UPSC IAS Agriculture Books References

Exam Suggested Reading for Preliminary

 Agronomy By Yellamananda Reddy
 Soil Science - D.K Das Or Brady
 Plant Breeding By B.D. Singh
 Genetics By B.D.Singh
 Physiology By Pandey & Singha
 Indroduction To Horticulture - Kumar
 Handbook Of Agriculture By ICAR
 Agricultural Economics and Farm Management
 Agricultural Extension Education in India

Suggested Reading for Mains
In addition to the books listed above:

 Pathology - Singh
 Entomology - Vasantha Raj & David
 The Hindu - Survey Of Indian Agriculture
 Agricuture Statistics - Dept. of Agri. and coop. statistics at a glance - http://www.agricoop.nic.in