Tomatillo - odd leaf issue?

It looks similar to the problem I had on my grapes last year.
Some kind of leaf blister mite.

 

I would usually agree with Pete, but the yellow marks on the leaves would suggest fungal IMO, 1st check for evidence of insects, at dusk etc, if you cannot find evidence, then its def fungal possibly Septoria leaf spot.

 

Usually?

All I will add is the mites on my grapes last year were too small to see, well I couldn't see them with my eyes anyway.
Not suggesting you do this on tomatillo, FC, but at the first signs this year I sprayed with sulphur and it appears to have sorted the invisible insect.

 

Oh, I dont think it would be a good idea on tomatillo, especially if you have other plants close by.

The sulphur I used was specially fine for spraying roses.

Dont think ordinary flowers of sulphur is fine enough.

If its what I'm saying it is it might go away naturally at some point.
If its what @Cuttings is saying,then a fungicide would perhaps be best.

Think you need to have a google.

 

There are so many similarities with mites, fungal infections etc. So many plants, including well established trees can become victims. It is difficult to give a positive diagnosis from a photo. That is why I usually say my bit, about the value and purpose of a plants leaves.

It's upto the grower to decide at the end of the day. Using chemicals may sometimes appear to rid the plant of it's unwanted visitor, but chemicals can often damage the plant and in some cases may affect the fruit. Of whatever catagory the pest etc comes from, be it fungal, bacterial, viral or whatever. I suggest in a close enviroment with other plants, if the infection is large, then isolate the plant/s. Sightings in the early stages, then remove the affected leaves.

Growing plants under glass etc so often ends with the over enthusiastic gardener over-crowding and so often growing plants that require several different growing conditions. The latter can be like offering an invitation to many of the pests and disorders we become troubled by. I do it and OK it's often said. One learns by their mistakes. TRUE, but some mistakes can be costly. Hope this helps.

 

Just a thought, could it be flea beetles, if you disturb the foliage you can see them jumping off.

 

What ever it is, when you find out for sure, there used to be a product brand called PY, they did a range of treatments for edible crops, once applied, or the product dried, it was safe to eat the crop, havent seen it for a while.
If it is bugs you can use the following:
4 parts of any of the following oils, Neem, Lavender, white mineral.
1 part BIOLOGICAL washing up liquid.
4 parts water.
Put the desired amount into a sprayer/spray bottle, shake the bottle vigerously until the soloution is milky, apply the same as you would a pestercide, then again in a fortnight.
Insects breathe through their skin, this solution coats and sticks to the insect, basically suffocating them, important to use biological washing up liquid, as the run of the mill stuff is not good for some plants.