UC Nursery and Floriculture Alliance (UCNFA)
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UC Nursery and Floriculture Alliance (UCNFA)

From the UC Blogosphere...

Bee My Valentine

Honey bee foraging on flowering quince. (Photo by Kathy Keatley Garvey)

Bee my valentine. There's something about a honey bee foraging on a flowering quince that makes you long for Valentine's...

Honey bee foraging on flowering quince. (Photo by Kathy Keatley Garvey)
Honey bee foraging on flowering quince. (Photo by Kathy Keatley Garvey)

Honey bee foraging on flowering quince. (Photo by Kathy Keatley Garvey)

Full speed ahead--A pollen-laden honey bee heads for another quince blossom. (Photo by Kathy Keatley Garvey)
Full speed ahead--A pollen-laden honey bee heads for another quince blossom. (Photo by Kathy Keatley Garvey)

Full speed ahead--A pollen-laden honey bee heads for another quince blossom. (Photo by Kathy Keatley Garvey)

Honey bee adjusting her load. (Photo by Kathy Keatley Garvey)
Honey bee adjusting her load. (Photo by Kathy Keatley Garvey)

Honey bee adjusting her load. (Photo by Kathy Keatley Garvey)

The entrance: a honey bee enters a quince blossom. (Photo by Kathy Keatley Garvey)
The entrance: a honey bee enters a quince blossom. (Photo by Kathy Keatley Garvey)

The entrance: a honey bee enters a quince blossom. (Photo by Kathy Keatley Garvey)

Posted on Monday, February 8, 2016 at 5:17 PM

Good Day, Mourning Cloak

A mourning cloak, Nymphalis antiopa, as photographed Feb. 6, 2016 in the Carolee Shields White Flower Garden and Gazebo, UC Davis Arboretum. (Photo by Kathy Keatley Garvey)

If you go looking for a bumble bee, you might find a butterfly. And vice versa. The UC Davis Arboretum last Saturday (Feb....

A mourning cloak, Nymphalis antiopa, as photographed Feb. 6, 2016 in the Carolee Shields White Flower Garden and Gazebo, UC Davis Arboretum. (Photo by Kathy Keatley Garvey)
A mourning cloak, Nymphalis antiopa, as photographed Feb. 6, 2016 in the Carolee Shields White Flower Garden and Gazebo, UC Davis Arboretum. (Photo by Kathy Keatley Garvey)

A mourning cloak, Nymphalis antiopa, as photographed Feb. 6, 2016 in the Carolee Shields White Flower Garden and Gazebo, UC Davis Arboretum. (Photo by Kathy Keatley Garvey)

Mourning cloak touches down Feb. 6, 2016 on a butterfly bush, Buddleia
Mourning cloak touches down Feb. 6, 2016 on a butterfly bush, Buddleia "Morning Mist," in the Carolee Shields White Flower Garden and Gazebo, UC Davis Arboretum. (Photo by Kathy Keatley Garvey)

Mourning cloak touches down Feb. 6, 2016 on a butterfly bush, Buddleia "Morning Mist," in the Carolee Shields White Flower Garden and Gazebo, UC Davis Arboretum. (Photo by Kathy Keatley Garvey)

Posted on Monday, February 8, 2016 at 2:57 PM

What's Rotting My Nectarines...and Peaches!

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

Client:  I have 5 different varieties of nectarine and peach trees in my Central CCC backyard. I treat the trees in late winter for peach leaf curl using an organic - approved spray. That works great.

Nectarine with Brown Rot
picture: UCANR
My problem is that last year the fruit on one of my nectarine trees started rotting on the tree. The tree is about 6 years old. The fruit rots to a dark brown color. None of the other nectarine or peach trees have the same problem.

What do you think the problem is? What is the cure? I prefer to use organic methods.

Advice from the MGCC's Help Desk: Thanks for contacting the MGCC Program's Help Desk. From your description, the problem with your nectarine fruit appears to be caused by the “brown rot fungus”, monilinia fruiticola. Peaches can be attacked by Brown Rot as well.

Brown rot fungus is tough and can survive over the winter:

  • in infected twigs
  • inside dead blighted blossoms that remain on the tree
  • dry mummified fruit that has been left on the tree from the previous year
  • dry mummified fruit left on the ground from the previous year

Brown rot infection and disease development can take place over a wide temperature range and flowers can be infected from the time buds open until petals fall. Water must be present on the flower surface for infection to occur. Spores produced on the tree parts described above in spring are carried through the air by wind and splashing water to infect flowers of the new year's crop.

Peach with Brown Rot
picture: goodfruit.com
Prompt removal and destruction of fruit mummies and diseased plant parts prevents the buildup of brown rot inoculum and helps keep rot below damaging levels. Pruning trees to allow good air movement will also help. Good air circulation through the tree facilitates rapid drying of the foliage and flowers after rain or overhead irrigation (not recommended). Some varieties of nectarine are more susceptible to brown rot than others, as you have seen in your own garden!

Appropriate applications of fungicide is the usual preventive measure to prevent brown rot, especially if you've had it occur before. However, fungicides can only prevent brown rot; they will not cure brown rot so timely application is important. Organic fungicides do not appear to be readily available for home gardeners. Recommended applications of copper-containing fungicides or synthetic fungicides such as myclobutanil at pink bud stage - just before the buds open can help avoid serious fruit losses. Rainy periods will require more spray. Additional applications when fruit starts to color may be needed if rainy weather persists. Do not apply copper compounds after bloom.

More specific information can be found by following the links below:

http://www.ipm.ucdavis.edu/PMG/r540100211.html
UC IPM: UC Management Guidelines for Ripe Fruit Rot on ...

and

http://www.ipm.ucdavis.edu/PMG/GARDEN/FRUIT/nectarines.html

Good luck this year with your nectarines. Hopefully, pruning, sanitation, cultural care, and a timely application of a fungicide will minimize brown rot.

Please let us know if you have any further questions we can help you with, and thank you for contacting our program!

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


Note: The  UC Master Gardeners 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, February 8, 2016 at 1:07 AM

Daily Life For Master Gardeners

Black Rot

By Andrea Peck

 

Leave it to the orchid to be dramatic—even when ill.

Not long ago, I was having trouble with my orchid. It had not flowered in a long, long time. Its roots were flinging themselves into the air as if they were howling in protest. My expectations had sunk to survival mode. I just wanted it to stay alive. In a last desperate attempt to save it, I decided to repot it.

And, as I've been known to do in fearful situations, I went one step further and opted to repot it myself. Despite my lack of any experience whatsoever in orchid repotting this seemed like a reasonable endeavor. I held my breath and bought the special soilless mix. Then, I bought a special pot with holes in it. For a while, things went swimmingly. In other words, my repotting did not kill it. I moved it to a new home on the kitchen table—an area with bright, indirect light. It soon grew two nice green leaves. Things were looking good.

Then, alas, trouble—in the form of a bit of translucent mottling-- reared its head. It appeared innocuous, so I ignored it.  If I remember correctly, it looked like a large water spot, which it probably was.  I'd put my orchid out in the rain thinking only of free water.

Not long thereafter doom set in.

Doom in the form of an inky mass, jet black and seeping. It was as if the hand of evil was wrenching the leaf into a one-dimensional abyss. I found out that the heinous black spot had a name: black rot. A simple name reminiscent of a toothless pirate or slippery wraith.

Black rot is caused by two fungi, Pythium ultimum and Phytophthora cactorum. Apparently these two fungi are only able to survive in wet conditions.  The spores of the fungi are made of zoospores which are mobile in water—and capable of infiltrating the leaf. Once it has its hooks in the leaf, the spore develops a vegetative mycelium, which allows it to proliferate throughout the leaf. This is when the leaf begins to show the characteristic black blemish.

This plant disorder is serious. If left untreated, the zoospores will cavort gleefully right down to the root of the plant. Once that happens your orchid is ‘nevermore.'

Preventing death is easy if you catch it early.  Use a knife or scissors that are disinfected. Then cut off all infected tissue. If the problem is severe, this may mean cutting into the pseudobulb or even the rhizome. Once you have removed the infected portion, treat the ‘wound' with a fungicide. Interestingly, cinnamon is recommended by the American Orchid Society. You can even use cooking oil to make a thin paste with the cinnamon. Sounds tasty.

Prevention is pretty simple: keep standing water off of your orchid and allow the plant plenty of air circulation to minimize a buildup of moisture.

Well, that's it. I'm off to take my own advice with a pair of sharp scissors, a dash of cinnamon and a bit of olive oil.

Posted on Sunday, February 7, 2016 at 6:14 PM

Getting Ready for UC Davis Biodiversity Museum Day

Tabatha Yang, public education coordinator at the Bohart Museum of Entomology, works with visitors. (Photo by Kathy Keatley Garvey)

Are you ready for a Super Day of Science? The University of California, Davis is preparing for its fifth annual...

Tabatha Yang, public education coordinator at the Bohart Museum of Entomology, works with visitors. (Photo by Kathy Keatley Garvey)
Tabatha Yang, public education coordinator at the Bohart Museum of Entomology, works with visitors. (Photo by Kathy Keatley Garvey)

Tabatha Yang, public education coordinator at the Bohart Museum of Entomology, works with visitors.(Photo by Kathy Keatley Garvey)

Posted on Friday, February 5, 2016 at 9:04 PM

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