learns from the experts. They have advised cross-ripping at 30° or 45° rather than 90° angles as well as doing 2 passes – the first being a shallow one and the second going as deep as possible. Jaff also insists that the entire orchard is ripped, rather than just the rows. This is a part of his holistic management of the orchard which we will cover in more detail later on.

When Jaff ran with micro-sprinklers, he didn’t ridge the orchards but, since moving to drip irrigation, he has started to prep all orchards with ridges. He believes that the management of water, as a limited resource, is best done in these loose mounds.

Jaff builds the ridges very specifically, leaving no flat areas:

Once the ridges are shaped, the ‘dozer uses a 3-spline attachment to loosen the ridges again. If necessary, an excavator is brought in to finesse the shaping as was done in the lands pictured above. Jaff wanted the mounds a little more peaked than these had settled to. The minimum six-month resting period given to all prepared lands allows Jaff time to refine the ridge shape. Considering you only get one shot at land prep, it’s worth perfecting.  The extensive waiting period between land prep and planting allows the soil ecology to re-establish itself, ensuring that the young trees are planted into an active, healthy environment.


Jaff chooses to buy from registered suppliers for expansion orchards but has a small nursery on the farm where he grafts for his own gapping requirements.

Spacing was an interesting conversation – when he was at SAMAC they planted blocks in about 8 different parts of the country to test orchard density specifically. What they discovered was that the trees that touched each other first, produced earliest, justifying a dense orchard. The problems come in when managing this orchard beyond early production and whether this more intense management justified the earlier production. Some farmers plant densely to capitalise on this “buddy tree” concept, planning to remove every second tree when the orchard is in production but, more often than not, they find it too difficult to execute the buddies and end up trying to manage an overcrowded orchard. Jaff had a Nelmak 2 orchard in Levubu, spaces at 10m x 10m and it was his best producer per hectare … the debate is not settled.

Jaff’s preferred spacing, on flat land, is 9m x 4m. With ridges, he reduces this to 7,5m x 3,5m, depending on the cultivar. Why increase the density in ridged orchards? Jaff explains that the ridges increase the soil surface area and therefore the surface root zone between rows is broadened. Jaff also says that we have to find ways to increase the productivity of our lands. Slightly denser plantings contribute to that goal.

As in all things, finding the sweet spot is key. Balancing the temptation to plant more densely is Jaff’s belief that all parts of the orchard floor need to have some sun at some point in the day. The ridges are making this more challenging than it was in the flat orchards as temperatures differ from one side of the ridge to the other. Jaff’s advice is to keep this in mind when planning your orchards.

Once the land is prepped and rested, the underground irrigation is installed and the supports stakes placed. These are sturdy 1,8m x 38mm droppers that are driven 700mm into the ground. A layer of mulch is spread over the ridge and micro-organisms added.

The dripper lines are then rolled out and irrigation starts the day before planting. Holes are then dug, next to the stakes, just bigger than the bags. Rather than place the bags out in the field beforehand, they stay on a trailer and are passed to the planting team as required. They then remove the bag and place the tree in the hole at the same time. Jaff does this to avoid the sensitive roots being burnt while they lie in the sun before the planting team gets to them.

After the bag has been removed, the roots are loosened (not cut or broken) and placed in the hole. Because the ridges are loose, Jaff makes sure the new trees stay slightly proud of the soil level. After watering, he knows they will subside to the right height. Then the hole is filled up ¾ and the soil compressed tightly, all the way round. The rest of the hole is then filled with no further compaction. Jaff makes sure there is a few millimetres of soil spread over the top of the bag soil. He doesn’t make any bowls or dam-like structures around the tree unless the ridge is very pointed and the first watering will erode the sides.

A water trailer then comes through and each youngster gets 5 litres. The planters make sure the dripper point of the irrigation pipe is placed inside the bag area of the new tree and the irrigation runs for the next 24 to 48 hours, non-stop. Another team will come past and install the windbreaks and tie the young tree to the stake, loosely, with sisal string. These ties are never removed but the sisal does rot off eventually. A few months later, a second stake tie is placed higher up the growing tree. The young trees to not receive any additional fertiliser at this stage (planting), as they will still have slow release in the soil from the nursery. Their next small dose of slow release (granular) will be applied 6 weeks after planting, followed up every two weeks with small amounts of subtropical tree fertiliser. This continues for 3 years. As soon as the tree starts to crop, it is moved on to a different nutrition programme.

Jaff’s tips on nursery selection and tree health assessment:

  • Jaff recommends you establish a relationship with your nursery supplier. Spend time in the nursery and make sure their farming methods align with yours.
  • Personally, Jaff places focus on the potting medium where he won’t compromise on quality.
  • Graft points must also be smooth and matching. A thicker seedling paired with a thin graft could indicate a previously failed graft and therefore a potentially compromised plant.
  • Bag depth – Jaff likes the bags to be deep, giving the small tree plenty of room to establish a healthy root.
  • When the trees are ready to leave the nursery Jaff likes to see at least 60cm of growth after the graft point, with at least 3 flushes. Any less than this and he believes the tree is too vulnerable in the field.
  • Graft points must also be free of any tape, exposing neatly healed wounds, before going out to the field.
  • Before there were so many new cultivars, Jaff could accurately identify the young trees by their leaves alone. He advises that we all hone this skill and make absolutely sure that what you’ve ordered is what the nursery is growing for you. If you are placing a mixed order, try hard to keep the cultivars separate so that they are planted in the right place on your farm.

Here you can see the dripper lines, close to the tree, as well as the stake and two anchor points as well as the shade cloth screen. This is a newly planted Nelmak 2.


Unlike many of the other Cape farmers, Jaff does not recommend inter-planting cultivars. This advice must be taken in view of his being a large-scale commercial farmer. For him the additional management challenges of an interplanted orchard do not warrant the (unquantified) benefits.

He prefers to plant smaller blocks (1 to 2 hectares) of single cultivars, in close proximity to compatible pollinators. This way he can cater to specific cultivar requirements, harvest uniformly and strategically.

A lot of the research on cross-pollination points to an increase in nut set and nut size which, if Jaff has chosen to be a kernel producer, are secondary to uniformity and consistency. He has planted orchards with 3 rows each of two varieties before but the management difficulties outweighed the returns. As it stands now, he believes his efforts are better spent in other areas.

Cultivar selection

Jaff has 18 different cultivars on this farm. He planted this extensive assortment in the very beginning so that he could establish which ones performed best in this untested climate. Over the years, he has built extensive experience but overall, he leans towards the Hawaiian varieties because they align better with his goal of quality kernel production (consistency, roastability, shelf life, oil content etc). He warns that his goals are not generally consistent with the majority of mac farmers currently. As mentioned earlier, a lot of farmers now are aiming for volume, to supply the Chinese market. Given that context, here are Jaff’s views on some of the main players:

246 (Hawaiian) was his favourite in Levubu and it is still one of his favourites, here in the Cape. He concedes that it doesn’t deliver huge quantities and can have a bit of a thick shell but it makes up for these downfalls in hardiness, consistency and reliability – he can expect a good crop every year.

246 – Jaff points out that both 246 and 344 never set in clusters on his Levubu farm but here, they do.

Nelmak 2 (South African) was a favourite in Levubu but he didn’t plant them here in the Cape when he first arrived, fearing that the damp would cause pre-germination – a condition Nelmak 2 is susceptible to. Since he’s learnt that this area is not as wet as he anticipated, he has planted a few blocks but they are not producing commercially yet. He’s hoping the nuts won’t get as big as they did in Levubu – there he had them planted at a density of only 100 trees per hectare and they were still his best producing blocks.

791 (Hawaiian) is a cultivar Jaff avoids and, as a dedicated kernel producer, it is understandable that a nut with an inherent defect would not make it into his orchards.

For a similar reason, Beaumonts (Californian) are also not favourites on this farm – we all know that the kernels tend to break easily and consistency can also be an issue. Added to that, when night time temperatures dip below 15°C for a week, flowering is initiated, especially in the Beaumonts. Jaff explains that it takes a harsh hand to manage Beaumonts in this climate, especially on a larger commercial farm. Smaller growers might be able to harvest all year round but a bigger operation can’t. Jaff uses the Beaumonts to fill gaps in his harvest schedule; they are the only ones he sprays with ethapon, which he does at the maximum rate so that ALL the nuts drop – both mature and immature – the orchards are then harvested, cleaned and pruned if necessary, ready to start fresh. Jaff explains that this can feel very harsh as it is always difficult for a farmer to clear out nuts that could have set into another harvest but, it’s what he needs to do to manage a farm of this scale successfully.

Jaff’s well-disciplined Beaumont orchards.

The Australian varieties, A4 and A16, also don’t rate very highly although Jaff has gapped some orchards with these.

Jaff is not convinced of the scruffy, deurmekaar (direct translation: confused) A4s. On the left, we can see how it flowers on incredibly young wood although these flowers are a bit too late to produce a harvest in time this year.

814 (Hawaiian) is a rising star in this line up, bringing home a crack out that ranges from 29 to 38%. Jaff says they are proving to be brilliant producers but they require special attention, in terms of nutrition, especially when they over-extend themselves and produce a banger crop. If you don’t feed them sufficiently in a heavily productive year, they will produce nothing the following year. Potassium is an important part of this feeding and is often unavailable in these soils, because of the high chlorine levels. Jaff laughs that you could plant them in a bag of magnesium and they’d still need more.

Jaff announces that 788 is his current favourite on this farm. He knows that it also did well in Levubu, for a while, and then seemed to decline so he has watched for that trend to manifest here … so far, so good! He planted them when he first got here so they’re going on for 17 years and still producing well in terms of size and quality. They start flowering in March/April and keep going until October.

849 is a new cultivar for Jaff but one he is impressed with thus far. It is a very dense, large tree but delivers good consistency in terms of nut size. It tends to flower on older wood and sets in dense clusters.

816 took so long to come into production here that Jaff was just about to rework them when he figured out that they just needed a specific nutrition programme (basically more of everything) – they are ridiculously ferocious feeders. Because of this, they tend to be very susceptible to the chlorine toxicity issue on the farm.

816 – instantly recognisable by lighter green, shiny, rounded leaves. Bear on young and old wood. If branches are healthy, they should all bear.

741 (Mauka) is a cultivar I had not met before – Jaff says that, although they produce good nuts, they are very tall, upright growers; difficult to control and, for this reason, they don’t make his list of favourites.

344 – In Australia it is known as the “managers choice” because it always looks healthy and strong. Always the go-to tree if showing off to directors.

Although production was good, Nelmak 26 didn’t do well overall in Levubu where it suffered in the heat and seemed to be more susceptible to stink bugs. Jaff has planted one small block here and results show that the nut size is smaller and the production less than expected.

There’s a micro-climate factor in this area that Jaff didn’t experience in Limpopo; soil, climate, almost everything seems to happen in pockets. This means that one cultivar may behave completely differently from one block to another. Being a big famer, experiencing multiple micro-climates, gives you a perspective that smaller farmers may not have. Jaff advises that all farmers understand that this phenomena means they need to figure out what works in their environment as it might be very different to anyone else’s.

Nutrition Management

Correctly interpreting tree indicators must be some kind of super-power … if we could all speak “mac tree” we’d be wealthy indeed. After hanging around them for over 40 years, I am sure Jaff is more fluent than most of us … he says that it is far easier to recognise deficiencies in this moderate climate as opposed to the Levubu farm where excess rains and extreme heat often distorted the picture. Something else that helps tremendously is that fact that Jaff tests A LOT!  Four times a year the soil, leaves, flowers and soil water (at three different levels) are tested. All this information is analysed through comparisons (eg: to see what’s in the soil but lacking in the leaf etc) and documented so that trends can be identified. So far, they only have 2 years’ worth of data on the macs but the patterns are starting to emerge and will shed light on a lot of mysteries.

Jaff employs an independent (of any manufacturer or agency) consultant to help verify the shortages and requirements in the orchards, based on the test results, trends and tree indicators. He uses this input to formulate a nutrition programme for the macs. Jaff likes to feed the younger, unproductive trees generously and differently to the producing orchards.

Chlorine toxicity: We’ve come to learn that the presence of some elements inhibits the availability of others. Chlorine is one of those ‘problem’ elements that cause trouble and, unfortunately, it is abundant in these soils. It seems to be in the clay layer prevalent throughout the area as well as in the decomposed shale – which is no surprise as these may be different forms but almost certainly the same recipe. These soils are also rich in sodium, another harsh element, likely to burn the trees if in oversupply.

Jaff explains that the trees struggle to differentiate between chlorine and potassium so, if potassium is not available, they take in too much chlorine. This will manifest as leaf burn, shown in the pic of a 344 tree below:

The best treatment is to increase potassium. The best form depends on the time of the year, advises Jaff – personally he likes to use potassium sulphate in the warmer months and switches to potassium nitrate when the temps start to drop. Jaff says that, during these cooler months, the chlorine seems to rise; he’s not sure whether it has something to do with the level of the water tables or lower evaporation levels on the surface, or a combination.

The potassium is supplied through the fertigation system or, in extreme cases, as a foliar feed. Potassium nitrate is absorbed far quicker than any other form of potassium. Jaff says it has taken a while to figure this whole chlorine issue out and he knows he still doesn’t have complete understanding.

Copper, zinc and iron deficiencies require careful management. Although the water is high in iron, the availability to the trees is sometimes a problem. Phosphorus and Iron have a mutually antagonistic relationship meaning that the presence of each inhibits the availability of the other. It’s a fine balance that Jaff is very cautious with and tries, as much as possible, to rely on combinations to provide what the trees need.

Jaff says that macs are definitely 2-year cycle trees. This is something I often hear debated so it was nice to have an expert opinion. 2-year-cycle means that whatever you do with your macs this year will profess in the year after next. This dispels the common theory that some macs are alternate bearing. Jaff substantiates this by confirming; “if there’s no crop, there’s a reason, and it has nothing to do with alternate bearing.”

In spring and early summer Jaff will broadcast fertiliser so that the entire orchard floor benefits. This encourages growth of all the weeds and grasses. I have heard farmers say that they avoid broadcasting because weeds “steal” the fertiliser but Jaff explains that they cannot “steal” your fertiliser because they are not going anywhere; the best they can do is recycle it and this all comes down to orchard management. Jaff’s strategy is to encourage as much diverse vegetation in the orchard as possible as these plants all contribute to breaking up the soil which aerates and enriches the underground environment.

814 with a magnesium shortage – which has also been caused by chlorine toxicity.

Lime & Gypsum is applied across the farm every year at a standard rate of 1 tonne per hectare. If soil samples advise more, or different forms, then that is accommodated. Over Jaff’s years of experience he has learnt that soils will always require this supplement and, because it moves through the soil so slowly, it is best to keep the supply constant. Calcium also helps combat the chlorine issue.

Moisture Management

Wolwedans dam, which borders the farm, is the sole water source for irrigation. A 150m vertical lift is necessary to get to the orchards. This dam was built for Mossgas but is now used as the supply for Mossel Bay municipality. It is one of the deepest dams in South Africa, measuring 76m deep at the wall. In the 2010 drought, Jaff’s surface pumps dropped 30m. The surface water of the dam is good but, below 1m, it is ice cold, dead water. As the seasons change, krill grows in this top metre and blocks the filtration system, so Jaff has to lower the pump into dead water for a period.

Dam, with Beaumonts on the bottom left of the picture. Jaff chose to plant them here, on the outside of the farm so that there would not be any nuts on the ground, potentially lost to the bushpigs.

Although Jaff’s personal preference is for microjects, low-flow drip systems have been installed in all the new orchards on this farm. Although supply is secure for now, Jaff believes that agriculture’s biggest challenge will come in the form of water security, especially in the Cape and this is the only reason he has made the change. Populations in the Southern Cape are growing and it’s only a matter of time before water allocations are reassessed. If farmers don’t anticipate and plan for that, it could spell disaster.

So, as a system, Jaff believes that microjets out-perform the low flow drips. In his opinion, soil that is not constantly wet can support a far healthier ecology. Oxygen, which is often dispelled by moisture, is essential to environmental well-being. Drips also don’t function well as a part of Jaff’s overall orchard floor maintenance strategy because they only service about 30% of the surface area. In Levubu, Jaff had an orchard that was spaced at 10m x 10m. It had a micro-jet sprinkler system and, at 10 years old, the entire orchard floor was covered with roots. These trees always navigated droughts so much better as the roots had been encouraged into a more expanded forage area, extending their range and resource pool.

Jaff’s ultimate strategy is to:

  1. cover the whole orchard floor in mulch,
  2. make sure there is sunshine on the whole orchard floor and
  3. broadcast nutrition on whole orchard.

Jaff believes that the entire orchard should be managed holistically, rather than just the rows. Drip irrigation just doesn’t work with this strategy.

One thing he has learnt is that the drip system requires modifications early on, with the small trees, so that the water is delivered INTO the bag zone. Because the potting medium, around the roots of the newly planted trees, lacks capillary strength to pull water from outside of this zone, many trees can be lost as a result even if there is irrigation in the vicinity. Jaff installs extenders from the closest dripper when the tree is planted.

Jaff uses two lines, with alternating dripper placement. As the trees grow, the lines are moved further away from the stem.

Ordinarily, an irrigation system designer will specify the layout of the blocks but Jaff prefers to turn this around – he designs the orchard layout, as it works for his purposes, and requests that the irrigation specialists design accordingly.

As with all good farmers, Jaff is suspicious of the technology and verifies everything it reports by inspecting it in person, with a spade and energy. Even when the technology isn’t wrong, the 3 probes per block can feel insufficient, especially in a large orchard and human scrutiny is always valuable.

Micro-jets in the older orchards.

Filtration system for whole farm’s irrigation system. Little receiving dish is the wifi for remote communication.

Tanks on trailers are brought to this point (block irrigation control) where they connect in and apply block-specific fertigation.

And this is where we’ll take a break, picking up again in the February edition of TropicalBytes which will be out on Valentine’s Day!