SURVEY AND MANAGEMENT OF VIRAL DISEASES IN STRAWBERRY (Fragaria ananassa Duch.) CROPS IN DISTRICT SWAT

Abstract

Strawberry (fragaria ananassa Duch), is among the most important berry fruits, that belongs to the family Rosacea and genus Fragaria. A number of viruses are known to infect strawberry reducing its yield drastically. Field survey was conducted to figure out the status of viral diseases in strawberry crop of district Swat, Khyber Pakhtunkhwa, Pakistan. The survey result revealed the incidence and prevalence of viruses infecting strawberries in district Swat during the growing season 2021-22. Symptoms like mosaic, necrosis, chlorosis, crinkling, reddish discoloration of leaves and petioles were observed in all the strawberry growing areas surveyed. DAS-ELISA results also confirmed the presence of Strawberry latent ring spot virus (SLRSV), Strawberry mild yellow edge virus (SMYEV) and Tomato ring spot virus (ToRSV) in strawberries of district Swat. The highest average disease incidence (14.7 %) was recorded for SLRSV followed by SMYEV and ToRSV (14 % each). In a single field, the highest SLRSV incidence as high as 20.0 % at village Sherpalam tehsil Matta, whereas the least disease incidence was recorded at village Baghderai tehsil Khwaza Khela (11.7 %). Maximum disease incidence of SMYEV in any single area was recorded 16.7 % also at village Sherpalam tehsil Matta followed by 15 % infection at village Baghderai tehsil Khwaza khela, the lowest disease incidence of 11.7 % was recorded at village Duresh khela tehsil Matta. The highest recorded ToRSV disease incidence in single individual area was 16.7 % again at village Sherpalam tehsil Matta whereas the lowest incidence was recorded 11.7 % at Khwaza khela, district Swat. In viral disease management experiment, among the three insecticides used to control aphid vector Butler was comparatively better in controlling the aphid vector and hence the virus transmission. The order to effectiveness of different insecticides in management of viruses was Butler, Actara, and Bolton with highest number of aphids (24.51) and high disease incidence (25.67 %) recorded in control where no insecticide was used. From the data it is concluded that the insecticide butler gives best result against aphids followed by Actara and Bolton.