These products including cotton and other varieties and BT, are produced in the USA, Canada, Argentina, China, South Africa, Mexico, Spain, Australia and India and now are being distributed all over the world. On the other hand, there is a very strong consumer resistance against such GM products in various international markets.
Nevertheless there are also strong lobbies in each country in favour of such products and campaigns are underway to persuade farmers and policy makers to help introduce Bt cotton varieties in Pakistan on the pretext that not only it would require chemical spraying against bollworms, farmers’ profitability would also go up very high, It is argued that since BT cotton and other transgenic varieties are environment-friendly; no harm will come to soil and other natural flora.
The subject under discussion being vast, this article will remain confined to only one aspect, and that being control and resistance against the bollworm in BT cotton.
Although the growth and development of such crops look natural, biotechnology gives them powers which they could never have achieved through normal or conventional means. Bt cotton for example, is genetically engineered to produce an insecticide, Bt toxin which comes from bacterium, Baccilus Thurinqiensis (Bt) so the plants would kill their own insect pests.
This power comes due to a crystal-shaped toxin (ICP), which is a natural insecticide, emitted by common soil bacterium (Bt). Consequently, companies behind the production of such crops describe the phenomenon as sort of green revolution.
The Bt cotton is said to be environment-friendly, high yielding and increases profitability of farmers. The Bt. Toxin has some value for clean environment as it kills bollworm and closely-related species without chemical sprays.
It can be presumed that Bt. Cotton could fit well with sustainable agricultural practices, like those that use beneficial insects to help kill pests like bollworms.
But it is not the whole truth and it might be surprising to know that Bt cotton will not do away with all chemical spraying. It doesn’t kill all cotton pests except bollworm and for all other insects the usual broad-spectrum chemical sprays have to be used.
Fat economic returns have been reported in various studies which reflect higher yields for Bt cotton and/or the lower cost of controlling insects and pests. Reed, ‘stewart’ and ‘laughlin’, 2000, for example, documented an average 11.4 per cent yield advantage for Bt cotton in Mississippi (USA) over a five-year study period.
Similarly, ‘Stark’ confirmed an 11 per cent yield increase for Bt cotton iii Georgia (USA). Experimental plots and yield trials also find a significant yield advantage for Bt cotton; generally ranging from 7 to 12 per cent.
The yield advantage for Bt cotton reflects a combination of innate agronomic advantages and better insect control, particularly for sub-threshold purposes.
In contrast, according to the National Cotton Council of America 1996-03 in the US and China, Bt cotton overall has posted less than a 10 per cent gain in yield over regular varieties. Even with that small yield boost on Chinese farms, Bt cotton decreased use of pesticides and dramatically increased a typical farm’s income in recent years, says Per Pinstrup-Andersen of Cornell University.
“The public sector has to invest in research for the good of poor farmers including genetic engineering,” he says, adding. “the thing that concerns me is that insects will develop resistance.”
The Bt gene is slightly less efficacious against cotton bollworms. However. supplemental oversprays are often required to achieve effective control of cotton bollworm in Bt cotton, though the number of applications is far less than necessary with conventional technologies.
But there are not so encouraging reports, for example Carriere,according to the National Cotton Council of America, 2003, says that success of Bt. varieties depends on avoiding pesticide resistance. Lab work has shown that pink bollworms already carry gene variants that in certain combinations can provide immunity.
The daily Hindu (Jan 26, 2003) and Gene Campaign (April 15, 2003) presented the data on India’s very first GM crop, Bt cotton collected from 100 farmers in Andhra Pradesh and Maharashtra. The data clearly shows that Bt cotton was not resistant to the bollworm and farmers sprayed about the same amount of pesticides on both, thus showing no great saving in pesticide. Field data also show that the Bt cotton plant is weak and that the boll size is small, the length of cotton fibre is shorter than in non-Bt cotton, so the yield is less and the quality poor.
On the economic side, the input costs were almost Rs1000/acre higher than for non-Bt conventional cotton varieties. The Bt seed alone costs four times as much as good varieties of non-Bt cotton; savings on pesticides were merely Rs.217/acre while the Bt seed was Rs1200/acre more expensive. The failure of Bt cotton varieties is bitter and widespread. The environmental conditions and the insect pest complex available in Pakistan are not much different than India. One can imagine the fate of the farmers with Bt cotton.
In another study in China during 2002 by four Chinese state- owned science institutes, scientists suggested for the first time that the crop was permanently damaging the environment and that insects were building up resistance to Bt toxin. It suggests that GM cotton, which incorporates a gene isolated from the bacterium harms the natural parasitic enemies of the cotton bollworm, the pest that it is designed to control. It also indicates that populations of pests other than cotton bollworm had increased in Bt cotton fields and some had replaced it as primary pests. The scientists found that the resistance of Bt cotton to bollworm decreased significantly over time. GM cotton, they said, will require increasing amounts of traditional chemical oversprays to control the pests within a few years.
A report covering five years of commercial production of Bt cotton in China, published by Greenpeace, says bollworm control is no longer complete by the third and fourth generations of the pest, and control falls to 30 per cent after 17 generations. The scientists said Bt cotton would probably lose all resistance to bollworm after 10 years.
According to the first Australian research into the potential for impacts of genetically modified (GM) insect resistant cotton (called lngard-R or Bt-cotton) on soil biodiversity it has been observed that Bt-toxin is expressed in roots at a similar level to leaves. The fine roots have higher levels of toxin than bulk roots.
In addition, this research has shown that cotton roots also appear to release Bt-toxin, as has previously been shown in corn, although the amount of toxin released is difficult to quantify and the mechanism(s) by which it is released remains unknown.
If Bt-toxin enters the soil environment and accumulation occurs, the potential for adverse impacts to non-target organisms and soil ecosystems, both on-site and off-site, would need to be evaluated. If the observed trend is real, its significance is not yet clear since the changes to soil biota could be detrimental, neutral or beneficial to agricultural soil ecosystems.
According to the daily Hindu (Jan 26, 2003), the official write-off on Bt cotton performance in Andhra Perdesh says that Bt cotton was a disappointment and the Bt variety had failed to yield desired results. The farmers paid up to Rs. 1600 for a Bt cotton packet as against Rs.450 to 500 of normal varieties. However the yield was said to be below or on par, with the local hybrid varieties. The standing Bt crop in over 30,000 hectares in Maharashtra has been damaged severely.
The Bt cotton in Australia was introduced with a storehouse of promises, the promise of clean, green crops and seed that promises Australians a less pesticide-polluted environment. But in Australia the performance had not fulfilled the promises as under Australian conditions, the level of Bt toxin drops drastically at the end of the season. So the Australian farmers would still have to spray before harvesting.
There are doubts about keeping of “refuses” which may help the insect rather then the toxin. A “refuge” is a normal non-Bt crop planted near the fit crop on an area covering 4-10 per cent. Heliothis breeding up in the refuge won’t get a bite of Bt, so they won’t build any resistance. The plan is that when resistant heliothis charge out of the Bt crop they’ll meet the non-resistant hehothis heading out of the refuge. They don’t fight though, but mate and their offspring should lose most of their resistance to Bt but the worry is that the pests may not behave according to plan.
In case of commercialization of Bt cotton in Pakistan, there is every possibility that the expression of Bt in cotton plant will not be uniform as the cotton belt spreads right from Punjab to lower Sindh and comprises very harsh and diverse agro-ecological conditions.
Nevertheless, there were firm promises, acid assurances about the success of Bt cotton but it can safely be concluded that the Bts have not come up to the expectations under comparable agro-climatic conditions of three very important cotton growing countries like India, China and Australia.
According to reports some farmers tried to grow Bt cotton in Sindh but so far all such attempts of introducing Bt cotton in Sindh and Punjab have failed to deliver desired results as the cotton crop was attacked heavily by virus, pathogenic and minor pests like juiced, and white fly.
Moreover none of the cotton varieties imported from abroad has shown success under local environments, therefore the same may be expected of the Bt varieties if not developed locally.
The food safety and environment friendliness of Bts are still controversial and very sensitive issues.
About half of our local edible oil production comes from cotton and the cottonseed cake after extracting oil is fed to the milk animals and poultry.