A precision agriculture expert has declared drone technology as the perfect fit for macadamia farms, pointing out that the longevity and high value of the trees put them on the front seat for the best place to apply drone technology.
Based in South Africa, Ken Treloar has been in the precision agriculture business since his Aerobotics days, with a special focus on how drones can enhance the farming experience. Now also an author, Treloar maintains that drones have a perfect home on macadamia farms.
“Macadamias are a very good fit for drone technology,” Treloar told agriculture publication, ProAgri, recently.
“Not because drones are trending. Not because the spraying, surveying or maps look impressive. And definitely not because every farmer needs yet another dashboard report.
“Drone mapping and macadamias make for a near-perfect and practical pairing. Trees are long-term, high-value assets that require expert management. In short: every tree matters.”
As he argues, missed anomalies can cost a farmer more than just one season: a weak tree, a missing tree, poor drainage, a blocked irrigation line, uneven canopy development, recurring pest pressure or persistent chlorosis can all carry a cost for several subsequent seasons.
South Africa tops the world in producing macadamia nuts, with over 81,000 hectares of dedicated trees primarily located in in the provinces of Mpumalanga, Limpopo, and KwaZulu-Natal.
While highly profitable, macadamia farming requires hot, subtropical climates, deep well-drained soil, and significant upfront investment, as it takes several years for trees to bear their first commercial harvest.
Queue in the need for drone precision.
“Small differences in tree performance become large differences in nut-in-shell outcomes. All things being equal, sound kernel recovery and kernel quality are the big ones.
Treloar went on to list down the invaluable competencies that drone technology brings to the macadamia orchards.
Drone mapping
“We see trends and patterns,” he says, adding that, through their maps, drones provide a new layer of visibility and enhanced ways to spray, bait or seed cover crops.
“We see variation red flags and outliers. We see where orchards are uniform, where they are not and where there’s sub-par performance.”
A word of caution though – it is not about the drone; neither it is about the map itself. But the data the map gives you.
“The point is not the drone. It’s the decisions that follow. A pretty map is not enough. One mistake farmers can make with drone data is stopping at the map.”
A colourful normalised difference vegetation index (NDVI), normalised difference red edge index (NDRE) and a red, green and blue (RGB) or thermal layer map may look useful, but the real question is always: what
now?
Treloar further argues the same goes for spray applications and asks why farmers are not utilising spot spraying or variable rate applications (VRAs) where it makes sense.
“Which block needs attention? Which trees are outliers? Which zone to scout first? Where should we go for leaf and soil samples? Which irrigation lines need checking? Where should we compare yield, cultivar performance, soil type, pest pressures or pruning?”
Utilising objective source data comparatively leads to educated decisions and tailored next-steps, he says. It’s a valuable approach, and where drone data becomes a return on investment (ROI) engine for production teams.
Tree inventory
A drone survey can help identify how many trees are present, where trees are missing and where gaps exist.
“This is not just a neat counting exercise. Missing trees represent missing productive capacity. In young orchards, this helps with replanting plans, survival-rate checks and nursery orders. In bearing orchards, it helps quantify what the block can realistically carry.”
Then there is canopy size and variation.
“Canopy tells a story,” Treloar says.
“Uneven canopy development can point to soil variation, drainage problems and phytophthora prevalence as well as irrigation pressure differences, nutritional imbalances, pest pressure hotspots, wind exposure and frost pockets.
“They can all display in some way through the canopy status metrics, especially when paired with other drone data metrics available. All historic management issues or cultivar-specific growth patterns can also be tracked with drone scans over time.”
While a drone does not give the final diagnosis, it does show where the diagnosis should start. This is especially relevant in integrated orchard management.
“A productive macadamia orchard is not only about yield in one season. It is about keeping the block in a productive stage for as long as possible. It is a sustainability game.
“Once canopies become too dense, inter-row light declines and roots become exposed, spray penetration suffers and production can begin to decline. Drone-derived canopy metrics help farmers and managers see orchard statuses (or changes) early and objectively.”
For tree health and vigour monitoring, multispectral data, including indices like NDRE and NDVI, highlight differences in canopy condition. These indices should be interpreted carefully. A low value does not automatically mean a specific disease, deficiency or irrigation fault.
But it does highlight trees or zones that behave differently from the rest of the block, says Ken.
“Outliers. Red flags. The areas of concern or focus. Outlier detection, in essence, allows us to move from broad observation to targeted inspection.”
Thermal drone data is also instrumental in detecting where transpiration patterns differ across an orchard. In practice, patterns often point to water stress, over-irrigation, blocked emitters or pressure variation.
“Drone data shows the above-ground pattern. Soil probes, irrigation records, soil maps and field inspections help explain the below-ground reasons. This is why drone data should not be viewed in isolation.”
Drainage issues, shallow soils or root-zone problems (among others) are also possibilities. Macadamias rely on a healthy, active root zone in a big way. Feeder roots, soil moisture, soil structure, pH, organic matter, drainage and ground cover. These factors influence whether a tree can take up water and nutrients effectively and efficiently.
On timing
Treloar insists on the importance of timing in macadamia farming. Drone surveys during flowering, nut set, nut drop, shell hardening, oil accumulation or harvest time may all tell a different story.
“The same block can look vastly different depending on cultivar, season, crop load, recent rainfall, heat stress, pruning, irrigation scheduling and stage of growth,” he says.
“That is why farmers and managers should not only ask, ‘What does this map show?’ They should rather ask, ‘What does this map show at this point in the season?’ Timing is important.”
For example, a weak zone during flowering may affect nut set, he says.
“A stress pattern during shell hardening or oil accumulation may raise different questions about water, nutrition and crop load.
A canopy map before pruning may support contractor negotiations, or row access decisions, groundcover management, access routes and spray penetration discussions. The value improves when drone data is placed inside the macadamia calendar in a strategic way.”
Better scouting, sampling and pest focus
On a farm, macadamia trees are rarely uniform. Some are stronger; some are weaker; some rows sit on slightly different soil; some areas carry more water; some dry out faster.
Some zones are more exposed to wind, while other blocks have cultivar differences that affect flowering, nut set, nut drop and harvest timing.
If sampling ignores this variation, the results can be very misleading, in Treloar’s view.
“Drone data can guide smart sampling by identifying representative areas, weak areas and strong areas. This is useful for leaf analysis, soil checks, pest scouting, nut counts, yield estimates and block comparisons. It also improves scouting.
“Instead of walking randomly or only inspecting the areas that already look poor from the road, a farmer can inspect outliers. These are the trees or zones that differ most from the rest of the orchard.”
This is useful where pests such as macadamia felted coccid, stink bugs, thrips or other orchard issues may be developing in pockets. Drones do not replace proper pest monitoring’ rather, they help focus attention, says Treloar.
Yield, quality and records
Macadamia farmers think in terms of NIS, dry-in-shell (DIS), saleable kernel recovery (SKR), quality, crack-out and long-term block performance, and this is where he believes drone data is still underused.
“A block that looks good from the road is not always the block that performs best. A large canopy is not automatically a profitable canopy. A strong-looking tree may carry poorly. A smaller tree may be efficient. The real value comes when drone data is compared with yield records, cultivar, tree age, soil type, irrigation design, pruning history and processor feedback.”
He says one survey gives a snapshot, but several surveys over time show direction.
In such eventuality, Ken emphasises the importance of asking the right questions.
“Is the weak zone spreading? Are young trees catching up? Did the intervention work? Is the canopy closing too quickly? Is ground cover disappearing in shaded inter-rows? Is the same area underperforming every season? That is where the data becomes powerful.”
From monitoring to application
Drone data also becomes useful when it feeds into application decisions.
“In summary, a scan can identify weak zones, strong zones, stressed areas, canopy variation, missing trees or possible irrigation-related patterns.
“This information supports VRA either through ground-base equipment or through spray drones, where appropriate and legally compliant.
“In practice, spraying may include spot-spraying, targeted foliar applications, micro-element programmes, pest or disease interventions or specific orchard applications such as sunburn protection products.”
The right approach depends on the product label, crop need, canopy structure, timing, terrain, spray coverage requirement and operator capability, argues Treloar.
“I would not position spray drones as a blanket replacement for conventional sprayers or mist blowers. But I do see a clear role for them in precision application work. Especially true where access is difficult, soil conditions are challenging, terrain is uneven or the treatment area is specific.
“The same thinking can apply to seeding drones. In younger macadamia orchards with open inter-rows, drone seeding may have a role in establishing cover crops where access, timing or wet soil conditions make conventional equipment less practical.
“Cover crops and living ground cover support soil structure, reduce erosion, improve orchard-floor conditions and contribute to the biological functioning.”
Using drones to solve actual problems
A farmer makes decisions today that may only show their full result years from now. That is especially true with long term tree crops such as macadamias.
“Can it help me identify weaker trees? Can it help me find irrigation problems earlier? Can it improve sampling? Can it help my team prioritise scouting? Can it support pruning decisions? Can it reduce waste? Can it protect yield,
quality or margin?”
A poor decision around planting, irrigation, pruning, drainage, nutrition or pest control can echo for many seasons. A good decision can build value for decades.
“That’s why I have so much respect for agriculture. It is not just production. It is stewardship. It is business. It is risk management. It is science. And it is also deeply human.”
Which is perhaps why Treloar urges farmers to always start with identifying the problem, rather than getting a drone before looking for problems it can solve.
“Where are my weak trees?” is better than “I need a drone survey.” “What is causing variation in this block?” is more useful than “Can I get another map?
“Good farming has always required observation. Drone technology, in essence, gives us another way to observe. A different perspective. And in macadamias, where every tree is a long-term investment, improved observations lead to better decisions.”
About Ken Treloar
An agriculture technology consultant, Ken Treloar is also a writer, speaker and strategist, focused on precision agriculture for perennial crops.
He helps farmers and agribusiness teams to read drone data with clarity and act on insights with purpose. His work has appeared online, in various industry publications and at live presentations.
Treloar’s first book, Drone Data Metrics for Orchard Farming, focuses on helping farmers and industry professionals practically understand drone-derived data. He is currently working on his second book, focused on drone use for macadamia orchard management specifically. It is designed to be as accessible and practical as his previous book.
“Drones interest me because they give the farmer a new, advanced layer of visibility. A drone does not replace the farmer, the agronomist, the consultant or the person walking the orchard. But it does help them to see the farm differently,” says Ken Treloar, a worldwide expert in the intersection of plant science, farm management and technology.
Ken holds an MBA in Business Administration and a BTech degree in Landscape Technology and Horticulture. This strong background eventually led him into the AgTech space, and more specifically into drone-based orchard monitoring.
He is currently with HolmStone (part of the RusselStone Group), where his work has advanced into the broader space of renewable energy, infrastructure and long-term resilience for agricultural and industrial businesses.
“Farmers need better data, better energy systems, better water use, better logistics and better decision-making. All of these things form part of building stronger farming businesses through agricultural technology innovation,” Ken says.