By knowing where those models break down, researchers will be better able to improve them. The computerized models predict crop yields for wheat, one of the world’s most-consumed foods.

Scientists use crop models to foresee which parts of the world may face the greatest food shortages, so that efforts to improve food production can be directed to those places.

The researchers made the discovery by analyzing the effectiveness of 27 wheat models created by top scientists from around the world under both normal and climate change conditions. Their results are reported in a study published online this week by the journal Nature Climate Change.

“What we found was that, if you gave them enough information, there are a lot of models that can reproduce experimental data very well,” said Senthold Asseng, an associate professor in the UF agricultural and biological engineering department and the study’s lead author.

“But when it comes to climate change, when we start manipulating the climate data similarly to how climate change will play out in the next 50 to 100 years, the models started to disagree more and more,” said Asseng, a faculty member in UF’s Institute of Food and Agricultural Sciences. “And they started to disagree, particularly with increasing temperatures and carbon dioxide.”

Wheat, which accounts for 20 percent of calories consumed globally, is one of the world’s three most important crops, along with rice and maize.

In the past 100 years, global temperatures have risen by more than 1 degree Fahrenheit, according to the U.S. Environmental Protection Agency. Carbon dioxide levels in the atmosphere have increased by nearly 27 percent in the last 55 years to 400 parts per million, the highest level in about 2.5 million years, according to the Scripps Institution of Oceanography.

Jim Jones, an emeritus distinguished professor in the UF/IFAS agricultural and biological engineering department and a co-author of the study, said crop models are essential for pulling information from many different sciences into one place.

“As agricultural scientists we need to have an understanding of how our food systems are going to respond to the future challenges associated with climate change,” Jones said.

Ken Boote, another co-author of the study and emeritus professor in the UF/IFAS agronomy department, said researchers are now working together to improve their models using information such as new temperature data from different areas of the world.

The research is part of AgMIP, or the Agricultural Model Intercomparison and Improvement Project, an international effort to assess crop models and understand climate change’s impact on food production.

UF is one of three organizations, including the NASA Goddard Institute for Space Studies in New York City and the U.S. Department of Agriculture, leading the AgMIP project.

Principal investigators for AgMIP are Cynthia Rosenzweig, based at the Goddard Institute, Jones with UF/IFAS and Jerry Hatfield with the USDA’s Agricultural Research Service.

Asseng coordinated the wheat study with co-author Frank Ewert, a professor with the Institute of Crop Science and Resource Conservation at the University of Bonn in Germany, and worked with scientists from 15 countries to conduct the research.

It showed local food represents about 20 percent of all Florida food purchased for at-home consumption, except restaurant take-out food, said Alan Hodges, an Extension scientist with UF’s Institute of Food and Agricultural Sciences.

The study was based on a statewide consumer survey. Prior estimates from other states had local food accounting for about 5 percent of all food sales, he said.

“We are doing relatively better in Florida, in moving toward food self-sufficiency,” Hodges said. “I can only attribute that to the favorable year-round growing conditions we have for fruits and vegetables.”

Hodges’ study is part of a larger project that involves consumer preferences about local food, said Tracy Irani, a UF professor of agricultural education and communication and development director for the Center for Public Issues Education, or the PIE Center.

Irani and graduate assistant Joy Goodwin headed the portion of the project that examined consumer preferences. Irani said data suggest local food sales might be up because consumers are paying closer attention to the things they eat, due to nutrition and health coverage in the media.

Increased awareness results in increased sales, she said. However, consumer participants said their purchase of local food would be likely to increase with increased advertising and marketing of local foods.

“Consumers perceive that there are health, quality and economic benefits to locally grown,” Goodwin said. “That will continue to motivate purchase behavior, all other things being equal.”

Projections based on the statewide consumer survey indicate that local food sales in Florida totaled $8.3 billion in a one-year period. An estimated $6.1 billion was spent at grocery stores but only $320 million in restaurants, Hodges said.

“Restaurants have huge potential there to buy locally produced meats, vegetables and other items,” Hodges said. “My suggestion is, if you want to see more local food on the menu at your favorite dining spot, ask for it.”

Hodges and postdoctoral research associate Thomas Stevens headed the economic study. They mailed surveys to 7,500 Florida households, receiving about 1,600 responses.

The researchers took survey results and used regional economic analysis computer software to make projections about local food sales statewide. The survey was mailed in mid-2012 and asked respondents about the previous year’s purchases.

Some highlights of the results:

• Two-thirds of respondents said someone in the household bought local food at least once in the previous year.
• Among all Florida households, 62 percent bought local foods at farmers’ markets, 53 percent from retail supermarkets, 28 percent from restaurants, and 5 percent from community-supported agriculture or other direct transactions.
• The average spent on local food was $1,114 per household. That number was higher in Central and North Central Florida, compared with South Florida or the Panhandle.
• Almost three-fourths of the total estimated revenue — $6.1 billion –- was spent on local food at retail grocery stores. Consumers also spent $1.8 billion at farmers’ markets, roadside stands and U-pick farms. Restaurants and other food-service establishments accounted for $320 million, and other prearranged farm-to-consumer sales totaled $103 million.

Because there is no accepted definition of what constitutes “local” food, Hodges’ survey allowed respondents to define the term – and most often defined it as food produced within 100 miles of the consumer, he said.

The study is available on Hodges’ website, at http://tinyurl.com/cg8v3lc.

The larger project investigates ways of connecting farmers and consumers. It’s supported by a specialty crops block grant obtained by the UF/IFAS PIE Center. Information about the larger project is available at http://piecenter.com/localfood.

The grant was funded by the U.S. Department of Agriculture; the study also received support from Alachua County and UF’s offices of sustainability.

To watch an interview with Hodges about the local food study, visit http://tinyurl.com/bycexkd; to see Hodges and others from the larger project discuss local food, visit: http://tinyurl.com/axjxosm.

Battelle, a global research and development organization, released a study Tuesday that shows agriculture, forestry and fisheries production in a 13-state region of the southeastern U.S. plus Puerto Rico and the Virgin Islands generates $240 billion in regional economic activity and supports more than 2.2 million jobs, with labor income totaling $62 billion.

According to the Batelle study, agbioscience research and development spending went from $213 million to $501 million from 2000 to 2010.

“I think what this study clearly tells us is that for Florida to continue to see this kind of economic growth, we’ve got to continue to invest in these areas,” said Jack Payne, the University of Florida’s senior vice president for agriculture and natural resources. “Agriculture and related sciences touch nearly every aspect of our lives. They’re a robust driver of our economy and they will help our state thrive as the country pulls itself out of a rough economy.”

Agbioscience, as defined by the report’s authors, includes not only research related to the food we eat, but the development, production and use of plant and animal organisms for food, health, fuel and industrial applications.

The study offers case studies that highlight technological advances and research being done by the southeastern land-grant universities. They include UF Institute of Food and Agricultural Sciences’ research that shows irrigation can be vastly reduced by using soil moisture controllers and its work on renewable fuels.

Sustaining the Extension Service and Experiment Station System, further investing in it, and addressing its challenges are keys to maintaining the strength of the economic and social fabric of the nation, the region and the state, the report’s authors said.

The full report may be viewed at: http://www.LSUAgCenter.com/SouthernAgbioscienceImpact.

Battelle is one of the nation’s leading charitable trusts focusing on societal and economic impact and actively supporting and promoting science, technology, engineering and mathematics, or STEM, education.

The University of Florida is among 15 land-grant university sponsors of the study, commissioned by the Southern Association of Agricultural Experiment Station Directors and the Association of Southern Regional Extension Directors.

The eight-year, $4.2 million study was funded by the Florida Department of Environmental Protection to determine the effectiveness of current UF/IFAS fertilizer recommendations, which have been in use since about 2000, said John Hayes, UF/IFAS dean for research. Florida has more than 5 million acres of home and commercial turf.

“This work is an important body of information generated here to address important questions about nutrient management,” Hayes said. “We’re proud to communicate our findings and we hope they will play a substantial role in helping residents, industry personnel and policymakers protect water quality.”

Three hours of technical presentations from a Jan. 15 live symposium are available at http://tinyurl.com/be2la7q and a three-minute video aimed at educating the public has been posted at http://tinyurl.com/ajy4ytr.

The results generally are consistent with current UF/IFAS recommendations for fertilizer use, Hayes said, but the Florida Department of Agriculture and Consumer Services plans to review the state’s urban fertilizer rules in light of the study findings. The agency will hold public meetings to seek comment about possible changes.

The study involved three locations, numerous establishment, fertilization and irrigation practices, and multiple turf varieties, including St. Augustinegrass, zoysiagrass, centipedegrass and bahiagrass.

Despite the differences, researchers made several basic conclusions:

* Very little nutrient leaching results from summertime application of UF/IFAS recommended fertilizer rates to healthy, growing turfgrass.

* Summertime fertilizer bans could potentially deprive healthy turf of nutrients when needed most, threatening turf health and quality.

* Nutrient leaching can result from fertilizer application to dormant or unhealthy turf.

* Newly laid sod should not be fertilized for 30 to 60 days because it will not have an established root system for effective nutrient uptake and it is likely to carry nutrients from fertilizer applications at the sod farm where it was grown.

The study involved experiments conducted at UF/IFAS research facilities in the Panhandle, Gainesville and Fort Lauderdale, using turf, soils and management practices common to each area. The state’s most popular turf, St. Augustinegrass, was studied at all three sites.

Faculty members John Cisar, Jerry Sartain, Laurie Trenholm and Bryan Unruh led the study and presented their research findings at a public meeting in Citra, where much of the footage was shot. The video includes a question-and-answer session with the scientists, and comments from Andy Rackley, director of agricultural environmental services for FDACS.

Several researchers mentioned that their findings raised new questions and pointed out the need for additional research on topics including the use of biosolids and other organic nitrogen sources, the use of reclaimed water, turfgrass phosphorus requirements, and the effects of summertime fertilizer bans.

“We’re in some conversations with DEP (the state Department of Environmental Protection) still about moving forward with some additional data analysis,” Unruh said.

He also noted that the results suggest UF/IFAS’ nutrient recommendations for zoysiagrass may need to be modified, but any changes to those nutrient recommendations must come about through a vetting process by the Plant Nutrient Oversight Committee, a team of administrators and scientists who review all nutrient recommendations from UF/IFAS.

Extension personnel will be trained to help them communicate the findings to homeowners and there may be additional public workshops, Trenholm said.

Homeowners with unhealthy lawns should contact county extension personnel to discuss the problem and not automatically assume that fertilizer is needed, Cisar said.

“If you have a lawn that’s in bad shape, it makes sense to ascertain why,” he said. “It may be that the grass needs fertilizer but it could be something else, like a lack of proper irrigation, proper mowing height, or the grass isn’t getting enough light.”

In some parts of the world, water is in short supply, but farmers often devote what they can to rice farming because the crop is so important. However, research has led to a simple but profound solution that requires less water – growing rice in fields, a practice called aerobic rice production.

The practice relies on rainfall plus limited irrigation to meet the plants’ moisture needs. It requires about 40 percent less water than paddy-grown rice, according to a University of Florida study in the current issue of Agronomy Journal.

Aerobic rice production is gaining popularity in India and Southeast Asia, particularly in drought-stricken or upland areas, said Rao Mylavarapu, a professor with UF’s Institute of Food and Agricultural Sciences and one of the study’s authors.

Mylavarapu is working to address a major challenge in aerobic rice production: yield. In the two-year study, conducted in Hyderabad, India, researchers grew rice in irrigated fields and paddies. The first year’s aerobic rice harvest weighed 39 percent less than the paddy harvest; the second year the difference narrowed to 15 percent.

“Right now, there’s no way you can get the same yield under optimal conditions,” he said.

He explained that grain production is influenced by a rice plant’s ability to use nitrogen, which in turn is influenced by moisture availability. In other words, paddied plants grown in standing water have an advantage over aerobic plants receiving modest irrigation. And, the rice varieties used for paddied production are different from the ones in aerobic production.

But in a drought there may not be enough water to keep rice paddies flooded. Under those circumstances, aerobic production can ensure that a community has rice to eat, while the paddied plants wither away.

“The real impact of aerobic rice will be shown in a rainfall shortage year,” Mylavarapu said. “However, in a rainfall shortage year, we have to be able to provide supplemental irrigation to aerobic rice and keep the root zone moist. So if there’s a very bad drought, even aerobic rice will fail.”

He adds that few rice varieties have been developed specifically for aerobic production. In time, breeders may develop improved varieties and close the “yield gap” with paddied rice.

Currently, Mylavarapu’s focus is on another aspect of the cropping system – overall grain production in systems where rice is rotated with corn. This approach is used on about 8.65 million acres in Asia because little soil preparation is needed to plant corn in a field following aerobic rice. In contrast, rice paddies must be drained and converted from a flooded anaerobic system to an aerobic system before the land can be used for corn.

In the study, researchers found that corn yields were about 5 percent higher when the corn followed aerobic rice, compared with paddied rice.

So far, aerobic rice production hasn’t caught on with U.S. farmers, but that could be just a matter of time, he said.

“In the U.S., water quality is usually a bigger issue than water quantity,” Mylavarapu said. “Certainly, it (aerobic rice) will become a very important factor for the U.S. to consider in the future, with climate change.”

The United States is the world’s 10th largest producer of paddied rice, with annual production of about 12 million tons, according to the United Nations’ Food and Agriculture Organization. Arkansas is the leading U.S. rice producer; Florida ranks seventh.

The study was funded by the U.S.-India Agricultural Knowledge Initiative through the U.S. Department of Agriculture. The research team included Mylavarapu, UF colleagues Dakshina Kadiyala and Yuncong Li; Gudigopuram Reddy of North Carolina A&T State University and M.D. Reddy of Acharya N.G. Ranga Agricultural University in Hyderabad, India.

GAINESVILLE, Fla. –– Tropicana Products Inc., a division of PepsiCo Inc., has pledged $1.5 million to endow a professorship specializing in innovative citrus research to strengthen the Florida citrus industry, the nation’s largest, University of Florida and Institute of Food and Agricultural Sciences officials and company representatives announced today.

The endowment, to be known as “The Tropicana Professorship for Florida Citrus Innovation,” will support teaching, research and outreach efforts dedicated to the future of the state’s citrus industry.
The research is expected to target, among other things, advanced production systems, efficient water use, protection of natural diversity and sustainable citrus production.

Jack Payne, UF senior vice president for agriculture and natural resources, said the gift is much needed. Payne said it will fund a professor who will target research efforts aimed at helping the industry become more sustainable.

“Every agricultural industry must work to become more sustainable and our state’s citrus growers are helping lead the way,” Payne said. “The research goal here will be citrus trees that flourish with little impact on the environment. It’s a wonderful goal and this sort of corporate partnership is critical to helping us reach it.”

A more sustainable citrus industry, he said, would mean trees that thrive with less fertilizer and irrigation than are currently required, and being able to plant more trees per acre.

Oranges have been grown in what is now the state of Florida since the 1560s, almost 150 years before they were reported anywhere else in what would later become the continental United States, according to historical records.

“As the largest buyer of Florida oranges, ensuring that Florida citrus remains vital, competitive and sustainable for generations to come is paramount,” said Neil Campbell, president of Tropicana Beverages, North America. “The University of Florida is world renowned for its agricultural research and science initiatives and we can think of no better partner.”

Tropicana Products Inc., a division of PepsiCo Inc., is a leading producer and marketer of branded fruit juices. PepsiCo is a global food and beverage company with net revenues of more than $65 billion.

Mike Haycock, vice president of operations for Tropicana, said that as a longtime member of the Florida citrus community, the company understands how important this is to the state because, “Florida is where it all started for Tropicana back in 1947.
“Through this work and investment, together, we will help drive innovation and create solutions for a sustainable future for the Florida citrus industry, which continues to face serious challenges,” Haycock said.

The Tropicana gift follows another $1 million in USDA grant funding to UF/IFAS for citrus. Those funds will be used to support research aimed at preventing the insect that transmits citrus greening from being able to spread the disease.
Since 2006, the citrus greening, known to scientists as Huanglongbing, has cost Florida’s economy an estimated $4.54 billion in lost revenues and 8,257 jobs by reducing orange juice production, UF/IFAS studies have found.
Michael W. Sparks, executive vice president and the CEO of Florida Citrus Mutual, the largest cooperative associated dedicated to helping the state’s citrus growers, called Tropicana’s gift a much-needed one.
“Florida citrus growers are currently facing the biggest disease challenge we’ve ever faced in HLB and the only way we are going to beat it is in the laboratory,” he said. “This endowment is a huge step forward in strengthening the resources we have in the fight against HLB and Tropicana and UF-IFAS should be commended for their commitment to a sustainable future for our $9 billion industry.”

The data were published in the December 2012 issue of the journal Xenobiotica.

Scientists have been aware of the so-called “grapefruit juice effect” since 1989. Compounds in the fruit called furanocoumarins inhibit the action of an enzyme that breaks down certain medications in the human digestive system.

The phenomenon poses a health risk because it can produce unexpectedly high levels of these medications in a patient’s bloodstream. Doctors, pharmacists and prescription drug labels warn patients to avoid grapefruit and related products under these circumstances.

The phenomenon is a disappointment for fans of the tart treat, but Fred Gmitter, a faculty member at UF’s Citrus Research and Education Center in Lake Alfred, is part of a team working to address the problem by developing a hybrid between grapefruit and selected varieties of pummelo that have been shown to have low furanocoumarin content and can transmit the trait to their offspring.

In the current study, researchers investigated the effects of furanocoumarin compounds, testing each one to determine the amount required to slow the enzyme reaction by 50 percent. The results showed that a handful of furanocoumarins had the strongest effect.

More importantly, juice samples from 40 different hybrids and their parents were tested directly for their overall effect on enzyme activity, and one of the selected hybrids approved for impending release, known as UF 914, was among the samples with the lowest effect.

Gmitter said further study is needed to learn how low furanocoumarin levels must be to reduce the interaction risk.

Other members of the research team included David Greenblatt, Yanli Zhao, Michael Hanley and Jerold Harmatz of Tufts University School of Medicine and Tufts Medical Center in Boston; Chunxian Chen of the Lake Alfred center and Paul Cancalon of the Florida Department of Citrus in Lake Alfred.

Wagner Vendrame, an associate professor of environmental horticulture with UF’s Institute of Food and Agricultural Sciences, is trying to improve a technique known as cryopreservation, in which living cells or tissues are frozen in liquid nitrogen at minus 321 degrees Fahrenheit for later use. So far, his results from cryopreserving orchid seeds have been promising.

The Florida orchid industry generated more than $43 million in sales in 2011. It produces orchids for both the specialty and mass market using hybrid plants that can be cultivated and are thus not in danger of extinction as many orchid species are.

By freezing seeds, orchid breeders can store them for later use if they have space constraints and are only able to germinate a portion of their seed stock, said Vendrame, who is based at UF’s Tropical Research and Education Center in Homestead. Freezing could also enable scientists to store endangered plants for future studies and restoration efforts.

“It could be a good means of preserving other types of plants that might be disappearing from the face of Earth,” Vendrame said.

There are more than 30,000 species of orchids in the world, and Florida is home to 99 of them — the largest number of naturally occurring orchid species in the United States.

Of the native orchid species in Florida, more than half are either threatened or endangered, including the ghost orchid that was made famous with the book “The Orchid Thief” and the 2002 film “Adaptation,” starring Nicolas Cage and Meryl Streep.

Overcollection and habitat loss are often the biggest threats to wild orchids.

In a study, published in the current issue of the journal Scientia Horticulturae, Vendrame’s team used hybrid orchid seeds to evaluate two cryoprotectants, Supercool X1000 and phloroglucinol. These compounds are added to solutions used for pretreating living tissues before being frozen. Cryoprotectants are similar to antifreeze and minimize freezing damage to tissues by preventing the formation of ice crystals within cells.

The team treated one group of seeds in a solution containing Supercool X1000, another with a solution containing phloroglucinol, and a control group where the solution had no cryoprotectant added. After being frozen for 24 hours, scientists removed the seeds from the liquid nitrogen, thawed them and tried to sprout or germinate them. Successful germination meant a seed had survived freezing.

Adding Supercool X1000 to the pretreatment solution only increased seed germination by about 1 percent more than the solution alone. But adding phloroglucinol increased seed germination by nearly 30 percent.

Altogether, about 79 percent of the seeds treated with phloroglucinol germinated.

So it’s pretty significant,” Vendrame said. “These are excellent results.”

The study is one of the few that has looked at phloroglucinol, which is extracted from brown algae, as a cryoprotectant for plants, he said.

Guillermo Salazar, a UF/IFAS Florida Yards and Neighborhoods extension agent in Miami-Dade County, is an orchid enthusiast who has studied the plants under Vendrame.

He attributes the fascination with orchids to their uniqueness and diversity.

“There are thousands of different species with diverse shapes, colors and scents,” Salazar said. “And they can be found in a variety of ecosystems, from growing on cliffs to in trees and beside rivers. It just really makes them interesting, and you want to experience them all.”

He said there are some orchid species that have disappeared completely and others that can only be viewed in private collections.

“If we could have the possibility to preserve a particular species that is endangered, then future generations would have the ability to enjoy them as well,” said Salazar.

In addition to Vendrame, study authors also included Renato F. Galdiano and Eliana G.M. Lemos with the Universidade Estadual Paulista Júlio de Mesquita Filho in Jaboticabal, Brazil and Ricardo T. Faria with Universidade Estadual de Londrina in Londrina, Brazil.

Though the initial investment can run from $18,000 to $25,000 per acre plus labor, high tunnels deliver better quality fruit, bigger early yields and higher prices if growers beat competitors to market, said Bielinski Santos, an associate professor with UF’s Institute of Food and Agricultural Sciences.

The study, published in the current issue of HortTechnology, tracked two growing seasons on a commercial blueberry farm in Alachua County. The results showed that temperatures outside the tunnels plunged to freezing or near-freezing 61 times during the study. Temperatures fell that low just three times inside the unheated tunnels.

High tunnels may increase air and soil temperatures and protect the plants from wind and rain damage, leading to better flowering and more fruit, said Santos, based at UF’s Gulf Coast Research and Education Center in Balm.

Plants grown in the tunnels produced about 4.5 tons of ripe fruit per acre by the end of March; no ripe fruit came from similar plants grown outdoors during that time. Wholesale prices for domestic blueberries are highest early in the season, starting at about $7 per pound in early April, he said.

“Usually, Florida growers start harvesting in early April,” Santos said. “The more fruit you can harvest early in the season, the more money you’ll make.”

Growers can also save money with high tunnels because they minimize the need for another freeze protection strategy – sprinkling the plants with water to form a layer of ice. In the study, tunnel-grown plants needed about one-tenth the water for freeze protection as plants grown outdoors.

The study involved two blueberry varieties developed at UF, Snow Chaser and Springhigh. Snow Chaser is especially well-suited to life in high tunnels, Santos said.

Made by stretching thick plastic sheeting across an arched frame, high tunnels resemble Quonset huts, he said. Although they have variable dimensions, most tunnels have roofs anywhere from 8 to 20 feet high, with ends and sides that can be open or sealed, depending on the weather.

The technology is popular in other parts of the world but still catching on in the United States, Santos said. In Florida, high tunnels and other protective structures account for about 250 acres of production, mostly for high-value crops such as blueberries, strawberries, tomatoes and bell peppers.

“We always thought it was really complicated and expensive,” Santos said. “So for the past six years I’ve tried to ‘vulgarize’ the technology and develop a system anyone can use.”

Santos said he knows of one Florida blueberry grower using high tunnels; the owners tried 2 acres in 2010 and later expanded to 80 acres. Others have expressed interest in the system.

Santos and co-author Teresa Salame-Donoso, a research associate at the Balm center, have begun collecting data for an economic study on blueberry production in high tunnels.

“We already have some numbers, and we’re collecting the kind of information growers need to make up their own minds about using high tunnels,” he said. “I see more people doing it eventually.”

In a study published this week by Proceedings of the National Academy of Sciences, researchers with UF’s Institute of Food and Agricultural Sciences announced their discovery of the enzyme and showed how the common tomato plant generates large amounts of it as the fruit ripens.

Chemical reactions triggered by CXE1 improve the fruit’s flavor profile by reducing the presence of acetate esters, volatile chemicals commonly associated with plant defense and plant-to-plant communication, said molecular biologist Harry Klee, an eminent scholar with UF’s horticultural sciences department.

“We do believe this phenomenon makes the fruit more palatable,” Klee said.

Previous UF/IFAS tomato research has shown that consumers do not like the contributions that acetate esters make to tomato flavor. Many of them are pleasant in isolation — for example, butyl acetate has a sweet, banana-like odor — but don’t match consumers’ ideas of good tomato taste, he said.

Klee and his colleagues are involved in a long-term effort to uncover genes and biochemical pathways responsible for producing the volatile chemicals that give fresh tomatoes their characteristic flavor and aroma.

Ultimately, they hope to show that great taste is dependent on just a handful of compounds in the right proportions. Breeders can use the information to guide their efforts to develop improved varieties.

The team discovered CXE1 and four similar enzymes while analyzing tomato genes that appeared to play a role in establishing the acetate ester content of tomato fruit.

To better understand the role CXE1 plays in tomato flavor, the researchers investigated what would happen without it.

They engineered tomato plants that produced very little of the enzyme. The fruit from those plants contained higher-than-normal levels of acetate esters.

The team also analyzed Solanum pennellii and Solanum habrochaites, relatives of the tomato plant that produce green-skinned fruits unpalatable to people and seldom eaten by animals. The fruits contained large amounts of acetate esters, compared with tomato fruit. Furthermore, analysis showed that those plants produced little CXE1.

In laboratory tests, CXE1 inhibited the activity of numerous acetate esters, though the enzyme was more active against some than others.

It’s possible, Klee said, that high CXE1 production in tomato plants is a trait that evolved in tandem with red-skinned fruit, providing a survival advantage. Perhaps the red color drew attention from animals and the pleasant taste inspired them to eat the fruit, leading to seed dispersal that established the plant in new areas.

Though this study may shed light on the tomato’s distant past, Klee is much more interested in its future.

“Because acetate esters are negatively correlated with consumer liking, we want to find ways to get rid of them,” he said. “I always tell people there are probably five or 10 chemicals we need to optimize to achieve an ideal flavor balance in tomato, and I think CXE1 is probably part of that group.”

Besides Klee, the research team included Charles Goulet, Melissa Mageroy, Nghi Lam, Abbye Floystad and Denise Tieman, all with UF’s horticultural sciences department.

UF Institute of Food and Agricultural Sciences researchers will receive about $1 million of that research funding over five years, said Jack Payne, UF senior vice president for agriculture and natural resources.

Payne said the funding represents much-needed financial help for UF/IFAS researchers battling the disease, first detected in Florida in 2005.

“Citrus greening represents a devastating burden on this state’s economy and we’re working around the clock to help,” he said. “The USDA’s announcement Monday is wonderful news, and we greatly appreciate the efforts of Jackie Burns of UF/IFAS and Harold Browning of CRDF and everyone else who made this happen.”

Citrus greening, known to scientists as huanglongbing, or HLB, was discovered in a backyard citrus tree in Los Angeles earlier this year and now threatens California’s citrus industry.

U.S. Secretary of Agriculture Tom Vilsack announced the grant Monday as part of a $101 million funding package to support America’s specialty crops producers, who provide fruits, vegetables, nuts and other foods for millions of meals each day.

Greening has cost Florida’s economy an estimated $3.63 billion in lost revenues since 2006 and poses a huge threat to the state’s $9 billion citrus industry, the nation’s largest. It weakens and eventually kills infected trees. For now, there is no cure, although growers are using cultural management strategies to keep groves productive.

Burns, director of UF’s Citrus Research and Education Center in Lake Alfred, said Tuesday morning that scientists will use the money, part of a five-year grant, to find a way to eliminate the Asian citrus psyllid’s ability to vector, or transmit, the bacterium that causes citrus greening. The tiny invasive insect is the only known vector for the disease.

Researchers hope to produce an Asian citrus psyllid biologically incapable of carrying or passing on the greening bacterium, either by pinpointing a natural mutation or through genetic engineering, Burns said. The insect could then be reared in laboratories and released to mate with wild psyllids, ensuring that the no-transmission trait would spread.

UF/IFAS researchers have dedicated much time and effort to finding effective control strategies for the disease and its vector. The funds will go to the CRDF, also in Lake Alfred, a direct-support organization of UF aimed at eliminating greening.

Browning, chief operating officer of the CRDF, said the new funding represents a novel approach to citrus greening research that “complements very well the work UF and other institutions, including the CRDF, are doing to help solve the problem.”

Formed in May 2009, the CRDF is a nonprofit corporation set up to manage and provide oversight for funds raised to bolster research to aid the citrus industry. The CRDF’s 13-member board of directors is made up of representatives from the citrus industry, academia and government. Its mission is to advance disease and production research and product development activities to ensure the survival and competitiveness of Florida’s citrus growers through innovation.

The funds are being awarded through the Specialty Crop Research Initiative, part of the USDA’s 2008 Farm Bill.

The herbicide, a chemical called thaxtomin, occurs naturally in Streptomyces bacteria that cause potato scab, a major disease of potatoes worldwide.

A study describing a key step in the process that could lead to its commercial production is published in the current issue of the journal Nature Chemical Biology.

Rosemary Loria, a professor and chair of the UF/IFAS plant pathology department, is a co-author of the publication. She worked on the study while at Cornell University and has continued the research since joining UF’s Institute of Food and Agricultural Sciences in 2011.

In the study, the researchers describe an enzyme in the bacteria that is essential to producing the herbicide and showed that without the enzyme, thaxtomin production doesn’t occur.

This is important, Loria said, as it could allow researchers to increase the amount of thaxtomin the bacteria produces, which must happen for the herbicide to become commercially viable.

“So we could within the next couple of years be able to create a strain of bacteria that would produce much higher levels of thaxtomin than the natural strains produce and that will assist in getting thaxtomin onto the market,” Loria said.

Thaxtomin works as an herbicide by causing the abnormal growth of plant cell walls. Loria said the chemical could be used as a pre-emergence herbicide to kill weeds when they are just starting to sprout and most vulnerable to thaxtomin.

And since it is a natural herbicide produced from bacteria rather than one created in a lab, it can be used on organic farms, she said.

Study co-author Evan Johnson was on the research team with Loria at Cornell and is now a plant pathology postdoctoral associate at the UF/IFAS Citrus Research and Education Center in Lake Alfred.

He said advantages natural herbicides offer over lab-synthesized herbicides include more specific targeting of the organisms they control and faster breakdown in the soil.

“Because it’s naturally produced in the soil, it can generally be broken down more easily by organisms in the area,” Johnson said. “It’s something that the organisms in the soil that break down organic matter are used to seeing.”

Other study authors were Sarah M. Barry, of King’s College London’s department of chemistry, school of biomedical sciences; Johan A. Kers, of the industrial products division of Intrexon Corporation in San Carlos, Calif.; Lijiang Song, Philip R. Aston and Gregory L. Challis with the University of Warwick department of chemistry in Warwick, U.K.; Bhumit Patel, of the Fraunhofer USA Center for Molecular Biotechnology in Newark, Del.; Stuart B. Krasnoff and Donna M. Gibson, of the U.S. Department of Agriculture – Agricultural Research Service Robert W. Holley Center for Agriculture and Health in Ithaca, N.Y.; and Brian R. Crane with Cornell University’s department of chemistry and chemical biology in Ithaca.
The United Kingdom Biotechnology and Biological Sciences Research Council and the National Research Initiative of the USDA Cooperative State Research, Education and Extension Service funded the research.

Shoppers often assume farmers’ markets sell only the freshest crops from small, local operations, said Mickie Swisher, an associate professor with UF’s Institute of Food and Agricultural Sciences. But with the number of U.S. farmers’ markets more than quadrupled since 1994, big-volume produce dealers sometimes use them to sell items shipped from other states or countries.

When that happens, customers may feel outraged or indifferent, depending on whether they’re committed to eating local or just want a pleasant excursion, said Swisher, one of the study’s authors.

The findings, published in the current issue of the journal HortScience, suggest that farmers’ market managers can keep serious and casual shoppers happy by requiring honest labeling and creating opportunities for patrons to mingle, she said.

“It’s a matter of knowing what consumers want, and I think this study has some insights that could be useful,” Swisher said.

For example, if the rules governing a farmers’ market are silent on the issue of non-local food, locavores would probably want to see that situation resolved, she said. Solutions might include barring non-local food, restricting it to certain parts of the market or requiring vendors to indicate where their merchandise was produced.

For patrons who want to socialize, management should provide amenities such as seating areas, particularly if any vendors offer ready-to-eat food.

In the study, Swisher and colleagues Zhifeng Gao of the UF food and resource economics department and Xin Zhao of the horticultural sciences department surveyed more than 120 shoppers at farmers’ markets in three Florida population centers – a major metropolitan area, a medium-sized city and a small town.

The survey asked shoppers about their expectations for the food sold at farmers’ markets, Gao said. The results showed that a large percentage believed much of the merchandise was locally grown, freshly harvested, organic and sold by growers themselves.

Then researchers asked participants if they would continue patronizing a farmers’ market after learning they had purchased an item that defied their expectations.

If the item was less fresh than expected, about 75 percent would continue patronizing the market; if it wasn’t organic, 66 percent would continue, he said. If the item wasn’t grown by the vendor 62 percent said they would return; and if it wasn’t local only 53 percent would visit the market again.

Using additional data analysis, the researchers determined which shoppers were most likely to stop visiting a farmers’ market that offered non-local food. Those were the shoppers who believed it was important to buy local food, or thought patronizing farmers’ markets was better than shopping at supermarkets.

The number of U.S. farmers’ markets increased from 1,755 in 1994 to almost 7,900 in 2012, according to the U.S. Department of Agriculture. So it’s imperative for managers to stay on top of emerging trends, including the ones consumers don’t like, Swisher said.

“Farmers’ markets have come a long way in the past few decades, and I think there’s a lot of potential if we don’t spoil it,” she said. “The farmers’ markets that are well-run and aboveboard will get the lion’s share of the business.”

Up to 20 percent of show pigs at the 2009 Minnesota state fair were infected, and an infected animal was also found at the 2009 South Dakota fair, the researchers report in the September issue of the Centers for Disease Control and Prevention’s Emerging Infectious Diseases journal.

The findings come in the wake of recent CDC warnings to fairgoers and reports of new swine flu strains, called H3N2 variants, in people who had direct or indirect contact with pigs at agricultural fairs.

“The new H3N2 variant viruses that are circulating now in pigs and apparently affecting people at pig shows are offsprings of the 2009 pandemic virus that spread throughout the world,” said lead investigator Dr. Gregory Gray, chairman of the UF College of Public Health and Health Professions department of environmental and global health, and a member of UF’s Emerging Pathogens Institute. “It mixed with the viruses that were already present in pigs and out has come a new progeny virus.”

Between July 12 and Aug. 10, health authorities have confirmed 153 cases of H3N2 variant infections in four states. And with county and state fair season in full swing, the number of infections is expected to rise.

For the summer 2009 study, Gray, then the director of the University of Iowa’s Center for Emerging Infectious Diseases, and his team evaluated pigs and their handlers at the Minnesota and South Dakota state fairs. The researchers collected completed questionnaires from handlers, and swab samples from pigs’ nostrils. All the pigs had been deemed healthy by a veterinarian before being permitted to enter the show.

Of 57 pigs examined at the Minnesota fair, 11 tested positive for swine flu, and of 45 pigs examined at the South Dakota fair, one tested positive. Most of the flu-positive pigs had nasal samples collected within 24 hours of arrival at the fair, so the results suggest the animals were infected before they got there.

The presence of influenza A in healthy-looking pigs is consistent with a 2011 Canadian study that demonstrated that as many as 90 percent of infected pigs may not show clinical signs of viral infection.

In addition, six of seven viruses the researchers isolated from pigs in the 2009 study were identical to the pandemic H1N1 virus that had first been confirmed in humans just five months earlier, in April of that year. In a follow-up telephone survey, two human study participants reported influenza-like illness.

“Pandemic influenza is a good example of how certain strains of influenza can spread in both human and pig populations at the same time — this is obviously of serious concern,” said Juergen A. Richt, the Regents Distinguished Professor at the Kansas State University College of Veterinary Medicine, who was not involved in the study. “The recent sharp increase in cases of influenza associated with the novel H3N2 variant at local and state fairs throughout the Midwest further confirms this phenomenon. It is important that we increase public awareness that animals, such as pigs, cattle and sheep can carry viruses that might be of concern to the general public.”

The UF investigators recommend that swine show visitors follow the CDC’s guidelines: Wash your hands before and after exposure to animals, don’t eat or drink in areas where animals are kept and avoid contact with animals if you are experiencing flu-like symptoms or if the animals appear sick. People who are pregnant, younger than 5 or who have weakened immune systems should avoid exposure to pigs and pig barns.

Eating pork from a pig infected with influenza does not appear to cause infection in humans, according to the CDC.

Workers involved in swine farming, food animal veterinarians and people who raise show pigs should receive seasonal flu vaccinations and consider using gloves in their work, Gray said. And swine show organizers should consider using inexpensive rapid-diagnostic tests to determine onsite whether the show pigs are carrying viruses that could spread to humans. Such testing is especially important since studies show that accurate infection surveillance cannot be based solely on observation of signs in animals, Gray said.

“We really need a much better understanding of how common these infections are in U.S. pigs and how they are spreading,” Gray said. “Public health, veterinary health, environmental health and the pork industry must work closely together in understanding influenza transmission as some of these viruses can cause significant health problems in man and pigs, as well as major economic harm to agribusinesses.”

This tropical fruit crop reproduces sexually, meaning there are male and female papaya trees. But there’s also a third type with the reproductive capacity of both genders. This type is called a hermaphrodite and, unlike male or female plants, it can self-pollinate.

Now, a study involving current University of Florida researcher Jianping Wang helps explain how the plant’s sex chromosomes evolved over time to produce the three genders. Wang was lead author of the paper and performed the work while a postdoctoral fellow with the University of Illinois at Urbana-Champaign.

The findings, published last week by Proceedings of the National Academy of Sciences, shed light on evolutionary processes. The data might also have practical value for papaya growers, who say they get bigger yields and better fruit from hermaphroditic plants.

“In the future, if we understand the process of sex determination clearly, not only can we evaluate young plants before they’re in the ground, and select plants with the gender we want, but also we can identify the sex determination genes and manipulate a pure inbred papaya plant for papaya growers,” said Wang, an agronomy assistant professor with UF’s Institute of Food and Agricultural Sciences.

That approach could be used for other crops that reproduce sexually, she said. For example, asparagus growers prefer to raise male plants.

In the study, Wang and colleagues led an eight-institution team that analyzed genes from sex chromosomes, long strings of DNA sequences that code for anatomical traits we know as gender. The researchers worked with a group of genes in a sex-determination region of the chromosome that controls development of flowers with both male and female characteristics in hermaphrodites, and also a corresponding region from female sex chromosomes. First, they mapped the DNA sequences from both regions of the sex chromosomes and then compared the sequences.

Comparisons revealed that the female sex chromosome region had a shorter DNA sequence – about 3.5 million DNA base pairs, compared with 8.1 million base pairs for the hermaphroditic plant. Many of those extra DNA sequences appear to distinguish the hermaphrodite from the female plant.

This finding supports a hypothesis about the evolution of sex chromosomes: Genders only develop after DNA sequences become altered and a species established two distinct but similar genomes. Later, it’s believed, these fundamental genetic differences become more pronounced and give rise to distinctive sex types.

Since arriving at UF in 2010, Wang has been sequencing genes in bioenergy crops such as energycane, searching for genes that influence the potential value of the plants as feedstocks. Ultimately, she wants to help produce crops with high biomass yields, good disease resistance and chemical profiles well-suited to processing.