This book contains all the basic info related to potato diseases mainly viral problem. Some other crops are also discussed with pathological point of view. Fundamental research was performed on Potato Viruses (PVs) with different analytic ways including ELISA Test.Out of 26 varieties/lines during 2013-2014 there was no line found to exhibit high resistance against potato virus S. The results suggested that out of twenty six varieties/lines during 2013-2014, seventeen varieties/lines Cardinal, SH-5, Astrix, FD 35-36, FD 69-1, FD 69-2, Lady Roseta, Crusier, 393574-61, 391202-158, 396240-21,...