Yellow leaves on greengage

My daughter sent me a pic of the shoots on her greengage which is still quite young. They are pale yellow with green veins. I suspect iron or magnesium deficiency so told her to give it a foliar feed with seaweed extract. She put some blood fish and bone on it earlier in the year.
I am wondering whether to tell her to prune back the yellow shoots. What do you guys think?

 

I'd wait for them to green up.

 

I have a plum tree that had the same ssue ,I feed it with seaweed now and also i improved the drainage of the soil around it as the soil was a bit compacted and is a clay soil , it's a picture of health now

 

Thanks guys!