Cotton
Scientists and farmers have developed a number of strategies to reduce the need for large quantities of pesticides and fertilizers when growing cotton.
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One of the greatest challenges of widespread cultivation of a single species of plant is that the crop is extremely susceptible to disease and insect predation; growing cotton requires more pesticides than any other crop. Working around the challenges of growing cotton has been a project throughout the 7,000-year history of cotton’s cultivation.
In 1901 a blight on Peruvian cotton prompted Fermín Tangüis, a Puerto Rican agriculturist, to study which cotton seeds were less affected by the fungus. He conducted experiments for 10 years and finally developed a strain of cotton that was not only disease-resistant, but also grew and performed much better. By 1918, Peruvians began exporting the Oro Blanco, “white gold,” and together with sugar exports, sales from these commodities allowed the nation to cover its budget. Today, Peruvian Tanguis cotton is valued worldwide.
Modern science has been able to take a more direct approach to make cotton more disease- and insect-resistant. By genetically modifying a strain of cotton to include a segment of DNA from the bacterium, Bacillus thuringiensis (Bt) the plants are provided a natural insecticide against the larvae of moths, beetles, butterflies, and flies. As a result, a smaller volume of pesticides should be required to grow this type of cotton. Another strategy that has been adopted to make cultivation more efficient has been to genetically modify cotton to contain a specific resistance to the glyphosphate pesticide known as Roundup®. In this way, the broad spectrum herbicide can be used on fields without harming the cotton while effectively controlling weeds. Both of these strategies were designed to reduce the amount of pesticides that would be used on the fields and that would subsequently enter the environment.
Considering the numerous pests that can infest and damage cotton, the challenge to farmers wishing to produce organic cotton – which is defined as not genetically engineered and free from fertilizers and pesticides – cannot be underestimated. These farmers must substitute integrated pest management approaches that might include growing slightly different plant varieties that have natural resistance to identified pests, crop rotation, physical removal of weeds, and greater biodiversity. Because these products tend to be more challenging and labor intensive, organic products are commonly more expensive than their non-organic counterparts, but they demonstrate an effort to leave a smaller footprint in the environment.
More information about cotton can be found at http://www.cotton.org/edu/faq/ and http://www.sustainablecotton.org/.