UC Nursery and Floriculture Alliance
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UC Nursery and Floriculture Alliance

From the UC Blogosphere...

Bee-Bopping with the Penstemon Margarita BOP

A honey bee approaches a Penstemon  Margarita BOP. BOP? That means

So we purchased a sky blue Penstemon cultivar with a tag labeled "Penstemon Margarita BOP." BOP? Bureau of Prisons? Bottom...

Posted on Tuesday, May 22, 2018 at 4:31 PM

Fire and Fury in a Pollinator Garden

A male flameskimmer dragonfly, Libellula saturata, perches on a bamboo stake. (Photo by Kathy Keatley Garvey)

Just call it "Fire and Fury in a Pollinator Garden." That would be the firecracker red flameskimmer dragonfly, Libellula...

Posted on Monday, May 21, 2018 at 4:16 PM

Invasive pest takes up residence in the Northeast

Spotted lanternfly. (Photo: Wikimedia Commons)
The spotted lanternfly, native to Asia, first came to America in 2014 when it was found in Pennsylvania. Despite a quarantine, populations have been discovered in New York, Delaware and Virginia, reported Zach Montague in the New York Times.

“They've been appearing in grapes, and we have reports from growers last year of a 90 percent loss,” said Julie Urban, a senior research associate at Penn State.

The reporter also contacted UC Cooperative Extension advisor Surendra Dara, who published an article in 2014 about spotted lanternfly in Pest News, a UC Agriculture and Natural Resources eJournal about endemic and invasive pests in California.

Surendra Dara.
"The Pennsylvania Department of Agriculture recently reported the first detection of yet another invasive hemipteran pest in the U.S.," Dara wrote in his article. "While efforts to have a good grip over other invasive hemipterans like the Asian citrus psyllid, the Bagrada bug, and the brown marmorated stink bug are still underway, there is a new pest that could potentially impact industries ranging from lumber to wine."

Dara told Times' reporter that lanternfly has the unusual ability to lay eggs on almost any surface — plants and soil as well as wheel wells, train cars and shipping containers.

“Most pests deposit their eggs on their host plant, or very close, so they already have food available,” Dara said. “Those that have the advantage of being able to lay eggs on non-plant material obviously have a better chance of surviving and spreading."

Posted on Monday, May 21, 2018 at 1:21 PM

My Apricot Tree Didn't Produce Fruit This Year

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

Client's Request:  I've managed to grow an apricot tree from seed. It's now big enough that it has produced a few apricots in prior years. However, it hasn't produced any fruit now for several years. What is preventing fruiting and what can I do to get fruit?

apricot
Help Desk Response:  Thank you for contacting the UC Master Gardener Program Help Desk. Congratulations on growing an apricot tree from a seed! I understand that you would like to know why your tree has not produced fruit for several years and what you might do to get fruit.

The apricot tree's lack of fruit production could be due to flower or young fruit damage from weather; it could be due to reduced pollination, also potentially affected by weather; it could be due to tree damage caused by a pest or pests, or it could be a nutrition issue for the tree.

Weather
Fruit trees form their flower buds in the fall. Lack of rain or high winds can damage buds before they blossom. Spring rains or late-spring frosts can also damage or kill buds and blossoms. Apricots in general perform best in climates with dry spring weather. This year we had both late frosts and spring rains in parts of the County. Last year we also had significant spring rains, and prior to that several dry years in succession. So, weather could certainly have had a negative impact on the fruit production of your apricot tree for the past several years.

Reduced Pollination
Pollination issues could also have played a role. Fruit production depends on pollination, which is the transfer of pollen from the male part (anther) of a flower to the female part (pistil) of the same or another flower usually of the same species. Apricots are self-fruitful, meaning that they may be pollinated by pollen from another flower on the same tree, or in the case of apricots, by pollen from the same flower. The transfer of pollen from one variety to a different variety of the same type of tree is called cross- pollinationAlthough not required, cross-pollination does improve the number of fruit that form on apricots. Pollinators, such as bees, are usually responsible for apricot pollination.

This link to a Penn State University extension website
https://extension.psu.edu/pollination-requirements-for-various-fruits-and-nuts
identifies several factors can effect pollination:
Temperatures below 55-60°F reduce bee activity
Windy and rainy weather can slow bee activity
Presence of other flowers -- the fruit plants generally are poor nectar producers and bees will naturally seek out the best nectar producing flowers
Most insecticides will reduce bee activity -- therefore do not spray them during bloom

Pests affecting apricot trees

Apricots are susceptible to a variety of pests, listed at this link:
http://ipm.ucanr.edu/PMG/GARDEN/FRUIT/apricots.html
These include sucking and boring insects and other invertebrates, and bacterial and fungus diseases. If, after reading the descriptions, you suspect that you have any of these issues, there are controls suggested at the same link and sub-links. 

Cultural care
The best prevention is good cultural care. Maintaining a good fertilization program can keep your tree vigorous and help prevent infections. Adequate irrigation will help as well.
http://homeorchard.ucanr.edu/Fruits_&_Nuts/Apricot_Prunus_armeniaca_L/
http://ipm.ucanr.edu/PMG/GARDEN/FRUIT/CULTURAL/apricotfert.html
http://homeorchard.ucanr.edu/The_Big_Picture/Irrigation/

With respect to pruning your tree, apricot trees should be pruned in late summer, since they are susceptible to a fungus infection if pruned during wet weather. Because of this, they should be pruned in August -- after fruit production is complete, and early enough to allow time for pruning wounds to close prior to the beginning of winter rains. Information on pruning apricots can be found at this link.
http://ipm.ucanr.edu/PMG/GARDEN/FRUIT/CULTURAL/apripruning.html

I hope that this information is helpful. If you have any questions about the material in these links, or anything else, please contact us again. 

Good luck with your tree!

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


Note: The  UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer our 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, although we will be moving this spring. We will notify you if/when that occurs. 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 21, 2018 at 12:13 AM

It's Pollinator Discovery Day Sunday at UC Davis

Pipevine swallowtails at the UC Davis Arboretum. (Photo by Kathy Keatley Garvey)

Meet the pollinators, And meet the UC Davis researchers, UC Master Gardeners, students and community members who study them...

Posted on Friday, May 18, 2018 at 5:36 PM

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