Young cucumber plants are getting yellow spots on leaves

Hi this is my first year gardening. My cucumber plants that I started from seeds are now approximately 5-6 inches tall. The problem is now I’m starting to see these yellow spots on the leaves and I’m wondering if they will make it this season. I’m planning to transplant them out end of April. Any advice on what I can do to save them or prevent what’s causing the yellowing?

Please let me know what can be done. Thanks!

My experience with cucumber, is that direct seeded grow much better than transplanted. You might try planting these, and plant some seeds next to them on the same day, and see which does better. That'll help you decide what to do next year.

Thanks I’ll try that. Any idea on what I can do with the current young plants?

Make sure they are getting 5-6 hours direct sun, high humidity can cause that also

not sure where you are or what the weather is like. did the spots appear just after they were first put in direct sun? The new growth (with that one with the flowers especially) looks really healthy, but it also makes me wonder if maybe there is too much of something in the fertilizer they're getting?
If you can manage it, I would plant them out now (maybe stay alert to run outside and cover them if it suddenly gets cold in the next week or two), because especially that one with the flowers looks like it is raring to go.

Hi Tereza, thanks for your reply.

I am in Georgia zone 7b. It did get a chilly this whole week.

I did take them out last week to plant them in a bigger container (they were in smaller plastic cups prior to this) which gave the an hour of sunlight.

I also planted out two cucumber plants outside last week when I was upsizing the pots. Please see image below to see what they look like. They also have the yellow spots and its much more apparent on them.

I did watch a video online that says if the yellowing occurs it could be due to magnesium deficiency. Check that out here

what do you guys think? I really need help!

Looks like sunburn to me.