My Pumpkin leaves are yellowing and dying. It starts at the base of the plant and is everyday moving further down the vine. I have around 20 plants in all and some are worse than others. I have Big Max, Wyatt's Wonder, Luminas, and Atlantic Giants. WW are the worst. The vines are around 7-10 feet long with 2 feet secondary vines. I had several pumpkins set and grow to around grapefruit size, but they shriveled up. I have one pumpkin that is smaller than a volleyball on the AG vine. It has not shown any growth in the last 3 days. It has been in the 100 degree range here for the past 2 weeks. I water the pumpkins with an overhead sprinkler every other day with light waterings in between with a handheld garden hose. I also use a black tarp under my whole garden for weed control as my garden is on the small side. I wonder if this is hurting the pumpkin vines. I have also read about bacterial wilt, is this a possiblity? Any help would be greatly appreciated.