Cal. Lab. Code § 1156

Representatives designated or selected by a secret ballot for the purposes of collective bargaining by the majority of the agricultural employees in the bargaining unit shall be the exclusive representatives of all the agricultural employees in such unit for the purpose of collective bargaining with respect to rates of pay, wages, hours of employment, or other conditions of employment. Any individual agricultural employee or a group of agricultural employees shall have the right at any time to present grievances to their agricultural employer and to have such grievances adjusted, without the intervention of the bargaining representative, as long as the adjustment is not inconsistent with the terms of a collective-bargaining contract or agreement then in effect, if the bargaining representative has been given opportunity to be present at such adjustment.