A thorough examination of the vital role plant health plays in guaranteeing global food security can be found in Plant Diseases and Food Security throughout the 21st Century. This book explores the complex link that exists between plant diseases & agricultural output, emphasizing the ways that new pathogens and shifting environmental circumstances pose a global danger to food supply. The book is organized to provide readers a thorough grasp of a variety of plant pathology topics, such as past outbreaks, present difficulties, and potential future developments. An introduction to the main categories of plant pathogens, including nematodes, bacteria, viruses, and fungus, is given at the outset. The book also discusses cutting-edge molecular tools, remote sensing technologies, and conventional methods of diagnosis, highlighting their significance for early illness identification and efficient treatment. Subsequent chapters cover the introduction of novel infections, adaptation and mitigation techniques, and the influence of climate change on disease dynamics. In order to create crops resistant to disease, the book also examines genetic engineering, CRISPR technology, and integrated pest management. This book, which is intended for scholars, students, and politicians, emphasizes the need for a multidisciplinary strategy to protect crops and ensure the world’s food supply. It emphasizes how crucial global collaboration and environmentally friendly farming methods are to preventing plant diseases and guaranteeing food security in the twenty-first century.