That does look to me more like scorch than any of the diseases cucumbers can get and scortch happens when the plants loose water through transpiration faster then the roots can supply it, ie too little water.
How thick is the mulch?
How much organic matter is in the soil?
Florida soils, sand, are noted for draining really fast, not holding enough water long enough without the addition of lots of organic matter.

The mulch isn't very thick. It's some old hay I had laying around. They were turning brown before I put it on them. We have a lot of sand and are working on building up the soil. I was thinking that they got scorched from spraying them and they got too hot maybe? They have a lot of blossoms and little cucumbers on them so I hate to lose all that.

There is an old myth that persists that sprinkilng plants when the sun is out can cause burning of the leaves since the water droplets magnify the sunlight. That does not happen, and in some instances sprinkling midday could lower the temperature enough to be of benefit to the plants growing there. However, midday sprinkling might keep the pollinators from coming in and working those blossoms.
Look at the soil to see how moist it is and if that soil looks dry 2 inches down, water.

Ok, thanks. I picked more cukes today and there are a lot of them on there plus tons of blossoms. This is my first time growing them in FL (I grew up in NY and the soil and weather is much different). Not sure what to expect.