EFFECT OF PYROLIGNEOUS ACID ON GRAPE PRODUCTION AND DISEASE MANAGEMENT

Abstract

Pyroligneous acid (PA), a by-product of biomass pyrolysis, has emerged as a promising biostimulant in agricul-ture. This thesis investigated the biostimulatory effect of PA on grape (Vitis vinifera cv. KWAD7-1) production, juice, and wine quality, and its antifungal properties. The first study focused on the effects of PA (0%, 2%, 4%, 8%, and 12%) on metabolite accumulation in grape wine. Using Nuclear Magnetic Resonance analysis, 52 me-tabolites across seven compound groups were identified and quantified. The 12% PA treatment resulted in the highest °Brix content of the grape juice and significantly (p<0.05) altered the concentrations of organic acids, amino acids, and sugars of the grape wine. The second study examined the impact of varying PA concentrations (0%, 4%, 8%, and 12%) and application frequencies (14-, 21-, and 28-day intervals) on grape growth, yield, and chemical composition. The results showed that 4% PA applied at 21-day interval significantly (p<0.05) improved grape vine growth, and yield and juice quality parameters. The treatment also enhanced the accumulation of ben-eficial compounds such as carotenoids, phenolics, and flavonoids in grape leaves, pomace, and juice. The third study investigated the efficacy of PA on Botrytis cinerea disease management in grapes. Various concentrations of PA were evaluated for their ability to suppress B. cinerea growth and infection in vivo. The results demonstrated that PA exhibited significant (p<0.05) antifungal activity against B. cinerea, with higher concentrations showing greater disease suppression. These findings demonstrate that PA application can be an effective strategy to enhance grape wine quality, productivity, and manage fungal diseases. The research provides valuable insights into the use of PA as a sustainable tool for modulating grape and wine characteristics to meet consumer preferences and po-tentially improve nutritional value, while also offering an environmentally friendly approach to disease manage-ment in viticulture.