It is important to ask what isour baseline against which we compare the impact oftransgenic crops. The most reasonable baseline is currentagricultural practice with conventional crops. There may be erosion oftraditional practices,particularly in developingcountries. It is very important to preserve traditional practices, such as farmer saved seeds, where they are of vital importance to local agriculture. Interestingly, hybrid rice varieties are widely used in China because of their higher yield.
Farmers have to buy new seeds each year.
For progress to be made in cropimprovement, programmes either have to be publicly fundedand seeds made more or less freely available, or supported by private companies who need a financial return for their investment. Patents last for in the region of 15-17 years, so in many instances a transgene patent will have less than 10 years to run when a new transgenic variety is released commercially. This needs to be taken very seriously if we are to maintain sufficient genetic diversity in plant varieties. Transformation can however provide a means of inserting transgenes into locally adapted varieties without long periods of backcrossing. The evermore clinical control of pests, diseases and weeds are likely toleave little food in the agricultural environment to support adiversity of wildlife.