@gfrederickk, hello
I had a similar problem with my cucumbers about a month ago, I'll present my solution (assuming my diagnosis is correct. although, do try and find someone that can give you a second opinion on the matter presented).
In my case, When I addressed the problem in a thread here, the main answers I got were:
1. Powdery mildew fungi
2 Pests (Thrips maybe)
I tried using insecticidal soap, but it did not do much. after a few weeks, I have noticed that the plant grew a lot of new leaves, and they were okay + the flowering process was completely fine, and cucumbers appeared to be normal.
I suggest trying the insecticidal soap and/or other treatments you find more effective.
Against the Powdery mildew, I think you can make a home-made substance (made out of baking soda or something, not sure) - that may help.
If you want, you can read the thread I made about the problem, and see if it's similar to your case, and if you want to try the methods suggested there.
Hello, I'm quite new to the Gardening business, I always loved plants, but recently I started taking it to a new level, being more professional and caring. I found this forum a few days ago, and I decided that the best thing I can do right now, is to take some advice from professionals that...
www.gardening-forums.com
Good luck.