It shall be unlawful for the Director of Agriculture or any deputy or other employee of the State Department of Agriculture to be interested directly or indirectly as owner, agent or solicitor in the manufacture, purchase or sale of any article, commodity or product over which the director, deputy or employee may have supervision in an official capacity. It shall not be a violation of this section for the director, any deputy or other employee to own, lease or operate a ranch or farm. [Amended by 1959 c.229 §12; 1967 c.208 §9]