Pourreza, who earned his Ph.D. at the University of Florida in 2014, worked on early detection of Huanglongbing disease of citrus. Huanglongbing, an incurable disease that is spread by Asian citrus psyllid, has seriously impacted citrus production in Florida. The disease has been found in commercial and residential sites in all counties with commercial citrus.
Early detection allows growers to remove infected trees before the disease can spread to healthy trees. Currently HLB infection is confirmed when leaves with yellowing and blotches are submitted for PCR testing, which is expensive and time consuming. However, the yellowing can be also symptomatic of other conditions, such as nutrient deficiency.
“We discovered we could see the symptoms of Huanglongbing using a camera, a set of cross-polarizers and narrow band lighting before it is visible to the human eye,” Pourreza said.
He said the yellow blotches on HLB-infected leaves are caused by starch accumulation.
“If we could detect abnormal levels of starch in the leaf, we could tell it is affected with HLB,” Pourreza said. “Starch showed the ability to rotate the polarization plane of light. We used this optical characteristic to develop the sensing methodology.”
Pourreza said the team has patented the technique and is working on developing a commercial product. He is seeking funding to continue the research in California, where, to date, HLB has only been detected in isolated Los Angeles neighborhoods. Asian citrus psyllid is found in important California commercial citrus production regions from the Mexican border to as far north as Placer County.
Pourreza is based at the UC Kearney Agricultural Research and Extension Center in Parlier.
Almond farmers will remember a UCCE demonstration last February when the 50,000-pound Iron Wolf rolled like a tank through an almond orchard in Chowchilla, ripping whole trees into shreds and incorporating the wood into the soil.
Researchers are now considering a less dramatic approach to removing an old orchard and incorporating the wood chips into the soil onsite. Combining a traditional horizontal chipper with a wood chip spreader modified for this purpose can be a viable alternative to the now-mostly banned burning of old orchards or transport of almond tree residue to co-generation facilities that convert biomass to energy.
“It's still cheaper for the farmer if he or she can sell the wood chips for co-generation,” said Brent Holtz, UC Cooperative Extension advisor in San Joaquin County and the research leader. “But co-generation plants are closing and our research is showing that incorporating the biomass into the soil has many benefits.”
When the wood breaks down, it returns nutrients to the soil. Organic matter increases, resulting in carbon sequestration, important for moderating the release of greenhouse gases into the atmosphere that may contribute to climate change.
The chipper and spreader combination pencils out at about $1,000 per acre, while the Iron Wolf costs about $1,500 per acre.
“The Iron Wolf turned out much more expensive and slower than we anticipated,” Holtz said. “It could only grind up and incorporate about two acres of trees per day, while the horizontal chipper can chip 15 acres per day. With the chipper and spreader combination, the chips do have to be disked in, which most growers can easily do.”
The whole orchard recycling project was funded by the Accelerated Innovation Management program of the Almond Board of California.
Whole Orchard Recycling Demonstration
11630 S. Airport Way (near Roth Road), Manteca, Calif.
Thursday, Oct. 13, 2016
Whole almond orchard recycling and the effect on second generation tree growth, organic matter and soil fertility presentation
Brent Holtz, Ph.D., UC Cooperative Extension advisor
Kuhn & Knight Wood Chip Spreading Demonstration
Randy Fondse, G & F Ag Services, Ripon, Calif.
Morbark Horizontal Chipper Demonstration
Randy Fondse, G & F Ag Services, Ripon, Calif.
- Author: Pamela Kan-Rice
The integrated orchard management program, sponsored by UC Agriculture and Natural Resources and UC Davis, will provide participants with the practical, field-level information they need to successfully farm almonds. UC Davis faculty and UC Cooperative Extension specialists and farm advisors from throughout California will present their latest research.
Three full days of instruction include more than 35 presentations on orchard planning, evaluation and management of soil, tree training, irrigation, economics of almond farming, pest management and other topics.
New and experienced growers as well as other industry members interested in commercial almond production are welcome to attend. There will be opportunities to network with other participants and presenters, along with a chance to have questions answered by professionals in the industry.
The almond short course will be held at the Modesto Centre Plaza at 1000 L Street in Modesto. Registration for the program is $950 until Oct. 24 and includes full course participation, course materials, three lunches and two receptions, and continuing education credits.
For more information and to register, visit http://ucanr.edu/sites/almondshortcourse.
If you have questions about the almond short course, please contact Lauren McNees at (530) 750-1257 or email@example.com.
UC Agriculture and Natural Resources researchers and educators draw on local expertise to conduct agricultural, environmental, economic, youth development and nutrition research that helps California thrive. Learn more at ucanr.edu.
UC Agriculture and Natural Resources (UC ANR) has established a $1 million UC Cooperative Extension (UCCE) Presidential Chair for California Grown Rice, announced UC ANR associate vice president of business operations Tu Tran. The endowed chair will provide a UCCE scientist a dedicated source of funds to support scholarly activities focused on improvement of California rice production and quality.
Half the funds for the endowed chair was provided by UC President Janet Napolitano; the other half was donated by the California Rice Research Board. The announcement was made at the Rice Experiment Station in Biggs, Calif., on Aug. 31.
“The establishment of this endowed chair strengthens the long-standing public-private research partnership UC Cooperative Extension has had with the California rice industry,” Tran said. “Continued research advancements will help the rice industry maintain its reputation for supplying a premium product for domestic and world markets.”
The California rice industry has a long history of supporting research, said Seth Fiack, Glenn County rice farmer and the past president of the California Rice Research Board. As president of the board, Fiack shepherded the establishment of the new presidential chair.
“We, as an industry, have always taken it upon ourselves to fund research we see as significant,” Fiack said. “More than 100 years ago, rice growers established the Rice Experiment Station to keep them viable and sustainable. California rice chooses to have the highest investment in research on a per-unit basis among rice producing states.”
The Rice Experiment Station in Biggs is operated by the grower owned and funded California Cooperative Rice Research Foundation, in close collaboration with UC Cooperative Extension, UC Davis and USDA.
UC Cooperative Extension and UC Davis scientists focus on rice production research issues such as weed, disease and insect pest management, nutrient management and water conservation. They also conduct the Statewide Yield Tests, testing varieties and experimental rice lines in grower's fields, all with funding support from the California Rice Research Board.
Don Bransford, third-generation Sacramento Valley rice grower, praised the formation of the new UC Cooperative Extension Presidential chair for California Grown Rice.
“This is a partnership that has gone back many, many years,” Bransford said. “Much of the success of the California rice industry is due to our relationship with Cooperative Extension. Working hand-in-hand with UC, we've been able to supply markets with an extremely high quality rice and support the environment by providing critical habitat to more than 200 wildlife species.”
The new presidential chair will be awarded by UC Agriculture and Natural Resources to a UCCE specialist or advisor currently working in rice research or to recruit an external candidate to UCCE. The chair appointment will be for a five-year term, and then reviewed and renewed or offered to another specialist or advisor working on California rice.
Napolitano created the Presidential Match for Endowed Chairs in 2014 for UC campuses and UC ANR to use as an incentive to encourage donors to establish endowed chairs to fund research. Endowed chairs help attract and retain top-flight academics.
Led by Philip Martin, professor emeritus in the Department of Agricultural and Resource Economics at UC Davis, scientists analyzed all Social Security numbers reported by farm employers in 2014. The total number of farmworkers employed in California in 2014 was 829,300. The number of full-time equivalent jobs was 410,900.
“We have lots of people who do farm work in California,” Martin said. “If we could use more of them year round, we would not have to always be looking for immigrants.”
Interest in farmworkers and farm employment is growing in California and in the nation. Comments about illegal immigration by presidential candidates and a new law under consideration in California to require overtime pay for farmworkers have made farm employment part of a national conversation. California's labor-intensive fruit and vegetable production systems, the tightening of border controls and proposals to give some unauthorized workers a temporary legal status have also fueled interest.
“Many farm employers argue that there are farm labor shortages, while worker advocates counter that there is only a shortage of wages to attract and retain farmworkers,” Martin said. “Our objective was to provide a clearer picture of California's agricultural workforce by determining the actual number of wage and salary workers in agriculture.”
The research was based on information from the state's Employment Development Department, which collects data on farmworkers and wages paid when it collects unemployment insurance taxes from employers.
The results of the 2014 analysis are compared with previous analyses of farm employment going back to 1990. The data reflect a shift over the last 30 years away from direct-hire employment on crop farms and toward employment by farm labor contractors.
“Crop support services, like farm labor contractors, surpassed on-farm hires for the first time in 2007,” Martin said. “Since 2010, average employment reported by crop support establishments has been rising by 10,000 a year.”
In 2014, nonfarm crop support firms brought an average of 205,000 farmworkers to crop farms, while direct-hires on crop farms was 175,000.
“Our data show that California has a remarkably stable workforce,” Martin said. “We found that most farmworkers are attached to one farm employer, often a labor contractor who moves them from farm to farm.”
Average earnings for all workers who held at least one farm job during the year was over $19,000 in 2014, while average earnings of those who had their maximum earnings in agriculture was $16,500. Farmworkers who were employed by farm labor contractors had the lowest average earnings at $12,719.
In addition to Martin, the article was authored by Muhammad Akhtar, Brandon Hooker and Marc Stockton of the California Employment Development Department. California Agriculture journal is the peer-reviewed research journal of UC Agriculture and Natural Resources.