DEGENERATION OF POTATO VARIETIES DUE TO VIRUS INCIDENCE IN NORTH GUJARAT

The physiological causes and viral disease infections are the two main reasons for potato degeneration. Theseed potato infected with viral diseases degenerate in the following successive generations therefore the investigation wascarried out to evaluate the most popular potato varieties of Gujarat i.e. K. Badshah and K. Khyati against viruses (PLRV,mild mosaic & severe mosaic) and their subsequent degenerative effects on yield with comparison to fresh breeder seed.The three treatments viz., T1: Fresh breeder seed every year, T2: Previous seed produce using seed plot technique, T3:Previous seed produce without seed plot technique were evaluated. The studies were conducted for four consecutive yearsduring rabi 2017-2021. The results revealed significantly higher per cent plant emergence at 40 DAP was recorded in T1(Fresh breeder seed every year) and T2 (Previous seed produce using seed plot techniques) in all years as compared to T3(Previous seed produce without seed plot techniques). The per cent incidence of viral diseases at 75 DAP was recordedhighest (mild mosaic:16.67 %, severe mosaic: 17.67 and PLRV 21.83 in last year) in T3 i.e. Previous seed produce withoutseed plot techniques. Comparatively lower per cent incidence of viral diseases (mild mosaic:10.67 %, severe mosaic: 7.33 andPLRV 13.33 in last year) was recorded in T2 i.e. Previous seed produce using seed plot techniques and the least incidenceof viral diseases (Mild mosaic:1.83 %, Severe mosaic: 1.67 and PLRV 1.67 in last year) was recorded in T1 i.e. Fresh breederseed every year. The total tuber yield was higher in first two year in breeder as well as SPT raised seed. In Successiveyears the SPT raised seed tuber yield decrease. So, based on results it is concluded that seed producer can produce qualityseed tuber from breeder seed up to three consecutive years by using “Seed Plot Technique”.