Pioneering almonds In the Northern Cape

– Sanette Carrick 

It’s misty with thick fog on our way to Okkie Vermeulen and his co-partner Chris van der Post’s farm, Disselfontein, just outside Hopetown, nearby Kimberley. This team are doing groundbreaking work with their almond crop and we popped in to learn more about their work. Jaco Nolte of Agrico Kimberley is the project’s irrigation designer and Jaco joined us in our quest to learn more about Almonds in the Northern Cape. 

The beginning

Okkie and Chris wanted to plant a nut crop that will adapt and flourish in the specific environment with its extreme temperatures, and, at the same time, is in demand in local and international markets. After months of research and agronomic visits, soil analyses, planning and eventually designing the system, they took the chance and planted 54ha under almonds. Several trial blocks have been planted where different evaluations are carried out with, among others, tree spacing, feeding, fertilizer programs and many more. 

Jaco Nolte designed a micro and drip irrigation system. The micro system has a dual purpose in the design. It is used to create in the orchard a softer, more tropical climate for the trees during pollination and then also for frost protection during the cold months in the orchard. By placing the sprayers higher than the trees, frost management and cooling are applied. 

 The temperatures in a 54ha orchard can fluctuate to 3°C in several places and this results in the need to protect the small fruit from frost after pollination, which means that the tree row is constantly irrigated. Thus, a thin layer of ice forms around the fruit that keeps the temperature at freezing. The ice sheet must be washed off all the time to prevent ice build-up. The cost challenge is to have a well-designed system where the entire orchard can be irrigated at the right precipitation rate, simultaneously.

What does frost control mean and how can provision be made? 

Effective frost control is based on applying different principles, each of which will contribute to reducing the risk of cold damage. 

These include: 

  • Chris planted the trees on banks (ridges) that help with optimal root development and contribute greatly to tree health. Healthy trees are more resistant to the cold. 
  • Regular irrigation of the banks absorbs energy from the irrigation water and can release as much as 2°C of heat (BTU) from the damp soil surface into the atmosphere, providing an elevated minimum temperature around the fruit. 
  • Ensuring that drainage as well as build-up of cold air can be optimal. Cold air drains in the same way as water. Remove obstructions as well as unnecessary ground cover that can negatively affect drainage. 
  • Continuous overhead irrigation on the target area during extreme cold, to protect the flowers and fruiting from frost. 
  • The planting of various cultivars with different flowering and fruit set dates that ensure risk is spread. 

Part of Jaco’s design includes an additional drip irrigation system for a later phase of the development. The drip system will be responsible for feeding and irrigation, with the microsystem used for cooling and frost control. 

The Nonparell cultivar

Chris and Okkie looked for a cultivar that will adapt well to the specific area, hence their choice to plant Nonparell.  Almonds are all about colour, taste and texture. Nonparell is the sweetest almond with a pretty golden brown colour and a powdery texture. The cultivar also blooms three times per year, is self-pollinating but responds well to cross-pollinators. Along with Nonparell, a series of cross-pollinators were planted, this also reduces the risk and ensures the sustainability of the project. 

Originally, the trees were planted 2m in-the-row with rows 5m apar t. High density plantings of 1x5m orchards are also evaluated.

The almond tree is pruned only after planting for ideal tree formation. The branches are very soft and flexible and as the tree grows and produces nuts, the effective penetration of sunlight is promoted. Optimal vegetative growth is stimulated. When the tree branches become too heavy due to the harvest load and begins to bend downwards, the trees are tied up for reinforcement and to ensure that the branches do not break. 

Flowering and harvest time

Flowering and pollination times are around September, although the cultivar is self-pollinating, Chris also uses their bees to improve pollination. Harvest time usually occurs around March. A “shaking machine” is used with a net that goes around the tree’s trunk and then shakes the tree so that the nuts fall off. With the high-density orchards, a press machine can also be used that runs over the top of the trees and collects the crop. A large almond weighs around 1.2grams. 

Why almonds?

According to Chris, almonds are a commodity with a wider market than pecans. Almonds are used not only in nut form but also processed into flour, milk and beauty products. The price is also more stable, and of course, the South African market is not yet saturated, there is still great demand for the product. Of course, they also are also considering the export market, particularly seen as though California, a producer of almonds, is experiencing serious water shortages. Indeed, California produces 82% of the world’s almonds. 

More about the design

Chris and Okkie wanted a system which enables them to enjoy full control of their orchards. To make this possible, Phillip Kleinhans and Hein Venter of Agriplas inserted a Nutricontrol system, which it makes it possible for the farmers to control the system on their mobile phones and computers. 

The Nutricontrol system controls the on-and-off switch of pumps, the flushing of 16 sand filters, volumetric fertiliser application and 17 field or hydraulic taps. Everything is controlled through Agriplas RX receivers, as well as a water meter which is essential for effective resource management. Agriplas Gulf Micro Sprinklers are used for cooling and frost control. 

The idea is to add a weather station to the system later, as well as bet ter control of fertilizer programs. 

For any technical enquiries, Wimpie Maree can be contacted at Agriplas (wmaree@agriplas.co.za) or Jaco Nolte at Agrico Kimberley (jaco.nolte@agrico.co.za). 

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