Management of late blight of potato through fungicide scheduling

Abstract

Late blight of potato caused by oomycetes pathogen Phytophthora infestans, is a disease of major concern
all over the world responsible for 20-75 % yield loss. For more than a decade, management of late blight has become
increasingly demanding because of emergence of aggressive and more resistant new strains of the pathogen. In present
studies, potential management of late blight has been studied with a view to develop an effective and safe spray schedule
for management of late blight of potato. Results revealed that minimum disease intensity and disease incidence were
reported from prophylactic spray with fungicide Chlorothalonil 75 % WP @ 0.25 % followed by Dimethomorph 9 % +
Mancozeb 60 % WP @ 0.3 % and one more spray with Chlorothalonil 75 % WP @ 0.25 % treated plots. Minimum tuber
yield was reported from control plots while maximum tuber yield (42.60 t/ha in K.Khyati and 34.50 t/ha in K.Bahar) were
also recorded from the same treatment i.e. treatment Chlorothalonil 75 % WP @ 0.25 % followed by Dimethomorph 9 %
+ Mancozeb 60 % WP @ 0.3 % and one more spray with Chlorothalonil 75 % WP @ 0.25 %. This treatment proved as
the best fungicide scheduling treatment for management of late blight of potato by providing the maximum returns and
highest B:C ratio.