Artyszak, ArkadiuszGozdowski, DariuszPopielec, Rafał2026-03-242026-03-242025Current Agronomy 2025, 54/2: 129–141ISSN: 2081-2787 eISSN: 3071-740X10.2478/cag-2025-0011https://bc.iung.pl/handle/123456789/4753Winter rapeseed yields are reduced by many stress factors, including drought. Innovative ways to reduce losses that are also safe for the natural environment are sought. In 2021/2022–2023/2024, a field experiment was conducted to examine the effect of foliar application of Si + Ca (SmartSil SC Power®) on biometric traits of plants before harvest, seed and fat yield, seed quality, and gross and net production value of winter rapeseed. Fertilizer at a dose of 2 dm3 ha-1 was applied twice: in the BBCH 32 and BBCH 50–51 phases, and the effects were compared with the control combination. The fertilizer used caused a significant increase (by 8.0%) in seed yield compared to the control variant and increase in fat yield by 7.0%. The component features of seed yield included a significant increase in the number of seeds per pod (by 18.8%), and the qualitative features included an increase in NDF content (by 2.0%). For both variants, a significant effect of seed yield and fat content on fat yield was found, which was determined to a greater extent by seed yield than by fat content. Under the influence of foliar application of Si + Ca, the gross production value increased by PLN 769 ha-1(by 7.4%), and net production when used together with other treatments by PLN 605 ha-1, and when used separately by PLN 545 ha-1.enwinter rape, drought, silicon, calcium, foliar application, economic effectArticle