Abstract
Cereals are exposed to various external conditions during the growing period, which affects their growth, development, and yield. Silver nanoparticles represent a potential solution for alleviating the negative effects of temperature stress. This study examines the impact of silver nanoparticles on extract yield, proline concentration, and antioxidant activity of winter wheat and barley during the tillering phase under winter field conditions. Silver nanoparticles (AgNPs) were synthesized using a green method with an aqueous extract of Agrimonia eupatoria L. Two varieties of winter cereals, Simonida (Triticum aestivum L.) and Nonius (Hordeum vulgare L.), were foliarly treated with concentrations of 5 mg/ml and 10 mg/ml AgNPs-H2O. The experiment lasted for 10 days, during which the minimum temperature recorded was -7°C in field conditions. Proline concentration was higher in both varieties treated with nanoparticles compared to the controls. Antioxidant activity was assessed using the DPPH method on untreated and treated AgNPs-H2O samples, with evaluation of the antioxidant activity of the nanoparticles themselves and ascorbic acid as a positive control. Results showed that AgNPs-H2O increased proline concentration and antioxidant activity in both tested winter cereal varieties compared to the controls, while extract yield was higher with the application of certain concentrations. This highlights the potential of AgNPs-H2O to improve the tolerance of winter cereals to cold and low temperatures through increased antioxidant activity.