13 Plant Diseases Caused by Nematodes 13.1 Introduction 13.2 The Development of Nematology and Recognition of its Economic lmportance 13.3 The Nature of Disease 13.4 Plant Diseases Caused by Nematodes 13.5 Root Gall Forming Species 13.6 Species that Cause Gall and Lesion Formation on Stems,Leaves,and Seeds 14 Virus Vectors 14.1 Introduction 14.2 Historical Background 14.3 The Vector Nematodes and Their Feeding Processes 14.4 The Nematode-transmitted Viruses 14.5 Transmission Crteria and Procedures 14.6 Vector and Virus Associations 14.7 Geographical Distribution 14.8 Persistence of Nematode Populations and Viruses 14.9 Virus and Vector lnteractions 14.10 Vector-virus lnteractions lnvolved in Vector 15 Physiological lnteractions between Nematodes and Their Host Plants 16 Taxonomy of lnsect Parasitic Nematodes 17 Resistance to Plant-parasitic Nematodes 18 Crop Rotation and Other Cultural Practices 19 Use of Antagonistic Plants and Natural Products 20 Biological Control of Nematodes by Fungal Antagonists 21 Biological Control of Nematodes with Bacterial 22 Biological Control of lnsects and 0ther lnvertebrates 23 Cost-benefits of Nematode Management through Regulatory Programs 24 Nematicides:Past and Present Uses 25 lrradiation Effects on Plant-parasitic Nematodes Index