As Bt Cotton turns 10, observational data certifies it a Super-Flop

Rajan Alexanderhttp://devconsultancygroup.blogspot.in/2011/07/as-bt-cotton-turns-10-observational.html

Recap of Bt's Introduction in India

Cotton is one of the most important commercial crops cultivated in India. Commanding around 60% share in the raw material consumption basket of the Indian textile industry ,it plays a major role in sustaining the livelihood of an estimated over six million cotton farmers and over 50 million people engaged in related activities such as cotton processing and trade. Textiles in turn accounts for nearly 20% of India’s exports.

In 1951-52, cultivated area for cotton in the country covered only an estimated 56.48 lakh hectares while today it stands roughly double of it - an estimated 111.61 lakh hectares last year. ((1 hectare = 2.471 acres)

Similarly, 60 years ago, the production of cotton was completely organic and of the desi (traditional) variety. Today, 85-90% of the production is accounted by transgenic seeds, this transformation coming in just 8 years. But adoption appeared more supply driven than need based:

• Since transgenic seeds are backcrossed with elite local hybrids, normal hybrids began disappearing from the market.  The increasing unavailability of the latter functioned as a powerful catalyst for speedy adoption of GM technology in the country.

Adoption rates really spiked in the country after the Supreme Court pegged the price of transgenic seeds to make it more affordable to farmers as compared to its prohibitive introductory prices.

Bt introduction also coincided with global cotton prices soaring due to supply side bottlenecks - largely due to falling production in China and US, two of the world’s largest producers and exporters of cotton. Bt  enabled cotton varieties that found a fit with global cotton demand.

Productivity that stood at a mere 92 kgs per hectare in 1951-52 increased with the progressive adoption of hybrid seeds till it logged around 400 kgs per hectare in 2003-04. That year can be treated as the pre- transgenic cotton’s productivity baseline in real terms as Bt’s share in area cultivated was then a mere 1% and inconsequential in impact to overall productivity of the cotton crop in the country. 

The introduction of GM seeds was justified on the grounds that poor yields were result of high pest infections that accompanied increased use of hybrids which in turn are prone to more severe pest attacks than the desi (traditional) varieties. A widely quoted statistics point out of that cotton cultivation in India which accounts for about 5 per cent of the total land under cultivation yet accounts nearly 45% per cent of all pesticide usage (Choudhary and Laroia, 2001).

Low yields meant though India had the largest hectare under cotton in the world, it came a distant third after China and the US as the leading producer globally. The cotton cultivation in India has been plagued with rising cost of cultivation, ineffective pesticides, adulterated seeds, and other inputs, leading to frequent crop failures (Bose, 2000).  

Nearly 65 per cent cotton cultivation is rain dependent and subject to heavy vagaries of monsoon rains. Continuous presence of cotton in the subcontinent makes it easy for pest; diseases and other biotic stress agents to survive multiply and cause frequent epidemics (Mayee, 2002). 

The cotton crop in India is in fact affected by over 145 species of insects and few species of mites. But research studies indicated that nearly 50% of all yield reduction is accounted by the bollworm complex particularly Helicoverpa armigera (Old World or American bollworm) and to a much lesser extent Pectinophora gossypiella (Pink bollworm), Earias vittella (Spotted bollworm) and E. insulana (Spiny bollworm). Annually it was estimated that 344 million dollars are spent on cotton pesticides. Bollworm control was estimated to cost farmers 235 million dollars yearly.  It was further claimed that 

“Bollworm caterpillars had become resistant to all insecticides recommended for control and none of the chemicals worked, even when mixed as cocktails at doubled concentration and despite repeated spraying of insecticides (6 to 20 times for each crop).”

In 2002 after many lengthy trials and tests, the Government of India (GoI) finally permitted the commercialization of a new variety developed by Monsanto, touted as an effective counter to bollworms and hence called Bolgard. By now, the American cotton variety became the predominant cotton variety cultivated in the country and the Bolgard was touted as an effective remedy against its principal pest - the American Bollworm.

The new variety has been designed by inserting the genes of naturally occurring aerobic bacteria in the soil called Bacillus thuringeinsis (Bt) into cotton. This bacterium produces a toxin that is lethal to the Bollworm, particularly effective against the American bollworm. Farmers in the US have traditionally used this property of the Bt bacteria to guard against infestation by the Bollworm by periodically dusting the cotton crops with dried extracts of soil rich in the bacteria. 

When a gene of these bacteria is inserted into cotton, the altered cotton variety continuously produces the thuringeinsis toxin. Monsanto claimed this would provide double benefit - continuous protection against the pest, minimising pesticide usage and costs on one hand and on the other hand increasing yields by 20-25 per cent by curbing pest damages. There are today nearly 350 officially approved Bt hybrids—up from three in 2002 in India, including many unapproved varieties.

Most of these varieties have been developed by local seed companies with the Bollgard I gene and the newly approved Bollgard II (MON 15985) with stacked genes Cry1Ac and Cry2Ab which gives improved resistance to bollworm and a few other pests. Two additional events were approved, the first indigenous Indian Bt gene (developed in collaboration with a public research institution) and using Cry1Ac was by the firm JK Agri-Genetics, Ltd and a second event (GFM event) based on a Chinese gene, with a fusion Cry1Ab-Cry1Ac introduced by Nath Seeds. In 2007, 135 varieties of Bt cotton were available based on four events, the two Bollgard, the one of Agri-Genetic and a second Bt gene.

Why this paper?

2011-12 will mark ten years since the GoI permitted the commercialization of transgenic cotton commonly known as Bt cotton.  The issue of transgenic cotton had been and continue to be one that generates heated controversy with claims made by civil society and counter claims made by Bt seed manufacturers. Many NGOs and environmental organizations have challenged its effectiveness; some accusing it of failing bio-safety and environmental safety norms while perhaps the most talked about controversy relates to the alleged resurgence of cotton farmer suicides in certain Indian states and their relationship with the use of Bt cotton.

This paper tries to analyze whether 10 years of observational data gives us any clues that can dampen the fires of this controversy. Specifically, it tries to answer two questions, both related to the main touted claims of the Bt industry:

a. Is Bt either a necessary or a sufficient explanation for increased in cotton productivity?

b. Have Bt succeeded in decreasing pest infestation in cotton to indirectly boost productivity and consequently bring about reduction in pesticide expenses?

The average productivity for the cotton crop for the period 2004-10 is 507 kgs per hectare, up 20% than the base year viz. 2003-04 as seen in the graph to the left.  Annualized productivity for eight years since Bt’s commercialization is around 4%, higher than seen in crops like rice or wheat.  More importantly, since the introduction of Bt, from a net importer of cotton, India catapulted to a net exporter of cotton as illustrated by the graph in the right.The Bt lobby in this country use both these graphs to claim Bt a runaway success as a technology. 

In 2003, David Zilberman and Matin Qaim, published a paper "Yield Effects of Genetically Modified Crops in Developing Countries" (Science, Feb 7, 2003, Vol. 299) that claimed that Bt introduction will increase cotton yields over 80 percent and went further to the extent of extrapolating this "phenomenal growth in production"to

cover the entire range of GM crops for the developing countries. This paper whipped up  a lot of passion with NGOs and environmentalists then denouncing the paper as fraudulent. With Bt 10 years old in India, NGOs and environmentalists should feel vindicated for their rage against the paper for over-hyping Bt’s potential yield.

But a 20% decadal jump in productivity is still 20% jump, which is whopping in agriculture by any yardstick. But is the Bt gene either a necessary or a sufficient explanation for increased in cotton productivity rates as observed during the last decade? The Indian Central Institute for Cotton Research Director Dr Keshav Kranthi in his recent article in Cotton24/7 admitted that that Bt cotton technology may not have been singularly responsible for the dramatic improvement of cotton fortunes in India. The following discussions provide some of the alternate explanations:

1. Bt piggybacked on an already rising yield curve

In 1951-52, cotton productivity was a mere 92 kg/lint per hectare but increased to 400 kgs/lint per hectare by 2003-04. So even before the introduction of Bt, the underlying long-term productivity trendline was fairly buoyant (See above graph).  This was fuelled by factors such as expansion of hybridization in cultivation in the country; improvement of management practices; better quality inputs; expansion of irrigation etc. Since Bt genes are backcrossed with local elite hybrids, the introduction of Bt Cotton varieties only gave further impetus to hybrid adoption within the country.                  Can non-Bt hybrids bring about a quantum productivity jump? We were told they can’t and that was the reason for introducing the Bt variety. So let’s have a look at observational data.

(Please note that in 2003-04 Bt’s share in area of cultivation was 1.1% - a share that reflects lack of critical mass to impact the overall productivity of the country and so treated as such by this paper. Besides yield potential of Bt hybrids at the time of introduction was relatively lower than as now. Desegregated yield data Bt and non-Bt validates this treatment by this paper).

So what does the data tell us? YoY 2002-03 to 2003-04 the productivity jump was a mind boggling 34%. Bear in mind this is an overwhelming performance by non-Bt hybrids. And further this happens to be an all-time YoY record jump - a performance a Bt inserted hybrid has not matched to date. The very next year, (when Bt’s share is only 5.7% and still lacking a critical mass), the increase in productivity was 18%. So even before Bt attained a critical mass to significantly impact overall productivity rates of cotton in this country, productivity rates spiked 52% in just two years!

So do we really need to insert a Bt gene into our hybrids or better-off without it?

Bennett et al (2005) who analyzed the effect of varietal differences showed that the host germplasm played a very significant role in yield increases. A NGO, Gene Campaign conducted an experiment that compared Bt cotton varieties Bt. 162 and Bt. 184 belonging to Mahyco-Monsanto and local hybrids Brahma and Banny and found yields of the latter 15-17% higher than the Bt varieties compared. 

The experiment proved that the Bt gene is neither a necessary nor sufficient condition for productivity increases in the cotton crop. It is equally possible that productivity increase observed during the last decade had been entirely brought about by the spread of hybrids with little or no contribution by the inserted Bt gene. 

Has India this potential to increase productivity via hybrids? Why not? We were the first to develop a cotton hybrid and still the leaders of the world in the area of cotton hybrid development.

2. Poor statistical correlation between Bt and productivity 

In 2004-05 the Bt share in area cultivated stood at mere 5.7%. Contrast this to in 2009-10 where it was a whopping 85%. Yet in both years productivity rate stood the same - within the 470-475 kgs/lint per hectare band! So where is the much touted correlation that links Bt expansion in the country with productivity gains? (See table above).

Remember the underlying long-term productivity trend? Well we seem to be losing at least some of its underlying buoyancy after Bt’s introduction.  Even worse, for the last 3 years of the last decade witnessed cotton productivity performing well below its short term trendline.

3. Huge productivity variations calls the bluff of the Bt gene magic

Bt has been hard sold as a sort of a magic remedy call it panacea or silver bullet for all problems confronting cotton cultivation in the country. 8 years into its commercialization, its bluff has been called. 

Overall productivity numbers mask wide heterogeneity in its distribution pattern. Apart from huge inter regional variances, even intra- regional data shows that Bt cotton did not have had the same marginal effects in each state.The Bt lobby finds difficulty in explaining why for example cotton yields in Gujarat surged from below the national average to presently occupy the position as leaders in the country in terms of cotton productivity while yield rates in Madhya Pradesh have in fact significantly decreased post Bt introduction?

Or why for that matter Maharashtra with around 40 lakh hectares under cotton cultivation manages a productivity rate of only 351 kgs/lint per hectare while Gujarat with 26 lakh hectares under cotton cultivated possess the highest in the country? Gujarat’s productivity has often been within reach of the average, international productivity rate (725 kgs/lint per hectare).

So in the central region that comprises of these three states and accounting for nearly 60% of the country’s cotton production, Bt performance is characterized by a high degree of unevenness. In more adverse conditions, the so-called Bt signature in productivity increase is either undetectable (Maharashtra) or negatively correlated with yields (MP).

So among the top three cotton states that account for the great majority of the country’s production, it is only Gujarat where Bt can theoretically claim success.  However even here, as the discussions in the next section illustrates, there are other conditions including Gujarat specific conditions that offer more convincing alternate explanations.

4. Alternate Explanations for Productivity Increases

a. Seed Quality: Poor seed quality is a pervasive problem in cotton cultivation. Only about 35 percent of cotton area is estimated to be sown with certified seed with assured varietal purity and germination before the entry of Bt varieties. Commercially available seeds are often of poor quality, with sale of uncertified, substandard, and second generation (F2) hybrid seeds not uncommon. Although supplies of certified seed are generally available, financial constraints lead most farmers to use retained seeds or opt for lower priced uncertified seeds from the market. Consequently, poor seed quality emerged a significant constraining factor for realization of the full yield potential of hybridization of cotton cultivation.

Now the Bt gene is backcrossed with local varieties. But why then are desi (traditional) varieties excluded?  It has low productivity and is not responsive to agronomic practices in terms of yield. So they are instead backcrossed with our elite local hybrids. Why? Their responsiveness to external inputs is much higher. Now hybrid seeds yield can be as high as 800 kg/lint per hectare (in the US it goes up to 1,200 kg/lint per hectare), under the right agronomic conditions and practices. So the introduction of Bt Cotton by default effect fastened the pace of hybridization of cotton cultivation in the country. Farmers began to get better access to quality and unadulterated seed materials that reflected in higher yields. To give the devil its due, Bt entry catalysed the improvement of cotton seed in the country in relative terms which in turn reflected itself as higher yields. That said there are as many as 700 brands of Bt Cotton in the market whose performance in the field and regions vary markedly. Performance depends into which elite germplasm the Bt gene is inserted to as they could vary widely in yield potential and agro-climatic adoption traits. The real problem is that the presence of so many Bt brands reduces the capacity of the Indian state to regulate Bt in the country. 

b. Seed treatment: Dr Keshva Kranthi pointed out that the chemical imidacloprid, popularly known as Gaucho, used as protection against leaf hopper, had been applied as a seed treatment. And since 2000 (two years before Bt introduction) every cotton seed had been so treated. Now imidacloprid is observed to generate 20-30% yield increases in the crop according to the Indian Central Cotton Research Institute.  Wait a minute. What's the growth rate seen during the last decade? 20-30%. What's the contribution of Gaucho? 20-30%? So what exactly has Bt gene contributed?

  Gaucho's main benefits are as follows:- Control of jassids, aphids and thrips up to at least 45 days after sowing- No dependence on weather conditions which may prevent or delay spray operations- Improved emergence of plants due to control of soil pests

Since Gaucho was introduced in 2000, we have comparative observational productivity data for non-Bt hybrids and those further treated with imidacloprid to tweeze out the latter’s specific contribution to yield growth. This was presumably the procedure used by Indian Central Cotton Research Institute to conclude that seed treatment through imidacloprid application can contribute upto 20-30% yield increases in cotton.

But in the case of Bt crops, all productivity increases are equated to Bt introduction as if no other factors may have played a contributory part. This helps Bt claim runaway success even if it was to be assumed to play a negative role in respect to productivity increases. That’s the power of the Bt lobby in this country that even research appears subservient to promotion of its agenda.

c. Irrigation: Cotton is highly responsive to water. But in India, most of the cotton is cultivated under rain-fed condition (Sundaram et. all, 1999). Thus the variability in yields is largely dependent on the monsoon.

This is why most Bt cotton seed packets carry the information - “Best grown in irrigated conditions” a statutory warning, but provided in very small fine print. Union Minister of State for Agriculture and Food KV Thomas replying to a written query in parliament: “In all other countries cotton is an irrigated crop whereas in India hardly 35-40% of the cotton is irrigated. Therefore, the scope of adopting balanced nutrition is limited.”  

In simple terms what the Minister was tacitly admitting that not only the yield potential was lower but the pest infestation potential was higher under dryland cultivation as compared to irrigated conditions.

Though India's decadal average productivity of 502 kgs/lint per hectare may look  abysmally low as compared to the international average of 725 kg/lint per hectare or China's 1260 kg/lint per hectare or even the US's 868 kg/lint per hectare, much of this difference can be explained away by lack of irrigation.

The difference between China and US in productivity rates only reiterate this fact- the relative share of dryland in overall cotton cultivation of the US being considerably higher than China though much lower than India.  If productivity data is accordingly desegregated to reflect this reality, what is found is that both dryland and irrigated cotton productivity of India are not too far away from their respective international productivity averages.

Dr.Keshva Kranti observed: “Bt-cotton hybrids utilize more nutrients and water for higher yields and profits, therefore the soils are getting progressively depleted and need more nutrient recharging.”  Minister PV Thomas commented on the same vein: “The scope of adopting balanced nutrition is limited” Both were obliquely admitting of Bt’s inappropriateness to dryland conditions that characterise much of our cotton cultivation.  Without water as an input, the degree of freedom is reduced in the choice of soil nutrition solutions, whether organic or inorganic.

Both in Maharashtra and Gujarat most of their cultivation is accounted by dryland. They however offer a striking contrast as case studies. In Maharashtra 97% of 4 million hectares of cotton is grown under rainfed conditions with 95% of its cultivation under Bt varieties. Yields doubled in Maharashtra, from 194 kg/lint per hectare in 2002 to 394 kg/lint per hectare in 2010. Compare this with Gujarat which manages a productivity rate around 700 kgs/lint per hectare.

How can we explain this? Dr Kranti gives us a clue to solving the riddle by revealing that maximum productivity gains were obtained from just  0.6 million to 0.7 million hectares in Gujarat whose land quality was enhanced by a watershed development programme that conferred this swathe of land the benefits of more than 100,000 check dams.

What we can take away from this learning is that we don’t need big irrigation or dam projects or even the Bt gene. Just simple micro-watershed projects are sufficed to bring about quantum jumps in productivity of cotton. Increasing the soil moisture content can make all the difference in how crops adopt to abiotic stresses like droughts. We don’t

even need to search every nook and corner of the world for solutions but in Gujarat we have a ready model for replication.

We now know the reason why at least one cotton farmer in Vidarbha daily commits suicide as painfully documented by renowned journalist P Sainath and why Gujarat farmers are enjoying the fruits of their newly found prosperity by going on a consumer spending spree. Now Dr Keshva Kranthi also took a dig on NGOs and environmentalists for blowing up Vidharbha suicides by highlighting that Bt cotton has spread almost 94% of all area cultivation and that productivity rates have more than doubled in Vidarbha. 

Well apart from stating the obvious what he conceals is that Bt Cotton is a highly input intensive crop and that the average productivity of 394 kgs/lint per hectare of the state simply does not offer the same amount of cushion to economically breakeven as compared to Gujarat’s over 700 kgs/lint per hectare, as per capita per day returns show wide variations between these two states. (Please note the productivity rate of Vidarbha is much below Maharashtra’s average)

Without irrigation, Vidharbha farmers face much more higher risks from abiotic stress and therefore more prone to suicides than a Gujarati farmer. The result was that in an area with a history of indebtedness, the high input costs of Bt cotton acted to further increase indebtedness. A study by Gene Campaign had shown that 70 per cent of small farmers had already lost their landholdings as collateral for loans that they could never repay. 

Suman Sahai, Director of Gene Campaign was quoted saying “that despite specific knowledge that Bt cotton would not work in rainfed areas, the government had introduced it in Vidarbha.” She further observed that irrigated farmers performed better in Vidarbha and suicide rates of the latter were much lower than dryland farmers. It follows that if we want to attain quantum jumps in cotn yields, irrigation rather than Bt would be a better and safer bet.

d. Quality land and agronomic conditions: These are key factors in bringing about quantum jump in productivity rates.

In the 0.6 million to 0.7 million hectares in Gujarat where cotton experienced a phenomenal jump in productivity, according to Dr Keshav Kranti farmers previously  grew groundnut crops, which being a legume enhances soil fertility. Cotton on the other hand depletes the soil by decreasing its nutrient content.  Cotton can of course grow on even mediocre soils but throw some soil fertility to it and its yields spike. This held true in the case of Gujarat. The land was fertile to begin which that made it all the more conducive for higher yields.

Further, since cotton was not previously cultivated in these lands, cotton specific pest pressure is low. But unless crop rotation is practice, Gujarat farmers too will experience progressive increase of pest pressure if they continue to cultivate cotton year after year.But compare the Gujarat experience with Vidarbha which has over a 1000 year history of cotton cultivation and where cotton was described all through history as white gold, being the principal economy of the region. It’s a no brainer to conclude pest pressures are higher in this region and consequently the challenges in maintaining and increasing yield rates are much higher in Vidarbha than Gujarat.

Significantly, where yield increases were needed most (Vidarbha), Bt failed to deliver the goods and where it was perhaps least needed (Gujarat), Bt claims credit for bringing about productivity increases!

e. Resource rich farmers: A review of literature finds many studies pointing to Bt’s unsuitability for small-scale and resource-poor farming systems. Early adopters tended to be the most prosperous and well-financed farmers, who were any way getting better yields than other farmers even before Bt seeds were adopted. (Stone).  Bt or no Bt they were more adept in increasing yields. And so part of the explanation for increased productivity need to be credited to the ingenuity of this category of farmers.

In hindsight, NGOs and environmental groups campaign against the exorbitant introductory prices for Bt seeds only succeeded in playing right into the hands of Bt seed manufacturers. Lowering of Bt seed prices can be identified as the single most significant factor that led to their rapid adoption within the country. If prices remained exorbitant, normal hybrids (without Bt gene inserts) would have acted as bulwark against the spread of Bt, confining the latter to few irrigated pockets and more resource rich farms.

But since this had not been the case, the high investment for cotton cultivation induces small and marginal farmers to cut corners by trying to procure cheaper but less effective or even spurious pesticides and seeds that are responsible for much of their lower yields, if not crop failures leading to higher suicide rates.

Conclusion

So back to the question: Is Bt either a necessary or a sufficient explanation for increased in cotton productivity? 

We can conclude it is a complete perversion to attribute productivity increases solely to the Bt gene though it may have indirectly contributed by catalyzing a quicker pace of hybridization of cotton within the country and relatively improving supply of quality seeds to farmers. Other factors such as irrigation and newer lands played a much more significant role in increasing productivity of the crop than the Bt gene itself.

Has the Bt gene reduced pest infestation and decreased expenditure on pesticides? 

The Theory"Resistance is a decrease in pest susceptibility that can be measured over human experience. When you use an insecticide to control a pest, some populations eventually evolves resistance." (Tabashnik).  

Under the stress of intensive chemical spraying the weaker members of the insect populations get weeded out.” (Carson). Evolution of insecticide resistance in >400 species of insects not only confirmed Darwin's survival of the fittest theory besides threatening agriculture and human health worldwide. This was the global experience of using hybrid seeds. Bt Cotton is just an accentuation of this trend as the only change now was usage of the same hybrids with a Bt gene inserted into their germplasm. 

Although scientists are trying to directly increase yield of some agronomically important crops using transgenic technology, success are so far eluding them (Jenner 2003). So any direct contribution to yield increase has to be accounted by the (hybrid cotton) germplasm in which the Bt gene is inserted. Accordingly, the Bt gene does not directly increase yields but only does so indirectly by reducing yield loss due to pests.  But the Bt gene is not designed to protect against all pests but only against the Lepidopteran insects that account for 50% of yield reduction attributed to pests in the country.

So theoretically the Bt gene’s contribution to increased yield is limited to the degree it offers crop resistance to Lepidopteran insects and thereby preventing loss in yields. Actual increase or decrease in Bt yield has to be in relation to the yield loss of the non-transgenic counterparts under the same cropping practice.  But in India presently there are an estimated 680 brands of BT cotton seeds whose vulnerability to different kinds of pests vary greatly, that includes the degree of their vulnerability to Lepidopteran insect pests. 

But because it confers cotton plant resistance to Lepidopteran insects, the Bt lobby further claims that farmers are able to reduce their input costs enabled by a decrease in the volume of insecticides sprayed (and associated costs) which in turn boosts income margins as spraying less insecticide also means lower application costs.  For small-scale farmers who does most farming activities by hand, this means less time for weeding and other management practices.

The history of insecticide resistance however informs us that adaptation by insects could diminish the long-term efficacy of Bt crops. Meihls et al report that resistance evolved quickly without refuges and slower or not at all with refuges. So as a technological fix, a refuge management strategy was mandated in many countries including India, to delay insect resistance, which requires refuges of host plants without Bt toxins near Bt crops to promote survival of susceptible pests.

The concept was based on the assumption that most of the rare resistant pests surviving on Bt crops will mate with abundant susceptible pests from nearby refuges of host plants without Bt toxins. If inheritance of resistance is recessive, the hybrid progeny from such mating will die on Bt crops, substantially slowing the evolution of resistance. 

This approach is sometimes also called the “high-dose refuge strategy” because it works best if the dose of toxin ingested by insects on Bt plants is high enough to kill all or nearly all of the aforementioned hybrid progeny. In principle, if a high dose is not achieved, resistance can be delayed by increasing refuge abundance, which lowers the proportion of the population selected for resistance to compensate for survival of hybrid progeny on Bt plants. 

NGOs and environmentalists on the other hand ridiculed this theory. They highlighted there is ample evidence that suggests that pests develop resistance to just about any pesticide thrown at them. Bt toxin secreted by the Bt crops is no different from other chemical pesticides. Early on it will cause a temporary reduction of pesticide use (and associated costs), but resistance will eventually develop. They predicted that pest resistance to Bt could appear in the field within three to five years.

Evidence vs Theory

Dr. Kehsav Kranthi, the Director of India’s Central Institute for Cotton Research in a 3 part paper entitled 10 Years of Bt in India provides a review of the Bt gene’s actual performance in the field. This is really a Government of India (GoI) review. Here's some extracts:

"The leaf curl virus started to resurface as a major problem in north India, primarily due to the introduction of more than 270 Bt hybrids in north India, most of which were susceptible to the leaf curl virus. Until 2005, 100% of cotton area in the north was under varieties. Now 95% of the area is under hybrids in Punjab and Haryana, while 40% of the area is under hybrids in Rajasthan. 

Productivity in north India is likely to decline because of the declining potential of hybrids; the emerging problem of leaf curl virus on the new susceptible Bt-hybrids; a high level of susceptibility to sucking pests (straight varieties were resistant); problems with nutrient deficiencies and physiological disorders; and mealybugs, whiteflies and miscellaneous insect problems that are likely to increase.

The tobacco caterpillar, Spodoptera litura, resurfaced as a problem again as predicted, because of the low toxicity of the Cry1Ac toxin on the species. Bollworms started reappearing on Bt cotton.

In February 2010, Monsanto, India declared that pink bollworm had developed resistance to Cry1Ac and that only Bollgard-II would be effective thereafter. Resistance monitoring studies at CICR showed that the American bollworm Helicoverpa armigera was also showing incipient tolerance in some parts of India.

The leaf hoppers showed very high levels of resistance of up to 5,000-fold to imidacloprid and other neonicotinoid insecticides in central India. The neonicotinoids were introduced barely a decade ago.

Progressive nutrient (macro and micro) depletion due to the source sink relationship because of Bt-cotton after Bt-cotton hybrid cultivation. Bt-cotton hybrids utilize more nutrients and water for higher yields and profits, therefore the soils are getting progressively depleted and need more nutrient recharging.

The cotton crop is showing nutrient deficiency symptoms in many regions, especially in rainfed zones where wilt and leaf-reddening problems are getting more severe over the years. The productivity is maximum in good soils."

So what are the salient points of the GoI’s evaluation of Bt Cotton’s performance during the last decade?

1. Imidacloprid ( used as seed treatment in cotton) that gave a 20-30% yield gain was succumbing to resistance, significantly, coinciding with the observed yield decline of cotton seen during the last 3 years. 

2. The Bt gene was touted basically a protection against the bollworm complex, particularly effective against the American bollworm.  A review of literature suggests the single-protein Cry1Ac products continue to more or less control the bollworm complex other than pink bollworm (Pectinophora gossypiella).

Two possible reasons are attributed to its ineffectiveness against the latter - either the period of expression of the Bt endotoxin does not coincide with the time of the bollworm attack or it's populations harbour three genetic mutations that confer resistance to Bt toxin (Morin et al, 2003), the latter being a more popularly accepted explanation. 

The real setback for Bt is that after proving that it could reduce the incidence of American Bollworm for some years, there is growing evidence of incipient resistance in the Central region accounting for nearly 60% of all cotton cultivation in the country.  Some of the reasons for that are as follows:

The toxic expression depending on the parental background of the hybrid varies widely due to the proliferation of brands.

In some plants, toxin expressions decreases 110 days after sowing to levels that are inadequate to protect the plants from bollworm attacks. (Doyle et al) However maximum and extensive damage potential from bollworms is in their early stages

In India, cotton bollworm is more serious than in USA or in China; this means that Indian farmers needed to spray more pesticides against bollworm as resistance built up.

The second-generation Bt cotton technology, Bollgard II containing two proteins, Cry1Ac and Cry2Ab introduced in 2006 was supposed to check both these limitations on the assumption that the combination overcomes pests that are resistant to just one toxin. But this too has not fully succeeded.  The assumption that the hybrid offspring produced by mating between susceptible and resistant moths are resistant had been falsified with the appearance of incipient resistance, indicating the opposite happening - the inheritance tends to be dominant.

3. Bt cotton by inserting a gene into hybrid cotton was intended to make manual spraying obsolete. In fact, that was the claim of their hardsell when it was first introduced in this country. The object was to make the entire plant toxic so that the insects feeding on it are killed by increasing toxicity to 1,000 times to prevent resistance build up. But in reality, Bt toxins Cry34Ab and Cry35Ab often does not meet this high-dose standard (Meihls et al) so it does not kill all insects feeding on the Bt crop but permits support to a significant population of resistant insects.  

Further since Bt’s endotoxins do not confer protection in the entire life cycle of the Bt plant, manual sprays though reduced cannot be eliminated pointed out Suman  Sahai of Ngo, Gene Campaign. She explains: “The expression of the Bt cotton gene worked for only 90 days while Indian cotton took 160 days to mature. In other words, during the crucial period when the crop needed protection from pests, it remained unprotected”

Besides, since the Bt gene confers protection against only Lepidopteran insects and not others like sucking insects, farmers continued spraying broad spectrum pesticides. This realization made Bt advocates such as Keshav Kranti to clarify that Bt is just one element in the total package of pest management, which is a big come down by Bt lobbyists who had claimed at entry that Bt will make manual spraying obsolete.

4. The impact of (2 and 3) was two-fold. On one hand it catalyzed the rise of hitherto unknown insect pests like mealybugs and on the other hand it also catalysed the resurgence of major pests that previously was brought under control. Besides it elevated other minor pests to major pests. If all these are an India specific development, Bt as a technology could be given a benefit of doubt. But it ties very well with similar happenings in other Bt growing countries, whether the US, China or Pakistan

Thus the rise of predation by non-target crops completely neutralized the gains of the Bt gene reflected on productivity rates which began to decline after peaking in 2006-07. Keshva Kranti observed: 

“A mealybug named Phenacoccus solenopsis, not observed earlier in India, has spread across northern, central and western states after it was first recognised as a cotton pest about five years ago. In desperation, farmers have begun to spray "extremely hazardous" pesticides on the cotton to fight the insect, which has a waxy coating over its surface that makes it hard to kill with less toxic pesticides”.

We neither have a transgenic gene nor a variety, whether hybrid or desi, that is resistant to this mealybug. As a result, farmers need to spray at least 6 times, just to contain its damages, at the cost of Rs 3,000-4,000 per hectare. 

5. The combined unintended side effect was these limitations of transgenic technology reinforced each other, spiking pesticide consumption and usage that resulted in indiscriminate killing of both pest and beneficial insects or bacteria including predators of till then minor pests of cotton. It was also found to having adverse effects on natural predators or parasites of bollworms themselves. Pesticide consumption after moderately declining till 2006-07 started rising again and accordingly input expenditure of farmers for pesticides which after declining till 2006-07 doubled by 20010-11.  A new study by a Washington University in St. Louis anthropologist by Dr Glen Stone (2011) used triangulation methods to confirm this trend. Stone observed that the prices of Lepidopteran insect’s pesticides remaining more or else constant at 2003 prices while those of sucking insecticides commanding a premium. 

So while Bt moderately succeeded in keeping in check one set of pest (Lepidopteran insects) damages, it created several sets of new pest damages (e.g. sucking insects) that completely negates its gains. The result had a telling reflection on productivity that peaked in 2006-07 at 554 kgs/link per hectare and then declined for three consequent years to 474 kgs/link per hectare.

6. Perhaps the most loaded statement in Keshva Kranti’s paper is when he notably observed: “The area under Bt cotton has reached above 90% in many parts of the country but farmers are not following the recommended refugia practices. The intensive Bt cultivation and the noncompliance of refugia is likely to hasten resistance development.”

The concept of a refuge on one hand reflects the inefficiency and on the other hand, the inappropriateness of Bt technology:

a. Inappropriateness: In countries like the US or China, land is less of a constraint than it is India, and so they can more afford to set aside 20% of the cultivation area for refuge as their average land holding sizes are much larger. In India, this is viewed as waste to put arable land for non-productive purpose.

b. Inefficiency: Bt was touted to have been designed to kill pests by increasing toxicity levels to 1,000 times. But this did not happen at all or at all the times as Bt endotoxins lacked consistency and timing of production of high dosage toxins.

At other times, despite the high dosages, pests survived by mutation to acquire toxin resistance all the same.

According to regulatory conditions, the size of the refuge belt should be either 5 rows of non-Bt cotton or 20% of total sown area, whichever is more. Due to small and marginal land holdings In the country, these norms are not followed. If in the US the default rate is 20%, whereas in India the compliance rate is less than 10%.

For quicker adoption of Bt seeds, sections of the Bt industry even argued there was in fact no need for a refuge. Manjunath (2004 & 2005) a former director of Monsanto India  argued instead that there existed a large number of alternative hosts like chickpea; pigeon pea; sorghum and tomato which could serve as natural refuge. Bt had then a share in overall cultivation less than 15%. So non-compliance of refuge requirements cannot per se explain the hastening of resistance build up. What can more probably completely explain it is that as Bt reached a share of 90% of area cultivation, it did so at the cost of cannibalizing this ‘natural’ refuge. There are several implications arising from this:

a. The effectiveness of Bt’s endotoxins reduces as the technology expands its share in area of cultivation.  The more it expands its share in area of cultivation, greater the prospects of pests acquiring resistance to its endotoxins. Now that Bt commands nearly 90% of area of cultivation, it signed its own death warrant. The question of ‘mass’ resistance is not of if but when it explodes. This is the real import of Dr Keshav Kranti comment:“Reduction in area of intercrops can hasten the development of bollworm resistance to Bt-cotton”  

b. The concept of refuge was for its touted utility to slow down the onset of resistance. The assumption is that pests surviving on Bt crops will mate with abundant susceptible pests from nearby refuges of host plants without Bt toxins and the inherited resistant gene will be recessive so that pests will be killed by endotoxins of the Bt crop.

Now recent studies show these series of assumptions as not completely correct. One bunch of studies point that the inherited resistant gene instead can be dominant too, particularly if the resistant insects mate among themselves! (Meihls et al & Ranjith et al).

Further a study (Anilkumar et al) published in the Applied and Environmental Microbiology concluded that in the case of Helicoverpa zea,, thought to have evolved from the American bollworm), the inheritance trait appears to be statistically more dominant than in other cotton pests. Accordingly, this might explain why Helicoverpa zea developed resistance to Bt.  

All these simply mean even if there is full compliance of the refuge system, its efficiency is highly questionable. The refuge is just a red herring explanation why Bt as a technology failed.

c. Further, if resistant insects visit a refuge, then it is not only for mating, it is also for food. Now here lies the danger of treating alternative hosts like chickpea; pigeon pea; sorghum and tomato serving as “natural” refuge. Damage from infestation to these crops increases, causing significant yield drops for them. Consequently, any benefit-cost analysis on Bt cotton should encompass its impact on “natural” refuge. A review of literature suggests that this is never done.

Despite the refuge system being integral in the Bt package, the irony is that cost implications whether land set aside, seeds and other inputs are not considered in the benefit-cost analysis of the Bt crop. Once factored in, it would look less rosy even if economical otherwise.

Conclusion

So back to the question:  Has the Bt gene reduced pest infestation and decreased expenditure on pesticides?

Bt’s weakness as a technology stems from not incorporating the lessons of our hybrid experience. To prevent resistance build up in insects, pesticide management should reflect its judicious use - finding the right toxin-pest fit; right dosage-degree of infestation fit combined with timely and required frequency of applications. This principle was observed to be violated in common practices of hybrid cultivation resulting in contributing to resistant build up in insects, necessitating application of new toxins and/or higher dosages to control the same degree of pest infestation.  

The endotoxins secreted from Bt besides does not permit effective control over of either their timing or dosage. The very fact that it targets only one set of insects, necessitates manual spraying of other categories of broad spectrum acting pesticides, including ‘cocktails’ that violates judicious norms of sustainable pest management principles. Since Bt does not offer protection for bollworms during the entire life cycle of the plant, it also entails limited manual spraying to complement its endotoxins. Multiple stacking of genes, the new generation of Bt’s are in fact no different from a ‘cocktail’ in effect except that it is much worse in impact.

The refuge system was neither complied with by farmers or if complied with, was ineffective to prevent the build up resistance.  In fact, the goal of refuge was defensive to begin with. Prevention was never its aim but only to delay resistance from developing long enough so that it becomes manageable, so that, perhaps, by the time super-bollworms evolve, there are new versions of super-Bollgard available to farmers to contain the threat so that the cycle begins again, escalating seed costs for farmers and boosting revenue earnings for seed companies.

The refuge system was a poor alternate to the system of crop rotation, one of the oldest and most effective cultural control strategies. It meant that the succeeding crop must be a different family than the previous one, based on the appreciation that most significant pests are crop specific and their populations can naturally decline if deprived of food by rotating crops, dying due to absence of food. Bt however created the illusion that it was a superior alternative by offering the refuge system.  

It is no surprise that the attempt to stall the evolution of insect resistance through transgenic crops producing Bacillus Thuringiensis (Bt) toxins ended up a failure as instead of pests getting killed, they instead began thriving on it. (MT Ranjith et al).  But Glenn Gladstone of Washington University in St. Louis in his study warns the failure goes much beyond this level: 

"Looking beyond the field level to the farm level you see the real problem was a set of factors that eroded the normal process of farmer evaluation of technologies — there were too many rapid, undecipherable changes. 

Each new technology — hybrids, then pesticide after pesticide — brought short-term gains but further eroded farm management. Bt cotton has raised yields on average, but already we are seeing erosion of benefits as non-target pest populations are booming. It has also brought a quickening of technological change and undecipherability, which is the real underlying problem."

This paper is written by Rajan Alexander, Development Consultancy Group, Bangalore. Rajan is a livelihood consultant and had been in the NGO sector for more than 31 years.  He can be contacted at rajan.alexander@yahoo.co.in