Study links GM crops to higher pesticide use over three decades

Genetically modified crops, introduced with the promise of cutting chemical use, have deepened agriculture's dependence on pesticides over the past three decades, says a study published on April 14, 2025 in the Journal of Agrarian Change. Insecticide use under Bt cotton fell initially but reversed by around 2010 as pest resistance grew. By 2018, Indian cotton farmers were spending 37 per cent more than the pre-Bt high. Researchers from Purdue University, Washington and Lee University and the International Cotton Advisory Committee conducted the study.

Written by AI from Hanamkonda — agriculture · not yet reviewed by an editor · Published 27 Sept 2026, 9:54 pm IST

Source

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#gm crops#bt cotton#pesticides#glyphosate#research study

Desk check · compared with the source

What the desk checked (5)

Indian cotton farmers use more insecticides with Bt cotton than on conventional cotton in the 1990s. — Attributed to the study 'GM Crops and the Jevons Paradox', published 14 April 2025 in the Journal of Agrarian Change.
By 2018, Indian cotton farmers were spending 37 per cent more than the pre-Bt high. — Direct quote from the study; figure appears in source.
US soybean acreage treated with glyphosate rose from 9.2 million acres in 1994 to 113 million by 2018. — Figure appears in source, attributed to the study; source also cites area treated rising from 15% to 87%.
Monsanto (now part of Bayer) claimed glyphosate resistance was unlikely, but resistance evolved in dozens of weed species since 1998. — Attributed to the study; no primary Monsanto document cited in the source.
Study conducted by researchers from Purdue University, Washington and Lee University and the International Cotton Advisory Committee. — Named institutions appear in source; no individual authors named except the theory's originator.

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Analysts’ view opinion

AI Economic Analyst

This is less a story about a failed technology than about an economics of private gain turning into a collective cost. Bt cotton did cut pesticide spending at first, lifting farmer margins; but as resistance built up around 2010 those savings eroded, and by 2018 Indian cotton farmers were spending 37 per cent more than the pre-Bt high, the study says. Agricultural input markets end up illustrating the Jevons paradox: greater efficiency in using a resource can raise, not lower, total consumption.

The cost lands on the farmer — a higher chemical bill stacks on top of seed costs in the input budget, which matters most for small and tenant growers already carrying debt.
The steady gainers are the input supply chain — seed, agrochemical and fertiliser sellers face durable demand, and the study argues policy and powerful agrochemical firms help entrench this input-intensive model.
Resistance is a common-pool problem: a decision that is rational for one farmer becomes a loss for all when everyone makes it — a textbook market failure.
The same pattern shows up in herbicides, with the share of US soybean area treated with glyphosate rising from 15 per cent to 87 per cent, showing how cheaper inputs invite heavier use.
Labour savings cut both ways — less time on weeding is a gain for the grower but also less paid work in rural labour markets.

What to watch — Watch whether cotton input costs keep climbing on this trajectory, and the resulting pressure on farm margins, rural credit and support-price and import policy.

This is the finding of a single study, and the story does not establish the net effect on yields, cotton prices or overall farm incomes, nor does it carry any industry or government response.

Deep dive

Research brief · 8 facts · 7 dates · exam-ready

The brief

Context

Genetically modified crops such as Bt cotton and herbicide-tolerant (HT) soybean were promoted from the 1990s on the promise that built-in pest and weed resistance traits would cut chemical spraying. A study published on April 14, 2025 in the Journal of Agrarian Change argues the opposite happened over three decades: GM crops became embedded in input-intensive monocultures that raised total pesticide use. The authors explain this through the Jevons paradox, the 1865 idea of William Stanley Jevons that greater efficiency in using a resource can raise, not lower, its overall consumption. India's Bt cotton is the paper's central case.

Key facts

The study, titled 'GM Crops and the Jevons Paradox: Induced Innovation, Systemic Effects and Net Pesticide Increases From Pesticide-Decreasing Crops', was published on April 14, 2025 in the Journal of Agrarian Change.
It was conducted by researchers from Purdue University, Washington and Lee University and the International Cotton Advisory Committee in the United States.
Data covered four GM crops: Bt cotton, HT soybean, HT and/or Bt maize, and HT rapeseed (canola).
With Bt cotton, insecticide use and input costs initially fell, but by around 2010 pest resistance and new pests reversed the gains.
By 2018, Indian cotton farmers were spending 37 per cent more on insecticides than the pre-Bt high, the study said.
US soybean acreage treated with glyphosate rose from 9.2 million acres in 1994 (pre-HT crops) to 113 million acres by 2018.
US soybean area rose from 24.9 million hectares to 36.1 million hectares, while the share treated with glyphosate rose from 15 per cent to 87 per cent.
Monsanto (now part of Bayer) claimed glyphosate resistance was unlikely due to its complex mode of action, but resistance has evolved in dozens of weed species since 1998.

Timeline

1865William Stanley Jevons proposes the paradox that greater efficiency in resource use can increase overall consumption.
1994Before HT crops, 9.2 million acres of US soybean treated with glyphosate; 15 per cent of area treated.
Since 1998Glyphosate resistance evolves in dozens of weed species, contrary to Monsanto's claims.
2002Sharp drop in bollworm spraying in India due to drought, not Bt cotton; Bt seeds were under 2 per cent of India's cotton acreage.
Around 2010Pest resistance and new pests reverse early insecticide reductions under Bt cotton; applications rise significantly.
2018Indian cotton farmers spending 37 per cent more than the pre-Bt high; US glyphosate-treated soybean at 113 million acres (87 per cent of area).
April 14, 2025Study published in the Journal of Agrarian Change.

Who has a stake

Indian cotton farmers — Face rising insecticide costs — 37 per cent above the pre-Bt high by 2018 — after initial savings from Bt cotton.
Agrochemical and seed companies (Monsanto, now part of Bayer) — Sell the GM seeds and herbicides; their resistance claims for glyphosate are challenged by the study.
Researchers from Purdue University, Washington and Lee University, International Cotton Advisory Committee — Authors of the study applying the Jevons paradox to GM agriculture.
Governments and national policies — Government support accelerated Bt cotton adoption; policies are said to support input-intensive monocultures.
US, South American and Canadian growers of HT crops — Saw dramatic escalation in herbicide use on soybean, maize, sugar beet and rapeseed as GM adoption spread.

Why it matters

The study questions the core justification for GM crop adoption — that biotech traits reduce chemical dependence — by showing pesticide use rebounded or surpassed earlier levels in India and other GM-growing countries. For India, where Bt cotton dominates cotton cultivation, rising insecticide spending directly affects farm costs, indebtedness risk and farmer health. It also feeds the wider debate on whether efficiency-led technologies can fix ecological problems inside input-intensive monoculture systems.

UPSC angle

Prelims pointers

Jevons paradox: proposed by William Stanley Jevons in 1865 — efficiency gains in resource use can raise total consumption.
Bt cotton is India's GM crop case in the study; HT soybean, HT/Bt maize and HT rapeseed (canola) are the other three crops studied.
Study published April 14, 2025 in the Journal of Agrarian Change by Purdue University, Washington and Lee University and the International Cotton Advisory Committee.
By 2018 Indian cotton farmers spent 37 per cent more on insecticides than the pre-Bt peak.
Glyphosate is the broad-spectrum herbicide linked to HT crops; resistance emerged in dozens of weed species since 1998.
In 2002 Bt seeds were less than 2 per cent of India's cotton acreage; the spraying drop that year was due to drought.

Mains framing

The study frames GM crops as a textbook case of the Jevons paradox: traits that made chemical use more efficient at the plot level triggered wider adoption, monoculture expansion and eventually higher aggregate pesticide use. In India, Bt cotton initially lowered insecticide costs, which — with government support — accelerated adoption; but by around 2010 pest resistance and new pest complexes reversed the gains, and by 2018 farmers were spending 37 per cent more than the pre-Bt high. The same dynamic appears with HT crops: US soybean area treated with glyphosate rose from 9.2 million acres in 1994 to 113 million by 2018 (15 per cent to 87 per cent of area), while resistance emerged in dozens of weed species since 1998, with similar escalations in South America and Canada. The authors argue the problem is systemic rather than varietal — GM traits are embedded in input-intensive monocultures backed by agrochemical firms and national policies, which also intensify fertiliser and fossil fuel use. The implication for policy is that technology assessment must track system-level outcomes over decades, not just early input savings, and that resistance management and diversification of cropping systems matter as much as the seed trait itself.

Key terms

Bt cotton: Cotton genetically modified to express Bacillus thuringiensis toxin against bollworms, adopted in India to cut insecticide sprays.
Herbicide-tolerant (HT) crops: GM crops engineered to survive broad-spectrum herbicides such as glyphosate, allowing weed spraying over the standing crop.
Jevons paradox: Economic theory (Jevons, 1865) that greater efficiency in using a resource can increase its total consumption.
Glyphosate: Cheap broad-spectrum herbicide central to HT crop systems; weed resistance to it has spread since 1998.
Input-intensive monoculture: Large-scale single-crop farming reliant on heavy purchased inputs — pesticides, fertilisers and fossil fuels.
International Cotton Advisory Committee: US-based body whose researchers co-authored the study along with Purdue and Washington and Lee universities.

Practice questions

Examine, with reference to Bt cotton in India, how the Jevons paradox complicates claims that technological efficiency reduces resource use in agriculture.
"GM crops did not fail as seeds; they failed as a system." Critically analyse this statement using evidence on insecticide and herbicide use over the last three decades.
Discuss the implications of pest and weed resistance for India's cotton economy and suggest measures for sustainable pest management.

Grounded only in the source report — figures and dates are the source's, not inferred.

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