The Biology of Horticulture: An Introductory Textbook, 2nd Edition

PART 1 HORTICULTURAL BIOLOGY 1

1 INTRODUCTION 3

Horticulture Defined 4

History of Horticulture 6

2 PLANT CLASSIFICATION 13

Early Classification Systems 13

Botanical Classification/Taxonomy 14

Horticultural Classification 18

References 22

3 PLANT STRUCTURE 23

The Cell 23

Organs 30

Flowers 49

Fruits 57

References 63

4 PLANT GENOTYPE 65

Genetic Improvements 66

Genetic Terminology 67

Fertilization 74

Heritability 74

Cloning Plants 77

Plant Breeding 79

Molecular Biology 81

Cross-Fertilization 83

Mutations 86

Pest Resistance 91

Summary 93

References 93

PART II THE AMBIENT ENVIRONMENT 95

5 LIGHT 97

Photosynthesis 99

Spacing and Orienting Plants for Light

Interception 103

Etiolation 109

Effect of Pigments 113

Photoperiodism 120

Light Quantity and Plant Growth 127

Light Sources and Their Use 133

Systems for Measuring Light 136

Summary 139

References 139

6 TEMPERATURE 141

Temperature and Plant Growth 142

Sugar and Starch Conversions 147

Soil Temperature 149

Temperature Monitoring and Control 154

Cooling Controlled Environments 155

Heating and Energy Conservation in

Controlled Environments 160

Temperature and Site Selection 166

Vernalization 168

Dormancy 169

Temperature Stress 172

Low-Temperature Effects 172

High-Temperature Effects 183

Temperature Fluctuations 185

Summary 186

References 186

PART III THE RHIZOSPHERE (ROOT ZONE) 187

7 WATER 189

Properties of Water 190

Horticultural Applications and Water Management 198

Irrigation 204

Timing and Amount of Water 218

Soil Moisture Measurement 220

Summary 226

References 226

8 SOILS AND SOIL MANAGEMENT 229

Characteristics of Soil 230

Aeration and Drainage 239

References 249

9 MINERAL NUTRITION 251

Early Knowledge of Essential Elements 251

Mineral Nutrient Uptake 252

Carbon, Hydrogen, and Oxygen 256

Macronutrients 257

Micronutrients 259

Fertilizer Practices 261

Fertilizer Sources 266

Inorganic Fertilizers 270

Fertilizer Application Methods 273

References 279

10 MULCHES 281

Advantages of Mulches 282

Use of Organic Mulches 282

Winter Mulching 284

Nonorganic Mulches 285

Limitations of Mulching 290

Summary 291

References 291

PART IV PLANT GROWTH SUBSTANCES 293

11 PLANT HORMONES 295

Major Plant Hormones 297

Growth-Promoting Hormones 297

Wounding and Stress Hormones 297

Growth-Promoting Hormones: Auxins 298

Gibberellins 304

Cytokinins 307

Brassinosteroids 311

Wounding and Stress Hormones: Ethylene 311

Abscisic Acid 315

Jasmonates 316

Other Plant Growth Substances 317

References 317

12 CHEMICAL CONTROL OF PLANT GROWTH 319

Dormancy 320

Apical Dominance 322

Apical Dominance 323

Growth Retardation 324

Vegetative Growth Promotion 326

Flowering 326

Sex Expression 328

Fruiting 329

Abscission and Harvest Aids 332

Summary 334

References 334

PART V HORTICULTURAL PRACTICES 335

13 PRUNING 337

Pruning 337

Summary 345

References 345

14 PLANT PROPAGATION 347

Vegetative Propagation 349

Cutting Propagation 349

Cutting Types 356

Layering 359

Specialized Plant Structures 360

Grafting and Budding 361

Micropropagation 364

Seed Propagation 368

Hardening-Off 376

Summary 377

References 377

15 POSTHARVEST HANDLING 379

Quality and Maturity 380

Biological Factors Involved in Deterioration 385

Environmental Factors Influencing Deterioration 387

Food Safety 389

Harvesting 390

Preparation for Market 391

Storage 397

Keys to Successful Handling of Horticultural Crops 403

References 405

Internet Resources 407

PART VI PLANT PROBLEMS 409

16 PLANT PESTS AND OTHER PROBLEMS 411

Plant Diseases 413

Fungi and Fungal-Like Organisms 416

Deuteromycetes or Fungi Imperfecti 425

Bacteria 425

Mollicutes (Phytoplasmas and Spiroplasmas) 427

Viruses and Viroids 427

Parasitic Higher Plants 430

Nematodes 431

Horticultural Practices and Plant Disease 432

Insects 432

Types of Insect Damage to Plants 437

Mites 445

Snails and Slugs 446

Vertebrate Pests 447

Weeds 450

Organic Approaches to Pest Management 453

Safety in the Use of Pesticides 454

Summary 455

References 455

APPENDIX 457

SCHEDULE A Field-Grown Processing Tomato (Lycopersicon esculentum) 458

SCHEDULE B Greenhouse-Grown Poinsettia (Euphorbia pulcherrima) 460

SCHEDULE C Balled and Burlapped Spreading Yew (Taxus cuspidata) 464

SCHEDULE D Apple, a Temperate Tree Fruit (Malus pumila) 466

SCHEDULE E Orange, a Subtropical Tree Fruit (Citrus sinensis) 470

SCHEDULE F Kentucky Bluegrass Sod (Poa pratensis) 474

Glossary 477

Index 493