Posts Tagged: 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.
/h3>/h3>/h3>The Heat. The Butterflies. The Butterfly Guru.
Don't expect to see UC Davis distinguished professor emeritus Art Shapiro monitoring butterflies on...
A cabbage white butterfly, Pieris rapae, nectaring on lavender in a Vacaville garden on June 24. Next Wednesday, July 4, promises to be a scorcher at 106 degrees. (Photo by Kathy Keatley Garvey)
A cabbage white butterfly, Pieris rapae, flutters its wings, ready to fly. (Photo by Kathy Keatley Garvey)
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.
/h3>/h3>/h3>/h3>/h3>/h3>/h3>The Art of the Bee
Thought for the day... Every time we see a honey bee "posing perfectly" on a Gaillardia, commonly...
A honey bee on a blanketflower, Gaillardia, in a Vacaville garden. (Photo by Kathy Keatley Garvey)
Rob Page: The Student, The Professor, The Scientist, The Administrator, The Legend
Internationally known honey bee geneticist Robert E. Page, Jr. is spotlighted in the...
Internationally known honey bee geneticist Robert E. Page Jr. checks out a swarm in Arizona.
Rob Page, as a doctoral student at UC Davis, with his doctoral research mentor, Harry H. Laidlaw Jr. Page received his doctorate in 1980. (Photo by Ron Stecker)