In Vitro Suppressive Effect of Agriculture Residues and Municipal Solid Wastes Compost Tea on some Phytopathogenic Fungi

Abstract

Aerated Compost Tea (ACT) prepared from four types of compost; Agricultural Residues(AR), Agricultural Residues enriched with Olive Pomace (AR+OP), Municipal Solid Wastes (MSW) and Municipal Solid Wastes enriched with OP(MSW+OP) in combination with bioagents have been analytically characterized and were tested for their antagonistic activity in vitro against Fusarium oxysporum and Rhizoctonia solani pathogens in comparison with the commercial chemical fungicides (Rhizolex-T). Assessment was carried out in terms of percent mycelial growth inhibition as well as Scanning Electron Microscopy (SEM) were used to explain the mode of action in the biological control of the pathogens under study. From the resultsall compost teas showed high levels of nutrients and microbial biomass content. The mixed treatment of compost tea gave the highest percent inhibition compared with individually treatments. AR compost tea+ Olive Pomace (OP)+ Microorganisms (MO) were significantly superior to the rest treatments showed 63.52% and 44.07% percent inhibition, same trend was detected with MSW+ Olive Pomace (OP)+ Microorganisms (MO) showing 57.41% and 43.89% against Rhizoctonia solani andFusarium oxysporumrespectively. SEM of tested pathogen mycelium removed from the confrontation zone showed aberrant morphology such as shrinkage, curling,mycelium asymmetry, partial distortions and lysis of fungal mycelium. In conclusion, these results provide evidence that the compost extract has the potential to become a good candidate for biological control as potential alternatives to the application of synthetic fungicides, and as plant promoters in crop production, for attaining environmental sustainability for farming and food safety.