Disease status of Alternaria blotch of apple in Himachal Pradesh, India

Abstract

Apple is one of the most important fruit crops of Himachal Pradesh and the economy of the state primarily depends upon this remunerative crop. Alternaria alternata f.sp. mali causes huge loss by infecting leaves and fruits. It infects mainly leaves (upto 50 to 60%) but sometimes fruits may also get infected. Leaf spot infection started early in the season which leads to premature defoliation. The fungus causes leaf spots which enlarge in zonate, circular or crescent shaped rings. Every season the crop is suffered from Alternaria leaf blotch in wet climate and has been appearing in moderate to severe form in different apple growing areas of Shimla district of Himachal Pradesh. The disease incidence and disease severity varied between 11.00 to 50.00 per cent and 6.20 to 25.90 per cent, respectively for two consecutive years 2015 and 2016.