UC Nursery and Floriculture Alliance
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UC Nursery and Floriculture Alliance

From the UC Blogosphere...

Coyotes are becoming a political problem in SoCal

Coyote management is fraught with emotion, says a UC wildlife expert.
Viewed by some as cute wild animals and others as malicious killers, coyotes have become a political problem in Southern California, reported Donna Littlejohn in the Daily Breeze.

The reporter spoke with Robert Timm, UC Cooperative Extension wildlife specialist emeritus and a coyote expert. 

"We all have a soft spot in our hearts for wildlife, it's why many of us went into the field," Timm said. However, left unchecked, coyotes kill pet cats and dogs, and even pose a threat to humans. "It's a very contentious issue and not an easy one to deal with. ... We all have our individual feelings about it and it's hard to separate that from what we know scientifically."

Coyotes have been making their way into Southern California suburbs since the 1970s, mostly living in the shadows. But when they become habituated to humans, conflicts can arise. Current management practices rely on deterrence and hazing. But when that isn't enough, trapping and removing some problem coyotes appears to send a message to the rest of the coyotes in the neighborhood, Timm said.

"If there are problem coyotes reported in a specific area and you go in and remove a few, it seems to wise up the rest of the coyotes and make them wary of people," Timm said.

However, many advocacy groups lobby against any kind of coyote management that uses traps or euthanization. Relocation of animals is illegal in California.

The coyote issue, Timm said, is fraught with emotion.

Posted on Tuesday, May 24, 2016 at 9:08 AM

Citricola Scale Eggs are Hatching

Adult citricola scales are lining up on the twigs.  Their eggs are hatching this month and crawlers are moving about on the twigs and settling on the leaves.  Adults are hard to kill with insecticides and the eggs under their bodies are protected from insecticides.  If you wait till all the eggs hatch and the crawlers move out onto the leaves, the insecticides will work better.  Usually egg hatch finishes towards the end of July.  You can check this by flipping over the female scales and looking to see if there are fresh eggs.

Cool wet springs favor egg hatch and survival of citricola scale, so be on your guard this spring.  See the Citrus IPM Guidelines for Citricola scale for information on treatments.  A new citricola scale-effective insecticide that will soon be added to the guidelines is Sivanto (flupyradifurone).  

Adult citricola scales with crawlers
Exit hole showing parasitism of a second instar scale

Posted on Tuesday, May 24, 2016 at 7:52 AM

Mosquitoes Are in the News Three-Fold at UC Davis and Here's Why!

Aedes aegypti, the mosquito that transmits dengue, yellow fever, chikungunya and Zika viruses. (CDC Photo)

Mosquitoes are in the news three-fold at the University of California, Davis. First, there's the upcoming free public...

Posted on Monday, May 23, 2016 at 4:40 PM

New nutrition fact label is a 'victory for consumers'

UC ANR nutrition expert Patricia Crawford counted the raisins in a cup of Raisin Bran to calculate the amount of added sugar. With the new labels, counting raisins won't be necessary. (Photo: Wikimedia Commons)
In two years time, the ubiquitous nutrition facts label found on packaged foods will differentiate between natural sugar and added sugar, reported Tara Duggan in the San Francisco Chronicle.

"It's a victory for consumers. The impact is going to be incredible," said Pat Crawford, director of research at UC ANR's Nutrition Policy Institute. "It's something in the nutrition field we've waited for years and years: to educate the public on how absolutely critical added sugar is and about the risk of heart disease, diabetes, obesity and dental caries."

The nutrition label changes were unveiled last week by First Lady Michelle Obama. The new label has bigger and bolder calorie information. It shows the amount of "total sugar" and below that, it shows "added sugars." The article gave an example of vanilla yogurt. On the current nutrition facts label, a consumer can see how much sugar it contains, but doesn't know how much of the sugar is from natural lactose in the milk and how much added.

Crawford noticed how hard it is to figure out when a friend asked how much added sugar was in Raisin Bran.

"I poured out a cup of cereal. I counted the raisins," Crawford said. She subtracted the amount of natural sugar in the raisins from total sugar listed on the nutrition facts label to determine the amount of added sugar.

 

Posted on Monday, May 23, 2016 at 11:29 AM

Yellowing Lemon Tree Leaves?

Advice from the Help Desk of the 
UC Master Gardener Program of Contra Costa County

Client:  I wondering if you could help identify the issue with some of the leaves on my Lisbon lemon tree? I typically water once a week and not again until it dries out.

Yellowing Lisbon Lemon Leaves
picture from client

MGCC Help Desk Response: Thank you for contacting the UC Master Gardener Program Help Desk with your question about your lemon tree. Thank you for the photograph which was very helpful.

The vein yellowing evident in the photograph you sent could be due to several factors:

  1. There is a virus that can cause vein yellowing, but it is not common in our area, and so is probably not the cause.
  2. Herbicide toxicity can cause this type of symptom. If you have used an herbicide containing either diuron or bromacil, that could be the cause. If you have not used herbicides, then the cause is probably nitrogen deficiency.
  3. Although nitrogen deficiency symptoms usually present as more general yellowing rather than prominent vein yellowing, nitrogen deficiency can cause vein yellowing when the soil is cold (usually during the winter months), or if stems or the trunk are girdled (mechanically constricted). If there are any ties around your tree, you should remove them.

Lemon trees need regular fertilization, particularly with nitrogen, to remain healthy and productive. If you have not fertilized your tree this spring, we recommend that you do so now.  You can either use ammonium sulfate or a standard citrus fertilizer.  Information on proper nitrogen fertilization of citrus, based on the age of the tree, can be found at this University of California website http://ipm.ucdavis.edu/PMG/GARDEN/FRUIT/CULTURAL/citfertilization.html.Or you can just follow the directions on the fertilizer label.

Citrus has many roots near the soil surface.  Lemon tree roots should not be disturbed by digging or cultivating, since damaged roots will negatively impact water and nutrient absorption. At least several inches of mulch under the entire tree is usually also recommended to protect the roots, keep the roots cool, retain Irrigation moisture, and minimize competing weeds. Keep the mulch at least 6” from the trunk.
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Citrus should be watered every 7 - 10 days during the dry season. Additional information on how to water citrus can be found (and/or downloaded free) at the University of California's website http://ipm.ucdavis.edu/PMG/GARDEN/FRUIT/CULTURAL/citruswatering.html .

I hope that this information is helpful.  If you water and fertilize the lemon tree properly but the leaves do not green up with 4 weeks, please feel free to contact us again.

Help Desk of the UC Master Gardener Program of Contra Costa County (JL)


Note: The  UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions.  Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA  94523. We can also be reached via telephone:  (925) 646-6586, email: ccmg@ucanr.edu, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog  (http://ucanr.edu/blogs/CCMGBlog/). 

Posted on Monday, May 23, 2016 at 12:11 AM

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