“Production credit association” defined — Associations subject to tax

As used in this part, unless the context otherwise requires, “production credit association” means a corporation organized and chartered pursuant to [former] § 20 of the Farm Credit Act of 1933, Act June 16, 1933, ch. 98, § 20, 48 Stat. 259 [repealed], engaged in business in this state, and not exempt by virtue of the laws of the United States from taxation by this state.