Wednesday 25 November 2009

feeding on bacillus: Classic example of Bt- brinjal

Do you know?

India is the Centre of Origin for Brinjal or Eggplant. It has been cultivated in India for the last 4000 years,grown all over the country, year-round and cultivation is estimated to be around 5 lakh hectares, total production of around 82 lakh metric tonnes with productivity of 200 to 350 quintals per hectare.

Now, lets see what is this Bt- issue all about? Bt- i.e bacillus thurengenesis gene isolated and incorporated into crop's genes so as to make the crop resistant towards certain pests. Oct 14, 2009 , genetic improvement and approval comittee (GEAC) cleared the release of bt-brinjal which has been promoted by MAHYCO along with TNAU, coimbatore and UAS, Dharwad. Looking into the current scenario of brinjal cultivation, it has been noticed that around 30-45% of produce is being infested by fruit and shoot borers. And the new technicals deviced, costs around 900-1200 INR, so a layman like me is unable to calculate the efficiency of these chemicals. And if we go through the claims of Bt- brinjal promotors, Bt- crop seems to be a viable option. According to them, it will reduce the loss due to borers upto 70-85% and simultaneously will improve productivity, hence incresing the net profitabilty of farmer. and will also reduce the cost of highly priced chemicals. Answering the concerns of human health and environment ,they claim there have been no significant difference between bt and non bt brinjal cultivation for biosafety tests like acute oral toxicity, sub chronic oral toxicity in rats, allergenecity of proteins to rats, germination, weediness and agressiveness test, soil - micro biota studies etc.

That is- WIN-WIN situation for farmers.

But then i keep on scratching my head, why there is such an uproar against Bt-crops. further, Ddgging deep into some of the research reports, the facts that i encountered were,

Several studies on Bt crops show that there are many potential health hazards in foods bio-engineered in this manner. GM-fed animals in various studies have shown that there are problems with growth, organ development and damage, immune responsiveness and so on. With Bt crops, a recent study from Madhya Pradesh in India shows adverse human health impacts in farm and factory workers with allergies caused by Bt Cotton. Itching skin, eruptions on the body, swollen faces etc., were also reported, correlated with levels of exposure to Bt Cotton.
A study from Phillippines shows that people living next to Bt Corn crop fields had developed many mysterious symptoms, especially during pollination time.
It has also been shown from studies elsewhere that genes inserted into GM food survive digestive processes and are transferred into the human body. They are known to have transferred themselves into intestinal bacteria too. Bt toxin had caused powerful immune responses and abnormal cell growth in mice. It has also been shown that all the Cry proteins in Bt crops have amino acid sequence similar to known allergens and are hence potential allergens.
Now, concerning environmental issues,
Resistance development in the target pest is predictable and therefore, even the companies promoting Bt Brinjal are already talking about resistance management. They say that a structured refuge of 5% of non-Bt Brinjal is needed as a strategy for resistance management.
There have not been adequate tests done to assess the changes to the farm level ecology or stress intolerance of Bt Brinjal. In the case of Bt Cotton, however, it is now admitted in official records that Bt Cotton is more vulnerable to sucking pests than non-Bt counterparts, that it is more stress intolerant and so on. Disease incidence on Bt Cotton is also seen to be higher than on non-Bt Cotton.
In the case of Bt Cotton, it is only after a few years of commercial cultivation that recommendations related to some changed management practices are being made by the industry and the government. It is obvious that the research phase of the development of the transgenic did not happen long enough or comprehensively enough for such lessons to emerge during the experimentation phase. Experiments then, are happening at the expense of farmers!

Further, farmers from various parts of the country are reporting a decline in their soil productivity after growing Bt Cotton. While the regulatory tests related to Bt toxin presence and persistence in the case of Bt Cotton showed that the half-life of Cry1Ac protein in plant tissue was calculated at 41 days [which could then persist in the soil as other studies from elsewhere show], it is not clear how in the case of Bt Brinjal it is non-detectable in soil samples tested. Worldwide, it is generally accepted that more studies are needed to understand the impact of Bt toxin on soil ecology.
In the case of pollen flow, it is well known that there is ample opportunity for cross pollination in the case of Brinjal. The rates of natural cross pollination may vary depending on genotype, location, insect activity etc. However, it has been reported that the extent of natural outcrossing is from 2 to 48%. Further, it is not clear whether there is enough data on the wild and weedy plants that are either close relatives or have some degree of cross-compatibility with these brinjal varieties.
Let us also consider a scenario where our predominant pest management strategy relies more and more on one gene – the Bt toxin gene, across crops for a range of pests. Such a monoculture of the gene across crops and varieties is bound to spell doom sooner or later.

Now, i can only request you people to have a serious thought over the issue and decide what should be your future? Because...............

जब खाने को नही रहेगा तो कमाओगे क्या?

1 comment:

  1. The document seems to be well drafted towards an approach that does kind of scare people away from BT but then We know that the needs of the future generation call for higher yield varieties at lower costs in all seasons. So eventually we will have to submit to Bio-engineering of food as well. in the mean time the only option available to us seems to be that of collecting more data on its implications at the ground level

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