Citrus is one of the major irrigated fruit crops in world. Shortage of irrigation water in critical growth stages not only reduces fruit yield but causes citrus decline. Deficit irrigation with drip system is one of the viable water management techniques to sustain fruit yield with higher water use efficiency and improved fruit quality in citrus. This book will give an insight knowledge of citrus tree response to deficit irrigation and guide the researchers, irrigation managers and students to do further research on citrus water management.