1. Crops Research Institute; Council for Scientific and Industrial Research; P.O. Box 3785 Fumesua-Kumasi Ghana
2. Department of Chemistry; Kwame Nkrumah University of, Science and Technology, PMB; Kumasi Ghana
3. Department of Biointeractions and Crop Protection, Rothamsted Research; Harpenden Hertfordshire AL5 2JQ UK
4. School of Biological and Chemical Sciences; Queen Mary University of London; London E1 4NS UK
5. School of Agriculture, Policy and Development; The University of Reading, Earley Gate; P.O. Box 237 Reading Berkshire RG6 6AR UK
6. School of Chemistry; Cardiff University; Cardiff Wales CF10 3AT UK