You are not the only one. Vine crops are the only crop out of a large number of crops I raise that have caused much trouble at all. I don't know how some raise vine crops so blithely. The troublesome ones are watermelon and cantaloupe. Squash, pumpkin, and gourds do ok.

Lots of organic matter that is still decaying probably cause more fungal problems.

I find that I can grow healthy melons for 2 years in the same area. After that they have been getting kinda sick...especially at the stage the melons are getting near maturity, but often before maturity. It takes a healthy plant to finish up the fruits to nice sweet maturity.

I planted melons in completely new ground a few years ago. The 3rd year I started having wilt on the lower end of the plot. Moving a few feet away helped some for 2 or 3 years. Then it got terrible. I moved about 300 north in a fencerow that likely never had grown any crop. WOW and WOW. The melons were almost unbelievable for 2 and 3 years. I had a crenshaw that weighed 22 pounds. Watermelons produced those big, sweet tasty melons. Then BOMB out.

That sounds all to familiar Wayne! I'm pretty sure the chicken manure/pine shavings I've been tilling in is how this got started... This garden is 30' x 40' & it was virgin soil when I first plowed it nearly 45 years ago... I live above the Kansas River in hill ground that's very poor, so I've had to haul lots of black dirt & cow manure in over time... My tomatoes were ate up with early blight every year and I've tried moving them to a raised bed to no avail, but there again I used fresh chicken manure in the raised bed.... Guess I'll need to plow a new patch for my melons, cukes, zukes, etc. because I think I'm wasting my time otherwise..