Safe, healthy and happy Thanksgiving
This is one of a series of stories featuring a sampling of UC ANR academics whose work exemplifies the public value UC ANR brings to California.
Through the COVID-19 pandemic, UC Agriculture and Natural Resources has continued to work to safeguard abundant and healthy food for all Californians, promote healthy people and communities, build skills needed in the workforce and help to develop an inclusive and equitable society. For insights into how the pandemic is affecting life in California and UC ANR's programs in these areas, UC's research magazine, California Agriculture, spoke with UC Cooperative Extension specialist Karina Díaz Rios about nutrition. Below is the edited conversation.
California Agriculture: How is the coronavirus pandemic affecting food security for people in California?
California Agriculture: So the pandemic is affecting people's ability to get enough food to eat. Is it also affecting their ability to eat healthy food?
Karina Díaz Rios: Food-insecure people tend to spend more of their food money at convenience stores, where
prices are often higher than the larger grocery stores and the variety and quality are usually lower. This means that the overall quality of the diet of food insecure households is about 5% to 10% lower than households that are food secure. That doesn't sound like much, but the average diet quality of folks in the United States is already suboptimal — around 60 out of 100. If 100 is the highest-quality diet, 60 is not much more than halfway there. So a reduction of 5% to 10% is really consequential. The issue is not that food-insecure people make bad choices. In buying certain kinds of food instead of others, people are making the right choices based on their circumstances. Shopping in convenience stores might be the logical action when time or other resources, like transportation or income, are limited — and when planning meals maybe isn't realistic because of lack of practice or other competing priorities. It's difficult to plan when your income is unstable.
California Agriculture: How does all this affect the work that you do?
Karina Díaz Rios: This is an area where there are challenges, but also opportunities. The Cooperative Extension army of nutrition educators is very well suited to help overcome some of the obstacles that the pandemic has posed for accessing resources, whether in-kind resources like food assistance or educational resources. They know their communities. They can identify the needs in their communities and help address them more easily than people who are not in such good touch with the community. Another extremely good thing about our Cooperative Extension system in California is that people are very creative. We have people who can come up with solutions in a heartbeat and implement them.
California Agriculture: Lots of children around the state won't be returning to school in the fall, at least at first. What effect does remote education, as opposed to in-school education, have on the food security issues that you cover?
Karina Díaz Rios: A large number of low-income students who qualify for food assistance and school meal programs are not going to get those meals if they don't go to school. There are efforts in several school districts to make sure that low-income children are actually receiving these meals. These efforts are particularly key right now, but it takes a great deal of planning and resources to make it happen. But also, these school meals only represent, at best, two-thirds of the daily caloric needs for children who get breakfast and lunch from school. So they can still be on a caloric deficit if they don't have enough food at home, which again, is more likely to be the case because of the pandemic.
California Agriculture: Do you foresee that the coronavirus is going to cause any long-lasting changes in the realm of nutrition? Or, after a vaccine is developed, do you imagine that things will more or less go back to the way they were?
Karina Díaz Rios: I am concerned that the people most affected by higher food insecurity due to the pandemic are going to be children. A lack of nutrients, even for a limited time, can affect children's ability to grow and thrive. So I just hope that these days are not going to have a lasting impact on these children — but it's a possibility.
Strawberries, which generated $2.2 billion for California growers mainly on the coast in 2019, are sensitive to soilborne diseases. Strawberry plant roots infected by fungi are unable to take in nutrients and water, causing the leaves and stems to wilt. The diseases reduce fruit yields and eventually kill infected plants.
To protect the delicate plants from pathogens, strawberry growers fumigate the soil with pesticides such as chloropicrin and 1,3-dichloropropene before planting transplants. Due to the potential negative effects on the environment and human health, however, use of fumigants are highly regulated and developing non-fumigant alternatives has been a priority of the strawberry industry.
For a biological alternative to manage soilborne diseases in strawberries, Joji Muramoto, UC Cooperative Extension organic production specialist based at UC Santa Cruz, has received a $411,395 grant from USDA National Institute of Food and Agriculture to study the ability of other crops to suppress strawberry pathogens in the soil.
Verticillium wilt, caused by Verticillium dahliae, is a common soilborne disease that can be controlled with anaerobic soil disinfestation (ASD), a fermentation-based biological treatment using carbon sources such as rice bran under plastic mulch in moist soils for 3 to 5 weeks in autumn. About 2,000 acres of berry fields, mostly organic, were treated with ASD in California and Baja California, Mexico, in 2019.
In 2008-09, the diseases fusarium wilt, caused by Fusarium oxysporum f. sp. fragariae, and charcoal rot, caused by Macrophomina phaseolina, emerged in Southern California and now threaten strawberry plants throughout the state.
ASD isn't as effective against F. oxysporum and M. phaseolina unless it is applied in summer on the coast. As saprophytes, they feed not only on living plants, but also can colonize crop residues and rice bran especially at lower coastal temperatures in autumn. Treating fields on California's coast with ASD during summer is difficult because it competes with the vegetable production period.
Based on promising studies in Asia and other areas, Muramoto plans to test alliums – such as onion, bunch onion and leek – and a certain variety of wheat (Summit 515) to see if they will suppress F. oxysporum and M. phaseolina. His team will conduct a series of greenhouse and field trials and test these crops with and without ASD to compare the effects on soilborne pathogens.
“Studies have shown the potential of using allium crops to control Fusarium wilt, and Summit 515 wheat for charcoal rot,” Muramoto said. “Our goal is to examine the effectiveness of suppressive crops, optimize them for California strawberry production systems, and evaluate their economic feasibility for commercial use.”
“No single tactic is likely to replace fumigants,” he said. “Integration of multiple biological approaches such as crop rotation, ASD, and use of resistant strawberry varieties is a key to develop a successful non-fumigant-based soilborne disease management strategy for strawberries. This project is a part of such broader efforts.”
At the end of the three-year study, he plans to share the results at workshops, field days and webinars.
Rachael Goodhue, UC Davis professor of agricultural economics; Carol Shennan, UC Santa Cruz professor of environmental studies; and Peter Henry, USDA Agricultural Research Service plant pathologist, are co-principal investigators on the study with Muramoto.
Also collaborating on the project are Christopher Greer, UC Cooperative Extension integrated pest management area advisor in San Luis Obispo County; Oleg Daugovish, UCCE vegetable and strawberry advisor in Ventura County; Mark Bolda, UCCE director strawberry and cane berry advisor in Santa Cruz County; Jan Perez, food systems specialist, and Darryl Wong, farm research manager, at UC Santa Cruz Center for Agroecology and Sustainable Food Systems; Miguel Ramos of Ramos Farm; Agriculture and Land-Based Association (ALBA); Driscoll's; Naturipe; and The Oppenheimer Group.
Consumers who purchase luxury cotton textiles want more than cool, soft, absorbent fabric. Increasingly, they demand clothing made from fiber grown using ecologically sound practices and they're willing to pay for it, said speakers representing the textile industry at a UC Cooperative Extension webinar on Healthy Soils for Healthy Profits.
A recording of the three-hour Sept. 17 webinar – which features clothing manufacturers, farmers and scientists – may be viewed on YouTube at https://youtu.be/rEm8pjbbnaE.
At the beginning of the webinar, UC Cooperative Extension conservation agriculture specialist Jeff Mitchell recalled the tragic 1991 dust storm on the west side of Fresno County, which reduced visibility on Interstate 5, causing a 104-vehicle pile-up that took 17 lives. The devastating accident foreshadowed debates about agriculture's role in reducing dust emissions, he said.
“It turns out that air quality was just the beginning,” Mitchell said. “There is now a whole cascade of expectations that buyers, consumers and the public are demanding of farmers about how food, fiber, feed and fuel crops are actually produced.”
Speakers from non-profit and commercial fashion and fiber organizations said they are anxious to get access to cotton grown using practices that promote soil health and sequester carbon to give their products climate-change mitigation cachet.
“What we envision when we look at the fields is groundcover year-round. Living roots in the soil year-round,” said Rebecca Burgess, director of Fibershed, a California non-profit organization that develops regional and regenerative fiber systems. “No-till or strip-till practices have garnered interest to protect soil from disruption, to avoid breaking up fungal networks. To produce cotton in a system that isn't eroding top soil.”
Wrangler jeans is a clothing brand that has successfully incorporated sustainably produced cotton into its products. The company worked with a group of Tennessee cotton farmers and the Soil Health Institute to produce 100% sustainable cotton jeans and sell them in its Wrangler Rooted Collection. Men's jeans in the collection run about $100 a pair. Ordinary cowboy cut Wrangler jeans range from $39 to $41 a pair.
Burgess said the fashion and textile industry is organizing itself to align with the 1.5-degree pathway, a target set by the Intergovernmental Panel on Climate Change that limits the rise in global average temperature to no more than 1.5 degrees C above pre-industrial levels.
“We want to work with farmers to enhance the ecosystem function of the landscape,” Burgess said. “We need to embed the cost of transitions into the cost of the cotton.”
Growing regenerative cotton in California comes with challenges that farmers are facing head on. Firebaugh farmer John Teixeira this year grew a multi-species cover crop that he terminated with a flail mower rather than a herbicide. He is making compost on the farm and in some parts of the farm spreading 8 to 10 tons per acre.
“We spread it on soil and also on cover crops to digest the cover crop,” Teixeria said. “We're adding bacteria. We would love to have more fungal diversity in the compost, but that's really hard. Fungi don't like to be disturbed. I believe microbes are the future. The key is to keep them alive.”
Gary Martin of Pikalok Farming in Firebaugh was using poultry manure on the farm, until it became prohibitively expensive. He then turned to cover crops and municipal compost to improve water infiltration, soil structure, water retention and increase organic matter. After three years, he added gypsum to improve the soil health.
He found that planting a cover crop without irrigation is a gamble.
“The net value of the cover crop is negative if it doesn't grow (because of a lack of rain),” Martin said. “Composting is more of a sure bet.”
Bowles Farm is experimenting with using a native plant cover crop.
“Native plants are designed to grow when we get moisture, and go away when we don't,” said Bowles Farm executive vice president Derek Azevedo. “It could be a habitat for pollinators.”
The company is also working on writing a carbon plan to map out how much carbon a cotton farm in Merced County can capture. The trial is managed with a multi-species cover crop, strip tillage, untreated seeds, fungal-dominated compost inoculation and a reduction in synthetic nitrogen.
“I can tell you already that the results of that carbon plan are being awaited by one of the brands in the San Luis Obispo area,” Burgess said. “They want to work with that cotton. They are excited to know what this can do for the climate.”
“We're interested in making products that stand the test of time, stay out of landfills, eliminating waste,” Daeschner said.
The company currently sources its high-end materials mainly from Italy, but is interested in transitioning to fabrics that are not only high quality, but also have a reduced environmental footprint. A new line, CO Natural World, focuses on the highest levels of sustainability, organic and regenerative materials, climate-beneficial wools, organic cotton, organic linen and recycled cashmere from garments that can no longer be salvaged.
“To create a garment that goes beyond the very least amount of harm to a garment that actually benefits the planet is the ultimate luxury,” Daeschner said.
The company is part of a network of five clothing brands that are working together to create the California Cotton and Climate Coalition, or C4 Coalition.
“We can do more together than we can do alone to boost the demand for beneficial cotton,” she said. “We are sharing pre-competitive information and pooling our financial resources to overcome existing gaps in the supply chain. And we will share our findings and results to attract new brands to the coalition.”
Calla Rose Ostrander, climate change communicator with the People, Food and Land Foundation, spoke from her home base in Colorado about opportunities for incentives to assist farmers in transitioning to healthy soils practices. She has been working with Maurice Marciano, the founder of Guess Jeans, and his daughter Olivia, who provided funding for part of the Bowles Farm project.
“They want to give back to the cotton community given the legacy of their company,” she said.
Ostrander said there is a network of philanthropic funders who may be interested in supporting the evolution of the cotton production system.
“There's a lot of commitment out there,” Ostrander said. “We're all trying to figure out how to do it and make sure that we can support the farmers in this transition. I'm really glad to see that the emphasis has stayed on supporting the producer and this idea has evolved. It takes time to build things.”
Opportunities and challenges for industrial hemp production in California are being revealed in a series of UC Cooperative Extension research projects.
As a crop relatively new to California growers and researchers, there is still much to learn about variety choices, how varieties and crop responses differ across regions with different soils and climates, best practices for nutrient management, and pest and disease issues.
UCCE industrial hemp field research efforts began in 2019 after the previous year's Farm Bill declared the crop should no longer be considered a controlled substance, but rather an agricultural commodity. Hemp is valued for its fiber and edible seeds, however, in California, producing hemp for essential oils including medicinal cannabidiol (CBD) is thought to offer the best economic outlook.
UCCE is working with Lafayette, Colo.-based Front Range Biosciences to test 10 of the company's hemp varieties in Ventura County and the west side of Fresno County. In Fresno County, the trial is underway at the UC West Side Research and Extension Center (West Side REC) under the direction of UCCE specialist Bob Hutmacher. UC Cooperative Extension advisor Annemiek Schilder, the study leader in Ventura County, intended to conduct the trial at the UC Hansen Research and Extension Center in Santa Paula, but the Ventura County Board of Supervisors enacted an emergency ordinance in January prohibiting hemp fields within a half mile of residential areas and schools because of the odor.
“The odor can be quite strong,” Schilder said. “Once plants start flowering, some varieties smell skunky. But the crop is related to hops, and other varieties have a more pleasant hoppy smell. Weather conditions also play a role in odor complaints.”
The Ventura County industrial hemp trial was planted at an Oxnard farm where a hemp crop was already being grown.
The trial includes mostly photoperiod-sensitive cultivars, where the flowering response is triggered by shortening day lengths in mid- to late summer in this latitude. Varieties that do not require the shortening day length to flower are called auto-flower varieties.
“Industrial hemp cultivars grown for essential oils, such as CBD, can be photoperiod-sensitive or not sensitive,” Hutmacher said. “The auto-flower varieties have potential to be more versatile in some production systems, in that they could be planted at a broader range of times of year since they don't respond to day length.”
The studies include growth and yield evaluations, monitoring for pest or disease threats in the San Joaquin Valley and coastal California, and periodic plant sampling to monitor the changes in plant THC and CBD levels over time. THC (tetrahydrocannabinol) is the psychoactive compound found in greater concentrations in cannabis varieties grown for marijuana. Legal requirements for industrial hemp production for essential oils, fiber or seed mandate monitoring concentrations of THC. The crop may not exceed 0.3% at harvest or it must be destroyed.
2020 cooperative irrigation study with Oregon State University
In a new 2020 study led by Oregon State University, drip irrigation trials were set up in California at the UC West Side REC and the UC Davis campus in addition to three sites in Oregon. These studies were set up to determine water use of industrial hemp under irrigation regimes ranging from about 40% to 100% of estimated crop water requirements, with comparisons of responses observed across the five sites with different soils, climate and other environmental conditions.
The same four varieties (two auto-flower and two photoperiod-sensitive) are being grown in irrigation studies at each of the five sites. The California locations in these trials were both planted in mid-June. The two auto-flowering varieties were harvested in late August and early September. The researchers expect to harvest photoperiod-sensitive types in late September or October.
The total water use of the different hemp cultivars under the different irrigation regimes will be determined using applied water measurements and assessments of soil water use between planting and harvest for each cultivar.
Some of the irrigation treatments impose moderate to more severe deficit irrigation to help assess the crop responses to water stress. Deficit irrigation is a method of conserving water by applying less than what might be considered optimum for maintaining rapid growth.
“This plant appears to be quite tough under deficit irrigation,” Hutmacher said. “We need to learn more about benefits and drawbacks to stressing the plants.”
The auto-flower cultivars tested have used less water than the photoperiod-sensitive cultivars because they can be grown in a shorter season. In the San Joaquin Valley, auto-flower cultivars in these studies were ready for harvest in 75 to 90 days after seeding.
“Auto-flower varieties may have potential to be grown in the spring and harvested by early summer, or planted in late summer and harvested before winter. With a short-season crop, and with a decent water supply, farmers could consider double-cropping with such varieties, increasing profits,” Hutmacher said.
2019 and 2020 planting density studies
In cooperation with Kayagene Company in Salinas, Dan Putnam, UCCE alfalfa specialist at UC Davis, and Hutmacher have conducted studies in 2019 and 2020 with two auto-flower varieties to determine crop growth, yield and THC and CBD concentrations of planting densities ranging from about 7,500 plants per acre to 30,000 plants per acre. Since some of the auto-flower varieties are smaller and earlier maturing than many photoperiod-sensitive cultivars, data in these studies will help determine the tradeoff between higher densities needed to increase yields versus increases in the cost of growing more plants.
The studies also provided opportunities for the scientists to assess plant-to-plant variation and impacts of flower bud position on THC and CBD concentrations.
“We feel that when this type of basic sampling method data is collected across a range of cultivars differing in plant growth habit, it may help better inform both researchers and regulatory groups in decisions regarding how to monitor plant chemical composition,” Hutmacher said.
Hutmacher and Putnam are also working with scientists at Davis-based Arcadia Biosciences to refine sampling methods.
“There are a lot of challenges when it comes to estimating maturity with these varieties,” Putnam said. “Each variety will mature at different times and deciding when is the best time is a key decision.”
Schools across the nation are removing chocolate milk from their meal programs to reduce students' intake of added sugar.
Some people are concerned the new policy will lead to a decrease in students' milk consumption and, specifically, reduce the essential nutrients that milk provides, such as calcium, protein and vitamin D. They also fear the policy could lead to an increase in milk waste. However, results from a study conducted by UC Nutrition Policy Institute may alleviate these concerns.
While the study found that the number of students who selected milk during lunch dropped by about 14% in the year the chocolate milk was removed, there was a no significant difference in the proportion of milk wasted before and after policy implementation. Milk consumption declined by about 1 ounce per student post policy implementation, resulting in a small but statistically insignificant decrease in the average amount of calcium, protein, or vitamin D consumed from milk.
The chocolate milk removal policy did result in a significant reduction in added sugar consumption from milk, by an average of 3.1 grams per student. These results suggest that a school meal chocolate milk removal policy may reduce middle and high school students' added sugar intake without compromising intake of essential nutrients nor increasing milk waste.
The study was conducted by NPI affiliated researchers Hannah Thompson and Esther Park from the UC Berkeley School of Public Health in collaboration with NPI researchers Lorrene Ritchie and Wendi Gosliner, and Kristine Madsen from the Berkeley Food Institute and UC Berkeley School of Public Health. The study was published online on August 27, 2020 in the journal Preventing Chronic Disease. The full study is available online.