Prosopis juliflora : stopping soil erosion, invasiove, toxic, good for charcoal (Google / allAfrica)

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Kenya: Toxic Plant Can Be Black Gold

Muchemi Wachira

3 August 2011

Almost four years have passed since a toothless goat was produced in court and the Government was ordered to investigate the damage caused by the Mathenge shrub.

And now the people most affected by the poisonous plant are being asked to turn to burning it for charcoal in order to make a living.

The High Court in 2007 obligingly declared Mathenge a poisonous plant, ordered the Government to destroy it, and instructed a commission to be set up to recommend the level of damages payable as compensation.

The case, which the Ilchamus community from Marigat took on the Government, created much interest especially when the Ilchamus took a toothless goat to court to show the damage the plant had caused. The goat, they said, had lost its teeth after eating the plant.

Yet although it was hailed as a huge victory for the community, their lawyer Thomas Letangule commented, “it was only a victory on paper since nothing has been implemented.”

Mathenge, which botanically is called Prosopis Juliflora, was introduced by the Food and Agriculture Organisation (FAO) jointly with the Government in 1983.

It was intended to curb soil erosion and desertification in arid and semi-arid areas of the county like Marigat.

“The intention was good as the shrub stopped soil erosion but what the Government failed to do is to carry out proper research on its side effects,” explained Mr Amos Lempaka who led the community in suing the Government.



The danger of the aliens : invasive foods crops in the drylands (Willem Van Cotthem)

As a plant biologist, I wonder why we accept that cargo vessels full of bulk food (wheat, corn, rice, bananas, … ) import tons of seeds of weeds, mice, rats, insects, spiders, bacteria, viruses etc., while one is shivering as soon as someone sends an envelope with carefully washed and dried seeds of a clean papaya, melon or watermelon to help hungry people in a developing country to fresh food or fruits.

What do we import with our luggage, our clothes, our shoes, when our airplane lands in a foreign country?

“One single avocado seed could destroy a country’s ecological balance.  A handful cherimoya seeds are ecological bombs. Invasive dragonfruit seeds could destabilize the national fruit market.

I hope to see once in my life time (only a couple of years left !) invasive tomatoes, carrots, onions or beetroots taking over the waste dumps or barren soils in the drylands.  It would be a remarkable, “maybe dangerous” step in the combat of desertification.

Invasion of the Algerian Sahara by zucchinis, red beetroots, carrots, watermelons, etc., grown from "foreign" seeds (Photo WVC)

What a catastrophe that would be.  The malnourished people should be enlisted to fight the invaders !

No Sir, it’s the law !

Conflicting pieces of evidence about invasive plant species (Science Daily)

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Are Invasive Plants a Threat to Native Biodiversity? It Depends on the Spatial Scale

ScienceDaily (Apr. 11, 2011) — The phrase “invasive plant species” typically evokes negative images such as broad swaths of kudzu smothered trees along the highway or purple loosestrife taking over wetlands and clogging waterways — and as such, invasive plants are largely viewed as major threats to native biodiversity. However, research has shown both that invasive species may be one of the most important threats to biodiversity and that plant invasions are rarely the cause for native species extinctions. How can these conflicting pieces of evidence be reconciled?


Invasive plant species are taking over millions of hectares of African farmland and grazing fields (New Agriculturist)

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Invasive species threatening African agriculture

Written by Maina Waruru

Invasive plant species are taking over millions of hectares of African farmland and grazing fields, reducing Africa’s crop yields by an average of 30 percent annually and costing farmers hundreds of millions of dollars in losses. “There has been very little research into the impact of these weeds in Africa despite the fact that they have invaded millions of hectares of land and are still spreading,” explains Arne Witt, head of the Invasive Species Programme at CABI Africa. “Some invasive plants such as Parthenium can reduce yields of crops like sorghum by up to 97 per cent in unmanaged lands.” Invading weeds are also displacing indigenous vegetation in natural pasture, and are posing a threat to biodiversity conservation in Protected Areas. However, only a handful of governments in Africa have developed national action plans or committed funds to fight these species, which are affecting millions of landowners.

South Africa is the only country in Africa with a comprehensive long-term programme aimed at containing and managing the spread of invasive plant species. But despite investing more than US$60 million every year, Witt warns that this level of investment is still inadequate considering that more than ten million hectares in South Africa have been invaded. CABI has just completed a UNEP-GEF project in Uganda, Zambia, Ethiopia and Ghana, where, in collaboration with national agencies, it strengthened policy, increased awareness and built capacity to manage these species. “While these governments have committed funds to manage the weeds, a lot remains to be done,” Witt adds. “Governments need to invest more and – even more importantly – implement policies.”


Climate change affects weeds (Science Alert)

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Climate change affects weeds

Tuesday, 18 May 2010


The report: Climate Change and Invasive Plants in South Australia, used climate projections to 2080 to examine how weeds may shift in range across the State. Detailed profiles are provided for 13 weed species, including options for managing them under climate change.

Lead-author, Dr Darren Kriticos from CSIRO’s Climate Adaptation Flagship, said projections of future climate scenarios indicating higher temperatures and less rainfall on average in South Australia could have a dramatic effect on the distribution and abundance of weeds. Continue reading “Climate change affects weeds (Science Alert)”

Are newly introduced vegetables and fruit trees dangerous ? (Willem Van Cotthem)

Since August 2007, the time that we launched our action ‘SEEDS FOR FOOD’ (, a number of people came up with questions about the danger of introducing new vegetables and fruits in developing countries.

We have already replied to these ‘interrogations’ in a couple of messages:

(1) Invasive vegetables?  Could they create problems? (Adam STUART / Patrick HARRY / Willem VAN COTTHEM)

(2) A convenient truth for combating hunger and desertification (Willem Van Cotthem)

Today, I like to bring to your special attention an article published by African Agriculture:

US farmers find opportunity in vegetables newly introduced by immigrants

Let me highlight some paragraphs:

  1. Maxixe, a Brazilian relative of the cucumber, is relatively unknown in the U.S., but it may one day be as common as cilantro as farmers and consumers embrace more so-called ethnic vegetables.
  2. Agriculture experts ……………are teaching farmers to grow non-native vegetables that appeal to a growing market  ……………. And as other customers become more familiar with ethnic foods, experts expect sales to grow even more.
  3. The number of Massachusetts-farmers markets that carry ethnic vegetables jumped by 25 percent in a year, ………………….
  4. Sales of ethnic vegetables have benefited from “buy local” marketing campaigns and federal farm legislation giving states grants to expand specialty crop production, …………………… There’s also been a greater emphasis on marketing specialty vegetables,
  5. ………. cilantro was considered a specialty item 25 years ago, but “now it’s on everything.” Bok choy, a Chinese cabbage, also was once considered exotic. “Now, it’s another leafy green,” ………………..
  6. His association helps Hmong, Kenyan, Mexican and other immigrant farmers adapt to U.S. agriculture and introduces them to local markets where they’ve been able to sell growing amounts of mustard greens, beans and other ethnic crops. “We see a huge demand for it across the board, from restaurants to small stores, big stores and farmers markets,” he said.
  7. With maxixe …………….., they grow chipilin …………….., a legume from Mexico and Central America; jilo …………. , an eggplant-like crop grown in Brazil and West Africa; and hierba mora ……………., a member of the tomato family.
  8. Even if farmers grow only a few ethnic crops, they benefit by having a greater variety that reduces the likelihood of serious financial problems if one or two crops fail, ………………..
  9. …………… ethnic crops represent a small share of what they grow compared with such items as sweet corn, pepper and cucumber, but that could change as immigration increases. “I don’t know if it’s going to be as big as summer squash or zucchini, but as the market evolves it will be more important,”…………….
  10. It also works with farmers to spur production of vegetables that have caught on with consumers, who’ve read about them or tried them in restaurants,………………….
  11. “Farmers are always interested in new and unique things. They’re interested in things that can make it to market.”
  12. “You’ve got to be careful about the products you grow because you may not have the market to support it.”

Malawi: Container gardening project of Patrick HARRY. Thanks to 'Seeds for Food', children are nowadays growing new vegetables and fruit trees in all kinds of containers.

Having read all this, we come to the following conclusions:

  1. If farmers and consumers in the US (where regulations for import of ‘foreign’ plant materials’ are extremely severe) are allowed to ‘embrace more so-called ethnic vegetables‘, why would smallholder farmers, with the help of international organizations an/or NGOs, not embrace well-adapted ‘new’ species of vegetables and fruit trees, e.g. by getting offered free seeds?
  2. If agriculture experts in the US are teaching farmers to grow non-native vegetables that appeal to a growing market, why can the experts in developing countries not take the lead to enhance the marketing chances of poor smallholder farmers.  Their organizations could easily, and at the lowest costs, provide the necessary quantities of seeds.
  3. If in the US other customers become more familiar with ethnic foods and experts expect sales to grow even more, why wouldn’t this bed the case in Africa, Asia and South America?
  4. If the already saturated Massachusetts farmers markets that carry ethnic vegetables jumped by 25 percent in a year, what could be expected for the markets in developing countries, where almost every woman sells the same vegetables and fruits at the same moment of the year, thus keeping the prizes low.
  5. Why would these smallholder farmers and their women not be able to sell ‘specialty products’?
  6. If a ‘specialty 25 years ago in the US’ could become ‘just another leafy green’, this can also happen in the developing countries.
  7. Associations in the US helped farmers to adapt to U.S. agriculture and introduced them to local markets where they’ve been able to sell growing amounts of crops. If we really want to combat hunger, child malnutrition and poverty, let our international and non-governmental organization make a priority of introducing ‘new’ vegetables to local markets, e.g. by concentrating first on the most drought-tolerant ones.
  8. Farmers growing only a few new crops would benefit by having a greater variety that reduces the likelihood of serious financial problems if one or two crops fail.
  9. Newly introduced crops represent a small share compared with the classical ones, but that could change, as people get accustomed to the new crops. “I don’t know if it’s going to be as big as summer squash or zucchini, but as the market evolves it will be more important,”.
  10. Smallholder farmers, wherever they live, are always interested in new or unique things that can make it to market.  Why wouldn’t they be able to spur production of vegetables that have caught on with consumers?
  11. Of course, they have to be careful about the products they grow, because the market to support it may not exist.  But isn’t that an interesting task for the international and national agriculture experts, assisting those farmers?

My answer to the question ‘Are newly introduced vegetables and fruit trees dangerous?‘ is therefore a categorical NO.

And, by the way, once potatoes, tomatoes and maize were ‘new’ vegetables or fruits on our market, didn’t they?

We are looking for support for our action ‘Seeds for Food‘ in order to help the smallholder farmers, if not all the hungry people of this world, to decent daily meals with a lot of safe, hazardless, reliable, trustworthy, harmless, healthy fresh vegetables and juicy fruits.

To produce climate-resilient food crops or to use existing ones (Willem Van Cotthem)

I have been reading a very interesting publication at IRINNEWS :

AFRICA: Finding the food crops of the future

(see my former posting and

If it ever occurs, climate change could make that classical staple foods can’t be grown anymore in the same climatic zones.  People would need to grow other crops. In our own country, which would be the food crops of the future? What kind of options for continued food security will we have?  Do we need scientists to do years of research work on climate models linked to agriculture and horticulture to determine which will be the crop yields in the future?  Or can we use existing climate-resilient crops in a ‘new’ environment created by the impact of climatic changes on the existing vegetation?

Some scientists believe that intensive research work is needed to produce these ‘new’ varieties of food crops, e.g. drought-resistant ones.  Models are already used and still perfected.  Some believe that experimenting with these models, or with genetic modification of existing food crops, ‘will save the time that would have been spent on field trials and help speed up the agricultural research cycle’ (see Jennifer OLSON in the article mentioned above). Therefore, highly estimated institutions provide extremely important research grants to encourage such ‘innovative solutions’.

I fully agree with Jennifer OLSON that ‘bioscience can improve crop resilience to climate change, or perhaps improve the shelf-life of a food product’, but I want to express my serious doubts about the necessity to spend millions of dollars on developing ‘new’ varieties of climate-resilient crops, when in nature one finds a considerable number of species and varieties of plant species that can successfully be introduced in regions or countries affected by climate change, e.g. drought-stricken areas.

It suffices to accept that under the new conditions these drought-resistant plants, having a high nutritional value for men or livestock, can be shipped as seeds from elsewhere to become the ‘new’ staple food.

If we can’t grow maize (corn) anymore, but another, less water-consuming cereal, why should we stay hungry?  If our region is not adapted to olives, oranges, almonds, papayas, bananas etc., why would we hesitate to choose other already existing fruits from other climatic zones?

It is my most sincere conviction that Africans can be perfectly happy with food crops now growing in Asia or South-America and vice-versa.  I also believe that we should pay more attention (do some rather inexpensive research work) on opportunities to introduce Asian or South American food crops in the African drylands or the other way around.

Do we need to fear invasive species ? Let someone explain first to us what would be an ‘invasive’ food crop.  Would it become a noxious weed?  Would we have to destroy it or eat it?

I leave that discussion open for now, trusting in the fact that if the Brazilians in their ‘Nord-Este Province’ have enormous plantations of the spineless prickly pear cactus (Opuntia ficus-indica with edible fruits and green disks that can be used as fodder, etc.), my good friends in the Sahelian countries or even in the Sahara desert would be bewildered if they could get a good opportunity to set up such plantations in their drylands.  Invasive species ?  No way, because the spiny prickly pear grows all over that part of the world.  Too expensive?  No way, because it suffices to put a disk in the dry soil to see it shooting.

2007 - Spineless prickly pear (Opuntia ficus-indica) growing in Algeria.

2007 - Spineless Opuntia ficus-indica is well-known as a drought-resilient species, producing huge biomass with a minimum of water, producing juicy fruits and green fodder for livestock. It should be planted in all the drylands.

This Opuntia is only one single example of a drought resilient species or variety that should be dispersed all over the desertified world, where it can help people to eat some fruits or give some fodder to their livestock.

Being a scientist myself, I have no hard feelings against enormous grants given to research work.  But accepting that research work must go on, I can’t stop dreaming of extremely inexpensive research work to disperse ‘all good things’ that Mother Earth is offering us today.

Everytime I am reading about the fantastic qualities of one or another plant species or a variety, I am dreaming about the possibility to use seeds or parts of that plant to improve the living conditions of all the people who don’t have the chance to profit from this exquisite species.  This way, my action ‘Seeds for Food’ was born. Whenever you have a chance to let a melon grow in the drylands, go out there and look at the eyes of a child when it bites for the first time in such a juicy fruit.

Why would we hesitate to send all the seeds of the melons we consume to climate zones where they can grow?  Why don’t we offer those rural people, or even the people in cities or towns in the drylands, a chance to grow avocado trees (Persea americana), tomato trees (Cyphomandra betacea), cherimoyas, spekbooms, pitayas or dragonfruits, …

Knowing that all these ‘goodies’ are already there, we do not have to wait for the results of years of research work.  We only have to take the decision to spread the ‘goodies’ around, of course in a well-organized way, e.g. as seeds.  That’s what ‘organizations’ are set up for.

To produce climate-resilient food crops or to use existing ones, for me it is no question anymore.


Read at : UNNews


New York, Nov 11 2009 10:05AM

It’s no longer than a grain of rice. But the mountain pine beetle is an insidious environmental predator, laying waste to swathes of forest in north-western Canada and exposing the local ecosystem to what could be a devastating new front in the battle against climate change.      The beetle is one of hundreds of what scientists call invasive species – animals, plants and organisms that “arrive, survive and thrive” in previously inhospitable territory and damage their host environment.      Now, as global warming alters temperature and precipitation patterns around the world, the threat posed by invasive species is rising, and scientists and United Nations officials are calling on participants at next month’s climate change conference in Copenhagen to agree to action to strengthen their ecosystems and to protect biodiversity.     Continue reading “INVASIVE SPECIES POSE HUGE THREAT TO ECOSYSTEMS (UNNews / CBD)”

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