A farmer harvests wheat this week along state Route 703 at the corner of Staeger Road east of Celina. About 80 percent of the wheat has been harvested in Mercer County, said Michelle Stahl, Mercer County Farm Service Agency executive director. Some producers have not been able to take off wheat due to spotty rain showers during the past couple of weeks, Stahl said. Mercer County farmers planted about 15 percent less wheat this growing season likely due to high input costs to grow the crop and low wheat prices, Stahl said. Harvest began in late June.