Raspberry brown leaf

The leaves turn brown and the canes are stunted.  The limey soil doesn't help but they are usually better than this.  Hopefully the pic uploaded OK so you can see the problem.

No picture -please read

http://www.gardenersworld.com/forum/the-potting-shed/uploading-pictures/5732.html

http://s1162.beta.photobucket.com/user/dr_d_r_brown/library/

I've ordered some Polka to replace the diseased canes.

look at magnesium deficiency on this site! my autumn raspberries always came through pale and yellow.  So I dressed them with epsoms salts early before start of growth then at first sign of yellowing leaves watered over leaves with dissolved epsom salts in water-they then looked much better!  I am moving them this year as getting v congested and woody.  They are 6-7 yrs old!don t know if that is old for raspberries!

Thanks, I'll give it a try.