Why does Taizo disown his brother in the novel, Daughter of Moloka'i?

Jiro, Taizo’s brother, convinces him to leave Hawai’i to come work his land in California, promising Horace half the land when he gets old enough. He does not tell Taizo that he is in a lot of debt. When the Japanese are interned, Taizo disowns Jiro as his brother because he considers it Jiro’s fault that they are in California.