Pumpkin Help

[Russell]

I purchased a Howard Dill pumpkin and have followed the backyard gardnener tips religiously. Two weeks ago (after selecting my self-pollenated female of choice) I trimmed off two lesser gals and also trimmed off four feet of stem about 10' after the selected pumpkin. Two days later the pumpkin began to shrivel and yesterday I removed it to avoid rot getting into the stem. Now I am awaiting some new girls to come along to see if we can get things rolling again. The plant is 20' long and has several male flowers currently, new shoots and is very lush for the last 15'. My present concern is the first five feet are showing spots of mold/blight on the foliage. Please let me know what I can do and some tips to avoid having my fruit shrivel again. PS - It could have been the hot temperatures we had - even though it was watered well.
Thanks for the help.