(AREA) -- Michigan corn growers will be able to vote on whether to double the assessment on their crop to support a program that promotes their industry. State Agriculture Department Director Jamie Clover Adams says the referendum was requested by petitions that more than 200 producers had signed. The proposal would boost the assessment rate from 1 cent per bushel to 2 cents per bushel. The additional revenue would be used for research, education and promotion of Michigan's corn industry. The Corn Marketing Program of Michigan was established in 1993 to seek ways to boost demand and create new markets. The referendum will be held from April 14-25. Ballots will be mailed to producers. To win approval, the proposal must receive more than 50 percent of the producer votes cast.