Please can you tell me what this is and how best to treat it?

Question

I’ve attached a photo. The hedge is affected to halfway along its length.

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Answer 1

This appears to be Mosaic Virus.
The yellowing spots are a big indicator.

Here is a few links with more information.

https://www.gardeningknowhow.com/plant-problems/disease/bacterial-leaf-spot.htm

https://www.gardeningknowhow.com/plant-problems/disease/plant-leaf-spots.htm