Ecofriendly method for suppressing damping-off disease caused by Rhizoctonia solani using compost tea

Abstract

Compost tea has a lot of potential for sustainable agriculture. The suppressive effect of compost tea on damping-off disease in beans (Phaseolus vulgaris), caused by Rhizoctonia solani, was investigated. The physicochemical properties of the tested compost tea showed the presence of dissolved solids (7070 mgL-1), organic matter (1280 mgL-1), nitrate (3840 mgL-1), and ammonium (90.0 mgL-1). The concentrations of phosphorus, potassium, calcium, and magnesium in compost tea were 22.7, 1540, 214, and 2.40 mgL-1, respectively. The highest inhibition of R. solani growth at a concentration of 30% compost tea filtrate was 87.0% and it was completely inhibited at a concentration of 50%. The application of compost tea or chemical fungicide (Rizolex-T) significantly decreased the pre- and post-emergence of damping-off and enhanced the plants survival. In spite of the total phenol content in bean plants infected with R. solani (15.6 µg·g-1 fresh weight), the treatment of infected plants using compost tea and the Rizolex-T caused further elevation in the phenol content, to 17.5 and 14.7 µg·g-1 fresh weight, respectively. These findings support the use of compost tea as a potential alternative to synthetic fungicides to help achieve environmental sustainability and food safety in farming.