The transgene was designed with a premature stop codon in the PRSV coat protein sequence to prevent expression of a functional coat protein because, at the time of engineering, it was thought that the protein itself was an important factor in resistance. RNA analysis later revealed that the plants with the best resistance exhibited the least detectable message, which was suggestive of the involvement of an RNA silencing mechanism . Conceptually similar to human vaccinations against polio or small pox, this treatment “immunized” the papaya plant against further infection. The genetically engineered papaya yielded 20 times more papaya than the non-genetically engineered variety after PRSV infection. By September 1999, 90% of the Hawaiian farmers had obtained genetically engineered seeds, and 76% of them had planted the seeds. After release of genetically engineered papaya to farmers, production rapidly increased from 26 million pounds in 1998 to a peak of 40 million pounds in 2001. Today, 80–90% of Hawaiian papaya is genetically engineered. There is still no conventional or organic method to control PRSV. Funded mostly by a grant from the USDA,stacking flower pot tower the project cost  $60,000, a small sum compared to the amount the papaya industry lost between 1997 and 1998, prior to the introduction of the genetically engineered papaya.Peer-reviewed studies of the genetically engineered crops currently on the market indicate that such crops have contributed to enhancing global agricultural sustainability.

As reviewed here, benefits include massive reductions in insecticides in the environment , improved soil quality and reduced erosion , prevention of the destruction of the Hawaiian papaya industry , enhanced health benefits to farmers and families as a result of reduced exposure to harsh chemicals , economic benefits to local communities , enhanced biodiversity of beneficial insects , reduction in the number of pest outbreaks on neighboring farms growing non-genetically engineered crops , and increased profits to farmers . Genetically engineered crops have also dramatically increased crop yields—.30% in some farming communities . As has been well-documented for Bt cotton in Arizona, the ability to combine innovations in farming practice with the planting of genetically engineered seed has had a huge positive benefit/cost ratio, far beyond what could be achieved by innovating farming practices or planting genetically engineered crops alone. The benefit/cost ratio of Bt crops is the highest for any agricultural innovation in the past 100 years. There are dozens of useful genetically engineered traits in the pipeline, including nitrogen use efficiency . Success of crops enhanced for this efficiency would reduce water eutrophication caused by nitrogenous compounds in fertilizers and greenhouse gas emissions resulting from the energy required to chemically synthesize fertilizers. The USDA Animal and Plant Health Inspection Service has developed a transgenic plum variety, the “Honey Sweet,” which is resistant to Plum Pox, a plant disease that infects plum and other stone fruit trees, including peach, nectarine, plum, apricot, and cherries.

Although Plum Pox is very rare in the United States, and its outbreaks are immediately eradicated, the Honey Sweet variety was developed as a precautionary measure to avoid a major disruption in the availability of plums, prunes, and other stone fruits should Plum Pox become widespread as is already the case in Europe Usda Animal and Plant Health Inspection Service 2009. Other promising applications of genetic engineering are those that affect staple food crops. For example, rice is grown in .114 countries on six of the seven continents. In countries where rice is the staple food, it is frequently the basic ingredient of every meal. Thus, even modest changes in tolerance to environmental stress or enhanced nutrition in rice can have a large impact in the lives of the poor. With regard to nutritional enhancements, some efforts have focused on vitamin deficiencies. Vitamin A deficiency is a public health problem in .100 countries, especially in Africa and Southeast Asia, affecting young children and pregnant women the most . Worldwide, .124 million children are estimated to be vitamin A-deficient. Many of these children go blind or become ill from diarrhea, and nearly 8 million preschool-age children die each year as the result of this deficiency. Researchers estimate that 6000 children and young mothers die every day from vitamin A deficiency-related problems . The World Health Organization estimates that improved vitamin A nutritional status could prevent the deaths of 1.3–2.5 million late-infancy and preschool-age children each year . To combat vitamin A deficiency, the World Health Organization has proposed an arsenal of nutritional “well-being weapons,” including a combination of breastfeeding and vitamin A supplementation, coupled with long-term solutions, such as promoting vitamin A-rich diets and food fortification. In response to this challenge, a group of Rockefeller Foundation-supported scientists decided to try to fortify rice plants with higher levels of carotenoids, which are precursors to vitamin A.

Using genetic engineering, they introduced a gene from daffodils and two genes from a bacterium into rice . The resulting geneticially engineered golden and carotenoid-rich rice plants were named “Golden Rice.” Results from human feeding studies indicate that the carotenoids in the second generation of Golden Rice can be properly metabolized into the vitamin A that is needed by children . One 8-ounce cup of cooked Golden Rice-2 provides  450mg of retinol, which is equivalent to 50–60% of the adult Recommended Dietary Allowance of vitamin A. Other studies support the idea that widespread consumption of Golden Rice would reduce vitamin A deficiency, saving thousands of lives . The positive effects of Golden Rice are predicted to be most pronounced in the lowest income groups at a fraction of the cost of the current supplementation programs . If predictions prove accurate, this relatively low-tech, sustainable, publicly funded, people-centered effort will complement other approaches, such as the development of home gardens with vitamin A-rich crops, such as carrots and pumpkins. In a sense, the resulting nutritionally enhanced rice is similar to vitamin D-enriched milk—except the process is different. Vitamin A fortification of rice is also similar to adding iodine to salt, a process credited with drastically reducing iodine-deficiency disorders in infants. Worldwide, iodine deficiency affects  2 billion people and is the leading preventable cause of mental retardation. The benefits of iodized salt are particularly apparent in Kazakhstan where local food supplies seldom contain sufficient iodine and where fortified salt was initially viewed with suspicion. Campaigns by the government and nonprofit organizations to educate the public about fortified salt required both money and political leadership, but they eventually succeeded. Today, 94% of households in Kazakhstan use iodized salt, and the United Nations is expected to certify the country officially free of iodine-deficiency disorders . The development of genetically engineered crops that are tolerant of environmental stresses is also predicted to be broadly beneficial. Such crops are expected to enhance local food security,ebb and flow an issue of importance especially for farmers in poorer nations that have limited access to markets and are now often dependent on others for their staple foods . The development of submergence tolerant rice , through a non-genetically engineered process that involved gene cloning and precision breeding, demonstrates the power of genetics to improve tolerance to environmental stresses such as flooding, which is a major constraint to rice production in South and Southeast Asia . In Bangladesh and India, 4 million tons of rice, enough to feed 30 million people, are lost each year to flooding. Planting of Sub1 rice has resulted in three- to fourfold yield increases in farmers’ fields during floods compared to conventional varieties. Although the Sub1 rice varieties provided an excellent immediate solution for most of the submergence-prone areas, a higher and wider range of tolerance is required for severe conditions and longer periods of flooding. With increasing global warming, unusually heavy rainfall patterns are predicted for rain-fed as well as irrigated agricultural systems. For these reasons, we and others have identified additional genes that improve tolerance . Such genes may be useful for the development of “Sub1plus” varieties. In Africa, three-quarters of the world’s severe droughts have occurred over the past 10 years.

The introduction of genetically engineered drought-tolerant corn, the most important African staple food crop,is predicted to dramatically increase yields for poor farmers . Drought-tolerant corn will be broadly beneficial across almost any non-irrigated agricultural situation and in any management system. Drought-tolerance technologies are likely to benefit other agricultural crops for both developed and developing countries. In addition to environmental stresses, plant diseases also threaten global agricultural production . For example, an epidemic of stem rust threatens wheat, a crop that provides 20% of the food calories for the world’s people. Because fungal spores travel in the wind, the infection spreads quickly. Stem rust has caused major famines since the beginning of history. In North America, huge grain losses occurred in 1903 and 1905 and from 1950 to 1954. During the 1950s, Norman Borlaug and other scientists developed high-yielding wheat varieties that were resistant to stem rust and other diseases. These improved seeds not only enabled farmers around the world to hold stem rust at bay for .50 years but also allowed for greater and more dependable yields. However, new strains of stem rust, called Ug99 because they were discovered in Uganda in 1999, are much more dangerous than those that destroyed as much as 20% of the American wheat crop 50 years ago. Effective resistance does not exist in American wheat and barley varieties, but recently resistance was identified in African varieties and molecular markers mapped to facilitate introgression of the trait using marker-assisted selection . Bananas and plantains are the world’s fourth most important food crop after rice, wheat, and maize. Approximately one-third of the bananas produced globally are grown in sub-Saharan Africa, where the crop provides .25% of the food energy requirements for .100 million people in East Africa alone. Banana Xanthomonas wilt disease, caused by the Gram-negative bacterium Xanthomonas vasicola pv. musacearum, is amajor threat to banana productivity in eastern Africa . Cavendish banana, which represents 99% of export bananas, is threatened by a virulent form of the soil-borne fungus Fusarium oxysporum called Tropical Race Four . The fungal leaf spot disease Black Sigatoka, caused by the ascomycete Mycosphaerella fijiensis, has spread to banana plantations throughout the tropics and is increasingly resistant to chemical control . Research to develop new methods to control these diseases of banana are underway in several laboratories.South Korea and the United States signed a free trade agreement on April 1, 2007, after an intensive year-long negotiation process. Although the bilateral negotiations have been finalized, the agreement must be approved by each country’s legislature for the agreement to be implemented, and it faces considerable opposition in each country. In the United States, the Bush administration slated passage of the Korean FTA as a major goal for 2008, but other events intervened and the administration had little influence in Congress. The Obama administration has not focused on trade issues yet. In Korea, although negotiated by the previous government, the agreement is strongly supported by the Lee administration. The Korea-United States Free Trade Agreement has the potential to be a significant demand driver for California agriculture. The Korean economy, comprised of almost 50 million consumers, has been growing rapidly for decades and has percapita income that exceeds those of many European countries and approaches that of Spain. As a relatively large, relatively high-income country with a well-developed food and fiber distribution system, Korea is a major market for agricultural goods of the type produced in California. As the country has become more industrialized overall, Korean agriculture has been increasingly losing competitiveness. Korea has relatively little arable land per capita and is now a highly urban country with agriculture accounting for only 3% of gross domestic product and 7% of the population. Because per capita income is high by world standards, Korea’s many small farms have relied on high domestic commodity prices to maintain farm incomes comparable to rapidly improving urban incomes. Nonetheless, the farm population is aging and rapidly declining in number. Despite high import tariffs, tight import quota quantities, and restrictive sanitary and phytosanitary regulations, Korea has become a major agricultural importer with imported products comprising an increasing share of food consumption expenditures.