An invasive pest from Asia is killing thousands of trees in Southern California, which may lead to the death of thousands of humans, reported Adam Rogers on Wired.com.
Polyphagous shot hole borer females drill holes inside trees to lay their eggs. In the process, they deposit a fungus that grows and provides food for larvae. The fungus gums up the trees' channels for water and nutrient transport, eventually killing it. Called Fusarium dieback, the condition is on track to kill 26.8 million trees across Southern California in the next few years.
With data from a U.S. Forest Services study, which found that fewer trees is related to respiratory and cardiovascular disease deaths in people, the reporter underscored the dire human-health implications of polyphagous shot hole borer.
Trees also provide valuable "ecosystem services," such as reducing light and heat intensity, protecting water, cleaning the air of pollutants, providing wildlife habitat and storing carbon. The forest service combined satellite data and field plot data to calculate the costs and benefits of trees. The potential loss of ecosystem services because of polyphagous shot hole borer is $1.4 billion, not including the public health cost.
“A normal response to an invasive pest means millions of dollars would be thrown at it,” said John Kabashima, UC Cooperative Extension advisor emeritus who is working on staving off a catastrophe. “This one has received hundreds of thousands.”
Kabashima and other scientists are identifying infected trees to cut them down and chip the wood to prevent further spread. The tell-tale signs are little holes and sugar volcanoes that tend to show up first on the north side of the trunk or limb.
"You have to get out and walk around each tree, which we're doing in Orange County parks," Kabashima said. "We go out on off-road Segways. We can cover square miles in a day."
Ceres Imaging, an Oakland-based start-up, is working closely with UC Cooperative Extension on its aerial imaging of farm fields, a fact that is helping the company gain trust by association, reported Emma Foehringer Merchant on Grist.org.
Ceres puts equipment on low-flying airplanes to take pictures that will help farmers optimize water and fertilizer application. According to field tests, the imagery works. Since 2014, Ceres has teamed up with UC Cooperative Extension to conduct field trials, including one for the Almond Board that measured the response of nuts to different rates of watering.
In that study, data from Ceres' imaging matched well with the UCCE ground "truthing," said Blake Sanden, UC Cooperative Extension water and soils farm advisor.
According to the article, "Ceres' relationship with the extension program has helped the company gain trust with sometimes-skeptical farmers." Sanden called UCCE trials the "gold standard of efficacy" for new products in the ag market.
There is also increased interest in precise water management after years of drought and cutbacks on federal water allocation.
"The attitude (among farmers) used to be, 'I can find water,'" Sanden said. "I would say that 30, 40 years ago, there was an attitude of hope ... that some of the restrictions on pumping water (would) go away." He said growers expected decision-makers "to come back to reality and understand that we've got to make money in California and grow food."
But the restrictions didn't go away. Instead, they became stricter. The uncertainty about water deliveries has made farmers friendlier to new technologies, like the one offered by Ceres.
California avocados are the best in the world. So says downtown restaurant manager Daniel Avalos in a Valley Public Radio story by reporter Ezra David Romero.
The fact that they currently thrive only on a small swath of coastal Southern California is being challenged by UC Cooperative Extension specialist Mary Lu Arpaia. She is on a mission to find avocado varieties that withstand the hot summers and cold winters of the San Joaquin Valley, where irrigation water and crop land are more abundant and cheaper.
She hopes to find avocado varieties that ripen at various times of year, and varieties that might be an alternative crop for citrus growers should huanglongbing, a disease that has devastated the Florida citrus crop, take hold in Central California.
"There's a void of California fruit on the market in the months of November, December and actually early January," Arpaia said. "So if we can find different selections that maybe are unique that fit into that window, then we help the entire California avocado industry."
Romero visited the UC Lindcove Research and Extension Center to see the trees in Arpaia's study. Currently, the vast majority of California avocados are the Hass variety. The goal is to breed varieties with similar eating quality that grow to a moderate height and have high yield. One potential that is already being produced by nurseries is called "gem."
"This is gem," said Eric Focht, a staff research associate in Arpaia's lab. "You can see it's a little more oval or egg shaped than Hass. It has the speckling on the skin. Now as this ripens, it will turn dark and a lot of times the speckled lenticels with get a yellow kind of golden color it it."
Another promising variety is called "lunchbox" because of its small size. According to Focht, it "just falls out of the skin." Arpaia said, "It makes wonderful guacamole and I found, with a non-replicated test in my refrigerator, the fruit doesn't brown."
Arpaia's favorite guacamole recipe is featured at the end of the story on the KVPR website.
The warmest winter since 1907 in south-central Texas has left its peach crop with inadequate chill hours this year, reported Lynn Brezosky in the San Antonio Express-News.
Without sufficient chill hours over the winter, the buds didn't get the re-boot they need to bloom in proper synchrony, which is important for blossoms to set fruit. The leaves have also been slow to emerge. "The trees look like it's still winter," said Jim Kamas, Texas A&M AgriLife Extenson horticulturalist.
“The lack of chill hours is a big deal,” said Larry Stein, extension horticulturalist with AgriLife Research & Extension Center.
The Texas trouble combined with a cold blast that destroyed half the crop in Georgia and North Carolina this spring mean peaches are likely to be in short supply this year.
The sweet spot, Brezosky wrote, may be California, the No. 1 peach producer in the nation. Roger Duncan, UC Cooperative Extension pomology adviser, could think of no major problems affecting the southern part of the state's fresh market peach crop.
“I think in general it's probably going to be just fine,” he said.
Trees in several parts of California are suffering greatly in recent years due to pests, fire, drought and now heavy rain. UC Cooperative Extension is working with landowners and communities to protect the state's natural environments, including its beloved trees.
UCCE plant pathology specialist Matteo Garbelotto said the wet 2016-17 winter is bad news for oak trees in North Coast areas because it has created conditions that support the spread of Sudden Oak Death, reported Bay Nature. He is recruiting volunteers for 15 “bioblitzes” in April and May to track the spread of the disease. See more on the Garbelotto website.
UCCE forestry and natural resources advisor Susie Kocher held a workshop in Sonora for owners of forestland in the Sierra Nevada, where the epic 2010-16 drought killed millions of trees. Sally Shilling of Capital Public Radio attended and reported on the meeting. "There's just a lot of changes that need to be made to get to a resilient forest and hopefully this situation will help people notice that we have a crisis and that we can move forward and make some changes in how we do business," Kocher said. The federal government and CalFire have programs that can help landowners remove dead trees and replant.
In Southern California, the polyphagous shot hole borer could kill as many as 27 million trees in Los Angeles, Orange, Riverside and San Bernardino counties, including parts of the desert, reported Louis Shagun in the Los Angeles Times. Mark Hoddle, UC Cooperative Extension biocontrol specialist, said that the tree loss is starting to cascade across the urban landscape. “Without shade trees, water temperatures will rise and algae will bloom in riparian areas, for instance,” Hoddle said. “As a result, fish, frog and native insect populations will diminish, along with the pleasure of hiking, because there'll be nothing to look at but dead boughs of trees.”
In Lake County, UC Cooperative Extension director Gregory Giusti gathered with 400 members of the community to replant trees in a park that was left treeless by the devastating Valley Fire of 2015, reported Elizabeth Larson in Lake County News. While a lot of people lost their houses, “It was the trees that made it their home. People wanted to live in the forest. They wanted to live among the trees. So this is a way to rebuild their home, to get back what was lost,” Giusti said.