NOVELTY, Mo. (WGEM) - With heavy rainfall constant in the region, Tri-State area farmers can begin to wonder how standing water could affect their yields this season. Professors at the Lee Greenley Jr. Memorial Research Farm may soon have an answer to how long is too long to save your crops. For the past four years, professors and students have been testing on corn plants, taking perfect crops at varying vegetation stages and flooding their roots for a variation of three days and seven days.