The results of the molecular diagnosis by PCR and Rt PCR techniques showed the presence of Potato leafroll virus Polerovirus (PLRV) and this was also confirmed by molecular detection of its protein coat gene CP2 in the fields of Al-Alam, Samarra, Balad and the field of study, in addition to the Alfamovirus Alfalfa Mosaic Virus (AMV), which showed The results of the molecular diagnosis and its presence in the fields of Dujail district. The results indicated that there was a noticeable difference between the treatments in the percentage of viral infection as it was found that the superiority was significant for the treatment of the algae A. circinalis and N. commune at the first dilution over the rest of the experimental treatments, as the percentage of viral infection in this treatment was at the lowest level and It reached 6.61%, as for the cultivars, the Burin cultivar was significantly superior to all the cultivars included in the experiment by showing the lowest rate of viral infection rate of 27.69% compared to the Arizona variety, which gave the highest infection rate of 40.01%.