Why is George so quick to say no to Candy about coming to there land

While George is talking about the 10 acre land Candy wants his own land. Candy wants the free land instead of being a old man who cleans up. He hears about how beautiful the land is and decides to ask if they he can live there. George says no because he knows that Candy lost a hand and would not be a big help "I gotta think about that"(59). He doesn't want to say it straight to his face but on the inside he doesn't want candy on the land.