Acta Physiologiae Plantarum

Hajihashemi, Shokoofeh; Chabipoor, Amal

doi: 10.1007/s11738-025-03874-6pmid: N/A

Effective water management in crops with high water requirements, such as rice, demands research to establish accurate irrigation systems for sustainable use of resources and ensuring feeding the world’s population at the same time. This research investigated how both bulk and nanoparticles forms of chitosan (Ch) and silicon (Si) on rice performance under delayed-flooding irrigation. The experiment involved applying foliar treatments of distilled water (control), Ch (0.05% w/v), nano-Ch (NCh; 0.05% w/v), Si (0.05% w/v), nano-Si (NSi; 0.05% w/v) and NCh-NSi (0.1% w/v) to 25 days old plants. The plant cultivation was carried out using a two-stage irrigation approach. Initially, for the first 40 days, the plants were irrigated to saturation. Then, a permanent flooding regime was established starting 40 days after sowing. Various plant traits including culm characteristics (wall thickness, major vascular bundle area, and thickness of mechanical and parenchyma layers), leaf features (thickness, length and dry mass) and grain characteristics (filled spikelet, and dry mass, length and number of fertile panicle) were enhanced under various treatments. Further, foliar treatments increased photosynthetic pigments, phenols, flavonoids, anthocyanins, carbohydrates, protein, proline, activity of catalase and ascorbate peroxidase, and total antioxidant activity. Overall, the bulk and nano-forms of Ch and Si improved rice-cropping system in the delayed-flooding conditions, with the highest yield achieved in NCh-NSi treatment. In conclusion, eco-friendly chitosan nanoparticles combined with Si offer a promising approach to boost crop yield and improve water resource management, especially in the face of climate change and water scarcity.