Table 2.
Yield impacts from using GM maize and cotton in Colombia.
| Crop | Yield of GM relative to conventional % difference | Range of yield impacts (where identified) | Source | Comments |
|---|---|---|---|---|
| Cotton (IR) | +35% 2007/08 | +9.2% to +75% | Zambrano et al7 | Reported growers in the interior region made significant yield gains whilst those in Caribbean region had mixed results and lower average levels of yield gain. See section for additional discussion |
| Cotton (IR) | None estimated | +29% to +48% | Fonseca L and Zambrano P10 | Yield comparisons from Cordoba (Coastal) region in 2009, comparisons by variety (containing only IR traits) |
| Cotton (HT and stack) | None estimated | −27% to −42% | Fonseca L and Zambrano P10 | Yield comparisons from Cordoba (Coastal) region in 2009, comparisons by variety (containing both HT and IR traits) |
| Cotton (stack) | None estimated | −23% to +21% | Zambrano14 | Small scale survey conducted in early 2010 with farms in El Espinal (Tolima) and Cerete (Cordoba) |
| Maize | +22% (stacked: IR and HT (tolerance to glufosinate) | None estimated/provided | Ávila Méndez K et al11 | Small scale survey in San Juan Valley (Tolima region) undertaken in 2009 |
| Cotton | +24.7% cotton stack | +3% to +39% | Céleres6 | Survey of farmers in main growing regions plus advisors, industry and public sector researchers |
| Maize | +16% maize stack | Zero to +31% | Céleres6 | Survey of farmers in main growing regions plus advisors, industry and public sector researchers |
| Cotton | +72% cotton stack | Not provided | Céleres15 | Small scale survey of farmers in main growing regions plus advisors, industry and public sector researchers |
| Maize | +8% maize stack | Not provided | Céleres15 | Small scale survey of farmers in main growing regions plus advisors, industry and public sector researchers |