History 82 United States 53 Plant Breeding and Genetics 44 Genetic Engineering, Gene Transfer and Transgenics, (New June 2002) 36 Biotechnology 35 Molecular Biology and Molecular Genetics, (Discontinued March 2000, Reinstated and Revised June 2002) 33 History and criticism 32 Biotechnology (General), (Revised June 2002) 29 Plants 25 Genetically engineered organisms 24 Foreign relations 23 Social aspects 22 Viral, Bacterial and Fungal Diseases of Plants, (New March 2000) 22 Plant Production 20 Plant breeding 20 Plant diseases 20 Plant Pests, (New March 2000) 19 Politics and government 19 Transgenic plants 19 Genetic engineering 18 American literature 17 Horticultural Crops, (New March 2000) 17 Plant Physiology and Biochemistry 17 Plant pests 17 Crop Produce 16 Agricultural Economics 15 Field Crops, (New March 2000) 15 Social conditions 15 Soil Water Management (Irrigation and Drainage), (Revised June 2002) 15 Taxonomy and Evolution 15