Gülcü, Barış2023-07-262023-07-2620220334-21231876-7184https://doi.org/10.1007/s12600-022-00997-1https://hdl.handle.net/20.500.12684/12207Hazelnut (Corylus avellana L. Betulaceae) is an economically important plant grown in the Black Sea Region of Turkey. Its production is greatly affected by fungal pathogens such as Erysiphe corylacearum which cause powdery mildew disease. As a first, we assessed the field performance of trans-Cinnamic Acid (TCA) against powdery mildew disease in hazelnut production fields and its phytotoxicity on treated plants. Three different concentrations of TCA (0.5, 1 and 2%) and control, a chemical fungicide (Collis, active ingredients: 100 g/l Kresoxim methyl +200 g/L Boscalid), were applied to young basal shoots around hazelnut trees. The fungal infection incidence, disease severity and effectiveness of chemical treatments were determined. None of the tested TCA concentrations caused phytotoxicity on the hazelnut leaves. TCA showed high antifungal activity against powdery mildew disease in field. Compared to control, Collis fungicide and TCA at 2% concentrations reduced >90% of E. corylacearum infection. TCA at 1 and 2% concentrations were as effective as Collis fungicide against E. corylacearum infection in the field. Our results indicate that TCA can be used to as an alternative to antifungal compounds in controlling powdery mildew disease.en10.1007/s12600-022-00997-1info:eu-repo/semantics/closedAccessErysiphe Corylacearum; Hazelnut; Powdery Mildew Disease; Trans-Cinnamic AcidXenorhabdus; Derivatives; PotencyArticle505109110962-s2.0-85127338430WOS:000774588900002Q2Q2