1. Department of Crop Science and Horticulture, Sokoine University of Agriculture, Morogoro, Tanzania
2. Plant Protection Division, Department of Research, Tropical Pesticides Research Institute, Arusha, Tanzania
3. Department of Food Technology, Nutrition and Consumer Sciences, Sokoine University of Agriculture, Morogoro, Tanzania
4. Department of Plant Agriculture, University of Guelph, Guelph, Ontario, Canada