Transgenic Bt Technology: 7. Benefits
Prof. C Kameswara Rao
Foundation for Biotechnology Awareness and Education,
Bangalore, India krao@vsnl.com, www.fbae.org, www.fbaeblog.org

Technologies come with some concomitant and some consequential benefits, both of which should be taken together in assessing the total benefits that accrue.   No technology is risk free.   Benefits of a technology should hence be weighed against minimal and acceptable risks and a favourable cost-benefit ratio.  

Risk assessment, mitigation and management are at the heart of regulatory processes.   Planting a non-Bt refugium along with Bt crops is a means of mitigating the risk of acquired resistance, and so is gene stacking (http://www.fbae.org/Channels/Views/transgenic_bt_technology2.htm). 

Stakeholder acceptance of a technology is rooted in a rational and balanced projection and not in hype.   Factual information will enhance the credibility of the establishment and help the consumer take educated and lasting decisions.

Concomitant benefits of Bt technology:

The most direct and the most important benefit of Bt technology is the control of the most damaging pest of particular crop, such as the American bollworm of cotton, stem borers of rice and corn, rootworm of corn, or Colorado beetle of potato.   As systemic pesticides, Bt toxins take care of these pests.   The other pests, on which Bt toxins have little or no effect, need to be controlled by pesticide application, preferably as a part of Integrated Pest Management (IPM) practices.

Bt technology imparts only tolerance of the targeted pest of a particular crop and not total resistance to it (Item A.1.0.2, 52nd meeting of the Genetic Engineering Approval Committee, Government of India; http://www.envfor.nic.in/divisions/csurv/geac/geac-52.htm).   In view of the variation in the expression of Bt genes, due to various internal and external factors,  (http://www.fbae.org/Channels/Views/transgenic_bt_technology4.htm), two or three pesticide applications are needed, against even the targeted pest, such as the bollworms of cotton, instead of the usual 15 to 20.   Even so, in a country like India, where over 50 per cent of pesticide application is on cotton, Bt technology results in very substantial savings on pesticide costs and labour costs associated with pesticide application, provided the farmer does not resort to ill-advised or panic spraying.

A survey by IMRB International indicates that during the last cotton season, in India as a whole, non-Bt farmers sprayed 5.5 times more pesticide than Bt farmers.  

Optimal cultivation practices are mandatory:

Any crop should be grown under optimal conditions to obtain the best benefits from Bt technology.   Although cotton is hardier than many other crops, it performs satisfactorily only under irrigation.   In India, cotton is often grown under near impossible conditions, as farmers are lured into growing a cash crop, irrespective of the infrastructure, and suffer disastrous consequences.   The Government Department of Agriculture, State of Andhra Pradesh, India, rather unsuccessfully advises the farmers to avoid growing cotton on red soils, particularly as a rain fed crop (http://www.A_P.cotton.magmt.htm).    A long time advice to grow cotton only in areas with the average rainfall of more than 60 cm per year, uniformly distributed throughout the crop season, is largely unheeded.   In many developing countries, the record of both the advice given to the farmers and of farmers taking it seriously, is dismal.  

Consequential benefits of Bt technology:
Bt technology’s consequential benefits are:

a)      a healthy crop, more biomass and more yield;
b)      reduced risk to farm labour involved in pesticide application; in the developing countries several thousand farm workers suffer or even die, due to unintended pesticide poisoning;
c)      far lower concentrations of pesticide residues on the produce and in the environment;
d)      reduced exposure of non-target organisms in the environment to pesticides, and so a better conservation of biodiversity; and
e)      the Bt farmer experiences a far lower tension and is certainly better off with Bt technology than the earlier scenario of ‘spray and pray’.

What is not to be expected of Bt technology:
Bt technology has no role to play in the following areas:

a)      Yield: Bt technology has no gene based influence on crop yield; nevertheless, there is a substantial increase in yield due to prevention of loss of the crop produce caused by the pests; Bt-farmers in India earned Rs. 6,000 (about US$ 135) more per acre, than the non-Bt farmers during the last season;

b)      Seed germination: failure of seed to germinate is often mischievously attributed to Bt technology; causes for the failure of seed germination lie in the varieties or cultivation practices or environmental factors; the percentage of germination of the seed of a Bt variety would be the same as that of its isogenic;

c)      Non-target pests:  Bt technology is specific pest targeted and has little or no effect on other pests;

d)      Diseases:   Bt technology does not cause or control any viral, bacterial or fungal diseases; such diseases as the viral leaf curl prevalent in northern India or the physiological disorder para-wilt that occurs after a heavy rain fall preceded by drought conditions, are erroneously attributed to Bt technology. 

September 19, 2005