Serological evidence of mixed infection of major apple viruses in wet and dry temperate zone of himachal Pradesh

Apple cultivation has revolutionized the socio-economic status of farmers in temperate zone of himachal Pradesh, the productivity is, however, very low (4.18 Mt/ha). among various factors, diseases play an important role in hampering productivity of apple. Virus and virus like diseases need greater attention for being the systemic in nature and they pass to successive generations through clonal propagation. during present studies, virus disease incidence was recorded as high as 80.00 per cent in 45 orchards surveyed in five blocks of Shimla district falling in wet temperate zone and 3.33 to 40.00 per cent among 39 orchards surveyed in dry temperate zone. Maximum incidence (80.0%) was recorded in Lambidhar village, followed by Fagu village (70.27%) of Mashobra block. ALP based DAC-ELISA conducted against four viruses revealed mixed infection in different varieties and was found to be positive for all four viruses i.e. ASGV, ApMV, ACLSV, ASPV in Royal Delicious, Red Gold, Super chief, Washington red delicious. Whereas, red chief, Oregon spur II, scarlet spur and top red showed positive reaction against three viruses except against ApMV. Golden Delicious has shown positive reaction for three viruses except for ASPV. DAS-ELISA was also done for the samples from selected orchards to confirm the presence of the viruses. Royal Delicious and Golden Delicious have shown presence of all the viruses, whereas, ASGV was found invariably in all the samples tested except in scarlet Gala and Oregon spur II.