SHOULD A FOOD AND FODDER PLANT ALWAYS BE CALLED AN INVASIVE SPECIES ?

 

Photo credit: OPUNTIA BIOGAS ELQUIGLOBALENERGY P9270040_2 copy

Huge plantations of spineless prickly pear for production of biogas.

HOW DO WE REACT IF A FOOD AND FODDER PLANT IS CALLED AN INVASIVE SPECIES ?

THE INVASIVE PRICKLY PEAR CACTUS (OPUNTIA FICUS-INDICA), NATURAL FOOD WITH  MEDICINAL PROPERTIES ?

By Prof. Dr. Willem VAN COTTHEM (Ghent University, Belgium)

2006-12-opuntia-04_2-algiers
2006-12 – Algiers – Spineless Opuntia in a garden is easily handled (Photo WVC Opuntia 04-2)

 

Opuntia ficus-indica (L.) Mill., the Indian fig opuntia or barbary fig is generally known as “the prickly pear cactus”.  

It is an evergreen, cold-tolerant, dense, massive, tangled, trunk-forming (to 15 ft, 5 m), segmented cactus of arid and semi-arid regions, possibly native to Mexico, but a domesticated crop species on all the continents.

It grows with flat, disklike, edible paddles, generally armed with sharp, hard spines and small, hairlike, easily detached (washed off) prickles (glochids).

On all continents there is also a variety (var. inermis) without the hard spines and thus more easy to handle.

The plant is commercially grown as a fruit crop for its large, sweet fruits (the tunas, beles, ficudinnia) and for its young green paddles (cladodes), called nopales.  Mexican natives have used this food for thousands of years.

imagesnopalitos
Edible nopalitos (Origin of the picture unknown)

FOOD and CULINARY USES

Young paddles (nopales) are sliced into strips and eaten with eggs or chili peppers (huevos and tacos).  These are very successful dishes in the Mexican cuisine.

All over the world, fruits are eaten either raw (after washing or burning off the glochids) or as jam and jelly.

The fresh fruit pulp contains vitamin C and betalain pigments with antioxidant properties.  Consumption of prickly pear fruit decreases oxidative damage and improves the antioxidant status in healthy humans.

Extracts are used in pharmaceutical and operational food industries.

In some countries, people use it to make non-alcoholic punches (aguas frescas), or alcoholic wines and liqueurs.

foc340_1
Farmers prefer to cut the cactus into smaller pieces and supplement with hay or straw. ICARDA – http://www.new-ag.info/en/focus/focusItem.php?a=340

FODDER (https://youtu.be/xsnBWBIek2g)

Cattle is not eating the paddles for their sharp spines, but these can be burned off.  Pads (paddles) are a useful feed supplement in the drylands because of their moisture content and food value.

It goes without saying that the paddles of the spineless variety (var. inermis) constitute an extremely interesting fodder for a lot of animals, particularly in the drylands (http://www.new-ag.info/en/focus/focusItem.php?a=340).

Dried pads or strips thereof can be ground.  Cactus meal can also be used as feed supplement.

MEDICINAL USES (https://www.drugs.com/npp/prickly-pear.html)

Prickly pears have been carried on ships to prevent scurvy. The fruits are a dietary supplement to decrease oxidative stress or to increase low blood lipid levels. Fruits without seeds are used as a laxative.

Opuntia contains many alkaloids.  Stems are antispasmodic, diuretic and emollient.

The flowers are astringent, used to reduce bleeding and to treat gastro-intestinal tract problems, especially diarrhea, and an enlarged prostate gland.

An extract of the prickly pear plant has a moderate effect on reducing hangover symptoms, apparently by inhibiting the production of inflammatory mediators.

DYE PRODUCTION (https://en.wikipedia.org/wiki/Cochineal)

A sessile, parasitic, scale insect (Dactylopius coccus) lives on Opuntias and produces carminic acid.  Extraction of this acid from the insect’s body and eggs leads to the production of the cochineal red dye for food colouring and cosmetics, a very valuable export product.

kenya-bof-research-002_2
Opuntia in a hedgerow – Photo Kenya – BOF Research 002_2.JPG

HEDGEROWS (CACTUS CURTAINS)

Opuntia ficus-indica forms dense, tangled, bushlike structures, used as barrier hedges (hedgerows).

BINDING MATERIAL IN ADOBE

It is used as a binding and waterproof ingredient in adobe, a natural building material made from sand, clay, water, and fibrous or organic material (sticks, straw, and/or manure), shaped into bricks.  Cactus juice from paddles and stems is commonly used as an additive to “earthen plaster”.
IS THIS CACTUS A REAL PEST ?

 

The prickly pear cactus covered with spines is generally considered as a noxious weed, an invasive pest species, because its uncontrolled growth causes ecological damage.

However, the question remains if this is also the case for its spineless variety (var. inermis).

Considering that “nopales” (young Opuntia pads) are commonly eaten as a vegetable in Mexico, Brazil and other S. American countries and that in this part of the world thousands of hectares are cultivated as “nopales plantations”, it becomes difficult to keep this spineless variety classified as a noxious invasive species.  In these countries, a real cactus industry has developed that seemingly does not harm the local ecology at all.

As this cactus grows remarkably with a minimum of water, one could wonder if the introduction of the spineless variety, with all its positive characteristics and advantages listed above (food, fodder, medicinal uses, adobe, hedgerows, …), still has to be considered as a factor causing ecological damage in desertlike environments.

Here is an interesting challenge : would it be preferable to keep the mostly barren, non-cultivated soil uncovered and submitted to erosion or would one rather opt for using this spineless cactus variety to :

 

  • Cover large parts of the barren soil with living, edible plants (see nopales);
  • Grow hedgerows around small gardens;
  • Create natural anti-erosion barriers;
  • Offer juicy fodder to the cattle.

 

 

Looking forward for comments.

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See also:

https://docs.google.com/document/d/1iDsE7wC3-tLrbvYsqYe5t4VUEWekaGpdy27rV0p25_A/edit?usp=sharing

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Published by

Willem Van Cotthem

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