Table 3 Data sources and assumptions required to quantify the impact of GE crops on pesticide use in the U.S., 1996-2011
From: Impacts of genetically engineered crops on pesticide use in the U.S. -- the first sixteen years
Parameter | Source | Supplemental table impacted | Basis and explanation |
|---|---|---|---|
National Pesticide Use per Acre/Hectare | NASS-USDA | 1, 2 | Best publicly available estimates of annual per acre herbicide and insecticide use |
Annual Gaps in NASS Survey Data by Crop | Interpolated | 1, 2 | Changes in total herbicide, glyphosate, and insecticide use occur linearly/annum when there are gaps in NASS pesticide use surveys |
Annual Application Rates of "Other Herbicides on HR Hectares" | (See Table 4) | 8, 9, 10 | Trends by crop on HR acres track changes in total herbicide use, as reported by NASS; changes from year to year are gradual |
Bt Cry Proteins Produced by Bt Corn and Cotton Plants | Projected (see text, Additional files) | 20-25 | Trait-specific expression levels by tissue taken from documents submitted by technology developers; used to quantify volume of each Bt endotoxin produced by plants per acre/hectare based on typical planting density |
Insecticide Use on Bt Corn | (Details in Table 4) | 11, 12 | Insecticide displacement as a result of planting Bt corn corrected for hectares not likely to have been treated in the absence of Bt corn cultivars |
Insecticide Use on Bt Cotton | NASS-USDA | 13 | Budworm/bollworm control insecticide displacement on hectares planted to Bt cotton is 100% |