Stefania De Pascale is Professor of Horticulture at the University of Naples Federico II. She is Chair of the ISHS Division Protected Cultivation and Soilless Culture and is on the editorial boards of a number of journals. Professor De Pascale is a leading authority on nutrient and water management of horticultural and ornamental crops. Youssef Rouphael is an Associate Professor at the University of Naples Federico II, Italy. He is Editor-in-Chief of Agronomy MDPI and has been a guest editor on biostimulants in several International Journals (Scientia Horticulturae, Frontiers in Plant Science and Agronomy MDPI). He is a member of the scientific committee of Biostimulant.com. He is internationally-known for his research in horticultural science.