Sensitive dependencies and separation distances for genetically modified herbicide-tolerant crops

Abstract

The amount of land available for the coexistent growing of both organic and genetically modified herbicide-tolerant (GMHT) crops depends on the separation distance between the two types of crop. The form of the decline in the proportion of land available for growing one of these crop types due to increasing separation distance is linear on a suitable scale, but with a slope and intercept that are sensitively dependent on the proportion of the other crop already present. Spatially explicit simulations from realistic scenarios indicate that a major increase in separation distances, currently under review by the UK government, may have serious implications for the future coexistence of organic and GMHT crops in the UK.

Enhancing Sustainability of Cotton Production Systems in West Africa: A Summary of Empirical Evidence from Burkina Faso

“…This regulatory regime is based on the assumption that separation distances are sufficient to reduce the probability of gene outflow events within an acceptable minimum level [104,106]. There is a wide variation in what constitutes such a minimum distance.…”

“…Most countries legislate the isolation of Bt crops at prescribed minimum distances from conventional non-Bt fields in order to manage risks of gene outflow [103][104][105]. This regulatory regime is based on the assumption that separation distances are sufficient to reduce the probability of gene outflow events within an acceptable minimum level [104,106].…”

The influence of pollinator abundance on the dynamics and efficiency of pollination in agricultural Brassica napus: implications for landscape‐scale gene dispersal

“…There is also interest in the extent to which GM genes may spread into wild relatives of B. napus (Wilkinson et al . 2003) and into conventional and organic crops (Ingram 2000;Ellstrand 2001;Perry 2002;Snow 2002). Potentially, the co-existence of conventional and GM crops may compromise a farmer's ability to certify produce for sale in the potentially lucrative GM-free market in Europe (Belcher, Nolan & Phillips 2005).…”

Coexistence in the EU—return of the moratorium on GM crops?

“…In ex ante coexistence regulations, preventive on-farm measures are prescribed volume 26 number 11 november 2008 nature biotechnology the cropped area 5,10,11 . In these cases, it is highly probable that isolation perimeters would interfere with adjacent non-GM maize fields.…”