The board shall, immediately after its appointment and after public hearing, formulate an effective plan and adopt a budget of expenditures for the forthcoming fiscal year. At a public hearing on the plan and the budget, any owner of winegrape acreage included in the district may make written or oral protest against the budget or any item in it. The plan and the budget, as thereafter approved by the board, shall be the plan and the budget of the district for the forthcoming fiscal year.