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 plain 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.
A portion of Placer County has been placed under quarantine for Asian citrus psyllid (ACP) following the detection of multiple life stages on citrus trees within the City of Lincoln.
The quarantine zone in Placer County measures 118 square miles, bordered on the north by Riosa Road; on the south by the Roseville City Limit; on the west by Brewer Road; and on the east by Fowler Road. The quarantine map for Placer County is available online at: https://www.cdfa.ca.gov/plant/acp/regulation.html#maps. Please check this link for future quarantine expansions in this county, should they occur. Quarantines in new counties will be announced separately.
This is a case where an individual moved infected trees from a quarantine zone into a clean county and ended up moving psyllid with the trees. This is how so many of our current pests are moving around - Shot Hole Borer, 1000 Cankers of Walnut, Emerald Borer, Gold Spotted Borer. On and on, we are the culprits of our own destruction. Pretty soon every pest known to plants will be everywhere. Sorry for the rant.
Since digging for strawberry plants destined for Salinas and Watsonville started at Macdoel just a few days ago, I thought it would be judicious to have a look at how many chill hours we've accumulated so far and what it means for additions to supplemental chill, especially for our day neutral varieties.
I checked with the Lassen Canyon nursery chill accumulator here: http://lassencanyonnursery.com/cumulative-chilling-hours-and-weather-conditions/ .
Looking at the data for Oct 18 of this year and running my calculations via the Utah model (which subtracts chill hours for temperatures realized above 60oF, see previous posts), we have currently accumulated 325 units of chill. Given that last year's chill accumulation was 164 units and by most commentator's opinion a decent accumulation, 325 accumulated chill units this year is very satisfactory.
So what does this mean for adjustments on supplemental chill? Personally, I think growers may want to take the strong field chill in stride, and now look forward to what sort of winter we are going to have. Looking at the NOAA data, we are probably in for a weak “La Niña” system this year, which according to the “Color Outlook Maps” for temperature, we have something like a 40% chance of having slightly warmer than normal temperatures in November, December and January.
The question then is what sort of adjustment should or needs to be made to supplemental chill. It's actually not an easy question to answer, given the strong field chill. Then again the odds of a slightly warmer than normal winter would give me some reason to err on the side of caution and go a tad longer than customary on the supplemental chill ./span>
ANR Learning & Development is sponsoring TWO “Crucial Conversations” trainings in spring 2017:
- Wednesday and Thursday, February 1-2, 2017, in Davis, at 2801 Second Street. On Wednesday, February 1, the training is from 8:30 a.m. to 5:30 p.m. and on Thursday, February 2, from 8 a.m. to 3 p.m.
- Wednesday and Thursday, April 26-27, 2017 at the South Coast REC in Irvine. On Wednesday, April 26, the training is from 8 a.m. to 5 p.m. and on Thursday, April 27, from 8 a.m. to 3 p.m.
- You may also select “I can participate in either session” when you pre-register.
Training is open to all UC ANR academics, UC ANR staff employees, and Cooperative Extension county-paid employees who have not taken the Crucial Conversations training in the past. All expenses related to the training (registration fee, travel, lodging, meals and training materials) will be reimbursed by UC ANR funds according to UC travel policy.
Twenty participants will be accepted for each training course. Individuals selected to participate in the training will need to participate the full period of the training. Therefore, if you cannot commit to the full 14 hours of training, we ask that you not pre-register for the training. We also encourage you to inform your supervisor of your interest to participate in this training.
If you are interested in the training, please pre-register by November 30 at http://ucanr.edu/survey/survey.cfm?surveynumber=19111.
Individuals who have pre-registered will be notified on December 9 of their acceptance to participate in the two-day training. A waiting list of those interested but not selected to participate in the training will be established in order for the trainers to contact you should individuals cancel from the training.
“Crucial Conversations” provides tools for talking when stakes are high, emotions are strong and opinions differ. The objectives of the 14-hour training are to provide the participants tools that will assist the participant in:
- Building greater personal influence and power
- Moving “stuck” work-related relationships and projects forward
- Improving personal, team and unit results
- Reducing stress from team frustrations and blocked communication
Your program-certified trainers Jan Corlett and Linda Marie Manton thank you for considering participation in “Crucial Conversations” training. If you have questions, please contact Jan Corlett at Jan.Corlett@ucop.edu.
View or leave comments for ANR Leadership at http://ucanr.edu/sites/ANRUpdate/Comments.
This announcement is also posted and archived on the ANR Update pages.
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