Plant propagation 61 plant layering 60 plant harvesting 59 Sociology 36 Genetics 30 metabolism 24 Plant cell 22 morphology 17 Crop improvement 16 Cytology 16 Plant physiology 16 Cell Division 15 Economics 15 Currency 14 Metabolism 14 Morphology 14 Trade Union 14 Wage Act 14 photosynthesis 14 Chromosomes 13 Engineering 13 Expenditure 13 Nucleus 13 Photosynthesis 13 Public debt 13 Taxation 13 Income tax 12 Management 12 Plant Breeding 12 unconscious mental forces 12