Well, based I what I see with your watering situation, I would say it is due to foot rot, and it's amazing it hasn't completely killed the tree. You should not have standing water in the well up against the trunk like that. It will promote a fungal infection (foot rot - Phytothphora), and will kill your tree. I would suggest you extend your water well all the way out to the edge of the canopy and a bit beyond (which is known as the drip line), and build up the soil just a bit towards the trunk, so any standing water will collect in a ring around the tree at the drip line, and not up against the trunk at all. You can always prune out any gangly or unwanted branches, I would make sure the canopy stays open, prune out any dead wood to the trunk (just don't prune into the branch collar) inside the canopy. Keep water off the trunk, that's the main issue I see here, and most likely the cause of all the bark damage.

Patty S.

1) I would remove the green stems at the base of the tree.

2) The watering basin should hold water at the drip line and not sit against the trunk of the tree. I suggest making a double ring about 6 inches wide at the drip line to protect the trunk.

3) The space of missing bark is damage where the bark has been removed. I see signs of response growth, so it is trying to heal over that area. Keeping the moisture away from the wound is the best help you can give.

4) You can trim the tree to control size as you like.

Thanks, I will make another barrier to protect the trunk. The standing water only sits there for ten minutes after watering if that matters, but I will keep the trunk dry. Any clue about the graft line? Rugbyhukr says to trim the green stems and that is why I am asking about the graft because I wasnt sure about those ones being part of the orange tree or rootstock.
Thanks,
Eric

This post was edited by ehits on Mon, Nov 18, 13 at 22:05

It's an orange... so I ain't not expert; but I would paint or wax the exposed portion of the trunk; and not cut anything else that is alive and growing... you can always do that later, if you choose.
Keep a good thought, treat the tree with good water and fertilizer regimens and have a little patience.

You say the tree has been in the ground for '4.5 years'. Do you mean four and a half years? It looks much older than that to me - could it even be 45 years?
Anyway, it is very difficult to say where the original graft line is. Your second photo looks at first like it shows a clear graft line. But because there has obviously been much damage in this area, it could be new trunk wood overgrowing and covering the original.
As you say that leaves on the low shoots seem identical to the rest, the only way of being absolutely certain is to wait until they fruit. If they are the same, it may even be that this is a not a grafted tree but a seedling or cutting. Or it may have been planted much too deep and the graft is below ground. That could also partly explain why there is so much damaged wood - rootstocks are used to reduce the susceptibility to such rots at ground level.
As others have said, you must ensure that the trunk is always dry. Each watering is allowing pathogens to enter. I would even scrape away a couple of inches of any loose soil from around the trunk.

The trunk is entirely shaded, so painting isn't necessary. The tree is at least four and a half years old (when we moved in). It didn't produce fruit the first year, and has progressively made more and better fruit each year. I will try and unbury the trunk a little more.

Please go back and re-read Patty S' post. I could not agree with it more. I love rugbyhukr's double ring basin suggestion.
In that line of thought, I would suggest that you get rid of any grass well beyond the drip line (at least double the diameter of the current basin ring). Water at the drip-line and do not allow water to collect or run to towards the trunk.

Your tree is being challenged to survive and unless you remedy the water / basin situation you are wasting your time.
George K.

This post was edited by Becauseican on Tue, Nov 19, 13 at 14:10

Painting or waxing an open wound is not just about sunburn; it is about protecting the bare wood from the entry of critters, molds, water, chemical sprays, etc.... sorta like "artificial bark"

Johnmerr, thank you.... "aha" on the painting/coating as artifical bark. I never thought of it this way.

Which makes me think of the following question. [ as i pull off the flagging tape/tanglefoot for the winter with sticky mess bleeding all over the trunks].
>> Is there a painting / coating that would perform well like an artificial bark and also keep the ants off? I am thinking that there may be a latex paint/coating that ants do not like to walk on; stays sticky??

George K

This post was edited by Becauseican on Tue, Nov 19, 13 at 14:45

rugbyhukr, you are saying that the watering basin should be a ring? like a 6inch ring at the drip line, like a circular trench? I want to be sure because I was told by the nursery to make a basin. Does this mean that water is only needed near the root's ends? Thanks for your patience, I am trying to understand. We just got about 3 days of rain so I have to wait until things dry out to paint the trunk for pest protection and to mess with the trunk/watering situation.

ehits, yes and yes. You can make a basin, BUT, the outer ring needs to be lower than the trunk, so that the water doesn't sit up against the trunk when the basin is filled. Even for short periods of time. Make sure the basin is large enough to extend all the way out to the edge of the canopy and a little beyond. That's call the drip line, and that's where a citrus tree's feeder roots reside. Not at the trunk, so there is no reason to have water sitting at the trunk for several reasons - no feeder roots there, and water sitting on the trunk can cause foot rot, which is certainly part if not all of the issues with this poor tree (possibly also some old mechanical damage I suspect, maybe a weed wacker?). This tree now does not have it's protective bark, so you really really need to protect what's left of that tree's trunk. I would remove more of the grass and extend the basin, but make sure the water when filled in the basin does not touch the trunk. Your nursery's recommendation is correct, but even with healthy trees, the water really should flow out, and sit at the outer edge of the basin, and not up against the trunk. Just make sure the soil slopes outward.

Patty S.

Thanks for the detailed description. I will need to check my new trees too.

Eric

I finally got around to modifying my well and painting the trunk to protect against future damage. I created in inner mound and shaped soil (after I took the pic) so the water gathers on the outer part of the well. I did notice a little spur off of the trunk in the damaged area that was pointing downward. I wonder if it was an old root? its like an inch above the soil. Here is the pic, but I still have some beautifying and shaping to do:
{{gwi:641749}}

Also, one of my lowest branches on the trunk has about 8 oranges on it that are quite a bit less orange than the others on the tree. Is this normal? Can there be ones that are slower to ripen than others?

Thanks for sharing the follow up. Oranges ripen at different times, the first being those on the upper SW side; it mostly has to do with heat units.

ehits, very clever. Well done. And, what John said about your oranges. I always love to see my Moro orange tree do this, it is quite interesting. All the oranges on the south side of the tree ripen first due to more sun and heat on the south side of the tree, and all the oranges on the north side of the tree always have more skin pigmentation and are more pigmented inside, due to the colder temps on the north side.

Patty S.