The tree in my yard and appears to be suffering from many problems. I don’t know much about citrus, but after some research I have a plan below (Plan A). I would be interested in other thoughts, assistance with priority and, if necessary, permission to start over (Plan B).

There are pictures that relate to the problems listed.
See: http://picasaweb.google.com/M.E.Brugger/Orange#

The problems are many!

01 – Age. The tree looks about 8-10 feet tall in the photo here. I thinking that this is about 1957 based on my father's shirt and the fact that I look about 3 (I am the youngster upper right). So it is at least 55 years old.

02 – Location. The tree is now on a 400 sq ft area that has driveways and buildings on three sides. To the north, after the lawn ends, there are pavers so at least some additional water can enter. Good news is the weather is fine here and the tree gets ample sun 10AM to sundown.

03 – Soil. I put in sprinklers and its still dry! And, even the grass has died out so I conclude the soil, after this many years, is depleted and dry. I started adding fertilizer last year.

04 – Roots. I don’t know if the tree was grafted onto another root system but the way the roots look I suspect so. These upper roots appear to run near the surface where there competition with what lawn is left.

05 – Trunk. The tree started forming lesions a few years back from which sap would ooze. I tried cleaning and sealing. Then two years ago, the bark began to peal. Last year I tried Bordeaux paste which is now about washed off.

06, 07 and 08 – Insects. I have tried insecticidal soaps to control the spiders and whiteflies. The ants are sprayed if on the lawn. Tree Tanglefoot was used to keep the off the tree.

09 – Weak branches. The branches now sag when the tree fruits. I’ve added rope here and there to help. Removing excess fruit (if there is such a thing!) also helps.

10 – Leaves. I think they are too yellow. Since the soil is still dry I’m sure its nutrition and not over watering. Several spots have dry material which I try to cut out. There are a few signs of growth but don’t think it is keeping up with the decay.

11 – Fruit. Some fall from the tree after developing splits. What did grow to maturity last year was as good as in past years. But, when picked, the stem holding to the tree would sometimes peel off the tree too.

Plan A
• Rip out the grass and top 2” of soil.
• Fertilize with Citrus-Tone (5-2-6 plus trace plus colony forming units).
• Add mycorrhizal fungi.
• Amend the soil with 1” of something
• Work the above to a 6-8” depth.
• Double the watering.
• Replace sod keeping clear of the tree by 3’
• Spray leaves with Citrus Orchard Spray (Sulfur 10%, Pyrethrins 0.25%)
• Reapply Bordeaux paste
• Reapply Tree Tanglefoot

Plan B
• Replace the tree

Comments are welcome. And thanks.

That tree is like a family heirloom. I hope you can save it. I would bet you can, depending on the effort you are willing to put in to save it. I'm interested in seeing the input you get. Best of luck!



Mark

The first thing I would do is bud a few new trees from it. That way you wont completely lose everything if something does happen.

It looks like you have a few things going on there. Gummosis being your main problem... Enarching would be an option on a smaller tree, but with the extent of damage up so far, that would be almost impossible at this point. With the tree in a weakened state, be very careful as any damage to the roots could cause the tree to decline very quickly.

If it were me, I would bud a few trees & leave it be. Once the new trees are a few years old you could replace the tree with one of the offspring.

I am in the opinion that old trees like this are a real asset to any property and you should totally try to save it espec. with the sentimental value it is almost like one of the family One it is gone it will take years to grow a replacement to any sort of decent size! Your plan sounds like the way forward. First priority IMO would be to kill off all the bugs sucking precious life out of your friend. Spraying with hort. oil and pyretherum would be my idea. You could also sprinkle some neem tree granules around the ground. Also later (but not at same time) spray for fungal probs with a copper spray to clear up that side of things. Then last i would look at enriching the soil with some peat/compost/sheep pellets/manure or a mixture of all on top of the old soil. i might be careful of digging it in tho as citrus roots are fairly shallow. This may also act as a mulch to retain the water around your tree. Lastly maybe an application of epsom salts. I am fairly new to citrus growing but this would be my plan of attack. Good luck!

Looks like a Phytophthora (Gummosis) disease.

Your soil already has all the mycorrhizal fungi that is required. You can add more if you wish but it will be a waste of money.

You certainly do not want to "Work the above to a 6-8” depth", as citrus roots ave very shallow and you will do a lot of damage to the tree.

There are better copper based fungicides available for citrus trees, than Bordeaux paste.

I would not amend the soil with anything.

Lastly, actually if it was my tree, I would not waste my time and go to plan-B. But it is not my tree.

I somewhat agree with Millet as I will only be delaying the inevitable. But, delay I must. Plan B will always be there.

Now that I know the roots are shallow so I will not do anymore than my initial test dig. And I can skip the mycorrhizal, and soil turning. I have to yank the grass and replace that but will keep the top 1” so the tree roots should be OK.

I would be interested in a recommended alternative for Bordeaux paste. The tree requires so much of it that it becomes a surreal aqua blue color for 9 months and is disturbing to the grand kids.

Thanks again. I'll report in another year.

Mark, I would recommend that you wait to see if Dr. Malcolm Manners sees and then answers this posting. Dr. Manners is extremely knowledgeable in these manners. - Millet (853-)

How annoying - I wrote a long reply, over 1/2 hour to write. And it has evaporated into the aether...

Oh well, will try again later.
Malcolm

Try number 2!

The short answer is, I believe your tree has citrus psorosis virus.

Side issues first:

1. roots/soil -- yes, it looks dry. I’d recommend irrigating.

2. fruit splitting -- related to #1 above. When a tree is water-stressed and then watered, there is the likelihood of fruit splitting, then falling from the tree. The way to avoid it is to never let the tree become so dry that it’s stressed (usually shows up as leaf wilting).

3. The cute little insects with the webs -- psocids. Among my very favorite of insects! Totally harmless, and if you have one of the species that walk in formation, like a marching band or a school of fish, they’re fascinating to watch, all synchronized under the web canopy. They feed on decaying organic matter and lichens/fungi on the bark surface and are harmless to your tree.

4. The main feature -- psorosis.

While I agree that phytophthora foot rot COULD be present, it doesn’t look right to me. Phytophthora most often occurs near the soil line or around the graft union; your tree shows lesions much higher on the trunk than I’d expect. Also, your tree looks like it has many smaller lesions, rather than the one big one one expects from phytophthora. It could also be Rio Grande Gummosis, but again I doubt it.

Here’s a comparison of symptoms.

Phytophthora:
1. Usually soil line or at graft union
2. Produces some oozing gum
3. The entire bark peels away, all the way down to bare wood
4. The wood is yellow or brown, never with any pockets in the wood (may be some pocketing of bark)
5. Because of #4, there are never any green galls.
6. Open, oozing lesions may smell sour or rotten
7. Lesions tend to grow rapidly in wet weather, then to recede or even disappear in dry weather.

Rio Grande Gummosis: An odd problem whose exact cause is uncertain. Some suspect a virus, but some believe it to be a disorder, perhaps related to too much chloride in the soil.
1. Most often on Grapefruit. At least in Florida, it’s rare on oranges. This alone causes me to think it’s not your problem.
2. Tends to occur higher on the trunk, and even on major limbs
3. Produces a lot of gum, which runs down the trunk and hardens into amber-like lumps
4. Only the thin, outer layers of bark peel away.
5. Lesions often show a concentric pattern of orange stripes on a paler beige background, rather like a somewhat crooked target
6. Eventually produces concave pockets in the wood, within lesions.
7. Those pockets may contain little warty galls, the grey-green color of some lichens
8. Wood is salmon colored, with the darker orange stripes

Psorosis virus:
1. occurs anywhere on trunk or major limbs
2. produces little or no gum (this one I wonder about in your case -- when you saw gumming, was it in rainy weather? It’s possible phytophthora got into an existing lesion, but in your dry-summer climate, I’d expect it to be self-correcting by this time of year)
3. outer layers of bark peel, usually NOT down to the wood
4. No wood pockets, and no green galls
5. Wood is brown. No orange stripes, and no rotting odor.

We don’t often think about psorosis anymore. It’s nearly extinct in US citrus. But your tree is old! California started their psorosis control program in 1937, but didn’t really get the budwood registration program going until 1956, and I think (but can’t find documentation at the moment) that it was at least that late that it became mandatory to produce psorosis-free trees. So your tree is old enough to predate that mandate.

Psorosis is a true virus, spread through budding with infected budwood or rootstocks. It is not contagious otherwise. It often has a symptomless incubation period of many years, and while 50+ years is a bit surprising, it’s not out of the question, with a mild strain. It’s not curable, but since it’s also not contagious, there’s no great hurry to remove the tree, until/unless it becomes non-productive.

If your problem really is psorosis, then I’d recommend against propagating a replacement tree from it; rather, I’d opt for a nursery-grown, virus-free tree. Even though it might be another 50 years for an offspring tree to show trunk symptoms, I suspect that you’d get reduced yields even though the tree is symptomless, and in any case, budding/grafting infected budwood onto uninfected scions is challenging -- the rootstock often has a “shock” reaction, and rejects the scion. So your budding success rate is much lowered.

I can’t prove from the photos and description that psorosis is the problem, but it’s one of those things that, if you’re old enough and remember the disease, it just has a look that kind of screams “PSOROSIS!” at you, and your tree does that.
Malcolm