Efficacy of Pseudomonas fluorescens and Organic Amendments Against Black Root Rot Disease Caused by Rhizoctonia solani in strawberry (Fragaria x ananassa Duch.)

Black root rot of strawberry caused by Rhizoctonia solani is one of the devastating soil borne disease. An experiment was conducted to evaluate the efficacy of organic amendments, PGPR (Pseudomonas fluorescens) and botanical treatment for the management of R. solani on strawberry. The study was laid out in Randomized Block design (RBD) including 4 replications with 8 treatments in pot condition at the greenhouse of Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh, during Rabi season 2023 - 2024. The treatments consisted of combination of FYM, vermicompost, biomix compost, neem cake, cocopeat and botanical neem leaf extract were used as soil amendments and P. fluorescens as root treatment for evaluation on the plant growth, yield, physicochemical parameters (TSS and total ascorbic acid), disease intensity (%) and benefit cost ratio of strawberry. The present investigation results revealed that T7 – P. fluorescens (0.3%) + FYM @ 100g + biomix compost @ 15g + vermicompost @ 15g + neem leaf extract @10% had the most promising results in term of maximum plant height (14.9 cm), maximum leaf number(15.75), days taken to first flowering (86 days), berry length (4.08 cm), berry diameter (2.84 cm), yield (38.87 qha-1), TSS (8.80 °Brix), total ascorbic acid (51.60mg/100g) and B:C ratio (1:2.24). It was also observed that T7 superior over other treatments giving least per cent disease intensity (30.75 %) followed by T6 – FYM @1 00g + P. fluorescens (0.3%) + biomix compost @15g + neem cake @15g + neem leaf extract @10% (35.50%). These findings highlight the potential of organic amendments, PGPR (P. fluorescens) and botanical treatments, as effective alternatives for managing black root rot disease caused by R. solani in strawberry cultivation.