IN-VITRO EVALUATION OF PLANT EXTRACTS FOR THE MANAGEMENT OF BLACK LEG OF POTATO

Potato crop is facing serious threat due to blackleg disease caused by Pectobacterium atrosepticum. For pathogen isolation and identification, diseased samples were collected, processed and confirmed through Koch’s postulates, gram staining, KOH test and Potato tuber assay. Nine plants extracts P. guajava (Guava), P. granatum (Pomegranate), S. pinnata (Plum), S. cumini (Kalajam), M. indica (Mango), T. indica, L.chinensis (Litchi), V.amurensis (Grapes) and C. verum (Cinnamon) were evaluated against Pa by using inhibition zone technique under Completely Randomized Design (CRD). Maximum inhibition zone was measured by S. cumini (7.640 mm?) followed by C. verunn (6.566), C. vinifera (4.159), T. indica (3.437), P. granatum (2.918), p.guajava (2.844), S. pinata (2.751), M. indica (2.344), L. chinensis (2.251) as compared to control, respectively. Interaction between treatments and concentrations indicated that C1 concentration of S. cumini (6.955) expressed maximum inhibition zone as compared to C. verunn (5.177), C. vinifera (3.177), T. indica (3.288), P. granatum (1.844), p.guajava (2.066), S. piñata (2.288), M. indica (1.066), L. chinensis (1.733) mm while C2 concentration of S. cumini (7.455) also expressed maximum inhibition zone followed by C. verunn (7.177), C. vinifera (4.122), T. indica (3.344), P. granatum (3.344), p.guajava (2.677), S. piñata (3.344), M. indica (2.733), L. chinensis (2.344) mm and at C3 concentration exhibited 8.511,7.344, 5.177, 3.677, 3.566, 3.788, 3.400, 3.566, 2.677mm inhibition zone of treatments as compared to control respectively. While interaction between treatments and hours showed that S. cumini (6.844, 7.622, 8.455) exhibited maximum inhibition zone and L. chinensis (1.566, 2.233, 2.955) expressed minimum inhibition zone at H1, H2 and H3 as compared to control respectively.