Showing posts with label Citrus. Show all posts
Showing posts with label Citrus. Show all posts

Tuesday, January 12, 2021

Citrus Cicatrix

 Question:

I have a very large, old and beautiful orange tree that has developed a fungus on the trunk. I’m looking for help in how I can treat the tree and prolong its life. As you can see, the bark is peeling and there is orange sap oozing out. What can I do?

Tear in tree, from both rat damage and possible sunburn. 

Rat damage scars. 

Answer:


Looks like rat damage, as well as some sunburn. Try painting the trunk and lower limbs with whitewash made of 50% water and 50% indoor white latex paint. 
In nature Citrus rely on their thick canopy of leaves to shade their relatively sun-sensitive bark.  If you trim a citrus tree too hard and too frequently it can develop a black sunburn on its trunk and larger branches. If you want to keep your citrus looking like a tree (it grows best when kept as a large, shrub like tree with its canopy going down to the ground), then it is a good idea to whitewash the trunk and larger branches. This protects them from sunburn and to some degree from insect infestation and rat damage.  Rats and other animals that might partake of the tree's thin bark (either to eat the sugary layer of vascular tissue underneath the bark or to sharpen their teeth) are discouraged by the layer of paint. The best paint to use is a 50-50 mix of water and white latex interior paint (interior latex paint is less likely than exterior latex paint to be loaded with preservatives). 

Thursday, July 9, 2020

Has The Yellow Dragon Been Tamed?

In this LAist story, researchers at UC Riverside may have found a cure or treatment for Huanglongbing disease of citrus. Anybody in the San Gabriel Valley who has wanted to grow citrus knows that because of concerns about Huanglongbing (which translates to  'yellow dragon' disease), citrus trees are not available in local nurseries, and that fruit from citrus trees here is under an agricultural stay-at-home order. Hopefully these researchers are on to something.

Chinotto citrus growing here at the L.A. County Arboretum and Botanic Garden. 

Saturday, December 15, 2018

A Miner Problem


The first call of the morning today was a request to bring in a leaf for a diagnosis of a disease on a citrus tree. I asked the caller what the situation was and they said that their citrus trees had what their neighbor called “Minor Disease”. They went on to explain how the new leaves of their citrus trees were curling and disfigured. I suggested that they send me some pictures of the problem first. Below is what I received from them:

Leafminer damage on citrus leaves (red arrows point to leafminer galleries). 


Citrus leaf miner (which is an insect and not a disease) affects the new growth of citrus. Control is mostly cultural. Avoid pruning citrus at all more than once a year. Do not feed citrus in the summer of fall, when leafminer is most active, instead feed your trees in the late winter or early spring. Feed mature trees only once a year ½ of what the label says. By keeping new growth to a minimum you can control the leaf minor because it only infests new leaf growth. Eventually over time natural predators will effect some control over the leaf miner, and it will become a low level pest on your trees.

If your citrus tree is young and just establishing levels of leafminer damage can be quite dramatic. You can remove the disfigured leaves, although doing so can harm the growth of the tree if the removal is extensive. If your tree is a sapling however, you need to control the leaf miner without removing the leaves as doing so could stunt the young tree’s growth. You could monitor for the flying moth that lays the leafminer eggs on your trees leaves and spray either Neem oil or a Spinosad containing insecticide on the leaves when the moths show up in a trap (a trap specific for citrus leafminer) . You can purchase these traps at your local full service garden center or, order them online.

Mentioned above (these are examples and are not recommendations)

Traps 1 2 3

Spinosad product examples 1 2

Neem oil product examples 1 2

Tuesday, November 28, 2017

Meyer Lemon Turns Green -Is it Infected With Yellow Dragon Disease?

I was sent this pic by a client who wondered if the green skin of this Meyer lemon meant that it had Huanglongbing disease, a malady that is threatening Southern California's citrus groves. He also added that other than the green skin, the lemon tasted the same. 

Well this citrus probably does not have Huanglongbing. The greening associated with the disease is usually very uneven. What is happening is probably a process called 're-greening' that is common in some oranges, like Valencias. After the oranges ripen their skins start turning green again. This does not change the sweetness of the orange or its taste. This 're-greening' can happen to Meyer lemons, because they are actually oranges that taste and look like lemons. Also, 're-greening' occurs more frequently during warm winters, which we are currently experiencing. 

Tuesday, June 14, 2016

Pink Lemonade Tree Suffering in the Pot

Q. Frank, this is a variegated leaf pink lemonade lemon tree bought last December. The fruit you see were present when bought.  You will notice there are several dropped leaves on the planting soil and I an eager to know what is causing them to drop.  The tree is watered irregularly but last week I hyper-saturated the soil when I neglected to move the hose in a timely fashion.  




Assuming the cause of the dropping may be insect related, the tree was sprayed two times in four days with neem oil. Now the question is what is causing the leaves to drop?  Was it my one-time over-watering? A combination of the over-watering and the neem oil? Would the over-watering cause the roots to become waterlogged? Will the leaves eventually start to grow back?

 I found the following bag of ‘garden soil’ with only a small quantity of content left in the bottom of the bag.  This leads me to the assumption this is what I probably used potting the lemon tree. While I might have mixed it with some other remnant gardening product found around the garage, soil or mix, this product probably represents the vast majority of the what I used. Visually this garden soil looks similar to what is in the pot around the lemon tree. Hopefully this product identification addresses your question, resolves the issue and provides a reasonable platform for further discussions and a solution/conclusion to the continuing episode of “The Falling Leaves". 


A. One of the most important components of potting soil is not the organic material, but the inorganic material that provides for drainage. Drainage is the word used to describe the soils ability to allow water to move through it. Media that is heavy in organic material prevents water from moving through it because there are few if any spaces for the water to travel, and a plethora of compounds and surfaces that actually cling to water (they are called hydrophilic compounds). This allows for a root-space that eventually becomes devoid of oxygen, a primary factor in root growth.

The substance in the bag that you have sent me a picture of is organic compost replete with lawn trimmings and table scraps. This product is fine to add to a garden where it is to be dug in and diluted with the sand, clay and silt that is already present in the garden soil, it is however, sheer poison if used alone in a pot. Not only does the water added to the pot saturate the root space and displace life giving oxygen, but the table scrap compost starts to ferment without oxygen. This anaerobic fermentation of the compost produces toxic compounds and gasses that hasten the death of the already oxygen starved roots. Having a hole in pot filled with this vile mix does little to improve the conditions as a physical force called the “capillary force” that is powered by waters’ attraction to small, cylindrical linear spaces keeps the water the soil like the two components of Velcro keep each other well attached.

So, as I suggested, you need to either replant the citrus in a pot with ½ cactus mix and ½ “potting soil “ (make sure the bag specifies the word ‘potting’) or replant a new one in the same. I would start with a new plant, as the weakened condition of the tree has made it labile to disease and has increased the possibility that if you transplant it, your will also transplant a large quantity of disease producing fungal spores (like Phytophthora, see video of spores) as well.

Wednesday, April 6, 2016

California the Orchard State Tour Links

Here are some interesting links that relate to the tour I gave Saturday, April 2nd here at the Arboretum


History of Orchard Culture in California

Story on Canary Island Grape -the so called 'Mission Grape'
California Wine History
Citrus Industry in California -A History
Los Angeles Agriculture - Agriculture and Natural Resources Blogs
What Grape Was Grown By the Mission Padres?
THE CITRUS LABEL GALLERY -Hundreds of Labels Collected By Members of the Citrus Label Society ï¾ 
Label Showing Santa Anita Racetrack and Sierra Madre

Fruit Growers Associations


California Rare Fruit Growers, Inc.
Fresh Fruit-Healthy Recipes: Sunkist Citrus Oranges, Lemons
California Avocados Commision
Almond Growers | Almond Board of California
California Walnut Growers
California Canning Peach Association
California Raisin Marketing Board
Western Growers
California, Arizona, & Texas Citrus
Citrus Research Board

Growers


L.E. Cooke Company -Their site is a treasure trove of information)
Dwarf Citrus Trees, Meyer Lemon, Kieffer Lime, Oranges – Order Online – Four Winds Growers (These are the growers that first developed dwarf citrus along with UCR)
Durling Nursery Inc (No Website, but follow this link for phone # and call; they'll e-mail you their availability)
La Verne Nursery

Saturday, January 17, 2015

Citrus Label Society's Last Sunkist Headquarters Meeting & Fruit Tree Tour Maps & Links

Today I went to the Citrus Label Society's final meeting at Sunkist Growers headquarters in Sherman Oaks California. Sunkist has sold the headquarters and is moving to (quite appropriately) Valencia California. In honor of this last meeting at their traditional meeting place the society had a citrus tasting and label exhibit.


 Over 40 varieties ofcitrus were brought in for sampling at the meeting. Included were such exotic treats as the Australian finger lime and the Buddha's hand citron.  Also on display the hundreds of citrus labels. These labels, dating from the turn of the century up until the 1930's, represented the hundreds of independent growers who shipped citrus from California to the rest of the United States.  Many of them are quite beautiful and some can fetch high prices; for example a turn of the century label picturing an early, horse drawn float in the Rose Parade was valued at over $4,000.

Rare Rose Parade Citrus Label

Santa Anita Citrus Label Shows Location of Arboretum and Racetrack.


Fruit Tree Tour Links:

Fruit Tree Tour Map


Tour Stops
Navigable Google Map (Open in Your Smart Phone)
Purdue Crop Index (Lots of Information on Fruit Trees etc.)
UCR Citrus Varieties Pages
The History Of Grafting
More on the History of Grafting

History of Orchard Culture in California


Edible Acorns
Story on Canary Island Grape -the so called 'Mission Grape'
California Wine History
Citrus Industry in California -A History
Los Angeles Agriculture - Agriculture and Natural Resources Blogs
What Grape Was Grown By the Mission Padres?
THE CITRUS LABEL GALLERY -Hundreds of Labels Collected By Members of the Citrus Label Society ï¾ 
Label Showing Santa Anita Racetrack and Sierra Madre

Fruit Growers Associations


California Rare Fruit Growers, Inc.
Fresh Fruit-Healthy Recipes: Sunkist Citrus Oranges, Lemons
California Avocados Commision
Almond Growers | Almond Board of California
California Walnut Growers
California Canning Peach Association
California Raisin Marketing Board
Western Growers
California, Arizona, & Texas Citrus
Citrus Research Board

Growers


L.E. Cooke Company -Their site is a treasure trove of information)
Dwarf Citrus Trees, Meyer Lemon, Kieffer Lime, Oranges – Order Online – Four Winds Growers (These are the growers that first developed dwarf citrus along with UCR)
Durling Nursery Inc (No Website, but follow this link for phone # and call; they'll e-mail you their availability)
La Verne Nursery


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