Do GM crops reduce pesticide use? Now that's an interesting question
GMOPundit
David Tribe
June 14, 2007
Excerpt…
Statement of
Leonard Gianessi
Senior Research Associate, National Center for Food and Agricultural Policy
Before the U.S. Environmental Protection Agency
Science Advisory Panel on Bt Plant Pesticides: Risk and Benefit Assessments
October 20, 2000
My name is Leonard P. Gianessi. I’m a Senior Research Associate at the National Center for Food and Agricultural Policy (NCFAP), a private non-profit research group here in Washington.
In July 1999, my colleague Janet Carpenter and I released a national assessment of the aggregate benefits of the planting of Bt corn, cotton and potatoes in the U.S. We are pleased to see that EPA was able to use our report in its analysis of the benefits of the Bt crops.
I’ll comment briefly on some differences in methodology between the EPA report and ours and offer some suggestions for improving the methodology.
One benefit measure that EPA does not include in its report is a measure of the increase in production that has occurred as a result of planting Bt crops. We estimate that the U.S. produced an extra 60 million bushels (or 4 billion pounds) of corn in 1998 by planting Bt corn and preventing damage from the European corn borer. That is the equivalent of 450,000 acres of corn that would have been destroyed by the corn borer, and this took place in a year with relatively light infestation (1998). Cotton growers produced an extra 85 million pounds of cotton as a result of planting Bt cotton to control insect pests.
EPA found the same problem that we did in estimating the impact of Bt corn on insecticide use. There was not a lot of spraying for the European corn borer before the introduction of Bt corn, and there is no a clear-cut set of pesticides that can be attributed solely to European corn borer control. EPA estimates, as we do, that the use of the insecticides recommended for European corn borer control went down, but these insecticides are used for other pests, as well. We come out at pretty much the same place – a modest reduction in corn acres treated with insecticides, perhaps 1 or 2% of 80 million acres. I suggest that EPA consider an alternative way of estimating the impact of Bt corn on insecticide use. That would be to estimate the increase in insecticide use if Bt corn registration were to be cancelled. Bt corn is being planted on 20% of the corn acres. Growers were not spraying 20% of the acres for European corn borer control; they were spraying only 5 to 8%. If Bt corn were to be taken away from U.S. farmers, the use of insecticides would rise significantly above the 1 or 2% reduction that occurred. For the first time, growers are using an effective control. They are seeing the value of controlling the pest, and without Bt corn, they are likely to spray 18 to 20% of the acres. I think that EPA could conduct such a simulation and estimate the potential increase that would occur. That is another way of estimating benefits – estimating what would happen if it were taken away….
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