Disease Immunization
From the 1950s to 1995, a ringspot virus affected the papaya industry in Oahu, Hawaii. This ringspot virus causes darkened rings to appear on the papaya, and is the most dangerous and widespread virus that affects the papaya. If a papaya tree is infected with the virus at an early stage in their growth will become stunted, and will not produce any commercially or economically acceptable crop. In 1978 Hawaii native Dennis Gonsalves and a team of researchers began to search for a way to control the disease. Using a method that was similar to human vaccinations, the team spliced the papaya DNA with a mild strain of the virus, making the immunizing the papayas. The genetically engineered papaya seed was distributed to farmers, and by September of 1999, ninety percent of the farmers had the transgenic seeds and seventy-six percent had planted them. The genetically modified papayas grew twenty times more crop than the ones with the virus, and the use of the genetically engineered crops essentially saved the papaya industry. The genetically engineered papaya seeds made it easy to grow crops in a time of crisis, and this method of genetic engineering can be used to save other crops that are attacked by disease.