Application of different fertilizers to cabernet sauvignon vines: Effects on grape aroma accumulation

BACKGROUND: Vine nutrition affects the composition of grapes, but how it impacts the aroma of grapes is largely unknown. OBJECTIVE: This work aimed to investigate the effect of different fertilizers: chemical fertilizer (CF), sheep manure-based organic fertilizer (OF), 50% organic fertilizer + 50% chemical fertilizer (O + C), 25% organic fertilizer + 25% chemical fertilizer [1/2 (O + C)], and soil conditioner (SC) on the aroma accumulation of Cabernet Sauvignon grapes. METHODS: The treatments were applied and samples were collected in 2019 at weekly intervals from August 7 to September 22. The grapes' chemical characteristics and volatile compounds were analyzed. RESULTS: The chemical results showed that the treatments had a positive effect on grapes, with a strong preference for the 1/2 (O + C) treatment. Grape aroma results showed that the concentrations of grape aromas in O + C-treated samples were lower than the other treatments. The OF treated samples had comparatively high (24.8%) volatile concentrations during maturity compared to other treatments, including the control (15.9%). Throughout development, samples treated with OF (17.4%) and CF (15.7%) had higher volatile concentrations than samples treated with SC (14.4%), 1/2 (O + C) (12.8%), and O + C (12.4%). However, compared to SC-treated samples, samples treated with 1/2 (O + C) increased the accumulation of terpenes and esters. The principal component analysis (PCA) results showed that samples treated with OF were strongly correlated to carbonyls, terpenes, and esters during maturity. CONCLUSION: The type and ratio of fertilizer used had a significant impact on the aroma profile of Cabernet Sauvignon grapes.