Should I Pull This Plant????

[Elayne]

Even though I have sprayed daconil every 7-10 days, I have a sick Mortgage Lifter. I have read through the posts on diseases, but have not really identified the problem. The color of the leaves went from dark green a few days ago to a pale yellowish green today---plus there are rusty looking blotches on some of the leaves. Should I try to treat this plant or just get rid of it? Any advice would be appreciated!As you can see, my tomatoes aren't setting fruit, only a few small tomatoes so far. The weather has been really hot here---over 100 degrees almost every day.