I can't seem to find the answer I need to identify and treat the spots on my cucumber plant. I've read that it may be a magnesium deficiency, bacterial or possibly an insect. Help me figure this out so I don't lose the crop.
Can you send us an image of the plant?
Here is an article on the care of Cucumber Plants.
https://www.gardeningknowhow.com/edible/vegetables/cucumber/tips-for-growing-cucumbers.htm
I have some brown pelts growing on the top of my cucumbers. What could it be?
How can I stop my cucumbers from splitting? I've cut 4 off so far but there are many more to come and I don't want to lose them all.
This article will help you.
https://www.gardeningknowhow.com/edible/vegetables/cucumber/cracking-in-cucumbers.htm
Why are my cucumbers getting a white powder substance on them making them rot and what can I do about it?
This would be either Powdery Mildew or Downy Mildew.
These articles will help you.
https://www.gardeningknowhow.com/plant-problems/disease/get-the-cure-for-powdery-mildew.htm
https://www.gardeningknowhow.com/plant-problems/disease/downy-mildew.htm
What is the cause/cure of the darkish "dust" on the lower leaves of my lemon cucumber vine?
Sounds like your cucumber plants have a case of what's known as "sooty mold," which means you have one of any number of common pests attacking your vine.
This article will help you get rid of the pests, if that's in fact what it is:
https://www.gardeningknowhow.com/plant-problems/disease/how-to-get-rid-of-sooty-mold.htm
Can you explain why two of my very healthy cucumber plants were healthy one day and very wilted and dying the next day? All my other cucumber plants are healthy, and I have several. I own a vegetable stand and have about 2 acres if veggies. Ground is sufficiently wet so they are not for lack of water.
Sounds like bacterial cucumber wilt, and if you don't handle it quickly it WILL spread.
This article may help you:
https://www.gardeningknowhow.com/edible/vegetables/cucumber/bacterial-wilt-cucumbers.htm
We get just the flowers, no cucumbers.
Your cucumber flowers probably are not being pollinated efficiently. This article will help: https://www.gardeningknowhow.com/edible/vegetables/cucumber/hand-pollinating-cucumbers.htm