If cross-pollination occurs, are negative agricultural or environmental impacts inevitable?
No. Specific impacts depend upon the crop, the function of the biotech genetic material and the commercial interests of the grower. Looking at the experience gained from growing conventionally bred crops for many decades, it seems that rarely, if ever, will cross-pollination of biotech and non-biotech crops have negative agricultural impacts. In a few instances, herbicide tolerance genes in conventional crops have made weed control more difficult, but manageable, in some crop rotation systems. On the other hand, there are no reports of insect resistance and disease resistance genes in conventionally bred crops causing problems for farmers. Trace amounts of cross-pollination between biotech and non-biotech crops could have negative economic impacts if regulatory agencies establish thresholds for genetic purity of non-biotech grain that exceed long-established standards.
