of Nicola Nosengo
Opponents of the use of genetically modified organisms in agriculture does, almost always, from concerns about their possible effects on health and the environment. But if these arguments now being compounded by even the suspicion that in reality GM crops are more expensive than traditional, life becomes very hard for their supporters. For this noise did the news come in these days of a search organized by the American Cornell University on cultivation of GM cotton in China , which showed that after seven years of application of these seed, Chinese farmers see substantially eroded the profits that had first taken from the reduced use of pesticides.
China was the first country to use extensively Bt cotton, which is genetically modified to contain the toxin produced by Bacillus thuringiensis , killing the main plant pests, the larva known as bollworm. As reported by Per Pinstrup-Andersen of Cornell at the annual meeting of the American Agricultural Economics Association in Long Beach, California, for the first three years, 481 farmers involved in the research had reduced pesticide use by 70 percent compared to the cultivation traditional, and had increased profits by 36 percent. However, within four years found themselves having to use the same amount of conventional pesticides producers up to earn 8 per cent less of them since the Bt seed cost three times more than traditional ones. The reason? The disappearance of the bollworm had encouraged the proliferation of other species of parasites, against which nothing can the toxin produced by the same cotton. To control these secondary pests now take up to 20 applications of pesticides in the course of a season. The
Bt cotton has been widely used in the four countries that are major world producers of cotton (China, United States, India and Argentina) for their economic security that seemed to provide. Today represents 35 percent of cotton crops in the world , and is widely utilizzato anche in Messico e Sud Africa. In Cina sono ben 5 milioni le aziende agricole che lo utilizzano.
Secondo Domenico Mariotti, responsabile della sede di Roma dell'Istituto di Biologia e Biotecnologia Agraria del Cnr, questi dati vanno però inquadrati nel particolare contesto dell'agricoltura cinese. “Prima di tutto, va ricordato che la coltivazione di cotone era praticamente scomparsa dalla Cina, ed è stata reintrodotta grazie al cotone Bt. Inoltre, in Cina le coltivazioni transgeniche sono state usate con un approccio troppo aggressivo e 'sfacciato', senza alcuna precauzione. Ci sono alcuni piccoli accorgimenti, usati per esempio dagli agricoltori negli Stati Uniti , che avrebbero permesso di prevenire this problem. For example, create areas of traditional cotton along the edge of cultivated fields with Bt cotton in this way we will maintain a small population of bollworm that continues to compete with other parasites keep their numbers low. It will prevent the bollworm developing resistance to Bt toxin.
assessments Mariotti coincide with those of the same authors of the study, inviting researchers and farmers to get in looking for solutions because the use of Bt cotton is not turned into reality in an even greater use of pesticides than traditional agriculture. Since the introduction of natural predators to control pests, forecasting required of those refuge areas planted with GM varieties not ; to develop more varieties of the plant can also ward off other predators. "Whether you are for or against GMOs, we must accept the fact that agriculture is a constant battle against plant pests," concludes the researcher of the CNR. "The more a plant yield, particularly the cotton is a plant very delicate, the more it is deprived of its natural defenses against parasites, and this also applies to the selection made with traditional crosses. "
China was the first country to use extensively Bt cotton, which is genetically modified to contain the toxin produced by Bacillus thuringiensis , killing the main plant pests, the larva known as bollworm. As reported by Per Pinstrup-Andersen of Cornell at the annual meeting of the American Agricultural Economics Association in Long Beach, California, for the first three years, 481 farmers involved in the research had reduced pesticide use by 70 percent compared to the cultivation traditional, and had increased profits by 36 percent. However, within four years found themselves having to use the same amount of conventional pesticides producers up to earn 8 per cent less of them since the Bt seed cost three times more than traditional ones. The reason? The disappearance of the bollworm had encouraged the proliferation of other species of parasites, against which nothing can the toxin produced by the same cotton. To control these secondary pests now take up to 20 applications of pesticides in the course of a season. The
Bt cotton has been widely used in the four countries that are major world producers of cotton (China, United States, India and Argentina) for their economic security that seemed to provide. Today represents 35 percent of cotton crops in the world , and is widely utilizzato anche in Messico e Sud Africa. In Cina sono ben 5 milioni le aziende agricole che lo utilizzano.
Secondo Domenico Mariotti, responsabile della sede di Roma dell'Istituto di Biologia e Biotecnologia Agraria del Cnr, questi dati vanno però inquadrati nel particolare contesto dell'agricoltura cinese. “Prima di tutto, va ricordato che la coltivazione di cotone era praticamente scomparsa dalla Cina, ed è stata reintrodotta grazie al cotone Bt. Inoltre, in Cina le coltivazioni transgeniche sono state usate con un approccio troppo aggressivo e 'sfacciato', senza alcuna precauzione. Ci sono alcuni piccoli accorgimenti, usati per esempio dagli agricoltori negli Stati Uniti , che avrebbero permesso di prevenire this problem. For example, create areas of traditional cotton along the edge of cultivated fields with Bt cotton in this way we will maintain a small population of bollworm that continues to compete with other parasites keep their numbers low. It will prevent the bollworm developing resistance to Bt toxin.
assessments Mariotti coincide with those of the same authors of the study, inviting researchers and farmers to get in looking for solutions because the use of Bt cotton is not turned into reality in an even greater use of pesticides than traditional agriculture. Since the introduction of natural predators to control pests, forecasting required of those refuge areas planted with GM varieties not ; to develop more varieties of the plant can also ward off other predators. "Whether you are for or against GMOs, we must accept the fact that agriculture is a constant battle against plant pests," concludes the researcher of the CNR. "The more a plant yield, particularly the cotton is a plant very delicate, the more it is deprived of its natural defenses against parasites, and this also applies to the selection made with traditional crosses. "
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