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Posts Tagged: UC Davis
Diagnosing herbicide problems takes detective work
Field day offers examples, tips for solving the mystery
A grower applies an herbicide to his tomato plants, or thinks a neighbor's treatment is drifting over her almond trees. A short time later, the leaves start to bleach or shrivel. Was it the herbicide? Or maybe water stress? Soil nutrients? Perhaps an insect?
Figuring out the causes of crop problems takes detective work, and like solving any mystery, it starts with knowing the signs, gathering evidence and asking questions.
The Diagnosing Herbicide Symptoms field day at UC Davis was an opportunity to see, up close, the shriveled cotton, scorched corn and dying sunflowers that can result when herbicides are applied incorrectly. Using the right herbicide – in the right proportion, at the right time and in the right field – can make the difference between a thriving crop and a financial loss.
A top take-away to avoid problems: “Don't do stuff at night!” laughed Becky Wheeler-Dykes, a UC Cooperative Extension farm advisor attending the June 26 event to better serve growers in Glenn, Tehama and Colusa counties. “The packages look the same. People grab the wrong jug.” And then, disaster.
Instructors were Brad Hanson, professor of Cooperative Extension; and Kassim Al-Khatib, the Melvin D. Androus endowed professor for weed science; both in the Department of Plant Sciences. They were joined by John Roncoroni, a Cooperative Extension emeritus farm advisor rooted in the department's weed science program. Attendees were a mixture of people from agriculture, industry, government officials, university researchers and Cooperative Extension advisors. The event was hosted by the Weed Research and Information Center, based in the Department of Plant Sciences.
Out in a field west of campus, visitors could see the progression of damage, from control plots with green and healthy crops to plants that looked sadder as herbicide concentrations increased. Visitors could see the patterns of damage for common foliar chemicals such as glyphosate, paraquat, and 2,4-D, as well as soil-applied herbicides from several chemical classes.
“There's a lot of detective work,” said Stephen Chang, a master's student in Hanson's lab aiming for a career in Cooperative Extension. “For example, the company that makes the herbicide says there shouldn't be a problem, but the grower says, there is a problem. This course helps with developing the skills to figure out what happened.”
It might not be the herbicide at all
Detective work and problem-solving frame the approach, Hanson explained. The cause of crop damage can be simple or complex. Like a good mystery, what appears to be a clue can turn out to be a red herring. Professionals need to draw on their inner Sherlock Holmes to observe and document symptoms, look for patterns in the plants and in the field, ask questions, gather information about the larger environment and collect samples.
An herbicidal Agatha Christie would then suggest: What if it's not herbicide damage at all? Participants learned to consider the possibility of insects, pathogens and viruses, as well as problems with water, nutrients, soil condition and even root damage from cultivation practices.
Hanson recalled puzzling over symptoms he found in an orchard. The culprit? “A leaking natural gas line,” he said.
More resources for herbicide issues
Participants also heard from Molly Mathews, deputy agriculture commissioner from Yolo County, on how a field investigation is conducted. Lawyer Robert Davies, of Donahue Davies LLP in Folsom, outlined the basics of what happens when there are lawsuits related to crop damage from herbicide drift.
The Diagnosing Herbicide Symptoms field day is part of a larger program of education and outreach offered through the Weed RIC, said director Julia Stover-Blackburn. It was the first time the event has been offered since the COVID-19 pandemic, she added.
- For more information about field days and resources, visit the Weed RIC webpage.
- For a thorough discussion of herbicide symptoms, visit this page overseen by Al-Khatib and sponsored by University of California Agriculture and Natural Resources.
- This online course follows an earlier version of the Diagnosing Herbicide Symptoms field program.
This story was originally published on the UC Davis Department of Plant Sciences website.
Postharvest Center: New research focus and outreach
Still providing the world with top-notch information
UC Davis has been a leading source of information for people handling, packaging and transporting crops since the beginnings of the Postharvest Research and Extension Center in 1979. Now, the center is strengthening its focus on the needs of industry, offering fresh courses, weaving strategic partnerships and expanding into digital media, all while building up its research capacity to better serve the needs of the produce industry.
“We're asking people in the industry, ‘How can we support you? How can we better listen to you?' We want people to know we're not disconnected know-it-alls,” said new center co-director Bárbara Blanco-Ulate, an associate professor in the UC Davis Department of Plant Sciences. “We're getting more faculty involvement, people with expertise in related fields such as quality engineering and safety, as well as bringing in emeriti faculty and people from around California. We're forming partnerships with organizations around the world, and we've opened up to people from other institutions around the country.”
“The larger the network, the more things we can do,” added fellow co-director Irwin R. Donis-Gonzalez, an associate professor of UC Cooperative Extension in the Department of Biological and Agricultural Engineering.
The foundation: Expanded research
The new co-directors will beef up the center's applied science component with the hiring of a research specialist. They aim to provide new information that can be used industry-wide as companies explore new ways to handle and store fresh produce.
“We're building the capacity to respond to industry requests for research,” Blanco-Ulate said.
New courses, national reach
Their first workshop, held recently, demonstrates the center's renewed vision and commitment to broad networking: The Agricultural Water Systems Workshop addressed current concerns around water management and risks to food safety. Partners in the course included the Western Growers Association, the University of Arizona, the University of Florida and Salinas-based Taylor Fresh Foods, Inc.
Courses given over the past several years that have been recorded will be posted to the center's new, online video library and to the center's YouTube channel.
“People can watch those courses for free,” Blanco-Ulate said. In addition, new courses will be offered in-person and hybrid.
The co-directors are working with the University of California to offer continuing and professional education credits to course participants.
Online resources – many for free!
The center's website features a database with scores of free product fact sheets, which are downloaded by users around the world. The fact sheets are so highly regarded that they are considered expert evidence in legal proceedings, Blanco-Ulate said. Visitors to the website can also find links to research papers published by UC Davis faculty, including seminal works by Adel Kader, who founded the center.
Books are offered through the center's online bookstore and include titles through UC Agriculture and Natural Resources. Ten new titles are being planned, including topic-specific updates taken from previous classics.
Debunking myths: Ethylene
A new newsletter deals with a new problem: Misinformation about food and food handling that spreads through social media. One example is the use of ethylene to ripen produce such as bananas, so that they can be safely stored until ready for the consumer.
“Ethylene is safe for humans and does not leave any harmful residue on produce,” Donis-Gonzalez wrote in the center's latest newsletter. Even better news, he added: The levels of ethylene used on food are a tiny fraction of the concentrations that would be needed to create an explosion, one of the false alarms being raised in social media.
Evolving with the times
After 47 years of service, these and more updates will keep the center at the forefront of an evolving postharvest world. The top goal: Meet the needs of agriculturalists, industry and consumers.
“We are adapting to new needs, with both the resources and the workshop we're offering,” Donis-Gonzalez said.
“As a land-grant institution, we take our outreach mission seriously,” Blanco-Ulate added.
Related links
More about the UC Davis Postharvest Research and Extension Center.
This story first appeared on the UC Davis Department of Plant Sciences site.
Understanding cattle grazing personalities may foster sustainable rangelands
Matching herds to landscape can support animal growth and ecological needs
Not all cattle are the same when it comes to grazing. Some like to wander while others prefer to stay close to water and rest areas.
Recognizing those personality differences could help ranchers select herds that best meet grazing needs on rangelands, leading to better animal health and environmental conditions, according to a new paper from the University of California, Davis, published in the journal Applied Animal Behaviour Science.
“Cattle can actually be beneficial for the rangelands,” said lead author Maggie Creamer, who recently earned her Ph.D. in animal behavior at UC Davis. “Vegetation in rangelands actually need these kinds of disturbances like grazing.”
Ranchers can add elements to the rangeland such as water, mineral supplements and fencing to influence where cattle graze, but little research has been done on how those efforts affect individual cows. Considering personalities could save money.
“If you're spending all this money to add a management tool in order to change the distribution of your animals, that's a huge cost to ranchers,” said Creamer. “Thinking about other tools, or selecting certain animals with these grazing traits, might be a better way to optimize the distribution on rangeland rather than spending a bunch of money for something that may ultimately not pan out for all your animals.”
Effects of grazing
Livestock graze on an estimated 56 million acres in California, and healthy rangelands host native vegetation and animals, foster nutrient cycling and support carbon sequestration.
Uneven grazing can degrade water quality, soil health and habitats. Optimizing grazing — including the even spread of cow pies — can improve the ecosystem while also reducing fuel loads for wildfires.
To better understand individual grazing patterns, researchers went to the UC Sierra Foothill Research and Extension Center in Browns Valley and tracked 50 pregnant Angus and Hereford beef cows fitted with GPS collars.
The research
The cattle, which were tracked from June to August over two years, had access to 625 acres of grasslands and treed areas ranging in elevation from 600 to 2,028 feet. In the second year, a new watering site was added at a higher elevation.
Across the two years, the cows showed consistent and distinct grazing patterns even when water sources changed. Age and stage of pregnancy did not affect patterns, though cattle tended to clump near water and rest sites on hotter days.
The cows that ventured into higher elevations and farther from watering sites had more variability in their grazing patterns than those that stayed at lower elevations near water. That suggests it may be harder for non-wanderers to adjust to some landscapes.
“Thinking about the topography of your rangeland and your herd of cows can benefit both the animals and the sustainability of the land,” said Creamer, who next month begins work as a postdoctoral scholar in North Carolina.
Gauging personalities
Keying in on personality type may sound difficult, but the researchers also found some clues as to how to pinpoint the wanderers and homebodies. Unlike cattle at feedlots, the breeding cow population, especially on rangelands in California and other western states, live largely “wild” lives and are rarely handled, save for vaccinations and weaning.
Research due to be published later this year found that paying attention to individual cow reactions during those events can help determine personalities. The cows that appeared more passive during those handling interactions tended to be nomadic.
“We found that you can maybe predict those hill climbers if you kind of look at how they act when the veterinarian or rancher handle them,” said senior author Kristina Horback, an associate professor in the Department of Animal Science at UC Davis.
Informing practices
For ranchers, the findings could be invaluable, said Dan Macon, a livestock and natural resources Cooperative Extension advisor in Placer and Nevada counties for UC Agriculture and Natural Resources.
“Any time we can improve our understanding of cattle behavior, particularly at the individual level, it can improve how we handle livestock and manage the landscape,” he said.
Macon said that during the recent drought, it was hard to get cattle into higher country, but if ranchers could have selected the nomads, it may have saved money in terms of ranch labor and other efforts.
“If you ask a rancher who has been attentive to their cattle over many years, they know the personalities,” Macon said.
For Creamer and Horback, the research opens new doors into understanding herd behavior and dynamics, one that could be a cheaper alternative to high-tech solutions.
“Animal science tends to look overlook the mind of the animal when searching for solutions to challenges,” Horback said. “It's always been a direct line to genetics for immunity or nutrition, but nothing about the mind of the animal. And that's such a loss. There's so much we can learn from behavior in the end.”
The Russell L. Rustici Rangeland and Cattle Research Endowment supported the research.
This article was first published on the UC Davis News site.
UCCE advisor Bruno guides, learns from dairies switching to milking robots
Automatic milking systems increasingly used in California amid labor challenges
When third-generation dairy farmer Shonda Reid first saw a milking robot at a farm show 13 years ago, she immediately recognized that the technology represented the future. Her father, however, took a bit more convincing.
“I came home and showed him and said, ‘This is what we need to do.' And he thought I was kidding!” said Reid, dairy and farm manager for Fred Rau Dairy, which has a herd of 1,400 milk cows in Fresno County.
Years later, after the family had visited several dairies using automatic milking systems (AMS) across the U.S., they installed their first six robots in November 2021. By fall 2022, they had 24 robots, evenly split between two newly built “free stall” barns where the cows can freely go to the milking machines.
As Fred Rau Dairy was one of the first in California to implement AMS at such a scale, Reid and her team have been instrumental in growing practical knowledge on these systems. She also has been a valued partner to Daniela Bruno, University of California Cooperative Extension dairy advisor for Fresno, Madera and Kings counties.
“Automatic milking robots are not a new technology, but it's new to California,” said Bruno, noting that the milking robots were first used on small, family-run farms in Europe, where the technology granted family members more time for rest and other pursuits.
To better understand the feasibility of milking robots for large dairies in California, Bruno – alongside former UC Davis School of Veterinary Medicine professor Fernanda Ferreira, University of Minnesota researcher Marcia Endres and other collaborators – began a project in 2020 to study the risks and opportunities of automated systems.
“The information is extremely useful for California producers to make informed decisions about implementing AMS on their facilities,” said Denise Mullinax, executive director of the California Dairy Research Foundation, which supported the effort through a competitive grant. “Cow care, labor requirements and profitability are key issues for producers, and CDRF was pleased to support this project which assists producers in understanding how AMS may impact those areas on their facility.”
Dairy farmer: ‘We needed to make some changes'
The project produced a paper analyzing existing research on automatic systems, which have been more widely used in the Midwest, where there are more small-scale, family-run dairies. In 2020, there were only 14 “box robots” in California, according to Bruno. Now there are about 200 across California – and both Bruno and Reid cited labor challenges as the primary reason for the increased use of automated systems.
“California suffers from labor quality and quantity issues,” Bruno said. “By bringing robots to California, you can minimize those problems.”
Higher costs of hiring and retaining employees, driven in part by new labor laws, are one factor. And then there's the reliability and availability of labor, as fewer people are willing to do the physically demanding work of conventional milking.
“People just don't want to milk in a flat barn [a conventional setup where the employee works at the same level as the cow] – there's a lot of kneeling, squatting, that type of thing – it's pretty tough on the body,” Reid explained.
Faced with labor shortages and mounting regulatory burdens, Reid said Fred Rau Dairy had to make the leap to automated systems to keep the 80-year-old dairy operation running.
“We needed to make some changes, or we're going out of the dairy business,” she said.
In a survey conducted by Bruno and her colleagues of large dairies using AMS across the U.S., a majority of the 29 respondents reported reductions in labor costs – but survey results did not offer a definitive picture on whether AMS improved bottom-line profitability.
Calmer, healthier cows
Nevertheless, most of the survey respondents said they were generally happy with their transition to automatic systems.
“It's totally met our expectations, and cow health has gotten much better, too,” Reid said.
In a typical conventional system where cows are outside in “open corral” pens, dairy employees must cajole the cows into the milking parlor. But within a “free stall” barn where the cows can voluntarily go to the milking robots when they want, as often as they want, the animals are much less stressed.
“When you think about cow handling, if you have robots, you don't have anybody pushing and screaming at them to walk to the parlor,” Bruno explained. “You have less cow-people interaction so they are more calm; there is less stress.”
In the survey of large dairies using milking robots, more than 90% of the respondents said their cows were calmer. Reid also noted that many people have noticed how calm their cows are in the free stall barns.
“They're not skittish, you can walk in and they don't run,” Reid said. “They'll just watch you or they'll even come up and start licking on your jacket or shirt.”
Bruno also said that many of the large dairies reported fewer cases of mastitis and other diseases, less lameness, and greater milk production. But she added it's hard to know whether the benefits can be attributed to the robots and their real-time monitoring technology – or to changes in the physical environment (cows save energy in the free stall barn setup, versus the open-corral system that requires walking to the milking parlor).
Dairy producers seek counsel on potential transition
Less bovine travel from outside to inside was a boon for Fred Rau Dairy during last year's unusually wet winter.
“Even if it's just a couple of weeks of rain, that mud and manure and everything – you do what you can, but oh my gosh – it's a mess,” said Reid, noting that easier facility maintenance during extreme weather was another benefit of switching to automatic systems within free stall barns.
Reid shared many of her experiences with attendees of an AMS Field Day in October 2022, arranged by Bruno, Ferreira and their collaborators. About 60 farmers, researchers, industry representatives and consultants visited Fred Rau Dairy and Jones Dairy in Merced County.
If a dairy producer is considering implementing automatic systems, Reid recommends that they research all their options, visit dairies that use the systems, and check who in their area would be providing service and technical support.
And there are crucial workforce considerations, as dairy workers must learn an entirely new set of skills and processes. Instead of spending their time fetching the cows, prepping them and milking them in the parlor, workers might need to gather and interpret data from the robots. “Cow people,” as Reid puts it, must become computer people.
“You have a group of people who have been with you for a while, and you hope that they can transition to the new technology of what you're doing,” Reid said.
During this technological transition, and on the myriad other challenges that dairy operators face, Reid said she is grateful for Bruno's expertise and responsiveness.
“If there's something that I need, she's been really good about trying to help – or putting me in contact with the right people,” she explained. “I've enjoyed working with her.”
The AMS project team also includes UC Davis School of Veterinary Medicine professor Fabio Lima, postdoctoral researcher Thaisa Marques and former postdoctoral researcher Camila Lage.
No-till annual wheat better for soil health in California’s climate
One more reason to adopt sustainable cultivation
California wheat farmers could both maintain their yields and improve soil health by growing annual wheat without tilling the soil year after year.
This could be one more encouragement to farmers to adopt a sustainable practice commonly called conservation tillage, no-till or minimum-till cultivation, impacting how we grow a grain that supplies about 20 percent of the calories and protein for people around the world.
A new study, by a team led by Mark Lundy, University of California Cooperative Extension specialist in UC Davis' Department of Plant Sciences, offers new insight for decades-long discussions around soil conservation, sustainable agriculture and climate-warming emissions related to growing our food. The study has been published in the journal Soil and Tillage Research. For the first time, researchers have shown that annual wheat that is not tilled each year is better for stashing carbon in the soil than perennial wheatgrass, while still yielding more crop in Central California.
Previous studies have looked at annual wheat that is tilled each year, annual wheat that is not tilled, and a cousin species, perennial intermediate wheatgrass (trademarked Kernza), which also is not tilled. But until now, no one has looked at all of the benefits and trade-offs together. Most importantly, “no one has ever controlled for tillage,” Lundy said. “And, no one has compared annual wheat to perennial intermediate wheatgrass over multiple years in a Mediterranean climate, which is what we have in California.”
This study also is unique because it delves into the deeper question of what is going on in the soil that drives the different results for carbon there. Soil carbon reflects various processes linked to plant activity and soil health. Measuring the different forms of soil carbon may also signal whether a farming system is accumulating carbon in the soil over time – a plus for reducing climate-warming gases in the atmosphere.
“Measuring soil carbon is complex and nuanced,” said Kalyn Taylor, the lead author on the paper. “We started this experiment because we wanted to know whether and how plant activity and tilling or not tilling would affect the carbon story belowground in California's climate.”
“When we started this study, we thought the crop being perennial or annual would drive the differences in carbon storage in the soil,” Lundy added. Specifically, they had expected perennial wheatgrass would lead to more carbon in the soil because of its deeper, better-established root system. “But that's not what we found,” he went on. “What we found was, it was the lack of tillage, plus the level of productivity of common annual wheat, that made the difference in soil carbon here in California.”
Soil carbon in annual vs. perennial grain
In 2017, Lundy, then-graduate-student Taylor, UC Davis Professor Emeritus Kate Scow and others on the team started measuring different forms of soil carbon in test plots at Russell Ranch, west of campus. Plots were planted with annual wheat that was tilled each spring, annual wheat that was not tilled and perennial intermediate wheatgrass (Kernza) that also was not tilled.
Each year, the researchers measured the carbon present in the soil, the amount of soil organisms (which have carbon in their bodies) and the amount of material the plants created.
At the end of three growing seasons, they found that land planted with no-till, common, annual wheat had the highest amount of soil organisms, measured as biomass, of the three treatments.
The researchers also found soil carbon is more likely to remain stable in the no-till, annual plots, compared to both tilled wheat and wheatgrass.
In addition, the no-till, annual wheat produced plant material more consistently than the perennial wheatgrass across the three years, which saw variation in rainfall.
“Overall, annual wheat grown without soil disturbance or tillage had both higher productivity and higher potential for storing carbon in the topsoil than perennial wheatgrass in our Mediterranean climate,” Lundy said.
Related research
“No-till annual wheat increases plant productivity, soil microbial biomass, and soil carbon stabilization relative to intermediate wheatgrass in a Mediterranean climate,” is online now and will be published in the January 2024 edition of Soil and Tillage Research.
The team also found that tilled annual wheat vs. Kernza stores total carbon at different depths in the soil profile and hosts distinct soil fungal communities, primarily in the root zone and topsoil: Taylor, K., Samaddar, S., Schmidt, R., Lundy, M. and Scow, K., 2023. Soil carbon storage and compositional responses of soil microbial communities under perennial grain IWG vs. annual wheat. Soil Biology and Biochemistry, p.109111.
Previous work comparing the perennial grain known as intermediate wheatgrass (trademarked Kernza) to annual wheat had not distinguished the extent to which soil health benefits are a function of the perennial nature of the crop. Read the story here.
This story was originally published on the UC Davis News site.
