Biotech has been around for 20 years. Why hasn’t it increased crop yields significantly in all that time?
Failure to Yield documents an extensive effort by the industry to increase yields through GE, with several thousand experimental field trials of GE traits associated with yield carried out in the United States over a period of 20 years (see Failure to Yield, Chapter 3). Still, only Bt corn has increased yield, and that small gain is for operational rather than intrinsic yield. One likely reason is that new yield genes often have much more complex genetic interactions with the plant genetic material than the few currently successful transgenes, and therefore cause more genetic side-effects that often lead to undesirable agricultural properties. Because of this, many of these new genes may not be successful, or may come with undesirable properties in addition to increased yield (see Failure to Yield, Chapter 5).
- What will be the effects of an increased UV-B radiation on crop and forest yields? Can plants protect themselves against increased UV-B?
- Most of the need for increased crop yield is in developing countries. Has GE increased food crop yields in those parts of the world?
- If GE crops haven’t significantly increased yields, why have so many farmers adopted them?