Integrating beneficial microorganisms and soil amendment for grapevine health: toward eco-friendly seasonal fungal disease management and soil improvement

This study evaluates the effectiveness of two biological agents, Trichoderma longibrachiatum and Pseudomonas yamanorum , together with compost addition. The results show that combining compost with the microbial consortium enhances the physicochemical properties of the soil by increasing nitrogen, carbon, and organic matter while reducing bulk density and nitrate levels. Furthermore, this combination stimulates plant defense mechanisms, leading to increased antioxidant enzyme activity and higher phenolic compound levels. The amendments also improved critical soil properties, increasing organic matter (up to 4.14%), organic carbon (up to 2.40%), and total nitrogen (up to 1.47 mg/g), suggesting that these effects may be linked to the richness of microorganisms in the compost. The combined treatments also reduced the symptoms of fungal diseases: the severity of Botrytis cinerea decreased from 82%–92% to 4.97%–7.71%; Erysiphe necator from 89%–95% to 2.34%–8.03%; and Plasmopara viticola from 70%–95% to 2.84%–5.66%. In conclusion, the use of compost and beneficial microorganisms as bio-stimulants could offer an effective and sustainable solution for improving grapevine soil quality and managing fungal diseases.