My Apple Tree Has Some Leaf Curl

[Biccylova]

and the leaves are covered with a dusty grey white deposit, whats wrong with it and is there any treatment please?

[alavahalf]

Sounds like 'Powdery mildew' .. can be treated with baking soda and detergent. I believe milk and mouthwash (honest) are also beneficial in combating the fungus.
Just google powdery mildew for images to compare your problem and treatments for remedies, quantities and mixtures.

[Biccylova]

thank you alavahalf, that looks exactly it.