Yellow spots on Mini-Munch/Socrates Cucumbers?

Hi Folks,

Hope you're all having fun and reaping the rewards of this good weather.

I'm growing six cucumber plants this year in a vented greenhouse, and a few of them have developed these spots on the lower leaves. Any idea what's causing it? Please see pics.

Production thus far seems quite healthy, about 150-180g per mini-Cucumber. I should add that I'm meticulous with keeping leaves dry n watering from below n they've had Tomatorite once a week, seems quite high potassium which I gather is good for fruit production.

Any knowledge appreciated! :-D

 

I think they might be scorch spots.
Water droplets with the sun shining on them.

 

Cheers both, I think Mosaic Virus is probably it as the leaves never get wet (except when I was putting the irrigation in and had some teething problems!)

Will look into it if owt can be done.

 

Cheers JWK, can it spread to my tomato plants do you know? I've got about 36 in there of five varieties, hoping they can be "kept out of it".

 

I am not sure that's M-Virus . Is it just one leaf or multiple leaves ? Other than the white dots the leaves look healthy , it looks more like a burn marking to me . Have you got anymore pictures of the whole plant or plants