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Are Artemisia annua plantations killing fields?

November 5, 2014 - 18:29 -- Pierre Lutgen

Artemisia annua has strong allelopathic properties as was documented by Mediplant for the high artemisinin hybrid. In other words the plant becomes invasive and inhibits the growth of other plants or cash crop on fields where Artemisia has been planted for the extraction of artemisinin by Bigpharma.

With WHO's blessing Keasling's synthetic artemisinin replaces the natural product: an economical disaster for African families who have invested all their meager resources in Artemisia annua plantations, lured by the promise of big profits.

Not only are they now confronted by poverty, but also by hunger and starvation. Their fields have become sterile.


Submitted by Pamela Weathers (not verified) on

Artemisia does not kill other plants. We have done field trials showing that here in the US. Furthermore, I several years grew A. annua in my vegetable garden and subsequent crops grew just fine afterwards. These were all vegetable food crops. We had tested the tillage of dried leaves into the soil to see if they might have an herbicide effect. They did not. The leaves acted more like a green fertilizer. Report is at this website:

Submitted by Marc Vanacker (not verified) on

Message received from a resident in Tananarive
"Yes, all the small farmers in the Tana area have cancelled their business relations with Bionexx because they noticed that alternating rice plantations with Artemisia had become a catastrophic failure, with yields 50pct lower than traditionnally. The soil of their farms is poor, lixiviated and they don’t have enough resources to buy fertilizers. Bionexx is now growing A annua on a large farm they have recovered from the Libyans who had received it in exchange of petrol. But Bionexx knows that they will be confronted by the same problem of allelopathy and fertility and they are switching to quinine plantations on the East coast.
In Madagascar this disastrous allelopathic effect of A annua plantations is known to everybody."

Submitted by Charles Giblain (not verified) on

Dear M. Vanacker,

I am more than stunned by your comments on our activities which are completely false and misleading. Please contact me at your leasure I would more than willing to have a face to face discussion with you on this topic. There are excellent studies undertaken in Switzerland on the topic of artemisia annua allelopathy which has been known for a long time. I can send them to you if you wish. regarding farmer reaction in Tana this is a bit ridiculous as we have never had any substantial acrage in this region (20 hectares) in comparison to the 2500 hectares that we have in cultivation with 10 thousand farmers in the other regions. Year after year the rice crop yields of our farmers grow not because of artemisia cultivation but because of imposed fertilizing techniques. I could go on and challenge what you have written but would much prefer a direct discussion with you. I can be contacted at
Looking forward to your reply
Best regards,
Charles Giblain

Submitted by Marc Vanacker (not verified) on

A very recent paper from Iran (MH Bijeh Keshhavarzi et al, J Biol & Envir Sci. Nov 2014) describes the allelopathic effects of Artemisia annua on lettuce Lactuca sativa. The aqueous extract on an outside plot significantly reduced germination percentage and rate, fresh and dry weight.

Another paper (Seyed Mohsen et al., Annals of Biological Research, 2011, 2-6, 687-69) describes the allelopathic effect of Artemisia annua aqueous extracts on vegetables and plants like Portulaca olearcea (pursley), Chenopodium album (goose-foot), Avena ludoviciana (oat), Plantago ovata (plantain). For the latter the effects are noticeable on germination percentage, germination rate, plumule length, radicle length, wet weight, dry weight.

A Chinese paper (Shen He et al., Ying Yong Sheng Tai Xue Bao. 2005 Apr;16(4):740-3) had previously studied the allelopathy of different plants. Artemisia annua affected the seedling height and fresh weight of radish, cucumber, wheat and maize around 50%.

Submitted by Nathalie Dommett on

I think the the issue is that A. annua does not belong to a large scale mono-culture which is economically advantageous but ecologically non-sensical. A. annua is a medical plant that belongs in a medicinal garden, problem will arise in a large scale crop. Same thing is happening in China with Rehmannia glutinosa, another major Chinese medicinal plant.