The director of agriculture may designate a deputy or an assistant to act in his stead in respect to the performance of his duties under this act. Where any deputy or assistant so acts, it shall be conclusively presumed that he was properly designated by the director of agriculture. Any official proceedings may be signed by such deputy or assistant in his own name. The signature of such deputy or assistant shall be followed by his official title. Where a deputy or assistant has been designated by the director of agriculture to act in his stead in connection with all the proceedings as to any project, then any notice required to be served upon or mailed to the director of agriculture may be served upon or mailed to such deputy or assistant. The director of agriculture is hereby empowered to appoint a deputy who shall have power to act in his place under any and all circumstances in respect to matters within the scope of this act, irrespective of whether or not he is authorized to appoint a general deputy.