Effect of Pseudomonas fluorescens, Organic Amendments and Botanicals against Fusarium culmorum on Black Turmeric (Curcuma caesia)

Rhizome rot is a soil-borne disease that severely affects black turmeric and is caused by Fusarium culmorum. An experiment was conducted at the Department of Plant Pathology in SHUATS, Prayagraj, to evaluate the effectiveness of Pseudomonas fluorescens, organic amendments, and botanicals against Fusarium culmorum. The experiment was carried out in the kharif season of 2022-2023, and various soil treatments were used, such as farmyard manure (FYM), spent mushroom compost (SMC), mustard cake, and neem cake. Pseudomonas fluorescens was used as a rhizome treatment. The results showed that the combination of all treatments (T9) had the least disease incidence (16.35%) compared to other treatments and the control (T0) (44.27%). To assess the radial growth of Fusarium culmorum on black turmeric, seven different botanicals from Manipur were tested at concentrations of 10% and 30%. These botanicals were Ageratina adenophora, Bidens pilosa, Centella asiatica, Plantago major, Strobilanthes crispus, Saurauia napaulensis, and Artemesia vulgaris. The antagonistic effect of these botanicals was evaluated in vitro, and the results indicate that the most significant reduction in biomass was observed with Ageratina adenophora at a 30% concentration, which showed a 78.5% inhibition rate with a radial growth of 2.66 cm. This was followed by Artemesia vulgaris, which exhibited a 75.3% inhibition rate with a radial growth of 3.16 cm compared to the control and other botanicals tested.