Agriculture in the Eastern Cape normally leans towards various livestock and citrus undertakings. Interestingly, the cultivation of pecan trees has increased over the past few years, mostly in areas such as Cradock and Somerset East which have sufficient water supply, thanks to the Great Fish River.
The farm Longacre, where pecan trees are cultivated, is located between Cradock and Hofmeyr. If you visit during harvest time, you will be met by the curious sight of tall, leafless trees.
The trees cover 70ha and are managed by Philip Antrobus whose late father, Michael, planted the first rows of pecan trees some 40 odd years ago. Philip’s great-grandfather, Geoffrey Antrobus, who came from England, bought the farm Normanskop and renamed it Longacre, somehow unwittingly doing justice to the neat rows of orchards that can be seen today.
Cracking a secret
“The word ‘pecan’ means to crack with a stone,” explains Philip. These deciduous trees grow fast, can get very tall, and can reach the ripe old age of 300 years. “The pecan tree is native to North America and the indigenous people used it to sustain themselves for three months during winter.”
When it is planted from seed (the nut), the pecan will not produce a tree that is identical to the parent. To cultivate a tree of a specific variety, buds and shoots from the parent tree must be grafted onto a seedling rootstock.
Pecan trees can live under six feet of snow, but certain methods are required to help get them there. “That is one of the reasons why we do not fertilise the trees after January, since it will promote growth and allow early frost to kill them later on.”
In the Karoo, pecan trees enter dormancy around the second week of May. Harvesting takes place from June until early August, while pruning is done immediately after. New trees can also be planted once the nuts have been harvested. Philip would like to expand the orchard size to 100ha, which will require new watering systems.
He makes the interesting observation that the Eastern Cape’s pecan tree production areas are at least three weeks behind that of the Northern Cape. The Northern Cape’s trees will start bearing leaves at around 1 September, whereas trees in the Eastern Cape’s only start showing their leaves in October. All sorts of things start happening then.
“Pollen shed, pistil activity and pollination of flowers all happen three weeks after the leaves have appeared. The Northern Cape has a three-week advantage, and they capitalise on the extra heat.” Philip adds that one of the challenges that pecan growers face in the Eastern Cape, is the cool easterly breeze, which lowers temperatures at night.
Good planning is key
Planting an orchard requires good planning. There are not many self-pollinating varieties. In basic terms, there is a Type I variety (protandrous with early- to mid-season pistillate receptivity and pollen shed) and a Type II variety (protandrous with mid- to late-season pistillate receptivity and pollen shed).
When planting trees, Philip alternates between four rows of Type I, and two rows of Type II throughout the orchard. “The Type I tree comes out of dormancy first and produces pollen. The Type II tree comes out of dormancy later and produces the female flower. The Type I tree will then pollinate the female flower of the Type II tree, which will produce the nut.”
An interesting fact about pollen is that it can fly up to 50m far. However, if the conditions are too dry, it will dry out and by the time it reaches the nuts, nothing will happen. This is what happened during the 2018/19 production season. “We experienced unusually warm winds during our pollen season,” says Philip. “Usually our weather is more settled, enabling the pollen to fly without drying out.”
Quantifying water use
An important factor, if not the most important, is that pecan trees love water. It is important that the available water is enough for the total requirement, even in dry years.
There are five critical watering periods for mature trees:
- Bud break in spring to initiate strong, vigorous growth.
- Nut sizing to develop a satisfactory size.
- Water stage of nuts to prevent nut drop.
- Kernel filling to allow full development of the kernel.
- Efficient pollination and foliar feeds to decrease leaf drop and stick-tights.
A tree can lose between 800 and 1 000ℓ of water per day due to evaporation, which is why an irrigation system can go a long way in insuring that each tree gets a minimum of 700ℓ per day. A safe guideline is to irrigate at least 60% of each tree’s canopy cover.
A crucial time for watering at Longacre is just before the nuts are harvested. It can be a tricky business, comments Philip, as the orchard floor should ideally be as dry as possible during harvesting.
Table 1: Pecan tree water requirements per South African region.
|Eastern region: Includes some areas of Natal, Mbombela and Makhado.|
|Annual requirement in m3 per hectare:||10 000|
|Daily requirement in litres per tree/day:||460|
|Central region: Includes Cullinan, Parys, Potchefstroom, Kroonstad, Ventersdorp, Klerksdorp and Bloemfontein.|
|Annual requirement in m3 per hectare||12 000|
|Daily requirement in litres per tree/day:||600|
|Western region: Includes Vaalharts, Hopetown, Douglas, Prieska, Groblershoop, Upington and Augrabies.|
|Annual requirement in m3 per hectare:||15 000|
|Daily requirement in litres per tree/day:||800|
Prospective pecan growers should realise that a lot of work goes into getting the trees to the production stage.
At Longacre, spraying typically starts in October and every two weeks thereafter, until the second week in January. Philip sprays macro- and micronutrients. “We don’t spray any insecticide. I believe once you start doing that, you’ll never be able to stop.”
Regarding pecan cultivation in general, the use of chemical products is only allowed when treating the following:
- Pests: Yellow pecan aphid, brown citrus scale, cottony cushion scale, various types of stink bug, bark borer and chafer beetles.
- Minor pests: White grubs and termites.
- Fungal diseases: Pecan scab, sooty mould and anthracnose.
It is generally advised that the effect that beneficial insects such as spiders, praying mantises, lady bugs and lacewings can have on pecan orchards, are considered before chemical products are applied.
A mindset and strategy
Philip remarks that anyone interested in cultivating pecan trees should not be expecting money to grow on it. “Starting out is expensive and can easily cost around R300 000/ha, with the expectation to start earning an income from the trees after a period of ten years.”
Concerning marketing methods, he likes to ‘think like an American’, meaning that the market as we know it was developed by Americans. “The only four regions in the world that are major pecan producers are North America, Mexico, Australia and South Africa, with China as the main importer of nuts worldwide.”
His currency preference is set on a fixed US dollar price. “The price for nuts is determined on a sliding scale in terms of nut size, namely over-sized, extra large, large, medium and small. The premium price is obviously set on over-sized nuts.”
He quotes his father, who used to say the following about pecan trees: “Luckily, pecan trees cannot read literature. Treat pecan trees like humans, with respect and care, and they will look after you.”
Although there are better and worse years in terms of production, he also believes that there will never be an overproduction of nuts.
First port of call
Philip’s advice for anyone who would like to sustainably cultivate pecan nuts, is to contact the South African Pecan Nut Producers’ Association (SAPPA). One of its main objectives is to supply correct information to the industry.
SAPPA is making substantial investments into proper research into pecan disease and insect monitoring, biocontrol development and water use. Technical staff also visit farms for inspections and take samples when needed.
“As board members we have identified the minimum requirements of what a pecan tree should look like,” says Philip. “This allows us to select the variety that will perform best in a specific area.”
The association is divided into nine different regions, with Region 5 representing the Eastern Cape. – Carin Venter, Plaas Media
For more information, contact Philip Antrobus on 082 560 7696 or send an email to email@example.com.