Various biotic stresses in cotton cause yield loss.  Among them, diseases take a heavy toll.  The cotton crop remains in the field for nearly six months or more. It is affected by more than sixty diseases and some of them are destructive causing huge crop loss. However, the disease scenario in cotton has gone through a continuous change during the past six decades.  Some diseases once considered major are now restricted to occasional incidence and vice versa. Presently more than 90% of the cotton cultivation in India comes under Bt-cotton. With the changes in cultivation profile i.e., cultivation of Bt-cotton, an array of new insects and diseases are observed accounting for profound crop loss. The whitefly vectored cotton leaf curl disease came to prominence causing two to three epidemics in the north zone in the last two decades.  Para wilt, once considered a minor disease became dangerous with