How do I stop my pumpkins from dying?

Question:I am growing pumpkins. They were growing just fine (a little on the miniature side, but at least they're there), until a gopher started eating away at the roots of the plants. I lost one of my best pumpkins. My dad stuck poisonous food in the gopher hole (he's a liscenced exterminator), and the gopher problems have stopped. But two out of four of my pumpkin plants are still dying, one of them with my biggest pumpkin on it! I have been watering them generously everyday, but the leaves of the two plants just yellow and die. I don't want my pumpkins to be next! If anyone out there has a real green thumb and could help me out, I'd really appreciate it!

Answers:
look at the plant where it comes out of the ground, if you see its been chewed on then you have slugs that come out at night and eating them, you cant see slugs in the daytime only at night, what i do is to put an old corn can or an old lid or something thats holds water, put some beer in it, level with the ground, they like the yeast that is in the beer, in the morning you will see them dead in the beer