AgBioForum, 7(1&2): 27-30. 2004 AgBioForum.

Global Impact of Insect-Resistant (Bt) Cotton

John P. Purcell and Frederick J. Perlak
Monsanto Company

Insect-resistant (Bt) cotton has been rapidly adopted since its

introduction in 1996. Farmers around the worldboth large and
smallholdersbenefit from this technology through increased
productivity, convenience, and time savings. The vast majority
of farmers using Bt cotton globally are smallholder farmers. The
economic, environmental, and social benefits derived from
adoption of this important tool have very positive implications for
the farmers, their surrounding communities, and the future of
agriculture.
Key words: Bacillus thuringiensis (Bt); insect-resistant cotton;
smallholder farmers; economic, environmental and social
impact

Introduction
Insect-resistant cotton was first introduced commercially in 1996. It is commonly referred to as Bt cotton,
because it produces an insecticidal protein from the naturally occurring soil bacterium Bacillus thuringiensis
(Bt). Global adoption of Bt cotton has risen dramatically
from 800,000 hectares in its year of introduction in 1996
to 5.7 million hectares (alone and stacked with herbicide-tolerant cotton) in 2003. Significant economic and
production advantages have resulted from growing Bt
cotton globally. Bt cotton can substantially reduce the
number of pesticide sprayings, which reduces worker
and environmental exposure to chemical insecticides
and reduces energy use. The quality of life for farmers
and their families can be improved by the increased
income and time savings offered by Bt cotton. These
economic, environmental, and social benefits are being
realized by large and smallholder farmers alike in eight
countries around the world.

Development of Bt Cotton
Bt cotton produces an insecticidal protein (Cry1Ac)
from the naturally occurring soil bacterium Bacillus thuringiensis (Bt) that protects the cotton plant from certain
lepidopteran (caterpillar) insect pests (Perlak et al.,
2001). Coker 312 cotton was transformed to express the
Cry1Ac gene from Bt, resulting in cotton plants that
were resistant to attack from major lepidopteran pests
(Perlak et al., 1990). Many years of development followed to deliver the trait in germplasm varieties that
meet the strict agronomic requirements of growers
worldwide (Perlak et al., 2001). In the United States,
Monsantos Bt cotton is known as Bollgard cotton.
Extensive testing of Bt plants has demonstrated their
safety and advantages (Betz, Hammond, & Fuchs,
2000). The food, feed, and environmental safety of Boll-

gard cotton was evaluated by regulatory agencies prior

to commercialization. Regulatory approval has been
granted in countries where Bt cotton is grown as well as
in countries that import Bt cottonseed products. Studies
were conducted on the safety of the produced proteins,
food/feed composition, and environmental safety. On
the basis of this evaluation, Bollgard cotton and its
processed fractions were found to be substantially
equivalent to conventionally bred cotton, and the Bt protein was shown to be safe for human and animal consumption. Bt cotton was found to pose comparable or
fewer risks to the environment than traditional cotton
treated with commercially approved insecticides.
Safety data on Bollgard has been provided to additional regulatory authorities globally, and regulatory
review continues in these countries.

Adoption of Bt Cotton
Global adoption of Bt cotton has risen dramatically
from 800,000 hectares in 1996 to 5.7 million hectares
(alone and stacked with herbicide-tolerant cotton) in
2003 (James, 2003). In 2002, Bt cotton was grown commercially in the United States, Mexico, Argentina,
South Africa, China, India, Australia, and Indonesia,
and precommercial plantings were grown in Colombia
(James, 2002). Bt cotton is a global product, with plantings in North America (United States), Australia, three
countries in Latin America, one country in Africa, and
three countries in Asia. Large-acreage farmers in industrialized countries (such as the United States and Australia) derive significant value from Bt cotton, but the vast
majority of growers are in developing countries. More
than six million Bt cotton farmers are in developing
countries; the vast majority of these are resource-poor
farmers in China and South Africa (James, 2002). A
number of studies have examined the significant eco-

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Figure 1. Potential economic and production benefits of Bt cotton. Adapted from Purcell et al. (2004).

nomic, environmental, and social benefits derived from

growing Bt cotton (International Service for the Acquisition of Agri-biotech Applications, 2002; Ismael, Bennett, & Morse, 2002a, 2002b; James, 2002; Pray, Huang,
Hu, & Rozelle, 2002; Purcell, Oppenhuizen, Wofford,
Reed, & Perlak, 2004).

Economic and Production Benefits

Significant economic advantages have resulted from
growing Bt cotton around the world (Figure 1). Bt cotton provided US farmers with an average net income
increase of $20/acre and increased the total net value of
US cotton production by $103 million in 2001 (Gianessi, Silvers, Sankula, & Carpenter, 2002). In China, net
revenue increases have ranged from $357/hectare to
$549/hectare in the three years studied when one compares Bt cotton with non-Bt cotton (Pray et al., 2002). In
South Africa, smallholder farmers in the Makhathini
region raised their yields and reduced their application
costs, netting an economic advantage for Bt cotton
growers of about $2551/hectare (Ismael et al., 2002a,
2002b). Yield advantages have been noted in a number
of studies, ranging from 510% in China, more than
10% in the United States, and more than 20% in four
other countries (James, 2002). A recent report found
that in field trials in India, average yields for Bt cotton
hybrids were 80% greater than non-Bt hybrids (Qaim &
Zilberman, 2003), although other results from India are
less dramatic (James, 2002). Production advantages can
result from the level of insect control achieved and the
time savings and reduced labor needs that may result
(Benedict & Altman, 2001; Edge, Benedict, Carroll, &

Reding, 2001). Bt cotton is a valuable option for growers, as it provides superior pest control of pests with several features that provide advantages over other insect
control agents (Benedict & Altman, 2001; Edge et al.,
2001; Perlak et al., 2001).

Environmental Benefits
Bt cotton can substantially reduce the number of pesticide sprayings, which can provide significant environmental benefits (Figure 2). A number of studies have
demonstrated that insecticide sprays are reduced by
using Bt cotton (Carpenter et al., 2002; Edge et al.,
2001; James, 2002). Growers in the United States
reduced insecticide use by 1,870,000 pounds of active
ingredient (AI) per year in 2001 (Gianessi et al., 2002).
In China, insecticide applications were reduced by an
average of 67% and the kilograms of active ingredient
by 80% (Huang, Rozelle, Pray, & Wang, 2002), while
South African growers reduced sprays by 66% (Ismael
et al., 2002a). The use of Bt cotton in place of conventional systems can positively impact nontarget organisms (NTOs) and beneficial organisms by preserving
populations (Head et al., 2001; Smith, 1997; Xia, Cui,
Ma, Dong, & Cui, 1999) and is compatible with integrated pest management initiatives (Benedict & Altman,
2001). In addition, Bt cotton adoption can provide secondary positive environmental impacts such as (a) saving on raw materials needed to manufacture chemical
insecticides; (b) conserving fuel oil required to manufacture, distribute, and apply such insecticides; and (c)
eliminating the need to use and dispose of insecticide
containers (Leonard & Smith, 2001).
Purcell & Perlak Global Impact of Insect-Resistant (Bt) Cotton

AgBioForum, 7(1&2), 2004 | 29

Figure 2. Potential environmental benefits of Bt cotton. Adapted from Purcell et al. (2004).

Figure 3. Potential smallholder farmer benefits of Bt cotton. Adapted from Purcell et al. (2004).

Benefits for Smallholder Farmers

Bt cotton and other tools which lead to more productive
agricultural systems can benefit smallholder farmers and
their broader agricultural communities (Figure 3). At the
macroeconomic level, the increased productivity can
stabilize production and reduce risks for lenders. At the
farm level, improvements in the insect control system
being used can positively impact the quality of life for
farmers and their families by increasing incomes, reducing insecticide sprayings, and offering savings in time
(Ismael et al., 2002a; Pray et al., 2002). The nutritional
demands of families may also be better met, as these
families now have increased income that could potentially be used for more food purchases and food consumption (James, 2002; Pray, Ma, Huang, & Qiao,
2001). Time savings may be particularly important for

women in South Africa, where women serve as heads of

many of the households. The time saved by using Bt
cotton may allow these women to care for children, elderly, or the sick or to engage in income-generating activities (Ismael et al., 2002a). Children were also a
beneficiary of this technology, as those children in
South Africa who no longer have to spray insecticides
could now potentially devote more time to educational
or other worthwhile pursuits (Ismael, 2002a). Water savings from using Bt cotton by reducing insecticide sprays
are another source of significant benefits for smallholder farmers. The use of Bt cotton on a typical 1.7
hectare farm in the Makhathini Flats region of South
Africa would result in a labor reduction of 12 days of
spraying, eliminate 100 km of walking, and save 1,000
liters of water while increasing income by $85 (James,
Purcell & Perlak Global Impact of Insect-Resistant (Bt) Cotton

AgBioForum, 7(1&2), 2004 | 30

2002). These cumulative benefits have dramatic social

relevance for a segment of society that can benefit most.

Summary
Bt cotton is an increasingly important tool for farmers
around the world. Large- and small-acreage farmers
benefit from increased productivity, convenience, and
time savings. The vast majority of farmers using Bt cotton globally are smallholder farmers who may reap economic, environmental, and social benefits from
adoption of this important tool for agriculture. Adoption
of this technology has led to positive implications for
the farmers, their surrounding communities, and the
future of agriculture.

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