help blight on watermelon leaves?

[noodles777]

I noticed a brown spot on one leaf I think it is blight by some of the descriptions I've read but they said it is typically caused by constant wetness. I'm in So Cal and it's definitely not constantly wet, I water them about 3 times a week and do everything i can not to splash the leaves. I would post a picture but I'm a dufus and i hurried and cut it off and threw it out. . any suggestions? I have 2 little plants and I planted them in different spots just to compare the difference. This one gets prety much full sun but the last week it has been overcast.