Salvageability of either of these grafted mangoes?

[rcpmtp]

Been having some trouble keeping newly transplanted grafted mangoes alive…. Some are doing well, others seem on their way out (defoliate, stem dieback). I’ve tried pruning them to stop dieback. Any chance either of these might survive?

Does this look like fungus?



Do the new buds here belong to the graft or the rootstock?

[JakeFruit]

Top is not fungus, looks like you are having root issues. Shriveled and dark areas on the trunk are very bad signs, it's almost assuredly not going to make it. Bottom pics seem to tell the same tale, with maybe a little more hope. You cut it back/down as the top died off, right? My guess is the roots don't like whatever medium(s) that is you have them planted in. If I'm right, those new growth shoots (which do look to be part of scion, not the rootstock) might develop, but the tree will continue to suffer and any new growth will die.

 I would reassess your potting mix. You can try and save the bottom one by replanting it in a new potting mix, you'd have to act fast, but you really need to get your potting mix figured out before you put more time/money into mangoes (plenty of threads on here about what store-bought or homemade mixes work well). Seedlings are pretty resilient to whatever they are planted in and the amount of water they are receiving, you'll think they are happy, then after the first year or so they'll start displaying signs that they are not happy. It can look like anthracnose or some other fungal issue, but it's usually your roots.

[rcpmtp]

Thanks, that's all very helpful.

I've tried two potting mixes: gritty mix (with some extra gravel to reduce water retention) and promix HP with some extra coarse perlite. In hindsight, I probably should have used perlite with a smaller, more consistent particle size and maybe added some sand... Any additional guidance would be appreciated.

[JakeFruit]

You don't list where you live other than 7A (which is going to come with ~possibly tremendous~ challenges no matter where you are). Your best bet is to find someone else in your general area or climate equivalent on here that's growing mangoes with success in pots, copy what they are doing. DIY potting mix comes with challenges, you might save yourself a bunch of frustration by buying something pre-mixed. Use the forum search function and try searching on "mango potting soil" or something similar. You should find product recommendations pretty easily (keep in mind what works great in one region might not perform as well in your climate). I killed a bunch of seedlings and young trees over the last few years learning the ins/outs of growing potted mangoes, and I still feel like I don't know what I'm doing sometimes