Cropping systems Plant Cropping Systems 8 Field Crops, (New March 2000) 6 Plant Production 6 Agriculture 4 Crop production 4 Biological Resources (Plant) 3 Biotechnology 3 Plant Breeding and Genetics 3 Plant breeding 3 Taxonomy 3 Viral, Bacterial and Fungal Diseases of Plants, (New March 2000) 3 Water management 3 Biotechnology (General), (Revised June 2002) 2 Crop Produce 2 Fertilizers 2 Fertilizers and other Amendments 2 Forage and Fodder Crops, (New March 2000) 2 Genetic improvement 2 Genetics 2 Geographical distribution 2 Green manures 2 Land Resources 2 Land management 2 Mechanization 2 Molecular Biology and Molecular Genetics, (Discontinued March 2000, Reinstated and Revised June 2002) 2 Nitrogen fixation 2 Organic farming 2 Origin 2 Oryza 2