Effectivity of different fungicides against foliar leaf spot pathogens of poplar under in-vitro and in-vivo conditions

: The incidence of leaf spots of Drechslera specifera and Curvularia lunata during April-June was observed to the extent of 72.68 to 88.55 and 11.45 to 27.32 per cent, respectively, whereas, Alternaria and Cercospora leaf spots were absent. The disease incidence of Alternaria alternata was maximum in the month of July-September ranging 19.11 to 29.23 per cent and that of Cercospora populina was higher in October-November than July-September being 18.60 to 28.70 per cent. In vitro testing of five fungicides namely Dithane M-45, Kavach, Blitox-50, Bayleton and Bavistin against D. specifera, C. lunata and A. alternata revealed Dithane M-45 to be most effective, whereas, Bayleton and Bavistin were least effective against all these fungi. The in vivo testing of fungicides in nursery proved Dithane M-45 at 0.20 per cent concentration best against D. specifera, C. lunata, A. alternata and C. populina as it totally inhibited the disease under field condition. Next effective fungicides were Kavach and Blitox-50, however, Bayleton and Bavistin were least effective