History 45 Biotechnology 35 Molecular Biology and Molecular Genetics, (Discontinued March 2000, Reinstated and Revised June 2002) 33 Biotechnology (General), (Revised June 2002) 29 Plant Breeding and Genetics 27 Biochemistry 21 Philosophy 21 Plants 21 History and criticism 18 Education 17 Soil Water Management (Irrigation and Drainage), (Revised June 2002) 15 Agricultural Economics 14 Plant breeding 14 Viral, Bacterial and Fungal Diseases of Plants, (New March 2000) 14 Genetic Engineering, Gene Transfer and Transgenics, (New June 2002) 13 Literature 13 Plant Production 13 Plant diseases 13 Psychology 13 Social Sciences 13 Taxonomy and Evolution 13 Field Crops, (New March 2000) 12 Genetically engineered organisms 12 Genetics 12 Irrigation 12 Plant Pests, (New March 2000) 12 Policy and Planning 12 Economics 11 Horticultural Crops, (New March 2000) 11 Immunity 11