[1]Department of Agricultural Mechanization & Irrigation Engineering Busitema University Tororo 236 Uganda;
[2]Agricultural Engineering and Appropriate Research Center National Agricultural Research Organization Kampala 7144 Uganda;
[3]Department of Agricultural and Biosystems Engineering College of Agricultural and Environmental Sciences Makerere University Kampala 7062 Uganda;
[4]Department of Agricultural and Biosystems Engineering Iowa State University 1340 Elings Hall Ames Iowa 50011-3270 USA;