Angela -

I am not an expert but dealt with something similar and got help from this forum. In my instance, it was over fertilization that caused the leaf damage on a small tebow mango. I'm not sure that's your issue but might be worth looking into. Here is the post:

http://forums.gardenweb.com/forums/load/tropicalfruits/msg092117373093.html

Hope it helps. Brett

Though fertilizer could certainly contribute to the issue some, salt burn has slightly different characteristics: the older leaves drop off and the edges of the remaining leaves are burnt.

This one looks more fungal in nature. The new growth is much more tender to fungus, and the over abundance of rain we've had this summer caused lots of fungal problems on susceptible cultivars.

What cultivar is it? It looks a bit like a seedling? If it were me, I'd probably be replacing it with a more fungus tolerant cultivar. The other option is to modify its culture - doing your best to keep it dry, witholding all nitrogen, and applying fungicide during the rainy season.

Jeff

It does look like burn. It seems the affect the young leaves more.

http://forums.gardenweb.com/forums/load/tropicalfruits/msg092117373093.html

In the disease description, it does sound like a fungus.
Lowes sells a Copper soap spray/fungicide for ~$6 in the Garden section. I'd first prune the diseased parts off and monitor new shoots for first signs of the disease re-occuring- applying the fungicide.
What is the source of watering/irrigation? Sprinklers? Try to avoid the leaves getting wet as disease spreads down the plant. Water only around the trunk.

I tend to agree with Jeff that this is a fungal isssue. You said it was Angie. I can assure you that this is not a characteristic of Angie. Definitely hit it with fungicide. If that does not work, there may be other factors that will not likely be treatable. Many viral or bacterial pathogens are not readily identifiable without expensive laboratory testing.

Harry

Thanks everyone for all the input. Great to know that this is not a lingering effect of cold damage. I am pretty certain it is not fertilizer burn, I know what that looks like on other plants and this is different. This plant has had very little fertilizer this year. About 2 oz of a no-nitrogen fertilizer on the soil, and a nutritional spray with minors.

I think the guess of a fungal problem seems most probable. It seemed to be much worse after last weekend's drenching rains. This tree does get hit by sprinklers - no way around that, but all 3 of my other mango trees get the same sprinkler treatment. So that alone doesn't seem to be the cause. Maybe because this tree took so much cold damage it is just less healthy and less able to resist fungal damage.

Harry, I'm glad to know that this is not characteristic of the Angie variety. What fungicide do you recommend? Are mangos suceptible to defoliation from copper sprays? How important is the exact type of fungicide? Or will most any sort do?

Thanks,

Angela

One possibility is it may be Apical Necrosis, which is a bacterial infection. I am not confident from the photos as the black necrotic lesions are meant to start as small angular shapes on the primary and secondary veins of the leaves. I can't really see much of the angularity of the infection in these photos, it seems rather blotchy, but the way it follows the central vein of the leaf to the apex looks like the way it behaves.
It is a relatively modern disease for Mango, and likes cool wet conditions such as those found in mediterranean winters. First detected in Southern Spain in the early 1990's I believe, but has now been reported in most mango areas with a similar climate. Being a bacteria, fungicides will not kill it. Copper Oxychloride sprays help to control it. The antibiotic streptomycin is used to control bacterial disease in fruit trees in the US. Here in Australia it is prohibited, so I don't know if it is effective. The causal bacteria is pseudomonas syringae pv.syringae. It spreads with water splatter and wind with rain is very effective. The bacteria itself initially comes down with the rain. It looks like being a problem for climates with cold, wet winters.
Anyway, if you hit it with copper as well as mangozeb, then you should get it if it is fungal. If it is bacteria, not so easy.

Angela:

The two I use are copper and sulphur. Copper for the anthracnose and sulphur for the powdery mildew. There are organic preparations of both. The copper is readily availbale in Home Depot or Lowes. The sulphur I bought on line somewhere. If application instructions are followed and you do not apply when it is really, really hot out, you should have no problem with leaf burn.

Harry

gomango, that bacterial disease sounds terrible - hopefully it isn't that. The shape is definitely splotchy rather than angular.

Thanks Harry for the information. Is what my tree showing anthracnose? Or some other fungal disease? I currently have both copper and sulphur that I use on other plants. I've got Lilly Miller Kop-R-Spray which is metallic copper in liquid form. Is that a good one? And I've got HI-YIELD wettable sulphur which is a powder that can either be dusted on or mixed with water to make a spray. How do you apply your sulphur? Do you spray or dust? Sounds like the one to start with is the copper - I'll put that on my weekend activity list.

You may want to be careful not to let this problem spread to your other trees. A few years ago I had a similar experience with a young tree. It showed similar symptoms to yours, all the new growth eventually blackened and died. The tree started at two feet tall, and gradually faded to a few inches tall as everything died. I burned it, but by then the disease had spread to a nearby large Carrie and mid-size Gary. The Gary died away very slowly. The Carrie lived and looked okay, because the mature leaves didn't seem to be affected. But it never bore fruit again; the blooms looked burned and deformed. I even cut off every single leaf-bearing branch, figuring I would kill either the tree or the disease. That didn't help (nor did various chemicals). The tree did leaf out again okay, but still didn't bear fruit ever again.

Thanks for the advice mangomandan. I have sprayed this tree with copper, so we'll see if that helps. I certainly hope I can keep the problem contained to just this tree. So far so good. My other mango trees are 25 to 50 feet away, so hopefully that is far enough to keep wind and environmental factors from spreading the disease. And I am very careful with my pruners, sanitizing between each tree...so fingers crossed. I figure I'll give this tree until next spring. If it hasn't started to recover, then I will replace it with something else. Any other precautions you'd suggest to keep the disease from spreading to other trees?

Angela - so you aren't disappointed in the worse case scenario, 25 to 50 feet is not enough distance should the disease be airborne. I know you don't want to do it but I would take a long thought as to if the one Angie may be worth risking damage to the rest of your mangoes.

Rob