Pictured Above: Two A4 trees that have been grafted in a row among the Beaumonts.
Suitable varieties and cross-pollination between different options are among the most important reasons for the success and sustainability of growing macadamia nuts in the southern Cape.
This is the finding of Braam van Wyk, a farmer in Hoekwil near the Wilderness, after trials with different varieties over a period of almost 20 years.
Van Wyk of the farm Toorbos – where 60ha of macadamias are in production with the eldest trees about 18 years in the ground – says over the years he has tested about 25 different varieties and now plants mainly the four best performers.
Originally from Vivo in Limpopo, he moved his entire farming enterprise onto 60ha at the Wilderness, after excessive expenses – due mainly to ignorance and lack of information about how macadamias do in the area – and almost lost the farm due to poorly performing trees until he found the real solution to good production.
In his trial block, the world-proven Beaumont was still doing well and along with that, he identified two hybrids, Nelmac 2 and Hidden Valley A4, as outstanding and cross-pollinators and Fuji (791) as an excellent cross-pollinator.
Macadamia farmer Braam van Wyk with a promising harvest.
Poor performance
Van Wyk planted blocks of Beaumont but the results proved disappointing until he realised the problem was the absence of cross-pollinators without which Beaumonts bear only every other year, even though there are many flowers.
Compounding the issue was the fact that the trees within the Beaumont block pollinated themselves throughout the year and could therefore never really produce a good crop because there were constantly nuts in different stages of development on each tree.
He described the trees as ‘messed up’ and even spraying with the growth hormone Ethapon-480 to make the nuts fall did not help.
The poor performance of his Beaumonts was linked to cool, wet weather when pollinators are not very active. This is a problem in all the production areas in South Africa although it’s at its worst in the Wilderness, which has cool, wet weather almost all year round.
“I then decided to introduce cross-pollinators in the form of Fuji, Nelmac 2 and A4 between the Beaumonts by grafting these varieties onto trees in the Beaumont block. This was clearly the solution to the poor yield.
Within about five years, cross-pollination increased my yield from an average of 0,5t/ha to 4t/ha in some orchards and saved my farm.”
One block that usually produced 10 tons suddenly delivered 70 tons! The trees had found their rhythm and now van Wyk’s Beaumonts flower and form nuts every year.
The grafted branch of an A4 clearly visible. When it is well established, all Beaumont branches will be removed.
Three pollinators
Van Wyk uses three varieties to pollinate blossoming and bearing nuts on very young wood, which releases pollen for cross-pollination within a year. The long flowering period can start as early as March and continue into October and this increases the chance of cross-pollination on Beaumont.
When Fuji is sprayed with Ethepon, only the mature nuts drop – imature nuts stay on the tree, making the variety the perfect pollinator for Beaumont as it blooms for a long period.
He says the Australian hybrid A4 also flowers very early and can produce commercial yields within three years. It performs particularly well in cooler coastal regions such as the southern Cape, has a high kernel yield of up to 45% and was one of the best in the trial block on Toorbos.
Van Wyk has also been planting Nelmac 2 for a few years – a variety that flowers early and it produces large nuts with a high cracking percentage. It is popular because it is a good pollinator for Beaumont with a yield that compares well with that of Beaumont. Other early hybrids that can be considered for cross pollination are Nelmac 26 and Nelmac D.
Since he discovered the secret of higher production from his trees, van Wyk ensures he “replaces” every third row in his Beaumont blocks with one of the above varieties by removing branches on the trees and grafting them with the varieties. Once large and established, he removes the Beaumont branches completely to eventually have cross-pollinators in every third row of each block. The first two trees in each Beaumont row are also grafted with pollinator varieties to ensure each tree is surrounded by cross-pollinators.
When new blocks are planted, he plants alternating rows of Nelmac 2 and N4. Together they produce a good yield.
Braam van Wyk in his nursery where he grows his own macadamia trees.
Soil and leaf analyses
The orchard rows run from north to south, or they follow the direction of the contour of the slopes. The sandy soil is well drained but has a clay layer at a depth of about 500mm. Where the ground is level, it is earthed up and the trees are planted on the banks and he also plants windbreaks of beefwood, Chinese poplars or Dutch alder.
Soil analyses are part of soil preparation and lime or dolomite is applied based on a soil sample from every 0,5ha. The normal planting density on Toorbos is 8m x 4m. Because it rains enough and the orchards are not irrigated, granular fertiliser is used and when trees begin to produce, they are fertilised based on age, soil and leaf analyses. “This precision farming practice has improved the entire farm.”
Van Wyk says that in the southern Cape the flowering period is from March to October and it tends to get longer as the orchard matures. It compensates for less satisfactory conditions, pests or diseases in a specific period.
His orchard management is the same as that in Limpopo or Mpumalanga with the same pests as the other regions, but not as numerous. Because of the high humidity, fungi sometime appears on flowers. He does integrated pest control with pheromone traps for moths while stink bugs are controlled chemically because no biological method is available for them.
A full load of nuts.
Minimal mechanisation
Van Wyk believes in creating work for the surrounding community so he mechanises as little as possible. “If labour becomes an issue, I will possibly mechanise more. I believe it is my social duty as a farmer to create work. In season, I employ 92 people – I don’t harvest and prune mechanically.”
In most cases pruning isn’t necessary as the wind dwarfs the trees. Skirting is necessary to allow weeds and grass to be sprayed while harvesting is unobstructed.
Although fertilisation and pest control form part of his input costs, he saves because it rains enough – on average between 56mm to 60mm a month – with irrigation necessary only between September and January. This keeps his electricity costs relatively low!
Because he rarely sprays against pests and uses conventional chemical fertilisers, his biggest expenditure in input costs is spraying the grass in the orchards with glufosinate-ammonium before the nuts start to fall.
The region’s yield is the same as the top producers in KwaZulu-Natal – Nelmac 2 and A4s have a cracking percentage of 45% – while Toorbos produces an average of 1,3 tons of kernels a hectare annually. Of its 68 tons that are cracked, 55 tons are whole and half nuts.
Having a depot of Mayo Macs Macadamias and a processor in George, marketing the product is not a problem. A facility that can crack nuts is part of the future plans for the southern Cape.
Definitely sustainable
Van Wyk says the biggest challenges of macadamia cultivation in the southern Cape are suitable varieties and availability of water. With correct varieties that produce a large enough harvest every year, macadamias in the region are definitely sustainable.
Macadamia cultivation in the southern Cape has grown from about 200ha in 2006 to currently around 2 000ha on four commercial farms. Since 2017, more orchards have been established based on the proven success of the industry in the region.
He considers the fall in the nut market to be more like a correction. “The days of nut in shell marketing are over. More focus is needed on varieties that produce larger and more whole nuts for the snack market. Producers must focus more on the quality of the kernel and on choosing the right variety for their farm’s microclimate.”
