Posts Tagged: food

UC Davis awarded grant to advance strawberry breeding, genetic tools

The $6.2 million grant centers on protecting crops in the future

The federal government is awarding $6.2 million to University of California, Davis, to study how to use breeding and genetic information to protect strawberry crops from future diseases and pests.

The four-year grant from the National Institute of Food and Agriculture (NIFA) centers on addressing expanding and emerging threats to strawberries, a popular fruit packed with Vitamin C and key to the diets of many Americans.

Enhanced plant breeding, gene editing and other technologies will be key to ensuring strawberry crops are sustainable in the face of climate change and possible restrictions on chemical use, said Steve Knapp, director of the Strawberry Breeding Center and a distinguished professor in the Department of Plant Sciences.

“We need to have the technology so that we can deal with the challenges strawberries face around the world,” Knapp said. “Can we use genetic knowledge to change the DNA in a specific way to get the resistance we need?”

USDA funding

The grant award was one of 25 announced Oct. 5 by NIFA – an agency of the U.S. Department of Agriculture – as part of the Specialty Crop Research Initiative program, which addresses “key challenges of national, regional and multistate importance in sustaining all components of food and agriculture…,” the agency said.

The strawberry industry has lagged behind crops like tomato and wheat when it comes to genetic and technical innovation, Knapp said, and the grant signifies that “now they want the foot on the accelerator.”

A key priority is identifying whether changing DNA molecules can improve disease resistance and what technologies would be needed. Ensuring some genes are expressed while others are suppressed would be part of the analysis.

“We're trying to build in natural resistance to pathogens through the genes that already exist but could be modified with this knowledge,” Knapp said. “If we were able to edit a gene that improves disease resistance, people would want us to use that in breeding.”

The intent is to produce disease-resistant cultivars and identify better ways to diagnose, prevent and manage disease. The research project will also include an economic forecast evaluating the consequences of production changes and communicating with farmers about the laboratory advances, according to the grant proposal.

Gitta Coaker from plant pathology and Mitchell Feldmann, Marta Bjornson and Juan Debernardi from plant sciences are participating in the research, as are scientists from California Polytechnic State University, UC Agriculture and Natural Resources, UC Berkeley, University of Florida and USDA's Agricultural Research Service.

San Diego avocado growers look to Cooperative Extension experts to manage water costs

San Diego County used to be home to nearly 25,000 acres of avocado trees but today there are about 14,000. The drastic decrease is largely due to rising costs associated with avocado production, namely the cost of water.

On September 28, avocado growers gathered at the San Diego County Farm Bureau offices for an Avocado Irrigation Workshop facilitated by Ali Montazar, University of California Cooperative Extension irrigation and water management advisor for Imperial, Riverside and San Diego counties.

“All of our information being developed right now is focused on [irrigation] efficiency. Growers want to know how much water they need and what tools they should use to be more efficient,” explained Montazar.

Workshop attendee John Burr, who has been growing avocados for 15 years, confirmed that irrigation represents over half of his annual production costs and that meeting the needs of his trees is a constant challenge. 

“The sophisticated research in avocado irrigation that Dr. Ali Montazar is conducting is the first of its kind that the University of California has carried out specifically in avocados. His presentation allowed us attendees the opportunity to see and learn about the technology he is employing – from soil moisture sensors to the California Irrigation Management Information System level equipped station.”

Burr is hopeful that Montazar's research will help avocado growers accurately determine the evapotranspiration in an avocado grove or water use specific to avocados, critical parts of how growers select tools to determine irrigation runtimes.

“His presentation that showed his research finding of the avocado Kc (crop coefficient), while very early into his project, was really interesting. It indicates the possibility that we may need to vary the Kc for different times in the growing season, but he is just beginning a two-to-three-year project that will hopefully deliver solid data on what the Kc for avocados is,” said Burr.

Colorado River uncertainty looms

San Diego's avocado production is primarily managed by small farms. According to Montazar, this adds a level of complexity to water management because there is a greater emphasis on irrigation tools and strategies being user-friendly and cost-efficient.

“We don't know the future,” said Montazar. “But we need to be prepared for all consequences. The Colorado River is experiencing a significant water shortage, and this could impact the water supply source for San Diego County from the Imperial Irrigation District Transfer in the future. It is wise to consider enhancing irrigation efficiency as the most viable tool to manage limited water supplies in Southern California.”

Water has always been an issue. In the 1970s, California's water program paved a way for an additional 98,000 acres of agricultural land.

According to a 1970 study analyzing the cost of avocado production in San Diego County, water costs “averaged 3½ acre feet per acre at $60 an acre foot,” which came with the assumption that water costs would remain relatively low and affordable for a long time.

Unfortunately, that is no longer the case. The county of San Diego gets the majority of its water from the Colorado River, which is concerning given five-year projections of the river reaching critically low reservoir levels by 2027.

In fact, beginning in 2023, the San Diego County Water Authority will be raising the rates for water, prompting growers to invest in more efficient irrigation practices (Table 1).

Table 1. Cost for untreated and treated water in San Diego County in 2022 and 2023.

NOTE: An acre-foot is about 325,900 gallons of water.

Training growers on irrigation a top priority

There are no loopholes or short cuts when it comes to irrigation because irrigation is the key to tree health. Ben Faber, Cooperative Extension subtropical crops advisor for Ventura and Santa Barbara counties, points out that tree health is how growers stay in business.

“You can mess up your fertilization program, and you can mess up your pesticide program, but if you mess up your irrigation program, you're out of business,” he said.

According to Faber, efficient irrigation requires a strong grasp on salt management.

 “We import water that has a lot of salt in it. So, you've got to figure out how to put the right amount of water on the root zone without causing root health problems,” said Faber.

This process requires meticulous care, as anything that gets below the root zone can cause groundwater contamination – something growers do not want to be responsible for.

While the latest irrigation technology, such as smart controllers, could help growers, Faber said that training and educating farm managers should be the priority. 

As Faber puts it, managing irrigation should be “like brushing your teeth” – something that growers do naturally and competently. Many growers are over-irrigating or wasting time trying to resuscitate dying trees. It's important to learn the needs of the tree and, in some cases, it might be best to stop watering all together.

The first step to water efficiency is acquiring knowledge and identifying needs. Because an over-irrigated tree looks just like an under-irrigated tree, it's crucial that growers learn to recognize the difference and plan accordingly.

This is where Cooperative Extension advisors and researchers come in. Opportunities like the Avocado Irrigation Workshop are ideal for growers looking for answers or support.

For more information and to learn about future workshops in San Diego County, visit https://cesandiego.ucanr.edu/.

 

The scent that could save California’s avocados

Scientists search for pheromone to disrupt insect mating

UC Riverside scientists are on the hunt for a chemical that disrupts “evil” weevils' mating and could prevent them from destroying California's supply of avocados.

Avocado weevils, small beetles with long snouts, drill through fruit to lay eggs. The weevil grubs or larvae bore into avocado seeds to feed, rendering everyone's favorite toast topping inedible.

“They're extremely hard to control because they spend most of their time deep inside the fruit, where they're very well protected from insecticides and natural enemies,” said UCR researcher Mark Hoddle, a UC Cooperative Extension entomology specialist.

Not only are the insects reclusive, they are also understudied, making information about them hard to come by. “All books on avocado pest management will tell you these weevils are bad. They're well recognized, serious pests of avocados, but we know practically nothing about them,” Hoddle said.

One strategy for controlling pests is to introduce other insects that feed on them. However, that is unlikely to work in this case. “Natural enemies of these weevils seem to be extremely rare in areas where this pest is native,” Hoddle said.

To combat avocado weevils in Mexico, an area where they are native, and to prevent them from being accidentally introduced into California, Hoddle is working with Jocelyn Millar, a UCR insect pheromone expert. They are leading an effort to find the weevil's pheromone, with the goal of using it to monitor these pests and prevent them from mating in avocado orchards.

Pheromones are chemicals produced and released into the environment by an insect that can be “smelled” by others of its species, and affect their behavior.

“We could flood avocado orchards with so much pheromone that males and females can't find each other, and therefore can't reproduce,” Hoddle said. “This would reduce damage to fruit and enable growers to use less insecticides.”

Alternative control strategies could include mass trapping, using the pheromone as a lure, or an “attract-and-kill” approach, where the pheromone attracts the weevils to small sources of insecticide.

The work to identify, synthesize and test this pheromone in the field is supported by grants from the California Department of Food and Agriculture, as well as the California Avocado Commission.

An initial phase of the project sent Hoddle to a base of operations three hours south of Mexico City, an area with large weevil populations. Using a special permit issued by the USDA, Hoddle brought weevils back to UCR's Insectary and Quarantine facility.

Hoddle and Sean Halloran, a UCR entomology researcher, captured the chemicals that avocado weevils release into the air. Possible pheromone compound formulas were identified from these crude extracts and are now being synthesized in Millar's laboratory.

“Weevil pheromones have complicated structures. When they're made in a lab, they can have left- or right-handed forms,” said Hoddle. Initially, Millar's group made a mixture of both forms to see if the blend would work as an attractant, as it is far cheaper to make the blend than the individual left- or right-handed forms.

Field work in Mexico with the pheromone cocktail by Hoddle, his wife Christina Hoddle, an associate specialist in entomology, and Mexican collaborators did not get a big response from the weevils, suggesting that one of the forms in the blend could be antagonizing the response to the other.

As the next step, the researchers plan to synthesize the individual forms of the chemicals and test the insects' response to each in Mexican avocado orchards.

Because the levels of avocado imports from Mexico are increasing, the risk of an accidental weevil invasion is rising as well. Hoddle is hopeful that the pheromone will be successfully identified and used to lower the risk this pest presents to California's avocado growers.

“We've been fortunate enough to be awarded these grants, so our work can be implemented in Mexico and benefit California at the same time,” Hoddle said. “The tools we develop now can be used to make sure crops from any exporting country are much safer to import into California.”

More than a TikTok trend, preservation is the future of food

UC Master Food Preservers give live canning demonstrations at Orange County Fair

If you visited the Orange County Fair in Costa Mesa during the past month, you might have seen the Master Food Preservers of Orange County in their rustic farmhouse-themed kitchen located in the OC Promenade exhibit hall.

If the decor did not catch your eye, the colorful rows of glass jars lined along the walls certainly would have. For an entire month, three volunteers conducted live canning demonstrations from 11 a.m. to 8 p.m. five days a week. They are with the UC Master Food Preserver Program, a public service and outreach program under UC Agriculture and Natural Resources.

The OC Fair is UC Master Food Preserver's largest event in Orange County. Last year, the UC Master Food Preservers engaged 7,000 people at their booth.  

For over 30 years, the UC Master Food Preserver program has trained hundreds of volunteers statewide to keep Californians safe as they use culturally appropriate and research-based practices to preserve food in the home and provide engaging ways to explore healthy food.

Food preservation has a deep history rooted in human survival. Whether freezing, drying, fermenting or pickling, preservation is a practice that has prolonged the life of food and humans. Other benefits include reducing food waste and increasing food security.

The latest form of preservation, called canning, was introduced in the early 1800s according to a Smithsonian article. By placing food in a glass jar and heating it to a certain temperature for a prescribed period of time, oxygen is removed and a vacuum is created. This process prevents the growth of undesirable bacteria, yeasts and molds, thus keeping the food from spoiling.  

This is what you would have found the UC Master Food Preservers demonstrating at the OC Fair.

During her shift, Flo Vallejo, UC Master Food Preserver since 2018, carefully chopped carrots and daikon into thin slices and placed them inside small mason jars with spices inspired by Vietnamese cuisine.

Between the produce donated by Melissa's Produce and the diverse spices donated by Tampico Spice, the possibilities of what you will see the UC Master Food Preservers canning are endless.

“This is something my great-grandmother, grandmother and mother did. I never understood it because they didn't let the little kids in the kitchen,” said first-year UC Master Food Preserver Alice Houseworth.

Many of the UC Master Food Preservers have some experience with canning, whether it be a practice passed down from generation to generation, or, in Houseworth's case, something they watched their elders do as a child. 

Some might view canning as a hobby, but according to the UC Master Food Preservers, food preservation is an opportunity to prepare for economic and climatic change. 

Esa Kiefer, another UC Master Food Preserver since 2018, expressed her concern for the rising prices of food and decline in arable land. “I feel like now is the time to prepare for these changing times,” she said. “Who knows what the future will look like for food?”

Perhaps the future of food will come from glass jars. 

“You can even can chicken,” Houseworth said. “When it's cheap at the grocery store, you can buy it and use the pressure canner and then eat it when chicken prices go up.”

Vallejo recalls when pickling and canning were trending on social media during the stay-at-home phase of the COVID-19 pandemic, making it difficult to find mason jars.

“Preservation has been done for a long time. When I saw a lot of people doing it during the pandemic, I thought it was just because people had time on their hands. But I realized that many became concerned about the food supply and accessibility,” she explained.

The resurgence in food preservation interest makes the work of the UC Master Food Preserver program much more essential. Whether you are feeding a large family, living in a food desert or managing a tight budget, food preservation ensures you are fed today, tomorrow and beyond.

To learn more about the Master Food Preserver Program or to locate the nearest program in your area, visit: https://mfp.ucanr.edu/.

 

 

Less water, more watermelon: Grafting can help growers yield more

UC Cooperative Extension advisor tests ancient technique, new to California melons

As growers across California navigate severe drought, supply-chain challenges and rising inflation, reducing inputs has become an existential necessity. And for watermelon growers, a new twist on a thousands-year-old practice is showing real promise.

In the summer of 2018, watermelon growers brought a pressing problem to Zheng Wang, who had recently joined University of California Cooperative Extension as the vegetable crops and irrigation advisor for Stanislaus, San Joaquin and Merced counties.

Growers were seeing an increasing number of their cartons rejected by supermarkets and other buyers because of the melons' inconsistent quality, and Wang wondered if the ancient technique of grafting would help the state's melon growers, who plant about 10,000 acres of the crop each year.

Although California is the No. 3 watermelon-producing state in the U.S. (behind Florida and Georgia), there has been relatively little research on the melon across the state.

“Watermelons seem to have attracted not too much attention compared to other cucurbits, both Extension- and research-wise,” said Wang.

Fresh from his postdoctoral work at The Ohio State University on grafting fresh market tomatoes, Wang knew that vegetable growers understood the theoretical benefits of grafting, which combines a scion (the above-ground part of a plant) with the sturdy rootstock of a related plant.

But watermelon growers needed to make sure the added expense of using grafted plants would pay off. They were looking for science-backed evidence that the technique could actually reduce costs overall, while maintaining or boosting productivity.

“Sometimes as farmers we want to test a new cultural practice or crop product,” said David Jarrett, field manager at Van Groningen & Sons, who grows watermelons in the San Joaquin Valley. “A person like Zheng can set up a meaningful experiment and he has the tools for qualitative and quantitative analysis; Zheng knows how to measure a hunch and assign it a verifiable number measuring success.”

In his first trials in partnership with growers in 2019, Wang tested whether they could plant fewer watermelon plants, spaced at greater distances apart, while producing a stable yield of high-quality melons. The idea was that grafted plants, which are more vigorous and grow larger leaves and wider canopies, would produce consistently marketable melons that could be picked up to seven or eight times during an extended harvest season.

“That way we can make one plant equal ‘two,'” explained Wang, noting that non-grafted plants tend to produce only two or three picks of good melons, with quality declining rapidly afterward.

Grafting shows 'a lot of potential for the future'

After two years of trials, the growers determined, with strong confidence, that watermelons planted 4-5 feet apart could produce a yield equal to – or surpassing – that of plants 3 feet apart (the standard for their non-grafted counterparts).

According to Wang, growers reported that, on average, their successfully grafted fields produced 15% to 25% more watermelons than non-grafted fields per acre, while using 30% fewer plants and the same amount of water and fertilizers.

With the potential for greater profitability, grafting could be a major boon during a particularly challenging time for growers.

“California agriculture is stressed competing for finite resources such as land, water, fertilizer and other safe but effective chemical tools, but outside of this realm we can improve some of our crops by grafting,” Jarrett explained. “Just as many tree crops are grafted, we are learning that other crops can be successfully grafted too; the goal is to create a heartier plant, which may grow better in marginal soils with reduced inputs.”

Confidence in the technique has led to a significant increase in the planted acreage of grafted watermelon across California – from less than 250 acres in 2018 to more than 1,500 acres in 2021. At the same time, growers have adopted 4 or 5 feet as the new “standard” spacing for their watermelon plants, enabling them to reduce their populations while maintaining or boosting yield.

“Using grafting has kind of opened a new channel in the watermelon world, and for all vegetable production in California,” Wang said.

Next up for Wang is testing various combinations of scions and rootstocks. This year, he began variety trials with rootstocks of various cucurbit family members (like hybrid squashes, Citron and bottle gourd), with hopes of producing results that watermelon growers could use to decide the best options for their local conditions.

“In sum, there are a lot of unknowns – but also a lot of potential for the future,” he said.

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