Almond Band Canker has No Cure

Almond Band Canker Creeping up Again

By Patrick Cavanaugh, Farm News Director

Themis Michailides, a UC Davis Plant Pathologist based at the Kearney Agricultural Research and Extension Center, recently told California Ag Today that almond band canker is becoming a big problem.

“This was a very old disease, and almost forgotten, but now we have major problems, particularly in the young orchards, first leaf, second leaf, third leaf, and it can also be found in six year old trees,” Michailides said.

Band canker is a fungal disease caused by a group of Botryosphaeria fungi that are very common in major crops like grapes, almonds, pistachios, walnuts, avocados, citrus and other crops, so they have a large range.

Band canker establishes itself as a spore inoculum that resides outside and also inside of orchards and waits for the right conditions, which are wetness and also high temperatures.

“It develops first like a ring, a canker that is a horizontal canker on the trunks of the trees and decays the wood and produces sap. It’s a disease that can kill young trees in the orchards,” Michailides said.

“Once you have the cankers developed in the trunks of the trees, there’s no cure, but we can prevent it by managing irrigation, trying to keep the trunks of the trees dry,” he said. “We need to develop protective sprays in order to avoid the development of the disease in young trees.”

“Once we have the water and the temperatures rise above 50 degrees Fahrenheit, the conidia – the spores of this fungi – will germinate and infect vigorous varieties we have now through the growth cracks,” Michailides said.

“It’s getting more serious, especially now, because we see that the disease is uniformly distributed throughout the orchard, which indicates to me perhaps that the inoculum is in the trees and not coming from the outside sources. We don’t see the patterns we saw years ago, where we had the source and then a center of disease close to the source,” Michalides explained.

California Ag Today2021-05-12T11:01:57-07:00December 26th, 2017|

Breeding for Pierce’s Disease Resistance Has Sped Up

Traditional Breeding Helps Find Resistance to PD

By Patrick Cavanaugh, Farm News Director

The glassy-winged sharpshooter is a major vector of Pierce’s Disease, which kills grape vines. Pierce’s Disease devastated the grape industry in southern California and lead to the creation of the Pierce’s Disease/Glassy-Winged Sharpshooter Board (PD/GWSS Board). Government programs to fund research on glassy-winged sharpshooters and Pierce’s Disease invest nearly $20 million annually.

California Ag Today recently spoke with Ken Freeze, the outreach and education director for PD/GWSS. He told us about two major methods of control and prevention that the board is funding.

“There’s the area-wide control program, which does everything it possibly can to pretty much keep the glassy-winged sharpshooter confined to basically the southern part of the state,” Freeze said.

This control program prevents the further spread of Pierce’s Disease into other parts of the state, which could devastate wine growers. In addition to preventing the further spread of Pierce’s Disease, the board is also funding additional research into hopefully finding a cure.

“We’ve got UC Davis Genetics Professor Andy Walker working on Pierce’s Disease resistant grapevine before the program, and he just released some of those vines to the UC Davis Foundation Plants Services.”

Freeze said this development has been done through traditional breeding, with the assistance of some new technology.

Walker’s traditional breeding is sped up by a lot of high tech tools. Previously growers would crossbreed, however they’d have to infect the vine and see if it got Pierce’s Disease.

“That could take a year or two. Now they know the genetic markers, so when the plant has only two or three leaves on it, researchers pull a leaf, do a DNA track on it, and look for that marker,” Freeze explained. “Depending on the marker, the vine either goes to the next step in breeding or it ends up in the trash heap. So that has just sped up that process incredibly.”

“Again, that’s all just using traditional breeding,” Freeze said.

California Ag Today2021-05-12T11:05:15-07:00December 4th, 2017|

Pierce’s Disease Research Advancing

Many Projects Under Way To Reduce Pierce’s Disease in Grapes

By Patrick Cavanaugh, Farm News Director

The glassy-winged sharpshooter vectors Pierce’s Disease, which has been devastating grape growers in California for the last few years. California Ag Today recently spoke with Ken Freeze, the Outreach and Education Director for the Pierce’s Disease/Glassy-Winged Sharpshooter Board, a program that uses winegrower’s assessments to fund research. He spoke with us about research that’s been carried out to hopefully find a cure for Pierce’s Disease.

Pierce’s Disease is caused by a bacterium, Xylella fastidiosa, that reduces the vascular function of the vine. The sharpshooter insect vectors the bacteria.

“Andy Walker, with the Department of Viticulture and Enology, UC Davis, has been working on Pierce’s Disease-resistant grapevines. We just released some of those vines to the Foundation Plant Services at UC Davis,” Freeze said. “There are 14 more that are in the wings about ready to go. Some nurseries will be able to get that pretty soon, but already there are about 4,000 of his vines planted. Some of them have been planted in Georgia and Texas, which are real hotspot for the glassy-winged sharpshooter and Pierce’s Disease.”

“Here in California, 2,000 vines were planted in Napa Valley right along the Napa River. Those vines are doing great,” Freeze said.

“We’ve got another project. University of Florida plant pathologist Dr. Don Hopkins has found a benign stain of Pierce’s Disease. It’s like inoculating a vine with a smallpox vaccination. That’s actually a company that’s working on commercializing that now,” Freeze explained.

“We’ve got another project that involves a modified root stalk that sends either a protein or a molecule up into the vine – a non-modified scion – five different ways that stops the Xylella fastidiosa bacteria literally in its tracks before it can cause Pierce’s Disease in the vine. That’s just a small sample of some of the really good projects.”

“One grower told me: ‘It’s not the end of the tunnel, but we can see it,’” Freeze said.

California Ag Today2021-05-12T11:05:15-07:00December 1st, 2017|

Paraquat Resistance in Weeds?

Weeds Now Showing Paraquat Resistance

By Patrick Cavanaugh, Farm News Director

There’s been weed resistance to glyphosate herbicide, but now some weeds show resistance to paraquat herbicide.

“When we see paraquat resistance at often a very high level of resistance, it doesn’t cause any visual injury, which is different than a lot of cases,” said Brad Hanson, a UC Cooperative Extension Weed Specialist at UC Davis.

“We’re dealing with a lot of glyphosate resistant weeds right now, and when you spay glyphosate on the resistant weeds, they are slightly injured and then they recover,” said Hanson. “With paraquat resistance, it’s very stark. You often don’t see any symptoms at all. I describe it almost as immunity. It’s such a high level of resistance.”

“We have glyphosate resistance to annual ryegrass and hairy fleabane, and we have some populations of those same weeds that are resistant to paraquat,” Hanson said. “We see a very temporary reduction in the photosynthetic ability, but within a few hours it bounces back to normal.”

The plant is taking that active herbicide molecule, and it is being sequestered. It’s taking that molecule and putting it somewhere in the cell where it cannot get to the photosynthetic apparatus that’s its target site. It’s a very unique and interesting kind of resistance challenge.

“I think we’re talking about multiple resistance to paraquat and glyphosate. The grower likely switched to use paraquat in order to kill the glyphosate resistant weeds, and then the weeds selected paraquat resistance on top of that.”

Patrick Cavanaugh2021-05-12T11:05:42-07:00March 6th, 2017|

Record Enrollment at UC Davis College of Agriculture and Environmental Sciences

UC Davis College of Agriculture and Environmental Sciences Really Rocks!

By Patrick Cavanaugh, Farm News Director

Helene Dillard, dean, UC Davis College of Agriculture and Environmental Sciences, is pleased with the big numbers of students attending the top-ranking College of Agricultural and Environmental Sciences.

Helene Dillard, dean, UC Davis College of Agriculture and Environmental Sciences

“It’s really rocking,” said Dillard. “We’re doing very, very well. We have one of the largest numbers of incoming students ever in the entire university. Our College has peaked out its 7,300 undergraduates. We’ve never had that many at one time.”

Why the increased interest in studying agriculture? Dillard said, “We think what’s moving that needle is that everyone is interested in food. They are interested in agriculture. And they are really interested in that intersection between agriculture and the environment. We have a record number of students that just cannot wait to come on board. We are really thrilled with how smart they are and how eager they are to learn.”

Among the many courses offered by the College, Dillard said Animal Science classes are probably among the most popular. “But of course, beer classes and the coffee class are really popular too. But right now, I’m seeing tremendous interest in agricultural economics and in animal science, to become veterinarians and ranchers, plus specific academic interest in poultry and sheep.”

“Again, those are all things that UC Davis does, so we’re really excited. We’re also seeing a lot of interest in plant sciences, more on that sustainable and food systems and our viticulture and enology program’s growing as well.

Recent Graduate Program Rankings for UC Davis College of Agriculture and Environmental Sciences and related disciplines include:

1st in agricultural sciences (Thomson Reuters ScienceWatch 2011)
2nd in agriculture and forestry (QS World University Rankings 2016)
2nd in agriculture worldwide (U.S. News & World Report’s “2016 Best Global Universities”)
1st in ecology and the environment (Thomson Reuters ScienceWatch 2011)
1st in food science and nutrition (Thomson Reuters ScienceWatch 2010)
1st in plant science (U.S. News & World Report’s “2016 Best Global Universities”)
1st in animal science (U.S. News & World Report’s “2016 Best Global Universities”)
1st for veterinary science (QS World University Rankings 2016)
1st among the nation’s veterinary schools (U.S. News & World Report’s “Best Graduate Schools” 2016)
Between 1st and 15th among 44 programs in nutritional biology (National Research Council 2010)
4th in environment/ecology (U.S. News & World Report’s “2016 Best Global Universities”)
Between 1st and 7th in Entomology among 28 programs (National Research Council 2010)
Between 5th and 29th among 116 programs in plant biology (National Research Council 2010)
Between 7th and 42th among 116 programs in plant pathology (National Research Council 2010)
13th in environmental engineering worldwide (QS World University Rankings 2016)
29th in environmental engineering worldwide (2016 Global Ranking of Academic Subjects, ShanghaiRankings)

(Source: University of California, Davis, Graduate academic program rankings.)

UC Davis College of Agriculture and Environmental Sciences

California Ag Today2021-05-12T11:17:11-07:00December 7th, 2016|

Livestock Economics for Western Producers

Livestock Economics: What Attributes Bring Higher Prices?

By Laurie Greene, Editor

At the 100th Annual California Cattlemen’s Association (CCA) & California CattleWomen’s (CCW) Convention last week in Sparks, Nevada, Tina Saitone, cooperative extension specialist, UC Davis Department of Agricultural and Resource Economics, described her research on rangeland and livestock economics. “Primarily, my focus has been on cattle — beef cattle to date — but I’ve also started some projects recently with sheep producers and the predator interactions they have specifically with coyotes. I am examining whether or not [producers] can use nonlethal depredation methods to mitigate those losses.”

“Right now, I have been concentrating on marketing characteristics of cattle,” she said. “I study those practices employed by producers, such as when they wean their cattle; how many vaccinations they have; whether they market [their cattle] as natural, grass-fed, or organic; and the impact that [these choices] have on their prices.”

Tina Saitone, cooperative extension specialist, UC Davis Department of Agricultural and Resource Economics

Interestingly, Saitone and her colleagues have mainly been using satellite video auction data. “Western Video Market Auction actually held their auction this month here in Sparks, Nevada because they can do it at different locations all the time. So, we use that data to figure out cattle characteristics and then determine the marginal impact that each of those characteristics has on price,” said Saitone.

Characteristics such breed, frame score, flesh score, and weight, are definitely controls in Saitone’s research model because those are main drivers of price. “But what we want to do is figure out — holding all those things constant —if a producer raises their cattle natural, what kind of premium does that bring them? We’re really looking for that incremental difference.”

One might expect certain factors such as natural or organic, to deserve a higher price, but there always has to be a buyer. “Right now, when prices are low relative to 2014 and early 2015, ranchers do have some opportunities to get some higher prices in what we would call niche markets. Consumers are increasingly demanding a wider range of characteristics. They want grass-fed. They want organic. They want natural, no hormones. All of these are what we would call credence attributes. If you go to the grocery store and you taste a steak, you probably don’t know if it was raised natural.”

Accordingly, the industry has third-party certification to assure consumers that when they pay a higher price for that product they are actually getting those traits. “Farmers actually have the ability to fill some of those niche markets that consumers have created with their demand and possibly get higher prices than just selling into traditional commercial channels.”

The data that Saitone has been looking at from Western Video is focused on Western states, including California. Certainly, location places Western producers at a persistent disadvantage because the majority of the processing capacity is in the central part of the country, with Nebraska being the hub. Saitone said, “When you think about cattle being raised in California having to be transported all the way to Nebraska, some 1600 or 1700 miles, not only do you have the cost associated with that transportation, but you also have shrink; you have mortality.

California Cattlemen’s Association (CCA)

California CattleWomen

UC Davis Department of Agricultural and Resource Economics

California Ag Today2021-05-12T11:17:11-07:00December 6th, 2016|

Algae in Soils Increases Soil Health, Better Crops

Is Algae in Soils a New Frontier in Plant Health and Yield?

By Patrick Cavanaugh, Farm News Editor

Could applying microalgae to the soil boost yield and strengthen plants? We spoke to Len Smith, chief business office, Heliae Development LLC., based in Gilbert, Arizona, in the southeast Phoenix metropolitan area. “Heliae is a company that is dedicated to unlocking the potential of microalgae,” said Smith. “We’ve been in business now for over eight years. We hope to be able to deliver microalgae products in a lot of areas, including in plant agriculture.”

“While we work with hundreds of algae species, the algae we are currently marketing for plant agriculture is a green algae. It is actually subject to genetic classification so I couldn’t even tell you the exact species at the moment,” noted Smith. “We’re working on several others as well. We have often seen in our early stage testing that many different kinds of microalgae have different positive effects on plant agriculture, so we’re bringing many of them along,” he said.

Unlock the secrets in the soil diversity

Natural Resources Conservation Service (NRCS) Soil Health Campaign

Smith said these algae are among the most common components in healthy soil. “A lot of what we’re doing is actually restoring what is already present in the soil. A lot of the scientists we work with think this is a critical component of the whole plant ecosystem below the soil line.”

Similarly, many university researchers are taking a closer look at algae. “We have about 30 university and contract research studies in, and we are working with growers. We have been selling the product in what I would consider almost a beta launch mode for about two years. So, we probably have about that same number of grower trials—maybe even double that,” said Smith.

Having the algae in the soil not only increased yields, according to Smith, it increased crop quality and strengthened the soil. “Benefits include root mass; in fact, we saw a 20 percent root mass increase in cotton. We have also seen the plant’s ability to grow in stressed environments such as heat stress and drought stress, in some of the work UC Davis did for us. We saw a 25 to 30 percent increase in overall yield in the stressed soils in which the algae was present, as compared to the control,” Smith explained.

Could it be that algae may be the new frontier in plant health and yield? “Yes, we’re very excited about what we’re doing. I would say we are opening a field here that nobody else is really paying attention to. I think that you will be seeing more of these products come to market, hopefully helping growers get better results in a restorative and natural way,” Smith said.

Heliae Development LLC.

Phycoterra

California Ag Today2021-05-12T11:05:43-07:00December 5th, 2016|

Improved Huanglongbing Detection in Citrus Trees

Projects Underway for Better Huanglongbing Detection in Infected Trees

By Patrick Cavanaugh, Farm News Director

The big problem with Huanglongbing Disease (HLB), also known as citrus greening, is that an infected tree, despite having no visual symptoms, could quietly be a massive reservoir of HLB. The main vector, the Asian Citrus Psyllid (ACP), could easily pick up HLB from that tree and spread the disease throughout the orchard.

Currently, the main push to contain the possible spread of HLB is by controlling ACP. Yellow sticky traps are positioned near every commercial orchard in California, as well as near non-commercial trees in neighborhoods. Finding a psyllid on a trap triggers mandatory spray programs to help eliminate all psyllids in the area.

Neil McRoberts, associate professor of plant pathology, UC Davis

“Yes, one of the most critical questions in managing in HLB is the trees can be infected for a long time before you can visually see the ACP there,” said Neil McRoberts, an associate professor of plant pathology, University of California, Davis.

“There is a group of scientists, funded by the Citrus Research Board of California (CRB), working on different early detection methods. Those are methods where you would be able to tell the tree was infected before you could see the tree is infected,” said McRoberts.

The CRB funded field trials in Texas over the last few years that have narrowed the field of competitors to two or three techniques. The CRB will continue to fund the two leading contenders in that race to determine the leading early detection technology.

In the first technique, researchers analyzed all the microbes that live on a non-infected leaf surface and studied how that profile of microbes changes when the tree gets infected. Detecting a change in microbe profile could indicate the tree is not as healthy as it should be.

“Researchers take the microbes that live on an infected tree, extract the DNA from those microbes and run the DNA through a sequencer. The sequencer identifies which types of microbes are there,” he said.

McRoberts said sampling for microbes is easy. Researchers use an industrial-sized swab on the leaf surface. “You literally clean the leaf surface with the swab until it’s squeaky clean, put that swab in a bottle and send it to a lab. When it gets to the lab, they extract the DNA out of it and the rest of the process happens from there.

A female Tamarixia radiata laying egg on an ACP nymph. (Photo by J. Lotz). Courtesy of Citrus Research Board

In selecting which trees should undergo microbe swabbing, McRoberts noted that the ACPs tend to attack the groves from the outer edges, inwards. “At different times of the day, the light will be on different edges of the grove depending on where the sun is and how warm it is. You can target your sampling towards the places where you’re more likely to find it, but still, finding those initial little infections is tough.”

The second method is a technique called metabolic profiling. A newly infected tree starts to produce different proteins and other chemicals in response.

Still another research strategy is analyzing things that stay in the tissue. “There’s a change in the profile of metabolites in the tree. If you run those metabolites through a mass spectrometer, the mass spectrometer will spit out a profile. You can tell the difference between a healthy profile and an infected profile,” McRoberts said.

“This is how the dogs come into the picture. Everybody knows that citrus has an odor. When the trees are infected, the profile of the chemicals and the composition of that odor change. We can’t smell it, but a very sensitive electronic detector device can sometimes pick it up. Remarkably, dogs can pick it up. We think that’s what happening with the canine detectors; they’re picking up some change in the smell of the trees.”

McRoberts said that dogs are amazingly accurate in detecting trees with HLB disease. “The best that we can tell from the trials involving dogs, the false positive rate is less than 1 in 1,000. I’m very confident with the detector dogs,” McRoberts said.

Featured photo: Adult Asian citrus psyllid (Photo by J. Lewis). Courtesy of Citrus Research Board

Citrus Research Board of California (CRB)

UC Davis Department of Plant Pathology

California Ag Today2021-05-12T11:02:00-07:00December 2nd, 2016|

Gary Schulz Gives California Citrus ACP and HLB Update

California Citrus ACP and HLB Update from Gary Schulz

By Brian German, Associate Broadcaster

The Citrus Research Board (CRB) recently held their annual California Citrus Conference in Exeter, bringing together a variety of guest speakers and research presentations. The Conference focused on pressing Asian Citrus Psyllid (ACP) and Huanglongbing (HLB) issues, along with political action updates and current projects that are important to the citrus industry. Gary Schulz, president of the CRB, said “We have a 21-member board and we’ve been planning this event for the last 12 months. It’s been 4 years since we held the last conference,” noted Schulz.

Gary Schulz, president, Citrus Research Board

The CRB is responsible for overseeing the California Citrus Research Program (CCRP), a grower-funded and grower-directed program created in 1968 under the California Marketing Act. The CCRP’s purpose to enable California’s citrus producers to sponsor and support research that furthers the overall industry. Therefore, close to 70 percent of the CRB’s overall budget is allocated to research.

Schulz said the Conference “was a great, great day to have a good update on some of the dollars the Citrus Research Board has been spending on the growers’ behalf on research.” Schulz explained HLB represents the single greatest threat that citrus growers have faced worldwide.

For the past seven years, the USDA and Congress have allocated between $10 and $12 million dollars annually for ACP and HLB research operations. Advocacy groups and other supportive ag organizations have contributed the difference to reach an annual ACP and HLB research budget of close to $90 million dollars a year. We fund a lot of UC Riverside and USDA agricultural research, service researchers, plus research at UC Davis and the University of Arizona,” Schulz noted.

Schulz, who has many years of experience in California agriculture, having served as general manager of the Raisin Administrative Committee and CEO of the California Raisin Marketing Board, stated that CRB has a great working relationship with California Citrus Mutual (CCM). “Joel Nelson and CCM have worked very hard with the packers to assess themselves, put together a private foundation, and work with the university,” Schulz said.

Featured Photo: Adult Asian Citrus Psyllid (Source: The Citrus Pest & Disease Prevention Program)

Resources

California Marketing Act

Citrus Research Board (CRB)

California Citrus Mutual

California Ag Today2021-05-12T11:05:44-07:00November 18th, 2016|

Initial Walnut Irrigation Can be Delayed

Walnut Irrigation Research Update

By Brian German, Associate Broadcaster

First springtime walnut irrigation can be delayed, according to a UC Cooperative Extension team in Tehama County working on some fascinating research regarding irrigation practices. Allan Fulton is an Irrigation and Water Resource Advisor who covers Tehama, Colusa, Shasta and Glenn counties. “We actually just finished one of our irrigation experiment harvests this weekend. It was looking at early season water management decisions, basically deciding when to begin the irrigation season,” Fulton said.

Allan Fulton, UC Cooperative Extension Irrigation Specialist

Growers typically begin irrigating their walnuts sometime between late April and early May. In order to be as thorough as possible in their experiment, Fulton and his team have been pushing the limits beyond what most growers would ever consider. “We had some treatments that got no irrigation until almost the end of June,” Fulton explained.

Now in its third year, the research experiment is generating information that will provide a variety of benefits. “The whole motivation is to avoid possible injury to the trees from irrigating too much, too early, from lack of aeration and damage to the root system,” Fulton said. Delayed irrigation, while having no impact on yield or nut size, can also provide a bit of water savings. “We’re trying to look for the sweet spot,” with less intensive early season irrigation in favor of root health, tree health and disease prevention.

The research is being conducted in the northern Sacramento Valley primarily using the Chandler variety of walnut trees. Fulton has spent some time working in the San Joaquin Valley as well and understands different weather conditions can be a significant factor when applying their findings to other regions. “Our spring rainfall is quite a bit different than other walnut growing areas. Usually we’ve got an added source of water that sometimes you might not have in the southern San Joaquin Valley,” Fulton noted. From his experience, he suggested growers could usually wait until “the first week of May in most years, before really getting pressed for irrigation.”

The location of the research exposes groves to the opportunity to receive “more rain during the dormant season with a better chance at a deeper profile in moisture before you ever break dormancy,” Fulton said. More regional rainfall is possible in the spring as well, while the trees are growing.

The information gathered so far indicates growers should not jump the gun on springtime irrigation, particularly if there is still any kind of standing water issues. “The data is starting to suggest that you’ve got some room. You don’t have to irrigate at the first sign of heat; you can use a little bit of the stored moisture coming out of winter,” Fulton said. He also noted “It’s a lot more difficult to recover from a damaged tree with a sick roots system,” than it is to recover from a lack of early season irrigation.

California Ag Today2021-05-12T11:05:46-07:00October 11th, 2016|