EVALUATION OF BETEL VINE CULTIVARS AGAINST SCLEROTIUM ROLFSII CAUSING FOOT AND ROOT ROT DISEASE

Abstract

A study was conducted at the Central Farm and at the Plant Pathology Laboratory of Sher-e-Bangla Agricultural University, Dhaka-1207 from July/2021 to June/2022 to isolate, identify and conduct pathogenicity test of the isolated organism and to screen out resistant cultivar(s) of betel vine against Sclerotium rolfsii causing foot and root rot disease. The causal organism of foot and root rot disease was isolated from infected root samples and identified as Sclerotium rolfsii. It was mass multiplied in barley grains and its pathogenicity was confirmed by Koch’s Postulates. Nine different cultivars of betel vine viz. ChL-01 (Chuadanga Local), MoL-02 (Moheskhali Local), KiL-03 (Kishoreganj Local), SaL-04 (Satkhira Local), CuL-05 (Cumilla Local), RaL-06 (Rajshahi Local), BP07

(BARI Pan-1), BP-08 (BARI Pan-2) and BP-09 (BARI Pan-3) were evaluated against Sclerotium rolfsii by screening experiment. The results were compiled based on physio-morphological features, days required for the visual expression of mycelial growth on soil surface, days required for the appearance of 1 disease symptom, disease reactions, yield and yield contributing characters. The vegetative growth parameters and morphological features of different cultivars of betel vine varied significantly to some extent. After inoculation, the days required for the appearance of mycelial growth on soil varied noticeably. The lowest 3 days were required for Satkhira Local, BARI Pan-2 and BARI Pan-3 and the highest 10 days were required for Rajshahi Local. No mycelial growth was seen on soil in Kishoreganj Local. The appearance of 1 st disease symptoms among the betel vine cultivars differed significantly. The highest incubation period (18 days) was found in Rajshahi Local and the lowest (4 days) was found in BARI Pan-2 and BARI Pan-3. No disease symptom was noticed in Kishoreganj Local. The disease incidence ranged from 0%-100%. Among the betel vine cultivars, Kishoreganj Local showed resistant reactions while three cultivars viz. Chuadanga Local, Rajshahi Local and BARI Pan-1 showed moderately resistant reactions. Other three cultivars viz. Moheskhali Local, Satkhira Local and Cumilla Local showed moderately susceptible reactions and the rest two cultivars viz. BARI Pan-2 and BARI Pan-3 showed highly susceptible reactions against Sclerotium rolfsii causing foot and root rot disease of betel vine. CFU/gram soil was observed the highest (3.04x10 6 ) in BARI Pan-3 and the lowest (0.06x10 6 st ) in Kishoreganj Local.