Eco-friendly Management of Blast Disease in Aromatic Rice by Formulated Antagonistic Fluorescent Pseudomonads under Natural Epiphytotic Condition

Abstract

The experiment was conducted in the field of Central Farming System (CFS) of Bangladesh Agricultural University under natural epiphytotic condition to evaluate the performances of formulated biopesticides comprising rhizopheric fluorescent Pseudomonads in aromatic rice plants cv. Kalizira. Antagonistic Pseudomonas fluorescens (BdPf) formulated in different carrier materials viz. talc, bentonite, palm oil, coconut oil and glycerin were applied for disease management. Root dipping of seedlings followed by foliar application with bacterial suspension at three stages of rice plants was done in order to reduce incidence and severity of blast disease. Disease incidence and severity were recorded at 30, 60 and 90 days after transplanting (DAT). Among 15 treatment combinations (T1 = 10% BdPf-6 talc, T2 = 10% BdPf-6 bentonite, T3 = 1% BdPf-6 palm oil, T4 = 1% BdPf6 coconut oil, T5 = 1% BdPf-6 glycerin, T6 = 10% BdPf-7 talc, T7 = 10% BdPf-7 bentonite, T8 = 1% BdPf-7 palm oil, T9 = 1% BdPf-7 coconut oil, T10 = 1% BdPf-7 glycerin,T11 = 10% BdPf-8 talc, T12 = 10% BdPf-8 bentonite, T13 = 1% BdPf-8 palm oil, T14 = 1% BdPf-8 coconut oil, T15 = 1% BdPf-8 glycerin), application of Pseudomonas fluorescens-8 (BdPf-8) formulated in talc (T11) and bentonite (T12) on the foliage significantly increased the vegetative, yield parameters, Benefit Cost Ratio (BCR) and reduced blast incidence and severity over control at every growth stage. Treatments T11 (10% BdPf-8 talc) and T12 (10% BdPf-8 bentonite) also gave the highest yield 2.56 t/ha and 2.50 t/ha with highest BCR 1.88 and 1.84 respectively. So, these findings reveal that biopesticide formulated with fluorescent Pseudomonads (BdPf-8) in talc and bentonite can be applied in the field for effective management of blast disease in aromatic rice