It is possible that this is a blackberry virus that has infected your plants, although other environmental factors (like cold injury) may also cause malformed leaves. You probably won't know for sure unless you get a leaf tissue sample tested.

After expanding your image, I can see that you have some nutrient issues which are indicated by the following:

- interveinal yellowing on some of the lower leaves

- and brown edges (possibly necrosis from too much salt)

- Also stunted new growth is an indication as well, usually of a Calcium deficiency.

Let me start by saying that even though I am using the work deficiency here that doesn't in any way mean your soil is lacking the nutrient, it may be, but more likely it is just a pH issue.

Clay tends to have a higher pH that limits a plant's ability to take up the nutrients it needs, even when there is way plenty in the soil. In general, AZ doesn't get enough rain to wash the salts our of your soil, so you may also have a built up of sodium, which causes plant leaf tips to brown. You may need to neutralize the sodium (Calcium Nitrate has worked best for me here in Southern CA). The Calcium displaces the sodium in the soil and the nitrate adds to the plant's vegetation. But, you first need to determine what will fix the problem. Maybe simply acidifying the soil would be sufficient. Try this - mix 1 T per gallon of water and pour it in a small trench 6-8 " from the base of 1 (one) your plants. Why one? Because you just want to correctly identify the problem/solution before you go full bore. And trust me on this 1 Tablespoon of vinegar per gallon of water is sufficient, any more and you risk seriously burning your plants roots. Also, if you have several plants, then you can try some 1 Tablespoon of calcium nitrate per gallon of water on another. Write down what you do to which plant so you can keep track. Lastly, you may want to try 1 teaspoon of epson salt (Magnesium - sulfate) dissolved in a gallon of water. The magnesium should address the interveinal yellowing, and the sulfate will help lower the pH of your clay. Do that once a week for a month or two, sometimes it can take a while for the effect to kick in. However, the vinegar usually reacts relatively quickly. So, if that hasn't worked after a month it likely isn't the solution.

Actually, over fertilizing in prior years could leave too much salts in the soils and result in stunted top growth as well, unless you are using all organic fertilizers. You could also try just running a lot of water over one of your plants. 6" of water will lower your soil salts by about 40% and 12" will lower them by 80%, so you can see why you might want to try that on one plant for starters (that's a lot of water). I use a 5 gal Home depot bucket with a 1/8" hole in the bottom - you want it to slowly saturate the ground around your plant. Usually three buckets full per plant on one day within about 6-10" of the plant is sufficient to lowers the salts substantially. ( 1T of vinegar per bucket will help lower the salts even more).

Hope that helps.

In arid regions, calcium is the element which builds up, not sodium.

Sodium can build up if softened water is used, or the gardener uses certain ill-advised home remedies.

Clay soils can be acid as they are here in the northwest.

What is the pH of your soil?

Does your region have problems due to caliche?

Consider contacting your county's Extension Service as they know your soil conditions and the most common problems.

use this interactive map to locate the office:

http://npic.orst.edu/pest/countyext.htm

Thanks all for your help. I did add gypsum to the soil a few months ago. Could that be the cause of the magnesium deficiency? I'll try a little epsom salt and see if it makes a difference. Although it does look a little like mosaic virus.

I have a very similar issue with my leaves, they're all sorta shrunken and deformed. Did you ever find a solution to this? Otherwise, I'm probably going to chalk this up to some sort of virus and get rid of the problematic plants.