This book brings together recent scientific contributions exploring the intersections of plant health, natural bioactive compounds, sustainable innovations in agricultural systems, and resource valorization. Divided into two focused sections: Phytochemicals and Essential Oils - Exploring Bioactivity in Plant Pathology and Fungal Diversity, and Biotechnological Advances in Agriculture and Resource Valorization, this book presents original scientific articles that detail practical approaches and findings from recent research. Seamlessly integrating traditional knowledge with recent advances in phytochemistry, microbiology, and biotechnology, this book is a valuable resource for teachers, researchers, agronomists, and students within academic and research institutions. Addressing key topics such as essential oils with antimicrobial potential, plant disease management, phytoplankton dynamics, and the valorization of agricultural and natural resources, it offers practical insights that contribute meaningfully to scientific knowledge and sustainable agricultural innovation.