Use drought tolerant Portulacaria afra (spekboom) to combat desertification, e.g. for the Great Green Wall.

 

Photo credit: Google

Figure 3.1: Portulacaria afra Jacq. (spekboom) tree. Notice the skirt of rooted branches

Spekboom multiplication for combating desertification 

by Prof. Dr. Willem VAN COTTHEM

Ghent University (Belgium)

One of the most interesting African plant species used to combat desertification, limiting soil erosion, producing a dense vegetation cover and a remarkable number of small, edible leaves (fodder, but also vitamin-rich food for humans), is the Spekboom or Elephant’s Bush (Portulacaria afra).

This plant species is swiftly covering dry, eroding soils and should be recommended to all global projects for alleviation of drought, combat of land degradation and halting of wind erosion.

portulacaria_afra_nana
Portulacaria afra, variety nana, a hybrid variety easily covering dry soils (Photo credit Google: http://kumbulanursery.co.za/sites/kumbulanursery/files/styles/plant-large/public/plant_pictures/portulacaria_afra_nana.jpg?itok=YLJ5wknw)

My good friend Johan VAN DE VEN of Bamboo Sur was so kind to offer me some rooted cuttings.  These are growing very well in pots and PET-bottles in my garden in Belgium.

yaiza_playa_blanca_-_calle_la_caveta_-_portulacaria_afra_02_ies
Photo credit Google: Yaiza Playa Blanca – Calle La Caveta – Portulacaria afra 02 ies.jpg (https://upload.wikimedia.org/wikipedia/commons/a/a7/Yaiza_Playa_Blanca_-_Calle_La_Caveta_-_Portulacaria_afra_02_ies.jpg)

In order to study different ways  of multiplication of this Spekboom (with succulent branches and leaves), I started taking off small lateral shoots  (cuttings) and planted them in some potting soil in a cake box.  I also planted some of the succulent leaves (see my photos below).

Within the plastic cake box humidity is kept high (condensation of droplets on the cover).  Therefore, I opened the cover from time to time to let some fresh air (oxygen) in.

Quite soon both the cuttings and the separate leaves started rooting.  The cuttings swiftly developed some new leaves.   A month later I transplanted them into small plastic bottles, twice perforated 2-3 cm above the bottom (for drainage, keeping a small quantity of water at the bottom for moistening the bottle’s content and the rootball).

Once fully rooted within the plastic bottle, I cut off the bottom of the bottle to set the lower part of the rootball free.  Then I planted the young Spekboom in a plant pit without taking off the plastic bottle, sitting as a plastic cylinder around the rootball.  That plastic cylinder continued to keep the rootball moistened (almost no evaporation) and it offered  possibilities to water the sapling from time to time, whenever needed.  Irrigation water runs through the plastic cylinder towards the bottom of the rootball, growing freely in the soil (irrigation water directed towards the roots growing into the soil at the bottom of the plant pit).  Thus a high survival rate was guaranteed.

It is clear that multiplication of the Spekboom with rooting cuttings and leaves is very easy.  It is another interesting aspect of this remarkable plant.  I can only recommend a broader use of the Spekboom for reforestation, fodder production and even production of bonsais for enhancement of the annual income (export to developed countries).

Here are some photos of this experiment.

2010-04-06 : A Spekboom cutting planted in potting soil in a PET-bottle is rooting very quickly in my garden in Belgium. (Photo WVC)
2010-04-06 : Massive root development in the bottle, perforated 2-3 cm above the bottom. (Photo WVC)
2010-04-06 : Lateral shoots with succulent leaves (Photo WVC)
2010-04-06 : Small cuttings in the back (lateral shoots) and some leaves planted in potting soil in a plastic cake box. (Photo WVC)
2010-05-23 : Rooted leaves, an easy way to produce a huge number of plantlets of the spekboom starting with one single cutting (Photo WVC)
2010-05-23 : Rooted small cutting (lateral shoot), ready to be transplanted (Photo WVC)
2010-05-23 : Rooted cutting transplanted into potting soil in a plastic bottle,
perforated at 2-3 cm above the bottom (drainage). (Photo WVC)

—————-Considering that people working at the Great Green Wall in Africa (or any other interested group on other continents) are looking for practical solutions to cover as soon as possible huge areas of a desertified region, one is tempted to believe that setting up nurseries to produce a sufficient number of plants should not be a problem (as these plants only need a minimum of water).

variegated-elephant-food-portulacaria-afra-variegata
Variegated Elephant Food (Portulacaria afra) – (Photo credit Google: http://www.budgetplants.com/369-thickbox_default/variegated-elephant-food-portulacaria-afra-variegata-.jpg)

I keep dreaming of successes booked with this nice edible plant species in the combat of desertification.  The day will come that the Elephant bush will be growing in all the drought-affected regions of the world.  Animals will eat from it, but also malnourished children and hungry adults will find it an interesting supplement to their food.

2287a
Portulacaria afra – http://www.ladwp.cafriendlylandscaping.com (Photo credit Google: http://www.ladwp.cafriendlylandscaping.com/PlantMaster/Photos/2287a.jpg)
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Published by

Willem Van Cotthem

Honorary Professor of Botany, University of Ghent (Belgium). Scientific Consultant for Desertification and Sustainable Development.