Posts Tagged: grapes
When consumers are asked in surveys whether they would buy genetically engineered (GE) produce such as fruit, most say they would not buy GE produce unless there were a direct benefit to them, such as greater nutritional value.
Yet with continuing invasions and spread of exotic insects and diseases for which there is no known control, the potential importance of trees or vines with some form of genetically engineered resistance is on the rise. In California, such diseases include Pierce's disease in grapes, crown gall disease in walnuts, and the invasive citrus greening (huanglongbing or HLB) in citrus.
"These are potentially devastating diseases to California growers, who produce 70 percent of the fresh fruit and nuts for the entire United States," notes Victor Haroldsen, scientific analyst at Morrison and Foerster, in the current California Agriculture. "They are also a mainstay of the California economy. Fruit and nut tree crops accounted for one-third of the state's total cash farm receipts, or $13.2 billion in 2010."
Now, however, Haroldsen reports that there may be a way to satisfy both consumers and growers — called "transgrafting."
"In transgrafting the genetically engineered rootstock can potentially confer the whole plant with resistance to disease. Yet the rootstock does not transfer the modified genes to the fruits or nuts produced," said Haroldsen.
Although over 10 years old, transgrafting technology is just now nearing commercialization, partly due to the long generation times of most trees and vines. Two such transgrafting applications are: a crown gall-resistant walnut rootstock, and a grape rootstock that confers moderate resistance to Pierce's disease.
"The key advantage of transgrafting is that the plant's vascular system can selectively transport across graft junctions the proteins, hormones, metabolites and vitamins from the roots without changing the heritable genes or DNA sequence in the fruit or nut." says Haroldsen.
In recent research at UC Davis, Haroldsen (a former graduate student) and his colleagues confirmed that modified DNA and full-length RNA from the rootstock does not cross the "graft union" into the scion, in the walnut and grape applications, or in a tomato model of these two systems.
"These current GE applications address root or xylem pests and diseases, but future applications will likely target traits aimed at consumer needs such as increased nutritional value or improved flavor," said Haroldsen. "If perceived risks to personal health and the environment could be reduced, genetic engineering could benefit not only growers but Californians around the state," he adds.
A new federal voucher that gives low-income women access to a range of fruits and vegetables could provide unique new marketing opportunities for California growers.
In 2009, the federal Special Supplemental Nutrition Program for Women, Infants and Children (WIC) began distributing monthly cash vouchers to low-income women with children to buy fruits and vegetables. The program reaches almost half of the infants and one-quarter of children under 5 years old in the United States.
A team of UC Cooperative Extension (UCCE) researchers and nutrition advisors has been exploring the possibility of developing a farm-to-WIC program that would link these low-income consumers with local growers. The purpose of such a program would be to increase the consumption of a wide variety of fresh produce, with a focus on locally grown produce when available.
UCCE conducted a survey of produce preferences and buying habits among WIC participants in Tulare, Alameda and Riverside counties in 2010. The full study is published in the January-March 2012 issue of California Agriculture journal.
Based on the results, the UCCE team developed a list of 19 produce items to promote in a possible new farm-to-WIC program. They are:
Although mustard greens and collards were not popular across all sites, the advisors gauged a potential market in Alameda County, so these were retained. Based on write-in responses, oranges were also added.
In California, which has the nation's largest WIC program, 82 local agencies serve about 1.43 million participants at 623 local centers, and WIC participants can redeem their monthly vouchers at 4,000 grocery stores statewide. About 40 percent shop at WIC-only stores, which stock and sell only WIC-authorized foods.
Stocking produce is relatively new to WIC-only stores; before rollout of new WIC food packages in October 2009, these stores were only required to stock limited amounts of fresh carrots. In the survey, most WIC participants (58 percent to 72.3 percent) responded that their preferred stores offered many choices, but fewer participants (18.5 percent to 41 percent) rated the produce quality as “excellent.” Key factors determining purchase decisions were produce quality and freshness, and nutrient value (vitamins and minerals). Cost was relatively less important, possibly because WIC participants procure the produce with the vouchers.
The list has served as a starting point for discussions with growers and WIC vendors.
“The survey showed that WIC participants were interested in purchasing fresh produce with better quality and more variety,” wrote lead author Lucia L. Kaiser, Cooperative Extension specialist in the UC Davis Department of Nutrition, and co-authors, in California Agriculture. “Some WIC participants that we surveyed said they avoided shopping at WIC-only stores in part because these interests were not met.”