What you are describing with the leaves getting crispy spots and eventually dying is somewhat normal. Cukes are generally not long lived plants and they do seem to shed leaves fairly easily. It may well be sort of environmental stress accelerating it, but this has happened on every variety of cuke I have grown as I recall and it's happened in containers, self watering containers, raised beds and directly in the ground. This 'normal' behavior is usually the oldest leaves not the youngest leaves. It could also be the onset of a foliage disease such as powdery mildew. If it's PM then at some point you should start seeing some whitish fuzz on some of the leaves. If no white fuzz anywhere then it's not PM.

If you fix the issue with the plant itself, which should be the main focus anyway, you'll fix the problem with the fruit. Good cukes won't grow on a poor plant. Simple as that. And that plant doesn't look well at all. Could be weather related, disease (be sure to check the link agardenstateof_mind gave), and/or could be a problem with the soil. So, how has the weather been? Is the soil draining properly or staying overly wet or too dry? Does your squash that was planted in a different bed have the same soil as the cucumbers? I see some white stuff on the soil in the first pic, did you sprinkle anything? "The picture looks like cross pollination with a squash plant. It may still be good to eat....never know till you try." Can't happen. As Peter said, they are completely different species and won't cross. Rodney

Alright I'll do so. I actually have to spray my tomatoes with serenade and baking soda mixture on Monday once all this rain is past, so I'll hit the cucumbers with that as well. So far it has worked great for the leaf spot on the tomatoes. It's keeping new growth from developing it too bad and my fruit won't rot anymore (usually) from the leaf spot.my grandma tells me that a tablespoon of baking soda per gallon of water kills off any blight or leaf spot for her as well, better than anything she's tried. I'm going to add that into the serenade mixture. While we're on topic with the compost, @digdirt2, my corn seems to be tasseling really well at this point, and is a beautiful dark shade of green. I did find out that my compost had added fertilizers, as you had discussed in my previous thread about the corn.

Since the newest leaves appear ok I'd suspect that the bought transplants may not have been hardened off and suffered some shock & sunscald. Can't rule out some early bug bites either. Best guesses.