Below is How To Plant Macadamia In South Africa
Specialist consultant and owner of Advanced Macadamia Consulting Kobus van Niekerk detail the best way to plant macadamia trees in a newly prepared orchard.
Marking tree positions (pegging)
Once the land has been prepared, the three positions can be marked by pegging sturdy wooden pegs into the soil. Reference points such as a road or a windbreak can be used to create a baseline for the rows, or baselines can also be referenced on the irrigation design, the land contour, or a fence.
Row direction must be decided upon according to soil types, erodibility, topography, or access to light. Where the slope gets steeper than between 5% and 8 %, row direction should follow the contour as closely as possible.
Tree spacing that balances the health of the orchard and pragmatic economic sense is 8m between the rows and 4m between the trees in the row. This will eventually allow for a 2m to 2.5m work area, where tractors and implements can move between the rows with ease. This distance limits the tree growth to between 6m and 6.5m.
By keeping the tree at a height of 75% to 80% of the row width using pruning, light is allowed onto the entire tree length, as well as onto the soil. It also helps to maintain a ground cover of grass or similar suitable plants.
Pegging the land must be done accurately and with assistance from GPS, a dumpy level, or a theodolite. Farmers are now making more use of GPS-guided tractors with a single tine tooth implement, drawing shallow furrows at regular intervals (8m or 16m) in a grid.
When the baseline is decided on, peg out the tree rows at an 8m distance every 100m. Take care to maintain the distance accurately at 100m. Over a ridge or through a gully, it is more accurate by sight than by using a measuring tape or a marked cable/rope. A hill or a slope pulls the distances closer. Each tree position should be accurately marked using a level distance.
Diagram 2 shows how measuring along the slope actually pulls the tree positions closer, compared with the distance measured at a perfectly level. These small differences over a few hectares pull the tree rows askew and out of the square, especially diagonally. This is less likely to happen using GPS equipment.
Once all the three positions have been pegged, making sure the exact positioning is maintained, put in two reference pegs using a wooden plank jig as illustrated in Diagram 3.
The planting jig is a plank measuring about 1.2m, with a notch cut in the middle and two notches cut exactly the same distance from the center notch.
The jig is placed with the tree position peg in the center notch. Then two reference pegs are driven into the ground, resting in the two side notches.
Applying fertilizer in planting holes
Once the holes have been dug, fertilizer is dropped into the base and then covered with topsoil before being well mixed.
This can be done by workers doing the planting. Once the soil and fertilizer are well mixed, follow up with another spade of topsoil to fill the hole to the same depth as the medium in the bag holding the young tree.
Once that is done the planting team can remove the bag. At this stage, the planter should hold the open root ball with one hand at the bottom while placing the other hand on either side or top of the root ball. If a very strong root is detected at the very bottom of the medium, with a sharp bed or kink, it can be pruned. This is the only stage where any root pruning needs to be done between germination and planting the tree.
Few trees need root pruning or trimming due to a bent tap root. At no stage during planting should the young tree be held by the stem. Once the tree is in the hole the jig can be positioned with the two outside notches snugly fitted around the reference pegs. The tree is then positioned in line with the middle notch, and the hole is filled with topsoil from around the planting hole.
The soil around the tree can now be lightly compacted.
Building a dam around the base of the tree
The planting team is followed by a worker who builds a dam at the base of the tree for watering purposes. The best method is to place a small car tire over the tree before gathering soil from the outside rim, which is then built up to the height of the tire. The soil removed from the hole before planting can be used to build the dam. Slow-release fertilizer can also be sprinkled around the tyre before it is covered with soil.
Watering the newly planted tree
Staking the tree
After filling the dam with water, one of the reference pegs should be used to stake the tree. The stake should be placed at a 45˚ angle. This keeps it out of the root zone and prevents the twine used to secure the young tree from slipping down. Raw sisal twine should be used. Tie the tree by binding it twice or three times around the stake before looping it around the tree.
The irrigation system can also be placed into position.
Once all the trees are planted the tractor can hook up the water bowser and fill each base dam with water.
This is to ensure proper soil root contact as soil washes into the plant medium and the air is removed from the immediate soil volume around the tree and the plant medium.
How long does it take to grow a macadamia tree?
“The trees take 18 months before they are ready to be sold to the farmer.
Once planted on the farm fields, you can expect the first crop in four to five years’ time.” It is also not a case of planting the seed, sitting back and watching it grow merrily either. “It is all an exact process.