Biopesticidal Activity for Controlling Root Rot and Root Knot Infection of Green Beans under Natural Field Conditions Utilizing Biowastes

The current study investigates using of alkaline black liquor (ABL), a byproduct of rice straw pulping, to create a bio-active formulation that can inhibit the growth of soilborne plant pathogens. ABL was first treated to precipitate lignin, silica, and fatty acids as a calcium complex (Ca-LSF). The resulting effluent was used to digest chicken feathers under mild conditions. The resulting protein hydrolysate was added to Ca-LSF complex affording a novel formulation to be evaluated against soilborne pathogenic fungi Fusarium oxysporum , Fusarium solani , Rhizoctonia solani , and Sclerotium rolfsii , as well as the nematode Meloidogyne incognita , the causal organisms of wilt, root rot and root knot diseases. The prepared formulation showed strong inhibitory effect against R. solani and affected viability of M. incognita . This effect increased with increasing concentration, up to 4%, which completely inhibited fungal growth. It was also examined under field conditions, where it reduced root rot and root knot infection. Application of this formulation as seed dressing showed higher efficacy against root rot and root knot infection than its soil drench treatment, although both treatments were superior to untreated control. The presented safe, cost-effective, and eco-friendly formulation could be used to control a wide range of soilborne plant pathogens.