1. Department of Mechanical EngineeringEskisehir Osmangazi University/TurkeyBati MeselikEskisehir26480Turkey
2. Department of Biological and Agricultural EngineeringUniversity of IdahoP.O. Box 440904MoscowID83844‐0904USA
3. Department of Agronomy and HorticultureUniversity of Nebraska‐LincolnP.O. Box 830915, N308 The Beadle CenterLincolnNE68583‐0915USA