How does Candy address the body of the girl after he talks to George and learns that their dream of the farm is no longer a reality? Why does he react this way?

Candy is really frustrated over what happened,

Old Candy watched him go. He looked helplessly back at Curley's wife, and gradually his sorrow and his anger grew into words. "You God damn tramp", he said viciously. "You done it, di'n't you? I s'pose you're glad. Ever'body knowed you'd mess things up. You wasn't no good. You ain't no good now, you lousy tart."

why did he react this way?

Candy is angry with her because she ruined his chances for his farm.