Compost Tea for Managing Soil-Borne Plant Pathogens in Vegetable Crops: A Field Evaluation

Abstract

Soil-borne plant pathogens pose a persistent challenge to sustainable vegetable crop production, leading to significant yield losses and environmental concerns due to overreliance on chemical pesticides. This study investigates the efficacy of compost tea, enriched with Trichoderma spp. and chitin, as a biocontrol solution for managing soil-borne diseases in tomatoes and capsicum under field conditions. Using a randomized complete block design, treatments included compost tea alone, compost tea with additives, chemical pesticides, and an untreated control. Results demonstrated a substantial reduction in disease incidence for Fusarium wilt, Phytophthora root rot, and Rhizoctonia damping-off, with the combined compost tea treatment achieving the lowest disease rates (as low as 9.6%). Soil microbial biomass and enzyme activities (dehydrogenase and chitinase) were significantly enhanced in biologically treated plots, suggesting improved soil health. Yield and biomass measurements showed that crops treated with compost tea and additives outperformed those in control and chemically treated plots, with increases of up to 90% in crop yield and 75% in belowground biomass. Nutrient uptake of nitrogen, phosphorus, and potassium was also markedly improved. Furthermore, qRT-PCR analysis revealed upregulation of key defense-related genes (PR1, PAL, and CHS), indicating the activation of induced systemic resistance in plants. A composite soil quality index confirmed the long-term ecological benefits of compost tea application. These findings confirm the potential of compost tea, especially when combined with microbial and organic additives, to serve as a sustainable and effective alternative to chemical pesticides for managing soil-borne diseases while simultaneously enhancing plant productivity and soil health. The study supports the integration of compost tea into holistic, eco-friendly crop management practices suitable for diverse agricultural systems.