Transgenic crop plants for resistance to biotic stress

The human population is everexpanding; conservative estimates predict that the population will reach ten billion by 2050 (United Nations Population Division), and the ability to provide enough food is becoming increasingly difficult (Chrispeels and Sadava 2003). The planet has a finite quantity of land available to agriculture and the need for increasing global food production has led to increasing exploitation of previously uncultivated land for agriculture; as a result wilderness, wetland, forest and other pristine environments have been, and are being, encroached upon (Ferry and Gatehouse 2009). The minimization of losses to biotic stress caused by agricultural pests would go some way to optimizing the yield on land currently under cultivation. For nearly 50 years, mainstream science has told us that this would be impossible without chemical pesticides (Pimental 1997). The global pesticide market is in excess of $30 billion per year (Levine 2007); despite this, approximately 40% of all crops are lost directly to pest damage (Fig. 1.1). These figures are simplified rough estimates; in reality crop losses to biotic stress are extremely difficult to quantify and vary by crop, year, and region.