In Vivo Control of Botrytis cinerea in Grapevine Using Essential Oil from Sweet Basil Cultivated Under Ozonated Water Irrigation

This study evaluated the efficacy of basil essential oil (BEO), extracted from basil plants irrigated with ozonated water, as a sustainable strategy to control grey mould (Botrytis cinerea, Bc) in grapevine, Vitis vinifera cv. Sangiovese. Bunches were treated with water (control) or BEO and, after Bc inoculation, disease progression (AUDPC), berry biometric traits and biochemical parameters were assessed. Treatment with BEO significantly reduced disease severity, lowering AUDPC values at 168 h post inoculation compared with untreated infected grapes, while limiting visible mycelial emergence. Anthocyanins and total phenols decreased following infection (−36 and −38%, respectively, in comparison to the control). By contrast, BEO-treated and infected grapes showed a more than 2-fold increase in resveratrol and condensed tannins, suggesting the activation of defence-related secondary metabolism. Lastly, glucose and fructose contents declined by 56% only in untreated infected berries, confirming active pathogen colonisation. These findings demonstrate that BEO significantly reduced grey mould development with enhanced defence-related metabolic responses, supporting its potential as an eco-friendly alternative to synthetic fungicides in sustainable viticulture.