SURVEY ON RICE BLAST IN SOME SELECTED AREA OF BANGLADESH AND IN VITRO EVALUATION OF SELECTED FUNGICIDES AGAINST PYRICULARIA ORYZAE

Abstract

Survey was conducted on rice blast in 110 rice field of 12 upazillas under 5 districts of Bangladesh namely Mymensingh, Kishoreganj, Barishal, Naogaon and Cumilla. Among the survey Muktagachha, Mymensingh was found the highest blast disease infected area and Bakerganj, Barishal was found the lowest blast disease infected area in Boro season 2017-2018. Pyricularia oryzae was isolated from infected leaf and panicle and identified based on cultural characteristics and conidia morphology. Eight fungicides namely Trooper 75WP, Seltima 100CS, Nativo 75 WP, Amister Top 250 SC, Azonil 56 SC, Autostin 50 WDG, Filia 525 SE, Dithane M-45 were tested for controlling mycelial growth of Pyricularia oryzae in vitro in the Plant Pathology laboratory, Department of Plant Pathology, Sher-e-Bangla Agricultural University, Dhaka-1207. Experiment was conducted in Completely Randomized Design (CRD) with four replications. Data on radial mycelial growth was taken at 7, 14 and 21 days after inoculation (DAI). The highest inhibition of mycelial growth was observed when Potato Sucrose Agar (PSA) was amended with Trooper 75 WP (Tricyclazole) followed by Filia and Nativo and lowest inhibition was recorded in Dithane M-45(Mancozeb) amended with PSA media. From these results Trooper (Tricyclazole) was found to be the best effective fungicide and is needed to further field evaluation for confirmation of the result.