part one GENERAL ASPECTS 3
chapter oneINTRODUCTION 3
Plant Pathology： The Science 3
The Concept of Disease in Plants 4
Types of Plant Diseases 4
History of Plant Pathology 7
The Role o f Fungi in Plant Disease 10
Discovery o f Other Pathogens as Causes of Plant Disease 12
Serious Plant Diseases o f Unknown Etiology 13
Early Development o f Plant Pathology 13
The Search for Control o f Plant Diseases 14
Interest in the Mechanisms by Which PathogensCause Disease 17
The Concept o f Genetic Inheritance o f Resistance and Pathogenicity 18
Epidemiology o f Plant Disease Comes o f Age 19
Molecular Plant Pathology 19
Development o f Plant Pathology Worldwide 20
Trends in Teaching and Training in Plant Pathology 22
Education and Information Technology in Plant Pathology 23
Plant Disease Clinics 23
Plant Pathology： The Practice 23
Certification of Professional Plant Pathologists 25
Significance of Plant Diseases 25
Kinds and Amounts o f Losses 25
Some Historical and Present Examples of Losses Caused by Plant Diseases 28
Plant Diseases and World Crop Production 28
Effects o f Changes in Agricultural Methods and in Human Society on the Development and Spread of Plant Diseases 34
Basic Procedures in the Diagnosis of Plant Diseases 37
Pathogen or Environment? 37
Infectious Diseases 37
Noninfectious Diseases 39
Identification of a Previously Unknown Disease：Koch’s Rules 39
chapter two PARASITISM AND DISEASE DEVELOPMENT 43
Parasitism and Pathogenicity 43
Host Range of Pathogens 44
Development of Disease in Plants 45
Stages in the Development of Disease：The Disease Cycle 45
Inoculation 45
Prepenetration Phenomena 46
Penetration 48
Infection 53
Invasion 54
Growth and reproduction of the pathogen（colonization） 54
Dissemination o f the Pathogen 56
Overwintering and/or Oversummering of Pathogens 59
Relationships between Disease Cycles and Epidemics 61
chapter three HOW PATHOGENS ATTACK PLANTS 63
Mechanical Forces Exerted by Pathogens on Host Tissues 63
Chemical Weapons of Pathogens 65
Enzymes in Plant Disease 65
Microbial Toxins in Plant Disease 73
Growth Regulators in Plant Disease 77
Polysaccharides 81
Suppressors of Plant Defense Responses 81
chapter four EFFECTS OF PATHOGENS ON PLANT PHYSIOLOGICAL FUNCTIONS 83
Effects of Pathogens on Photosynthesis 83
Effect of Pathogens on Translocation of Water and Nutrients in the Host Plant 85
Interference with Upward Translocation o f Water and Inorganic Nutrients 85
Interference with the Translocation o f Organic Nutrients through the Phloem 86
Effect of Pathogens on Host Plant Respiration 87
Respiration o f Diseased Plants 88
Effect of Pathogens on Permeability of Cell Membranes 89
Effects of Pathogens on Transcription and Translation 90
Effect on Transcription 90
Effect on Translation 91
chapter five HOW PLANTS DEFEND THEMSELVES AGAINST PATHOGENS 93
Preexisting Structural and Chemical Defenses 93
Preexisting Defense Structures 93
Preexisting Chemical Defenses 94
Induced Structural and Biochemical Defenses 96
Recognition o f the Pathogen by the Host Plant 96
Transmission o f the Alarm Signal to Host Defense Providers： Signal Transduction 96
Induced Structural Defenses 96
Cytoplasmic defense reaction 97
Cell wall defense structures 97
Histological defense structures 98
Necrotic defense reaction：defense through the hypersensitive response 100
Induced Biochemical Defenses 100
The hypersensitive response 100
Active oxygen radicals，lipoxygenases，and disruption of cell membranes 103
Reinforcement of host cell walls with strengthening molecules 103
Production of antimicrobial substances in attacked host cells 104
Detoxification of pathogen toxins 108
Immunization of plants against pathogens 108
Local and systemic acquired resistance 108
Defense through genetically engineering disease resistant plants 112
chapter six GENETICS OF PLANT DISEASE 115
Introduction 115
Genes and Disease 116
Variability in Organisms 117
Mechanisms of Variability 118
General Mechanisms of Variability 118
Specialized Mechanisms of Variability in Pathogens 119
Stages of Variation in Pathogens 121
Types of Plant Resistance to Pathogens 122
True Resistance 122
Apparent Resistance 124
Genetics of Virulence in Pathogens and of Resistance in Ho st Plants 125
The Gene-for-Gene Concept 126
The Nature o f Resistance to Disease 128
Genetics of Resistance through the Hypersensitive Response 129
Breeding of Resistant Varieties 135
Natural Variability in Plants 135
Effects o f Plant Breeding on Variability in Plants 135
Plant Breeding for Disease Resistance 136
chapter seven ENVIRONMENTAL EFFECTS ON THE DEVELOPMENT OF INFECTIOUS PLANT DISEASE 144
Effect of Temperature 144
Effect of Moisture 146
Effect of Wind 148
Effect of Light 149
Effect of Soil pH and Soil Structure 149
Effect of Host-Plant Nutrition 149
Effect of Herbicides 151
chapter eight PLANT DISEASE EPIDEMIOLOGY 153
The Elements of an Epidemic 153
Host Factors That Affect the Development of Epidemics 155
Pathogen Factors That Affect Development of Epidemics 156
Environmental Factors That Affect Development of Epidemics 158
Effect o f Human Cultural Practices and Control Measures 158
Measurement of Plant Disease and of Yield Loss 159
Patterns of Epidemics 160
Comparison of Epidemics 162
Development of Epidemics 163
Modeling of Plant Disease Epidemics 165
Computer Simulation of Epidemics 166
Forecasting Plant Disease Epidemics 167
Assessment o f Initial Inoculum and of Disease 167
Monitoring Weather Factors That Affect Disease Development 167
Examples o f Plant Disease Forecast Systems 168
Disease-Warning Systems 170
Development and Use o f Expert Systems in Plant Pathology 171
chapter nine CONTROL OF PLANT DISEASES 174
Control Methods That Exclude the Pathogen from the Host 174
Quarantines and Inspections 174
Evasion or Avoidance of Pathogen 175
Use o f Pathogen-Free Propagating Material 175
Control Methods That Eradicate or Reduce Pathogen Inoculum 177
Cultural Methods That Eradicate or Reduce the Inoculum 178
Biological Methods That Eradicate or Reduce the Inoculum 181
Physical Methods That Eradicate or Reduce the Inoculum 188
Chemical Methods That Eradicate or Reduce the Inoculum 190
Disease Control by Immunizing， or Improving the Resistance of， the Host 192
Cross Protection 193
Induced Resistance：Systemic Acquired Resistance 193
Plant Defense Activators 193
Improving the Growing Conditions of Plants 194
Use o f Resistant Varieties 194
Direct Protection of Plants from Pathogens 195
Direct Protection by Biological Controls 195
Fungal antagonists 196；Bacterial antagonists 197
Biological Control of Weeds 199
Direct Protection by Chemical Controls 200
Methods of application of chemicals for plant disease control 203
Types of chemicals used for plant disease control 208
Inorganic chemicals used for plant disease control 208
Organic chemicals：contact protective fungicides 209
Organic compounds： systemic fungicides 210
Miscellaneous organic fungicides 212
Antibiotics 212
Plant oils and petroleum oils 213
Growth regulators 213
Nematicides 213
Mechanisms of action of chemicals used to control plant diseases 214
Resistance of pathogens to chemicals 215
Restrictions on chemical control of plant diseases 216
Integrated Control of Plant Diseases 216
Integrated Control in a Perennial Crop 217
Integrated Control in an Annual Crop 218
part two SPECIFIC PLANT DISEASES 225
chapter ten ENVIRONMENTAL FACTORS THAT CAUSE PLANT DISEASES 225
Introduction 225
General Characteristics 225
Diagnosis 225
Control 226
Temperature Effects 226
High-Temperature Effects 227
Low-Temperature Effects 228
Low-Temperature Effects on Indoor Plants 228
Mechanisms of Low- and High-Temperature Injury to Plants 230
Moisture Effects 230
Low Soil Moisture Effects 230
Low Relative Humidity Effects 231
High Soil Moisture Effects 231
Inadequate Oxygen 232
Light 232
Air Pollution 233
Air Pollutants and Kinds of injury to Plants 233
Main Sources o f Air Pollutants 234
How Air Pollutants Affect Plants 234
Acid Rain 236
Nutritional Deficiencies in Plants 236
Soil Minerals Toxic to Plants 238
Herbicide Injury 240
Other Improper Agricultural Practices 241
The Often Confused Etiology of Stress Diseases 242
chapter eleven PLANT DISEASE CAUSED BY FUNGI 245
Introduction 245
Characteristics of Plant Pathogenic Fungi 245
Morphology 245
Reproduction 246
Ecology 246
Dissemination 248
Classification of Plant Pathogenic Fungi 248
Fungallike Organisms or Pseudofungi 248
The True Fungi 249
Identification 254
Symptoms Caused by Fungi on Plants 254
Isolation o f Fungi （and Bacteria） 255
Preparing for Isolation 255
Isolating the Pathogen 257
Life Cycles of Fungi 258
Control of Fungal Diseases of Plants 259
Diseases Caused by Fungallike Organisms 260
Diseases Caused by Myxomycota （Myxomycetes） 260
Diseases Caused by Plasmodiophoromycetes 263
Clubroot of crucifers 263
Diseases Caused by the Chromistan Fungallike Oomycetes 266
Pythium Seed Rot，Damping-off， Root Rot，and Soft Rot 266
Phytophthora Diseases 270
Phytophthora root and stem rots 270
Late blight of potatoes 274
The Downy Mildews 278
Downy mildew of grape 280
Diseases Caused by True Fungi 283
Diseases Caused by Chytridiomycota（Chytridiomycetes） 283
Diseases Caused by Zygomycetes 283
Rhizopus soft rot of fruits and vegetables 285
Diseases Caused by Ascomycetes and Imperfect （Asexual）Fungi 286
Sooty Molds 289
Leaf Curl Diseases Caused by Tapbrina 293
The Powdery Mildews 295
Powdery mildew of rose 297
Foliar Diseases Caused by Ascomycetes and Imperfect Fungi 298
Alternaria diseases 300
Rice blast disease 303
Black rot of grape 304
Needle casts and blights of conifers 304
Mycospbaerella diseases 307
Banana leaf spot，or Sigatoka disease 307
Cucurbit gummy stem blight 307
Cerospora diseases 309
Septoria diseases 310
Cochliobolus and Pyrenophora diseases of cereals and grasses 310
Stem and Twig Cankers Caused by Ascomycetes and Imperfect Fungi 317
Dothichiza canker of poplar 318
Black knot of plum and cherry 319
Chestnut blight 319
Nectria canker 319
Leucostoma canker 321
Antbracnose Diseases Caused by Ascomycetes and Imperfect Fungi 324
Black spot of rose 324
Glomerella diseases 325
Gnomonia anthracnose and leaf spot diseases328；Colletotrichum （Gloeosporium） diseases 329
Fruit and General Diseases Caused by Ascomycetes and Imperfect Fungi 331
Ergot of cereals and grasses 332
Apple scab 334
Brown rot of stone fruits 336
Botrytis diseases 339
Vascular Wilts Caused by Ascomycetes and Imperfect Fungi 342
Fusarium wilts 343
Fusarium wilt of tomato 343
Verticillium wilts 346
Ophiostoma （Ceratocystis）wilt of elm trees：Dutch elm disease 346
Root and Stem Rots Caused by Ascomycetes and Imperfect Fungi 350
Gibberella diseases 351
Fusarium root and stem rots of nongrain crops 352
Take-all of wheat 354
Sclerotinia diseases 355
Pbymatotrichum root rot 358
Postharvest Diseases o f Plant Products Caused by Ascomycetes and Imperfect Fungi 359
Postharvest decays of fruits and vegetables 361
Alternaria 361
Botrytis 362
Fusarium，Geotrichuni，Penicillium，Sclerotinia 363
Control of postharvest decays of fresh fruits and vegetables 364
Postharvest decays of grain and legume seeds364；Mycotoxins and mycotoxicoses365； Aflatoxins 365
Fusarium toxins 366
Other Aspergillus toxins andPenicillium toxins 366
Diseases Caused by Basidiomycetes 368
The Rusts 368
Cereal rusts 371
Stem rust of wheat and other cereals 371
Cedar-apple rust 375
Coffee rust 375
Rusts of forest trees 377
White pine blister rust 378
Fusiform rust 380
The Smuts 382
Corn smut 382
Kernel smuts of small grains 384
Loose smut of cereals 384
Covered smut，or bunt，of wheat 387
Root and Stem Rots Caused by Basidiomycetes 389
Root and stem rot diseases caused by the “sterile fungi”Rhizoctonia and Sclerotium 390
Rhizoctonia diseases 390
Sclerotium diseases 395
Root rots of trees 397
Armillaria root rot of fruit and forest trees 397
Wood Rots and Decays Caused by Basidiomycetes 399
Mycorrhizae 404
Ectomycorrhizae 404
Endonnycorrhizae 404
chapter twelve PLANT DISEASES CAUSED BY PROKARYOTES：BACTERIA AND MOLLICUTES 407
Introduction 407
Plant Diseases Caused by Bacteria 408
Characteristics of Plant Pathogenic Bacteria 409
Morphology 409
Reproduction 411
Ecology and Spread 412
Identification of Bacteria 412
Symptoms Caused by Bacteria 415
Control o f Bacterial Diseases of Plants 415
Bacterial Spots and Blights 416
Wildfire of tobacco 417
Bacterial blights of bean 418
Angular leaf spot of cucumber 419
Angular leaf spot of cotton 420
Bacterial leaf spots and blights of cereals and grasses 421
Bacterial spot of tomato and pepper 421
Bacterial speck of tomato 422
Bacterial spot of stone fruits 422
Bacterial Vascular Wilts 423
Bacterial wilt of cucurbits 424
Fire blight of pear and apple 426
Ring rot of potato 429
Bacterial canker and wilt of tomato 430
Southern bacterial wilt of solanaceous plants and Moko disease of banana 431
Black rot of crucifers 433
Bacterial Soft Rots 434
Bacterial soft rots of vegetables 435
Bacterial Galls 438
Crown gall 438
Bacterial Cankers 441
Bacterial canker and gummosis of stone fruit trees 442
Citrus canker 445
Bacterial Scabs 449
Common scab of potato 449
Root Nodules of Legumes 451
Plant Diseases Caused by Fastidious Vascular Bacteria 453
Pierce’s disease of grape 455
Citrus variegated chlorosis 456
Ratoon stunting of sugarcane 456
Plant Diseases Caused by Mollicutes：Phytoplasmas and Spiroplasmas 457
Properties of True Mycoplasmas 457
Phytoplasmas 458
Spiroplasmas 460
Other Organisms That Resemble Mollicutes：L-Forms of Bacteria 462
Examples of Plant Diseases Caused by Mollicutes 462
Aster yellows 462
Lethal yellowing of coconut palms 464
Elm yellows（phloem necrosis） 465
Peach X-disease 465
Pear decline 467
Citrus stubborn disease 467
Corn stunt disease 469
chapter thirteen PLANT DISEASES CAUSED BY PARASITIC HIGHER PLANTS 471
Introduction 471
Dodder 471
Witchweed 473
Broomrapes 475
Dwarf Mistletoes of Conifers 475
True or Leafy Mistletoes 477
chapter fourteen PLANT DISEASES CAUSED BY VIRUSES 479
Introduction 479
Characteristics of Plant Viruses 479
Detection 480
Morphology 480
Composition and Structure 480
Satellite Viruses and Satellite RNAs 484
The Biological Function of Viral Components：Coding 485
Virus Infection and Virus Synthesis 485
Translocation and Distribution of Viruses in Plants 488
Symptoms Caused by Plant Viruses 489
Physiology of Virus-Infected Plants 491
Transmission of Plant Viruses 491
Transmission of Viruses by Vegetative Propagation 492
Mechanical Transmission o f Viruses through Sap 492
Seed Transmission 494
Pollen Transmission 494
Insect Transmission 494
Mite Transmission 495
Nematode Transmission 495
Fungus Transmission 496
Dodder Transmission 496
Epidemiology of Plant Viruses and Viroids 496
Purification of Plant Viruses 497
Serology of Plant Viruses 497
Nomenclature and Classification of Plant Viruses 500
Detection and Identification of Plant Viruses 503
Economic Importance of Plant Viruses 505
Control of Plant Viruses 505
Diseases Caused by Rigid Rod-Shaped Viruses 508
Diseases Caused by Tobamoviruses：Tobacco Mosaic Virus 508
Diseases Caused by Tobraviruses 510
Diseases Caused by Furoviruses 510
Diseases Caused by Hordeiviruses 511
Diseases Caused by Filamentous Viruses 512
Diseases Caused by Potexviruses 512
Diseases Caused by Carlaviruses 512
Diseases Caused by Capilloviruses and Trichoviruses 512
Diseases Caused by Potyviridae 513
Diseases Caused by Potyviruses 513
Bean common mosaic and bean yellow mosaic 515
Lettuce mosaic 515
Papaya ringspot 516
Plum pox 517
Potato virus Y 517
sugarcane mosaic 518
Tobacco etch 518
Turnip mosaic 519
Watermelon mosaic 519
Zucchini yellow mosaic 519
Diseases Caused by Rymoviruses and Bymoviruses 519
Diseases Caused by Closteroviruses 519
Beet yellows 519
Citrus tristeza 519
Lettuce infectious yellows 521
Diseases Caused by Isometric Single-Stranded RNA Viruses 523
Diseases Caused by Waikaviruses 523
Rice tungro 523
Maize chlorotic dwarf 525
Diseases Caused by Luteoviruses 525
Beet western yellows 525
Potato leafroll 525
Barley yellow dwarf 525
Diseases Caused by Comoviridae 527
Diseases Caused by Comoviruses 527
Diseases Caused by Nepoviruses 528
Tomato ring spot 528
Cherry leaf roll 528
Grapevine fanleaf 529
Raspberry yellow dwarf，raspberry ring spot，and raspberry leaf curl 529
Diseases Caused by Brommoviridae 530
Diseases Caused by Cucumoviruses 530
Cucumber mosaic 531
Diseases Caused by Ilarviruses 532
Prunus necrotic ring spot 533
Diseases Caused by Isometric Double-Stranded RNA Viruses 534
Diseases Caused by Reoviridae 536
Diseases Caused by Negative RNA[（一）ssRNA]Viruses 538
Plant Diseases Caused by Rhabdoviruses 538
Plant Diseases Caused by Tospoviruses 539
Plant Diseases Caused by Tenuiviruses 541
Diseases Caused by Double-Stranded DNA Viruses 545
Diseases Caused by Caulimoviruses 545
Diseases Caused by Badnaviruses 546
Diseases Caused by Single-Stranded DNA Viruses 547
Plant Diseases Caused by Geminiviruses 547
Maize streak 551
Beet curly top 551
African cassava mosaic 551
Bean golden mosaic 552
Squash leaf curl 553
Tomato mottle 553
Tomato yellow leaf curl 554
Plant Diseases Caused by Isometric Single-Stranded DNA Viruses 554
Banana bunchy top 555
Viroids 556
Plant Diseases Caused by Viroids 556
Potato spindle tuber 560
Citrus exocortis 560
Coconut cadang-cadang 561
chapter fifteen PLANT DISEASES CAUSED BY NEMATODES 565
Introduction 565
Characteristics of Plant Pathogenic Nematodes 565
Morphology 565
Anatomy 565
Life Cycles 566
Ecology and Spread 566
Classification 568
Isolation of Nematodes 569
Isolation of Nematodes from Soil 569
Isolation of Nematodes from Plant Material 570
Symptoms Caused by Nematodes 571
How Nematodes Affect Plants 571
Interrelationships between Nematodes and Other Plant Pathogens 572
Control of Nematodes 573
Root-Knot Nematodes：Meloidogyne 574
Cyst Nematodes：Heterodera and Globodera 577
Soybean cyst nematode：Heterodera glycines 577
Sugar beet nematode：Heterodera schachtii 579
The Citrus Nematode：Tylenchulus semipenetrans 581
Lesion Nematodes：Pratylenchus 581
The Burrowing Nematode：Radopbolus 583
Stem and Bulb Nematode：Ditylenchus 586
Seed-Gall Nematodes： Anguina 588
Foliar Nematodes：Aphelencboides 590
Pine Wilt and Palm Red Ring Diseases：Bursaphelenchus 592
Pine wilt nematode：Bursaphelenchus xylopbilus 592
Red ring nematode：Bursapbelencus cocopbilus 593
Stubbly-Root Nematodes：Paratricbodorus and Tricbodorus 596
chapter sixteen PLANT DISEASES CAUSED BY FLAGELLATE PROTOZOA 599
Introduction 599
Phloem Necrosis of Coffee 601
Hartrot of Coconut Palms 604
Sudden Wilt （Marchitez）of Oil Palm 604
Empty Root of Cassava 605
Glossary 607
Index 619