Modulacija pridelka in fizioloških lastnosti rimske kumine (Cuminum cyminum L.) z nanodelci silicijevega dioksida pri različnih sušnih stresih

Water scarcity, exacerbated by climate change and population growth, threatens sustainable agriculture, particularly in arid regions. This study investigated the potential of silicon dioxide nanoparticles (nSi) to mitigate drought stress in cumin (Cuminum cyminum L.). A split-plot experiment, arranged in a randomized complete block design with three replications, was conducted over two cropping seasons in Bafgh, Iran. Drought stress was applied as the main factor at four levels (80%, 60%, 40%, and 20% of field capacity, FC), while subplots contained four nSi concentrations (0, 2, 4, and 6 mM). Results showed that severe drought stress (20% FC) significantly increased peroxidase activity (5.5-fold) and malondialdehyde levels (3.7-fold), while decreasing total chlorophyll (49%), seed yield (81%), and essential oil yield (64%). However, applying 4 mM nSi significantly alleviated drought stress by preserving TChl, and sustaining POD activity, resulting in lower MDA levels and improved SY and EOY. In contrast, 6 mM nSi did not mitigate drought stress and worsened its effects. These findings indicate that 4 mM nSi can enhance cumin's resilience and productivity under drought, while higher concentrations should be avoided.