Bioactivity of essential oils and plant extracts on the control of diseases caused by Phytophthora nicotianae in Solanaceae

ABSTRACT Essential oils (OE) and crude aqueous extracts (EBA) from apple-style-spanSyzygiumapple-style-spanapple-style-spanapple-style-span apple-style-spanaromaticumapple-style-span and apple-style-spanCymbopogonapple-style-spanapple-style-spanapple-style-span apple-style-spannardusapple-style-span and their major chemical components were investigated for in vitro and in vivo control of diseases caused by Phytophthora nicotianae in tomato (Lycopersicon esculentum) and eggplant (Solanum melongena). In vitro experiments were conducted using the agar dilution method with different concentrations of OE (0.1, 0.5, 1.0 ?L/mL) and EBA (1.0, 10.0, 20.0%) to evaluate their inhibitory potential on mycelial growth and zoospore germination. The obtained percent inhibition and minimum inhibitory concentrations were used to performed tests in fruits and seedlings under controlled conditions. The evaluated variables were mean lesion diameter on the surface of fruits and incidence and death of seedlings over six and 15 days of evaluation, respectively. The products that most inhibited mycelial growth and zoospore germination were obtained from S. aromaticum, at the concentrations of 0.5 ?L/mL and 10% OE and EBA, respectively. The treatments that most delayed the disease progress in fruits and seedlings, compared to control, were OE and EBA of C. naudus at 1.0 ?L/mL and 20%, respectively. Thus, products obtained from S. aromaticum and C. nardus have the potential to reduce the attack by this pathogen in tomato and eggplant.