1. Unit for Environmental Sciences and Management, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X1290, Potchefstroom 2520, South Africa
2. School of Mathematics, Science and Technology Education, Faculty of Education, North-West University, Private Bag X2046, Mmabatho 2790, South Africa
3. Indigenous Knowledge Systems Centre, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag X2046, Mmabatho 2790, South Africa
4. Döhne Agricultural Development Institute, Plant and Crop Production Research, Private Bag X15, Sutterheim 4930, South Africa
5. Agricultural Research Council–Vegetables, Industrial and Medicinal Plants, Private Bag X293, Pretoria 0001, South Africa
6. Department of Chemistry, Faculty of Natural and Agricultural Sciences, North-West University, Mmabatho 2735, South Africa
7. School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal (Westville Campus), Private Bag X54001, Durban 4000, South Africa