California Fruit and Vegetable

Tag: University of Florida Institute of Food & Agricultural Sciences

  • An Aromatic Tomato Could be Looming – a La Heirloom Varieties

    You can scarcely find a tasty, heirloom tomato in the grocery store. But University of Florida scientists helped discover a way to enhance tomato smell and taste. Breeding efforts over the last half century have emphasized traits that are important to producers – yield, disease resistance, appearance and post-harvest shelf life among them.

    While those traits are important, modern commercial varieties tend to fall short of the flavor potential shown in older varieties. But consumers want tomatoes that taste and smell good.

    Indeed, in a study published in 2012, consumers who taste-tested several tomato varieties preferred tomatoes with high levels of nitrogenous volatiles.

    For years, consumers have lamented what they deem as the bland taste of tomatoes. Any flavor you savor when you bite into the fruit comes from a combination of many aroma compounds. Some of those compounds contain nitrogen, and they add fruity, floral and tomato vine profiles to the flavor mix. Working on an international team of scientists, two UF/IFAS researchers helped find a route to several important nitrogen-containing tomato flavor compounds.

    In a newly published study, scientists showed that five of the compounds are part of a biochemical pathway for synthesis of these important flavor compounds.

    Using a closely related fruit, Solanum pennellii, scientists found a site on a chromosome essential to produce detectable nitrogenous volatiles in tomatoes, said Denise Tieman, a UF/IFAS research assistant professor of horticultural sciences.

    That data led scientists to identify a step in the pathway to nitrogen-containing flavor compounds.

    “Now that we know how these compounds are made in tomatoes, we can identify varieties that have the heirloom version of the enzyme and high levels of these flavor compounds, and we can breed this trait into modern tomatoes to improve flavor,” Tieman said.

    Tomatoes produce many aroma volatiles, including nitrogen-containing volatiles that are relatively rare in other fruits.

    Since these volatiles are active at low concentrations, increasing their levels does not impact yield or fruit size.

    Tomatoes are the most valuable fruit produced worldwide. Indeed, in 2020, American farmers harvested about 12,600 tons of fresh market tomatoes and 11 million tons of processing tomatoes from 273,00 acres. That adds up to $1 billion in revenue. Florida harvested 26,000 areas of tomatoes during the 2018-2019 season, valued at almost $426 million.

    The new research, published recently in the Proceedings of the National Academy of Sciences, was led by Harry Klee, a UF/IFAS professor emeritus of horticultural sciences and Charles Goulet, a professor of plant science at Universite Laval in Quebec City, Canada. — By Brad Buck, University of Florida Institute of Food & Agricultural Sciences

  • University of Florida Researchers Publish Award-Winning Findings on Grove Design to Produce Oranges Under HLB

    University of Florida Institute of Food & Agricultural Sciences —The American Society for Horticultural Science recently honored University of Florida scientists for new guidelines citrus growers may apply to their operations. The researchers study ‘Valencia’ orange production while trees are under the most serious citrus disease worldwide.

    “The 7-year study broke new ground on data we provide to local citrus growers who remain in business despite huanglongbing, or HLB,” said Ronald D. Cave, Director of the University of Florida Institute of Food and Agricultural Science’s Indian River Research and Education Center in Fort Pierce (UF/IFAS-IRREC).

    A few of the findings citrus growers may employ immediately from the study are:

    • High-density plantings produce more fruit—from 86% up to 300% more than trees not planted in high-density configurations under HLB.

    • The study showed that advanced management practices that included high tree density, fertigation, and drip irrigation led to higher fruit yield.

    • Additional research is needed to determine optimal fertilization rates for high-density sweet orange orchards under HLB-endemic conditions

    The award-winning publication, “Sweet Orange Orchard Architecture Design, Fertilizer, and Irrigation Management Strategies under Huanglongbing-endemic Conditions in the Indian River Citrus District,” appears in the December 2020 issue science of the scientific journal HortScience. The paper describes the scientists’ hypothesis, the entire research procedure, outcomes, and recommendations for further research.

    Members of the American Society for Horticultural Science (ASHS) Fruit Publication Selection Committee wrote about the paper’s significance. “Huanglongbing, also known as citrus greening, affects all citrus cultivars and causes serious tree decline. It is currently a major threat to the citrus industry. The results can influence the whole citrus industry to deal with HLB including orchard architecture design, fertilizer, and irrigation management strategies.”

    Rhuanito “Johnny” Ferrarezi and his colleagues conducted experiments to determine the variables that promote healthy fresh fruit harvests with the presence of HLB. Ferrarezi, along with fellow professors Mark Ritenour and Alan Wright, accepted the “Outstanding Fruit Publication Award” for papers published in 2020 at the ASHS annual meeting awards ceremony in Denver, Colorado, Aug. 6. Ferrarezi is an Assistant Professor of Citrus Horticulture; Ritenour, Professor of Postharvest Technology; Wright, Professor of Soil and Water Science.

    Others who contributed to the research and the award-winning publication are Arun D. Jani, a post-doctoral research assistant; Thomas James III, who manages citrus research groves; and Cristina Gil, an agricultural research assistant.

    “We strive to keep citrus growers in business even though HLB is reducing the profitability of infected trees over time,” said Ferrarezi. “The point is to sustain younger trees for a number of harvests to produce the healthy, delicious fruit that made the Indian River District famous.”

  • Citrus Growers Join Researchers for Field Day of Emerging Answers

    University of Florida Institute of Food & Agricultural Sciences — More than 50 citrus growers and researchers attended a field day to view 154 new citrus scion-rootstock combinations—some of which will result in the production of market-ready fruit from trees that tolerate the most serious citrus disease worldwide.

    The disease is called citrus greening. It has reduced Florida citrus production to about half of what it was when 950,000 acres were under citrus production. Most researchers and growers agree that new scion and rootstock combinations hold a lot of possibility to preserve Florida’s signature crop.

    The Millennium Block Drive-Thru Field Day 2021 took place on the morning of Thursday, Oct. 14, at the University of Florida Institute of Food and Agricultural Science’s Indian River Research and Education Center (UF/IFAS-IRREC) in Fort Pierce, Florida.

    IRREC researchers guided attendees from information tents positioned at strategic points among 20 acres of carefully managed rows of grapefruit, orange, pummelo, and mandarin trees. Each plot of a scion-rootstock combination was labeled and corresponded to a 12-page packet Ronald Cave and researchers presented to visitors upon arrival. Cave is professor and director of IRREC, and he leads the citrus research project, along with manager Tom James, graduate student Martin Zapien, and agricultural assistant Mac Hossain.

    “Our mission for the Millennium Block’s rootstock and scion trials is primarily to provide guidance to growers on the UFR rootstocks. There is also a secondary purpose to evaluate grapefruit and grapefruit-like hybrids,” said Cave. “No other trial like this is happening anywhere, but we need additional funding to continue with the trial until the trees are seven years of age.”

    University officials and staff guided visitors to specific trees where growers left their vehicles to observe trees up close.

    “The Millennium Block research project is taking the industry’s best scions and rootstocks and mixing and matching them to provide the industry with a brighter future, and some of the matches look promising,” said Doug Bournique, executive vice president of the Indian River Citrus League.

    Jeanna Mastrodicasa, UF/IFAS Associate Vice President for Operations, led the event at booth #2. She fanned through the pages of the packet Cave gave her and noted the colored rows and legends. “Here is a great map and a great key that explains how the coding works and which rootstock appears where in the grove,” said Mastrodicasa.

    In a row of grapefruit trees across from Mastrodicasa, IRREC Advisory Committee member Pete Spyke pointed to six trees of the same rootstocks. Spyke is a heritage Florida citrus grower who owns Arapaho Citrus Management in Fort Pierce, Florida. He lifted bunches of yellow grapefruit with pink blush from the 2-year-old trees. “Ray ruby grapefruit on UFR-15 rootstock shows the kind of thing we are after in the Millennium Block trials. It’s a very nice fruit—very high quality—excellent performance for a young tree,” said Spyke.  “The tree has two blooms, a regular bloom and a late bloom. We will capture data from both blooms.”

    At a second location, where white grapefruit trees grow, Chris Hernandez showed an attendee a tree that produces sweet grapefruit. Hernandez is a UF horticulture undergraduate student and an agricultural assistant at IRREC.

    “My favorite grapefruit is Seedless Surprise. The variety is super sweet, the best flavor in a grapefruit I have experienced. And the trees tolerate citrus greening well,”Hernandez said.

    At another grove position, viewers gathered around Ken Gioeli, UF/IFAS Extension St. Lucie County Natural Resources Agent, to learn about invasive, venomous, and harmless snakes that may be found in the grove. Gioeli recommends growers to be aware of four venomous snakes found in the Indian River District and how they can increase safety. He urged visitors to report Burmese pythons with a mobile application, I’veGot1.

    Several longtime citrus growers were surprised to find some varieties in a condition they did not expect.

    “There are some variations in the rootstocks,” said Matt Hamilton. He, along with his family, own Hamilton Grove Services, Inc., in St. Lucie County. “I am surprised that some of the rootstocks I expected would do well are not looking too good, but a few of the UF rootstocks look good.”

    “Our family has been in the business since the 1960s,” said Mark Hamilton. “We are grapefruit growers, and we want to stay in business.”

    Growers recall many of the Indian River District’s citrus production challenges. Freezes, insects, and diseases have caused setbacks and the scion rootstock combinations may bring a comeback.

    “We need to make sure the trends we see today are consistent as time goes on. Next year’s data should be much more enlightening,” said Spyke.

    “The approach we are taking to breeding is to find tolerant scions and rootstocks that impart tolerance to the scion. Those combinations will be less expensive to grow and will produce larger crops of good wholesome fruit and those two factors will allow growers to make a good profit in the future. The data will be applicable to any variety growing anywhere in the state, including processed fruit.”

  • Tomato Trade with Mexico could Cost US Growers $250M a year

    As Mexico increases tomato exports across the world, including to the United States, prices plummet for American growers. That practice could cost American growers as much as $252 million per year — or 27% in revenue — if imports from Mexico increase by 50% in coming years, based on historical trends, new University of Florida research shows.

    That’s a huge loss for American farmers, who produced 1.3 billion pounds of fresh tomatoes in 2020, less than one-third the harvest from the year 2000.

    That decline is due to competition from Mexico and other challenges, said Zhengfei Guan, an associate professor of food and resource economics at the UF Institute of Food and Agricultural Sciences.

    Zhengfei Guan, a UF/IFAS associate professor of food and resource economics at the Gulf Coast Research and Education Center, studies tomato trading and its impacts on American growers, among other areas of research.

    Guan just published a study on the consequences of intensifying Mexican competition for American growers. The market positions of Mexican and domestic tomato industries completely reversed over the past 20 years. Mexico now dominates the U.S. market, with three times more market share than the domestic industry. That change sparked Guan’s interest in pursuing the new study.

    “The two countries had a series of trade disputes over fruit and vegetables recently,” he said. “One reason is that surging imports from Mexico boosted by subsidies have depressed prices, and American growers are quickly losing market shares.”

    “The findings from our study will provide tomato producers and policy makers with important insights on the challenges and the sustainability of the U.S. tomato industry,” Guan said.

    In his study, Guan measured the potential losses the U.S. industry will sustain as a result of the increasing imports from Mexico, given the steep growth over the years. As a frame of reference, the volume of imported tomatoes from Mexico increased by about 60% over the years 2009-2019.

    Results of Guan’s research show that prices of domestic tomatoes are particularly sensitive to imports from Mexico in an increasingly saturated market. The imports are especially damaging to the Florida tomato industry which has about $400 million in sales and has the same harvest seasons as Mexico.

    The trade deficit complicates matters for farmers in several commodities – not just tomatoes. Specifically, fruit and vegetables — such as tomatoes, strawberries, peppers, cucumbers and melons – accounted for 50% of the total U.S. agricultural imports from Mexico in 2020, according to the U.S. Department of Agriculture. “But all may not be lost, if the US fruit and vegetable industry could revolutionize the production technology,” said Guan. “Mechanization or automation will be a game changer and is the future for this labor-intensive industry.” — By Brad Buck, University of Florida Institute of Food & Agricultural Sciences