Whenever a petition signed by a majority of the total number of adult landowners who together own a majority of the area embraced in the district requesting the appointment of an individual as commissioner is filed with the county clerk of the county in which the greater part of the territory of the district lies not more than 4 weeks nor less than 1 week before the first Tuesday of September, then the county clerk shall forward the petition to the appropriate appointing authority and, except for good cause shown, the appropriate appointing authority shall then appoint that individual as commissioner, if he is otherwise qualified.