Transgenic plants are rapidly dominating World agriculture and already the produce from millions of acres of transgenic insect and herbicide tolerant cotton, corn, soybean and canola being traded around the World, predominantly originating from the U. S. . By the end of the decade there will be few broad acre crops whose management would not have been changed uralterably by this new technology. The experiences from these early transgenic crops are in general good, providing good value to the farmer, but sporadic reports of poor performance of the transgenic traits and of variable performance of transgenic plants between different regions, suggest that we do not yet know enough about how genes function plants to perfectly predict the behaviour of transgenes under field conditions.