Macadamias: switching to machine harvesting

Harvesting macadamia nuts is highly labour-intensive, and Braam de Kock’s Lowveld farm is no exception. Tired of the stress of managing a large workforce, De Kock finally opted for mechanisation, and found the investment well worth it. Nonetheless, the process has had its challenges, he told Lindi Botha.

Macadamias: switching to machine harvesting
The orchard sweeper is used to gather nuts to the middle of the row for optimal collection by the harvester. Photo: Lindi Botha
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Braam de Kock’s farm on the outskirts of Mbombela, Mpumalanga, is without the usual flurry of activity that is typical of a macadamia nut farm in May. Instead, plumes of dust collect above single rows as the mechanised harvest gets under way.

During the harvest season that takes place between March and August each year, many farmers are faced with sourcing and managing hundreds of casual labourers to collect nuts off the orchard floor. For De Kock, this meant 100 workers for his 200ha farm.

“The plan was always to mechanise as much as possible. As the macadamia trees matured, our yields increased, which meant we were employing more and more people each year.

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“I prefer the workers to live on the farm, but I couldn’t accommodate all the people who were needed for the harvest. At one stage, we used a contractor to source and manage the labour, but we didn’t have control over the movement of people on the farm. There were many strangers coming and going all the time, and it was a security risk for us and the crop.

“But managing the workers ourselves was very time-consuming, as transport had to be arranged and coordinated. There were always people who came late, or a bus that had broken down or some other issue that caused frustration.”

All of this led De Kock to make the decision to mechanise four years ago and, in the process, he managed to cut his labour force by 60%.

“We still need people because the machines don’t get to every single nut. But managing 30 people is far [easier] than 100,” he says.

Moreover, many of his permanent workers have been upskilled to operate the machinery, which has brought an added benefit for his staff.

New systems, new methods
De Kock has been fortunate in that the layout of his 15-year-old orchards is conducive to mechanised harvesting.

“The rows are spaced 8m apart and the trees planted at 4m intervals in the rows, which is standard. This is perfectly adequate for mechanisation. We had to flatten contours in some of the blocks because the machines struggled to move over them. And we soon realised that if a big storm occurred, soil or branches washed into the rows and these had to be smoothed out so the harvester could get through.”

Cultivars planted on the farm include 814, Beaumont, Nelmak2, 819, 816 and 788. Ethephon is used on all the varieties to speed up ripening and to ensure that the harvest is completed by June.

De Kock notes that it is especially important to complete the Nelmak2 harvest timeously, as leaving the nuts on the trees for too long can cause some to start germinating, which lowers the quality of the nuts.

De Kock starts harvesting when the first nuts fall from the trees around the end of March, as these cannot be left on the ground until the bulk of the nuts mature. Once most of the nuts have reached maturity, ethephon is again applied to obtain the maximum nut drop.

A tree shaker, which is attached to the tree trunk with clamps, is then used to ensure that all the nuts are dislodged. According to De Kock, earlier types of tree shakers sometimes removed large chunks of bark, but newer technology has ensured that this is no longer the case.

The process, nevertheless, remains time-consuming.

“When we started, we couldn’t get through the whole orchard in a season, but the operators have since honed their skills and have become very proficient in moving from tree to tree, and ensuring that the clamps are placed around the trunks properly.”

A sweeper (an implement with large brushes) is then sent in to push the nuts to the middle of the row, and this is followed by the harvester, which goes through each orchard at least three times throughout the season. The harvested nuts are then put through a stone separator at the shed before being dehusked.

Finally, a team of workers is sent through the orchard once more later in the season to pick up the last nuts that have fallen.

Adaptation is key
Embarking on the road less travelled is always fraught with challenges, and this was no different for De Kock. He made the decision to mechanise virtually overnight, and recalls that from that moment on it was full steam ahead.

“We went in quite blindly, and we’re still learning and adapting,” he recalls.

He purchased two locally available Sicma harvesting machines and, following advice, bought a stone separator at the same time, as the harvester cannot distinguish between a nut and a stone.

“The stone separator goes hand in hand with the harvester; you can’t really do without it.

“Another problem we soon noticed was that the harvester can’t get up close against a tree trunk to harvest all the nuts lying there. In the first year, I got halfway through the season when I started wondering if I’d made a mistake because of all the nuts that stayed behind after harvesting. But then I managed to source a sweeper, as I realised that I had to make this work. The sweeper sweeps and blows the nuts from under the tree before the harvester moves down the row.”

De Kock notes that the key to successful mechanisation is adaptability.

“There isn’t a single piece of equipment we’ve bought that hasn’t required alteration or tweaking in some way. At least the machines are made in such a way that you can make changes to suit your needs.

“We realised quite early that we needed a full-time maintenance manager on site because the machines, with all their moving parts, require constant upkeep. Otherwise, I’d be stuck in the tractor shed the whole day playing mechanic instead of farming. Fortunately, parts are readily available locally.”

Because the harvest was collected sooner than before, De Kock had to adapt his dehusking and storing facilities to cope.

Other changes that were made included pruning the lowest branches to raise the skirt of the tree; this enabled the machine to move closer to the trunk.

“The higher skirt also assists with the more even spread of the fertiliser, and the workers who pick up nuts afterwards can access the nuts close to the tree trunk more easily.”
adapting to local conditions

De Kock laments the school fees that he had to pay to mechanise, but is quick to admit that this is part of farming.

“Things are constantly changing, and the day you say you’re done learning, you may as well retire, because then you’re not a farmer anymore.

“Australia is far ahead with mechanisation, but it doesn’t necessarily mean we can take what they know and apply it here. The biggest difference is that we have labour available, whereas they have no choice but to mechanise. The two can be combined, however, which is what I’ve done. I believe this is the most effective method and the easiest to manage.”

He adds that there is a host of implements on the market, and the macadamia grower has to decide what works best on his or her farm.

“In Australia, for example, they have a machine with a roller fitted with teeth that picks up the nuts, but not the sticks and stones, as it rolls over the orchard floor. We tested it over here, but it doesn’t really work unless your orchard floor is a beautiful, even lawn, as the Australians have.

“The Lowveld is also quite hilly, which can be a challenge for mechanised harvesting.

“We haven’t ridged our trees, because it would prevent the sweeper from reaching the nuts that fall and stay on the ridge.”

Critics of mechanisation have pointed to erosion caused by sweepers, but De Kock says this is not the case. “Yes, the sweeper does clear the mulch to a certain extent, but we put it all back again at the end of the season when we prune the trees. All the cuttings go through a chipper and are dispersed among the trees, so the soil isn’t left bare.”

Is mechanisation worth it?
De Kock admits that he cannot yet tell whether mechanisation has been worth the investment.

“I haven’t calculated to see when I’ll get my return on investment, or if mechanisation saves labour costs. The decision to mechanise wasn’t made to save on salaries, but to eliminate security risks and the difficulty of managing so many workers.

“In terms of management and other factors, I’m certainly satisfied. Compared with the stress of managing a big workforce before, everything is so much easier now. And at this stage, the price we get for the nuts justifies the investment.”

Email Braam de Kock at [email protected].

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