During the last decade biological science has experienced an era of unprecedented progress particularly in the field of plant physiology and so is true with physiology of fruit plants. Hence, the authors have thought of making an attempt to write this book entitled ???Fruit Tree Physiology???. However, there is dearth of books related to the basic concepts of plant physiology vis-a-vis fruit growing. Fruit physiology is a complex and dynamic subject who needs simplified form, so that the students pursuing bachelors or masters in fruit science could understand easily. Enrichment of student's knowledge base and to provide up-to-date information to the researchers has been our main objective. There are some of the reasons which have prompted us to write this book and we hope it will help in furthering the knowledge about fruit tree physiology. The book has been designed with the main consideration to serve a dual purpose of being a text and a reference. The entire book contains 12 pertinent topics including: Bud dormancy, Chilling requirement in fruit crops, Heat units and thermoperiodism in fruit crops, Physiology of flowering in horticultural crops, Fruit growth and development; Unfruitfulness in fruit crops-causes and control measures, Alternate bearing in fruit plants-causes and management, Parthenocarpy-a mechanism for seedlessness, Graft incompatibility-Causes and remedial measures, Physiology of dwarfism in fruit plants, Fruit Ripening-Biochemistry, physiology and regulation, and Abscission in fruit plant.About the Author Dr. Wasakha Singh Dhillon has contributed significantly in the field of education, who guided under graduate as class in charge and post-graduate students as major advisor. He had been actively involved in the restructuring of UG and PG course curriculum of horticulture, and prepared five practical manuals. Dr. Dhillon has also made remarkable contributions in horticulture research in the field of crop improvement, plant propagation, agro-horti-techniques and post-harvest technology. His scientific contributions led to the development of 10 varieties, 1 rootstock and 25 recommendations on different fruit crops, which are included in the Package of Practices for Fruit Crops of Punjab Agricultural University (PAU), Ludhiana. He was Principal Investigator of 3 adhoc research projects, edited 3 books and has published 116 research papers, 15 book chapters, 2 review papers and 1 technical bulletin. His achievements in teaching and research have been recognized as he was awarded Shri G L Chadha Memorial Gold Medal (2006) and Fellowship (2007) by Horticultural Society of India, and Shri Hans Raj Pahwa Award (2006) by PAU. He has also been selected for Meritorious Teacher Award (2010) ad SGS Nihal Singh Wala Best Teacher Award of the University.Z. A. Bhat is a Scientist in the Department of Pomology, Shere-e-Kashmir University of Agricultural Sciences and Technology (K)-Srinagar. He graduated from TNAU and post graduated from AMGRAU-Hyderabad and remained topper in PG (Hort.). He has worked on new generation growth regulators (Brassinosteroids and CPPU), revival of Ambri apple, canpy management, survey and selection in Ambri-an indigenous apple cultivator presently at the verge of its extinction. His current reseach is on transgenic and molecular approaches in fruit crops. Bhat is recipient of certificate of merit of PG; fellowship from Indian Council of Agricultural Research (ICAR-JRF); qualified NET and Kashmir Administrative Service-KAS (Mains-2004). He has many national and international publications to his credit.