Pictured above: Cover crops are not planted in the Neethling orchards, but natural grasses are prolific and quick to grow back after being cut. Moisture is retained in the soil and the tree roots remain cool as a result.
Mpumalanga citrus and macadamia farmer Neethling says his recipe for success is to make sure feet walk often in the orchards and eyes are continually searching the trees for signs of stress or disease.
It is this rule which saw him land the Green Farms Nut Company’s top sound kernel recovery (SKR) award for his crop in December 2022.
The GFNC awards for the 2023 harvest are scheduled for early next month, when the sound kernel recovery top achievers will be announced for this year’s crop.
At 40.4% sound kernel recovery, Neethling was miles ahead of the industry average pegged at 33.2%, and the 33% average for Mpumalanga in the 2022 harvesting season.
Willem Neethling and Barry Christie, Group Agricultural Technical Manager for Green Farms Nut Company.
Neethling has a mix of Beaumont, A4 and 816 varieties. While variety diversity is proven to have an impact on total kernel recovery, and therefore sound kernel recovery, keeping the unsound kernel recovery low requires good management practices.
“You can’t be a bakkie boer (a farmer who never gets out of his farm vehicle) and think you will get good quality,” says Neethling.
“When I walk in the orchards, I can see immediately whether the trees are healthy or under duress. And if I see a problem, then it must be rectified right away. Asking questions all the time and finding answers for those questions are key to our results.”
Having taken up the reins on the family’s Ora Farm less than a decade ago from his father, Chris, the young farmer says he now realises how important it is to understand how nature functions, and what is really going on below the soil. He says sticking to the basics, while keeping an eye on what is in his control and trying to be one step ahead of what is not in his control, is what he believes secured him a 4.5 ton per hectare dry nut-in-shell yield in 2022.
Groundwork
The first serious undertaking on what was mainly a citrus farm was when the macadamia orchards were established 17 years ago as a diversification strategy.
Initially, Beaumont was the predominant variety planted, but as the orchards were expanded, different cultivars were added.
Neethling says he has also witnessed the value of cross-pollination by planting different varieties near each other, and if trees in a block need to be replaced, a different variety from the others is planted in their place. And while the harvesting times for Beaumonts and A4s or 816s differ, harvesting is not complicated as each variety can be kept separate, he says.
As the nuts are harvested, the orchard floor is cleaned to make sure nothing is left behind where pests can breed or multiply. “Each worker has the responsibility to make sure the row in which they are working is clean before they can move on to the next row to harvest,” he adds
“Our staff understand that doing their tasks diligently is critical to the success of the farm. With the pruning process forming such an integral part of the farm’s success, training in this regard has also played an immense role. The training is provided by our processors, the Green Farms Nut Company.”
Another key management strategy is for staff to understand the purpose behind pruning in the orchards. “Our workforce understands how pruning – to a large extent – determines the yield and the quality for next year’s crop. This means they take their jobs very seriously. They also take great pride in pruning the trees correctly and are capable of making the pruning decisions on their own.”
The right cut
Barry Christie, group agricultural technical manager for the Green Farms Nut Company, said low unsound kernel results were achieved by pruning the trees. This, he said, ensured chemical applications penetrated the entire tree. Alternating the active ingredients in the crop protection chemicals was also important to make sure pests were unable to build up resistance, rendering the pesticides ineffective.
“Overlapping the applications is vital to make sure the trees are protected all the time.”
Pruning affects both yield and quality, as Christie says nuts form on all the new branches that grow after pruning. “The quality of the nuts is largely determined by how open the tree is and how much sunlight the nuts get. So, this year’s prune will help next year’s quality. The yield in two years’ time will be affected by this year’s prune since it takes around 18 months for those bearing branches to grow and produce. Growers therefore need to stay in an annual cycle of pruning to ensure continuous new growth, and constant sunlight.”
The key to pruning is to get light into the tree and reduce unnecessary growth that will not yield more nuts. Neethling has found that by pruning the trees from a young age, large trunks don’t have to be cut out later. This way, he does not waste inputs on growing unnecessary wood, and sunlight and chemical penetration are ideal from the start.
By not pruning a tree from a young age, he warns, it is allowed to make long, thick branches, which don’t necessarily produce nuts. “But if you cut that branch out, and allow the tree to push out several more, smaller branches, then your bearing wood is increased.”
With regards to cutting away too much of the tree and limiting the harvest, Neethling says he once had an orchard which was cut back severely because the canopy was just too dense. “I was amazed at how quickly the trees grew back, so there is no concern over cutting too much, and losing yield.”
Pruning forces trees to produce growth hormones, which promote a root flush, leading to leaf flush, he adds.
“Pruning is therefore a good tool to encourage growth in the tree.”
Neethling keeps his trees at 4m to guarantee the spray cart can reach every last branch on the tree. Skirting is done no higher than thigh height of the person pruning, so that bearing branches lower down on the tree are not lost.
By pruning the thick branches, smaller branches are allowed to grow, increasing nut bearing and preventing the development of an unproductive centre in the tree.
Optimal inputs
Keeping pests at bay is vital to ensure low unsound kernel. Neethling follows a crop protection regime where the orchard is sanitised before flowering, and all other chemical applications postponed until after flowering, where possible. This protects bees and prevents them from being interrupted while they are busy with crucial pollination.
“Pollination must be optimised at all costs, so we do anything we can to protect the bees. We have a lot of indigenous bush around the farm so there are huge numbers of bees in the area. I don’t need to hire in hives but I do put boxes around the farm so if they need a home, there is one.”
Checking for thrips regularly is also an integral part of the management regime. Branches are shaken over a mobile phone screen, which makes it easier to see the tiny insects. “Thrips multiply incredibly quickly so even if there are only a few today, there will be masses tomorrow, meaning it’s important to act quickly. This is not only important for the macadamias, but for the citrus, too. Having the two crops on the same farm is not ideal because thrips can become a big problem in both crops We have to keep a tight control on pest loads.”
If crop protection applications need to be made during flowering, Neethling stresses how important it is to protect the flowers. “Usually when I spray, I run at around 550 revolutions per minute on the Matrix 3000 litre spray cart. This means the fans can sufficiently push the chemicals into the trees. But during flowering, I drive a little slower and reduce the pressure so the flowers are not blown off, while still making sure the chemicals cover the trees.”
Neethling is not altogether comfortable with having to use harsh chemicals on the farm at all, since he believes it ultimately has a negative effect on the orchards. “But in many cases, it just can’t be helped. A few years ago, we were told to stop spraying glyphosate under the trees because it hinders growth in the trees. But in the Lowveld that is impossible – the weeds and grass just grow too fast. The reality is we can’t cut quickly enough. The impact on the quality of the citrus, especially, is too great as the insects live in the grass and then climb up into the trees,” he says
Ethapon also inhibits the trees, which means they need a little boost after an application. “I give them an extra helping of fertiliser to help them recover.”
The fertiliser mix is based on soil analysis. The farmer uses a formulation of kraal manure, decomposed nut husks, LAN fertiliser and dolomitic lime. The mix is applied about six weeks before flowering, and then another two more applications, two weeks apart. This gives the nutrients enough time to get into the soil and to allow the tree to absorb the nutrients in time for the follow-up applications.
On his irrigation management, Neethling says macadamias do not need too much water, and phytophthora could become a problem, particularly if the roots of the trees are submerged in water. Having tensiometers to measure soil moisture and guide irrigation is therefore another vital step to achieving a good yield, he adds.
The last step
Macadamia processers are increasingly tightening up regulations on nut deliveries to minimise the unsound kernel quantities the factories are required to sort. This has meant farmers must exercise more vigilance during on-farm sorting to maximise the quality they deliver.
A key part of the 40.4% sound kernel achieved by the Neethling farming operation was the result of two sorting processes on the farm.
The first is after harvest, where nuts run on a conveyor belt at a relatively slow pace, with bright lights overhead, to allow the staff to easily remove the bad nuts. Those nuts that make the grade are then dried and sorted again before being shipped to the factory.
This year, about two tons out of the 36-ton harvest were excluded on-farm. These nuts are cracked by an on-farm machine before being sorted once again. Any nuts that pass muster are roasted and sold on local markets.
And while the income from these nuts is not significant, it at least provides nuts to consumers in the local community.
Christie says while data suggest macadamia trees can continue to produce for up to 26 years, improved management and orchard establishment practices introduced in recent times are likely to push that estimate along.
