SCREENING OF RESISTANT CULTIVARS OF BETELVINE (Piper betle L.) AGAINST FOOT AND ROOT ROT DISEASE CAUSED BY Sclerotium rolfsii

Abstract

The causal organism of foot and root rot disease was isolated from diseased specimen with typical symptoms collected from affected betelvine. The isolate was pure cultured and identified as Sclerotium rolfsii The Sclerotium rolfsii was mass multiplied and the pathogenicity was confirmed by Koch’s Postulates. Eight betelvine cultivars viz. PB 001 (Chalitaguti) PB 002 (Chuadanga Pan), PB 003 PB (Moheskhali Pan), 004 (Laldingi Pan), PB 005 (Satkhira Pan), PB 006 (BARI Pan-1), PB 007 (BARI Pan-2) and PB 008 (BARI Pan-3), were explored in the screening experiment. Results were compiled based on physio-morphological features, days required for appearance of 1 st disease symptom, disease reactions, yield and yield contributing characters Betelvine cultivars were showed differential reactions against S. rolfsii causing foot and root rot disease. The vegetative growth parameters and morphological features of different cultivars of betelvine varied remarkably. The maximum vine increment per month (90.97 cm) was recorded in PB 003 and the lowest increment (46.87 cm) was in PB 006. The maximum length of internode (8.27 cm) was recorded in PB 004 and the minimum length (4.50 cm) was in PB 006. The maximum vine girth (1.63 cm) was recorded in PB 007 and the minimum girth (0.93 cm) was in PB 002. Significantly the highest length of leaf (22.07 cm) was recorded in PB 005 and the lowest (13.17 cm) was in PB 006. The leaf breadth (13.03 cm) was recorded the highest in PB 003 and the lowest (6.93 cm) in PB 006. The highest petiole length (8.63 cm) was recorded in PB 008 and the lowest length (4.03 cm) was in PB 002. The petiole breadth (1.13cm) was recorded the highest in PB 004 and the lowest (0.43 cm) in PB 008. The weight (g) of 100 petiole was recorded the highest in PB 004 (83.33 g) and the lowest weight (38.33 g) was in PB 006.The fresh weight of 100 leaves with petiole was recorded the highest in PB 004 (553.33 g) and the lowest weight (206.67 g) was in PB 006. The PB 006 produced significantly the highest number (23.00) of leaves per meter vine and the lowest number (13.67) of leaf was recorded in PB 003. The leaf number per plant per year was recorded the highest in PB 006 (414 leaves) and the lowest number was found in PB 003 (282 leaves). After inoculation, the time interval (days) required for appearance of 1 st disease symptoms among the betelvine cultivar differed significantly. The lowest incubation period (8 days) required for the cultivars PB 007 (BARI Pan-2) and PB 008 (BARI Pan-3). The highest incubation period (14 days) was required for PB 006 (BARI Pan-1). No symptom was appeared in the cultivars PB 004 (Laldingi pan). The disease incidence ranged from 0.00% - 100%. Among the betelvine cultivars, PB 004, (Laldingi pan) showed resistant (R) reaction while three cultivars viz. PB 006 (BARI Pan-1), PB-003 Moheskhali Pan) and PB 002 (Chuadanga) showed moderately resistant (MR) reaction. Two cultivars viz. PB 001 (Chalitaguti) and PB 005 (Satkhira) showed moderately susceptible (MS) reaction and the rest cultivars PB 007 (BARI Pan-2) and PB 002 (BARI Pan-3) showed highly susceptible reaction against S. rolfsii causing foot and root rot of betelvine.