The secretary of the board of directors shall cause a notice of the proposed merger to be posted and published in the same manner and for the same time as notice of a special election for the issue of bonds. The notice shall state that a petition has been filed with the legislative authority of the county or counties within which the irrigation districts lies by the board of supervisors of the drainage improvement district, joint drainage improvement district, or consolidated drainage improvement district or by the board of commissioners of a water-sewer district requesting that the drainage improvement district, joint drainage improvement district, consolidated drainage improvement district, or water-sewer district be merged with the irrigation district or irrigation districts, the names of the petitioners and the prayer thereof, and it shall notify all persons interested in the irrigation district to appear at the office of the board at the time named in the notice, and show cause in writing why the proposed merger should not take place. The time to show cause shall be the regular meeting of the board of directors of the irrigation district next after the expiration of the time for the publication of the notice.