(Beyond Pesticides, May 24, 2013) Insecticide sales have soared over the past year as target insects have developed resistance to crops genetically engineered (GE) to incorporate an insecticide. Contrary to industry claims that the technology would reduce pesticide use, crops like corn, engineered to protect against rootworm have been ineffective and farmers have begun applying additional insecticides.
The GE corn seed, developed by Monsanto, was released in 2003 to target a gene allowing plants to express a pest-killing toxin, Bacillus thuringiensis (Bt). The pesticide incorporated plant (PIP) was developed to kill western corn rootworm, a potentially devastating pest that does its greatest damage in chemical-intensive agriculture during its larval stage by feeding upon the plant’s roots. Severe feeding inhibits the plant’s ability to absorb moisture and nutrients and opens a pathway for attack from soil-borne pathogens. In 2011, entomologists at Iowa State University published a study verifying the first field-evolved resistance of corn rootworm to a Bt toxin. The researchers documented resistance to the Bt toxin Cry3Bb1. Now, almost a decade after the seed was introduced, almost two thirds of U.S. grown corn contains the Bt toxin, according to the U.S. Department of Agriculture (USDA).
Although USDA data shows an initial decline in the share of acreage treated with insecticides between 2005 and 2010 by 14 percent, there has been a documented surge in insecticide sales, supporting the findings of academic research on resistance. Pesticide manufacturers American Vanguard, FMC Corp, and Syngenta have all reported higher sales in 2012 and 2013 than in previous years. Syngenta alone reported doubling sales in 2012. Similarly, American Vanguard reported soil insecticide revenues rose by 50% in 2012, and doubling its stock prices.
“When Bt hybrids were introduced one upside was a reduction in soil insecticides,” said Michael Gray, PhD at the University of Illinois, but “”¦those gains are quickly being reversed.”
In early 2012, a group of 22 prominent entomologists, including researchers from land grant institutions in the Corn Belt and the USDA’s Agricultural Research Service (ARS), submitted formal comments to the U.S. Environmental Protection Agency highlighting the uncertain future viability of Bt corn crops considering the severe rootworm damage that Midwestern farmers were facing despite planting Bt corn.
In addition to the problem of resistance to rootworm, recent research shows that the cultivation of Bt corn has negative impacts on beneficial soil life. Before monoculture production became standard practice for many farms, the western rootworm could be effectively managed by crop rotations, including pasture, hay and legume crop components, because the insect starves in fields not planted in corn.
Pest resistance is an inherent part of pesticide use. Farmers do not have to remain stuck on a pesticide treadmill that demands ever greater amounts of synthetic inputs and rewards chemical producers at the expense of farm profitability and the environment. A better option is to adopt organic agricultural practices, an ecologically-based management system that prioritizes cultural, biological, and mechanical production and natural inputs. By strengthening on-farm resources, such as soil fertility, beneficial organisms, and biodiversity, organic farmers avoid the production challenges that chemical inputs, such as synthetic pesticides, fertilizers and antibiotics, are marketed as solving.
Source: Wall Street Journal
All unattributed positions and opinions in this piece are those of Beyond Pesticides.