Genetically engineered crops and pesticide use in U.S. maize and soybeans

Abstract

The impact on pesticide use of genetically engineered maize and soybean varieties has changed over time.

Re-registration Challenges of Glyphosate in the European Union

“…The study claims that increases in herbicide usage increased more rapidly on non-GM crops than on GM crops, and concludes that the replacement of glyphosate with other herbicides would be likely to result in increased chronic health risks to pesticide applicators. This strongly contradicts to earlier surveys (Heinemann et al, 2014;Benbrook, 2016;Perry et al, 2016), and is likely to be related to the fact that Kniss' study considered 159 herbicide formulations of 118 herbicide active ingredients, while herbicide-tolerant (HT) crops are designed against 8 herbicide active ingredients or active ingredient types (2,4-D, dicamba, glufosinate, glyphosate, oxynil type, sulfonylureas, imidazolinones, isoxaflutole), of which glyphosate by far is used most substantially in cultivation. Therefore, such an "overall" trend of all active ingredients considered, the vast majority of which not being related to HT crops is biased particularly for glyphosate, concealing the immense increases in glyphosate use in the grand average.…”

Agricultural GMOs—What We Know and Where Scientists Disagree

“…Looking at EIQ, the overall effect of GMO on pesticide applications becomes unambiguously positive for the three main crops cultivated in the USA. Farmers who adopted HT soybean and maize used herbicides representing lower total EIQ than those who planted conventional varieties, while those who adopted IR maize used insecticides at a level that also represented a lower EIQ than the levels used on conventional varieties [27,37].…”

“…Regarding the arguments on the production side, GMO crops generally see a decrease in total pesticide applications as measured by environmental impact quotient, or EIQ [27]. The EIQ is a commonly-used measure of that compares pesticides across multiple attributes in order to generate a single value to reflect overall toxicity [28,29].…”

“…A systematic survey of pesticide use on three major GMO crops in the USA-HT soybeans, HT maize, and IR maize-found that, relative to farmers planting conventional varieties, farmers who adopted GMOs reduced the total quantities of pesticides applied in the cases of HT maize and IR maize, but increased total quantities in the case of HT soybeans [27]. Looking at EIQ, the overall effect of GMO on pesticide applications becomes unambiguously positive for the three main crops cultivated in the USA.…”

Novel mechanism of thrips suppression by Cry51Aa2.834_16 Bt toxin expressed in cotton

“…Currently, Bt row crop plants express multiple insect‐protection genes that target economically important insect pests of crops . These advances in GE crops have improved pest management efficiency and reduced the use of insecticides in major row crops worldwide (i.e., corn, cotton, and soybean) . Despite widespread adoption of insect‐protection Bt traits in row crops, commercially available Bt row crop plants kill only a small number of species in two insect orders, Coleoptera and Lepidoptera .…”