The "Katy" apple tree?

[GF3]

I bought a Katy apple tree (MM106) in December 2021. When it arrived I planted it into a container. I intend to keep it in the container until next spring (2023) when I will plant it out ( I am reclaiming an unused part of the garden at the moment, which is on a slope)
My question is about the leaves on the Katy apple tree. The tree is growing well, it has put on a lot of growth and it even has one apple. But the leaves are curling/twisting, it is still putting out new shoots but four leaves on the top of the tallest branch have curled up, dried out and dropped off. Is this curling/twisting of the leaf common to the Katy tree? Or is it a case of me under-watering or over-watering? I have attached some photos.

[ameno]

That's what apple trees look like when they are wilting.
Given the current hot, dry weather, it's probably lack of water rather than over-watering.

[GF3]

Many thanks for the reply.
When I bought the "Katy" tree I also bought a "Bardsey" apple tree also on MM106. It is in the same type of container as the Katy and I water them at the same time with the same amount of water - the Bardsey is thriving, the leaves are in perfect condition and it has five very large apples on it. That's what made me think that the shape of the leaves might be typical for the Katy variety. I shall up the watering frequency and see if that improves things.
Thanks again for the reply.

[ameno]

It might just be that the other tree has managed to grow more roots, or else it came with more roots in the first place, and so is less prone to drought stress as a result.
Either way, as long as the pot has plenty of holes in the bottom it is almost impossible to over-water a tree like that at this time of year, so there's not harm in giving it some more.

[GF3]

The Bardsey was the larger of the two trees when they arrived last winter, so probably a bigger root system on it. I have moved the Katy tree to a more shaded part of the garden. I also watered it by leaving the hose pipe just trickling untill the water started dripping from the drain holes at the base. The container has many 1cm diameter holes drilled in the base and around the sides at the bottom, there are small stones in the base of the container - so drainage is good. I have laid some plastic cut from compost bags on the surface and cardboard on top of that and white nylon sacking on top of that to reflect the sun and heat. So, I shall see how things go. If things don't improve would it be a bad idea to plant the tree in the ground now? The area where it will go is now ready.

[ameno]

As long as you can get the tree out of the pot without damaging the roots much, I would actively recommend planting it out now.
Potted trees can be planted out at pretty much any time of the year, and the tree will have access to more water, and the roots will be kept cooler, if it is in the ground.
Just be sure to keep it well watered, even once you plant it out.