Technological change has driven economic progress in agriculture and will continue to play a crucial role in the 21st century. The latest wave of technological change in agriculture is based in molecular biology. Will horticulture participate? Genetically engineered crop varieties have been adopted on a wide scale in some agronomic crops, but horticultural crops face larger hurdles. High costs for research, development and regulatory approval combined with the small acreages planted and the diversity of varieties, will limit the potential for profitable applications of biotechnology to many fruits and vegetables, tree fruits and nuts, and nursery crops. In addition, there are market barriers. Like most important changes in agriculture, modern biotechnology has met with spirited political opposition from some quarters. Threats of political action may discourage food manufacturers and retailers from adopting biotech products that are wanted by some consumers and may be profitable for growers.