Hazelnut is the nut of the hazel and therefore includes any of the nuts deriving from species of the genus Corylus, especially the nuts of the species Corylus avellana. It is also known as cobnut or filbert nut according to species.
It is the second most expensive nut and needs cold and hilly terrain with a few days of sub-zero temperature. Therefore, Himachal Pradesh and Jammu and Kashmir, Silguri, Utrakhand & North-East states and other cool areas make the best choice in India. It takes three to five years for hazelnut plants to grow and yield fruit.
4 varaties availability : Tonda Gentile delle Langhe,Tonda de Romana, Tonda di Giffoni & Corylus cashmeriana
More details: http://jkmpic.blogspot.com/2017/03/hazelnut-cultivation-in-india.html