Ban or breed?

I’m not sure I was aware of the fact that grasspea (khesari dal, or Lathyrus sativus) was actually banned in parts of India due to its toxicity. Devinder Sharma, a food and trade policy analyst, thinks the ban should not be lifted, International Year of Pulses notwithstanding. Instead, alternative crops should be promoted, such as pigeonpea (arhar, or Cajanus cajan). It’s interesting that there’s no Indian grasspea in the genebanks that Genesys knows about (red),1 in stark comparison to pigeonpea (blue).


Lathyrism is a problem in situations where grasspea is pretty much the only thing you have to eat. In former times, when famines were more frequent, the ban probably made sense. But is this still the case? And in any case there’s also lots of research going on low-neurotoxin varieties. A ban is hardly likely to provide much of an incentive for such breeding work.

  1. But then Genesys doesn’t have the data from the Indian genebank. Yet. []

12 Replies to “Ban or breed?”

  1. Lathyrism arises when people eat grass pea almost exclusively over an extended period of time. They do so only when they have nothing else to eat, as grass pea survives in drought situations rather better than almost anything else. Banning grass pea cultivation is thus tantamount to banning food in such situations. I can’t endorse such a policy. As tragic as this is, in drought years eating grass pea is not as harmful as not eating it for the poorest of the poor. In normal years grass pea makes a valuable contribution to diets, and to soil fertility. For the last two years I have grown 48 breeding lines of grass pea and a composite on my farm in upstate New York. It’s a great crop – highly nutritious and tasty too. Should I be prevented from growing it? Banning grass pea is not really the solution to lathyrism. The solution lies in raising agricultural productivity, alleviating rural poverty and specifically in developing low-toxin varieties. In this regard, ICARDA’s work is to be commended.

    1. Cary: You need to be very careful growing possibly poisonous plants: the toxicity can depend on the growing conditions and the season – for example, the crop could be stressed in upstate New York. Mrs Popenoe killed herself eating akee fruit, being grown experimentally in Honduras by her husband, the great plant explorer Wilson Popenoe. Mrs Popenoe was no fool: she was a skilled botanist – having been on the staff at Kew – and a top-flight archaeologist, having excavated the “Playa de los Muertos”. In several continents I used to de-tox tropical gardens for friends with children: lots of pretty ornamentals that were deadly.

    2. Dear Cary,
      I do not know if I have met/seen you sometime.
      I am happy to know that you have L.Sativus in your form at NEW YORK !. I get a few mails sometime from friends in the US as to where from they can get L.sativus . Is it possible that you might be able to supply L.sativus to interested people within the US ?.

      1. It might be possible after the next growing season, but there are several issues I would have to look into first. Stay in touch.

  2. Our current understanding is that sulfur amino acids have a protective role against the toxicity of grasspea, while the human body has a great capacity to metabolise the toxin.

    This detoxification can be monitored by analysing the urine of individuals eating grasspea.

    What we do not know is the genetic variation in human populations to metabolise the toxin(s) and corresponding genetic variation in sulfur amino acid metabolism.

    With a better understanding of the population genetics of grasspea toxin metabolism in combination with adequate supplies of dietary sulfur amino acids, low toxin varieties may become obsolete as a breeding objective, so that breeders can focus more on yield.

    One key step to make progress in this direction is the development of a suitable animal model to elicit neurolathyrism experimentally in order to assess the safe limits of grasspea consumption and the protective limits of sulfur amino acid supplementation.

    During periods of food shortage and forced subsistence on grasspea, supplemental food (cereals) is imperative to prevent neurolathyrism.

    I don’t think that the low toxin varieties of grasspea are going to pose any more threat to human health more than other pulses.

    Excessive consumption of pulses also induces sulfur amino acid depletion, so balanced nutrition appears to be the key.

    I agree with Cary that banning grasspea is not the solution to the neurolathyrism problem.

    Grasspea is a crop that grows where other crops cannot grow. It is a multi-purpose crop as it can be used as a forage to feed livestock and it also serves as human food. It has drought and water logging tolerance, requires very little agronomic input and is hence a low risk crop.

    Low toxin varieties need to be able grow under such conditions, but do they?

    The best way to find out is to release them to farmers for production. They are available and ready to be used commercially. A great deal of effort has been invested to develop them, so now, after long delays they should be given a go. They are at present a good option.

    If we can find safe ways to manage the toxicity of grasspea, then even toxic varieties of this crop could be developed for yield by utilising its tremendous genetic diversity to provide a low input profitable cropping option to help alleviate poverty.

  3. Dirk: You say: “Grasspea is a crop that grows where other crops cannot grow”. I think the current emphasis on grasspea has more to do with its inclusion as a Seed Treaty Annex 1 crop (all Lathyrus species). Other pulses in Annex 1 grow where “other crops cannot grow” – for example the Moth bean (Vigna aconitifolia – included in Annex 1 as “Vigna et al.” – and there are lots of crops here). I have seen V. aconitifolia growing on barely stable sand dunes in the Tihama of Yemen intercropped with pearl millet, the driest production system I have ever seen. And the messy mish-mash of Annex 1 crops leaves out another good pulse – fenugreek [Trigonella foenum-graecum], used in wonderful mutton stews in Yemen (I’ve never managed to get this right at home). Not only is fenugreek a good food but it also has a wide range of medicinal uses.

    1. Hi Dave,
      Thank you for the reference to Annex 1 of the Seed Treaty.
      I’d stay away from using fenugreek as a staple (Ataxia and deaths occurred in sheep grazing fenugreek [Allden, W. G. and P. E. Geytenbeek (1980). “Evaluation of nine species of grain legumes for grazing sheep.” Proc. Aust. Soc. Anim. Prod. 13: 249-252.]

      Grasspea (Lathyrus sativus) as a crop has its niches ie. through pea weevil resistance, drought tolerance, ability to grow in mud after floods, low input requirements, wide adaptation (adaptability due to outcrossing).
      Mitchell (1971) has an informative summary of its agricultural aspects [see pp 35-39] and Chaudhuri et al. (1963) explain its role after floods.

      Mitchell, R. D. (1971). “The grass pea: distribution, diet, and disease.” Ass Pacific Coast Geogr Yearbook 33: 29-46.

      Chaudhuri et al. (1963) reported on the crippling
      effect of grasspea seeds harvested from crops that grew luxuriantly
      after floods, in fields covered with thick deposits of silt and
      sand. The mud from the floods prevented the seeding of other food
      crops, so people adapted by subsisting on grasspea with devastating results.

      Chaudhuri, R. N., et al. (1963). “Lathyrism: a clinical and epidemiological study.” J Indian Med Assoc 41: 169-173.

      1. Dirk: I’m not a sheep – I loved fenugreek mutton stew. The problem with growing low-toxicity anything is keeping the seed supply entirely controlled (impossible in developing countries). Just one mistake or one introduction of a toxic line and everything falls apart: farmers cannot tell toxic from non-toxic in the field (or can they??) and the seed production from then on is contaminated. One might even suspect (as with toxic cassava) that the toxic lines had some evolutionary advantage under biotic stress, more or less self-evident.
        I am very interested in the Chaudhuri et al. with grasspea growing luxuriantly after floods to the exclusion of other crops. This exactly fits with my ideas about crop origins – growing in natural monocultures in conditions where no other higher plant species could grow (with people gladly eating the resultant seed). Fire and, as here, flood are the obvious selective pressures that gave us our crop monocultures – farmers knowing their ecology better that agroecologists.

  4. Dear DR Enneking,
    It is about 5 Years since I started Having L.sativus
    in my daily diet (25-30 gms per day) first thing in the morning.
    I take it because of Homoarginine in it. It really Helps.
    You can call Khesari dal “WHOLE BODY VIAGRA ”
    What with ODAP activating PKC and downstream events and
    homoarginine increasing NITRIC OXIDE LEVELS you can`t expect more from a Nature`s Gift !
    Do eat Khesari dal ( L.Sativus every day)
    All the BEST

  5. Dear Dr Enneking,
    I was associated with the ICMR in all their meetings during the last 4-5 years.
    They have arrived at the right decision and I am glad that this will go a long way in giving this downtrodden its due place. I don’t like people Blaming Nature. I give herewith a link wherein I wrote my vies on khesari dal. It is available online.

    All I want to say are there.

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