Polka raspberry canes

I've noticed this on my Rasbury Canes on the Leafs does this mean I've got to pull every  raspberry canes up and burn them

If you've applied a lot of potash it could be the nitrogen is locked up. In that case, magnesium will sort it. Mix a tablespoon of epsom salts per gallon and water round the plants.
However, it could be easiest to just give them some Miracle Gro which is a high nitrogen feed with trace elements including magnesium. Liquid feeds are immediately available and the fastest solution.

I don't think there is any need to pull them up and burn them.  It doesn't look like a virus to me and you have done all the right things to feed them.   

It sounds like you are getting good crops off them, so enjoy your harvest and don't worry about it 

I've quite often seen leaves looking like that on my Autumn Bliss rasps - probably some sort of stress or nutrient deficiency, and a bit more TLC and a liquid feed usually keeps them going quite happily.

However, I have also lost a few plants (which I've had for donkey's years) from what I can only assume is some sort of virus, although in recent years their bed has gone from partly shaded to very shaded thanks to a neighbour's gigantic unpruned privet hedge, which is probably sapping their strength. 

The difference with the plants that die is that one by one all the leaves on the cane wither and go brown, followed by the cane itself dying, then the rest of the plant. 

As others have said, unless that's what's happening to yours, and they're producing well, don't worry about it.

I done that yesterday I gave them chicken pellets also  epson salt spray  all over but somebody said that I've got a disease called crinkle virus they were saying pul them up and burn them I can't do that as I'm getting plenty and plenty of fruit of themthey are only two years old I haven't gave them any potash

Whoever said pull them up does not know what they are talking about so ignore their advice. Epsom salts will certainly help. This sort of yellowing is common in raspberries so no need to worry.

Crinkle virus occurs in strawberries. It is not a single virus but a condition when the plants are old and infected by several viruses and their leaves a crinkled due to this. By then the plants are not yielding well and need replacing.

I would say textbook examples of magnesium deficiency. This does not mean that your soil is deficient in magnesium but rather that the plants have not been able to take it up. Drought or high potash are two of the reasons ut there are others.

I doubt if the fruit yield will suffer but Epson salts will stop other leaves going the same way but probably will not cure these. Most of us just accept that it is what raspberries do sometimes.