Apple tree leaf drop

[Jonny47]

Hi,
Probably really obvious but anyone recognise this leaf issue?
10% leaves have small to coin sized marks and then turn yellow and drop.
Advice welcome
J.

 

[Chuck-D]

Did you by chance water this tree while it was hot out ? If so well water or city water is far colder than rain water and can shock the leavs . Some plants will shed these leaves in favor of new growth

 

[Jonny47]

Thanks for the question and info, very kind. It has been watered by a sprinkler when watering the lawn it stands in the middle of but the temperature outdoors was no higher than 20 c ( 70 ish f) which is just warm. Also the two other trees nearby and also watered do not have the same issue.
leads me to think maybe something more? Or? What do you think?