Soil remains wet since March and tree leaves are yellow

My cherimoya that I planted in March now it's leafing but the leaves are small, yellow and some are split. Are these the signs of root rot? How bad is it and what corrective actions should I take?

I am thinking about root rot because the soil has remained wet since March (the last rain in my area, zone 10A, Northern CA). The soil is gray clay and heavily compacted. I haven't watered the tree since then except water to dilute fish emulsion. Note: I use the soil moisture meter to check and it always goes straight up to "wet" immediately.

I also made a mistake (that I only know now when researching this) that I put soil amendments into the planting hole. I dug a 3x3 hole, 2 feet deep. I back filled the bottom foot with the native clay soil (the top part I think). Then mix 1 bag of peat moss and a couple pounds of organic fertilizers (bone meal, worm casting, etc) with the native clay soil to back fill the top foot. The tree root ball is about 1 foot height and I planted it a little bit above ground level. Added a 10 in layer of mulch.

After planting about a week, I did some grating works on it (see pictures). Most of the grafts took and are leafing out.

How bad is the tree and what corrective actions should I take?

1. Usually you wait until a tree is established before you graft it.
2. Amending the planting hole has been proved contraproductive by science, as the roots then often do not grow to the native soil, but
stay in the soft nutrient-rich amendment

That being said, your tree doesn't look like a death-candidate to me,
however cherimoya is a highland-species apadted to periodical drought and therefore cannot survive
in permamently wet ground.
If you think the soil is too wet now you might remove mulch, or plant something that wicks the water away,
but i personally would leave it as it is.

If it remains wet during the rainy season you should think about increasing the drainage somehow,
for example replant it at some elevation.

R. Han, thanks so much for your response. You do make me feel better!

R. Han wrote:1. Usually you wait until a tree is established before you graft it.
2. Amending the planting hole has been proved contraproductive by science, as the roots then often do not grow to the native soil, but
stay in the soft nutrient-rich amendment

Lessons learned!

R. Han wrote:That being said, your tree doesn't look like a death-candidate to me,
however cherimoya is a highland-species apadted to periodical drought and therefore cannot survive
in permamently wet ground.

If it gets worse from here, what are the signs that I need to pay attention to? Do I need to correct the yellow leaves problem?

If you think the soil is too wet now you might remove mulch, or plant something that wicks the water away,
but i personally would leave it as it is.

R. Han wrote:If it remains wet during the rainy season you should think about increasing the drainage somehow,
for example replant it at some elevation.

Sounds like replanting is unavoidable as the soil is already wet in a drought year like this year

I'd hold off on any intervention until the tree gets more into its growth cycle and those new leaves reach full size. They look more like they're showing the light green of fresh spring growth than the yellow of deficiency. The last thing you want is to kill it with kindness. Subtropicals like cherimoya can take a little while to get their feet under them when we grow them outside their comfort zone.