Integrated effects of salicylic acid, hydrogel and sulphur on rapeseed growth under water-scarce conditions

Maintaining global rapeseed production in the face of water scarcity necessitates creative techniques to improve crop adaptability. Since rapeseed requires substantial water and conventional irrigation methods are unsustainable, enhancing water usage efficiency is essential for sustaining production. As water scarcity poses a substantial challenge, there is an urgent necessity for sustainable strategies, including the application of bio-regulators such as salicylic acid, hydrogel, and sulphur, to improve rapeseed yield in water-restricted environments, thereby safeguarding food security and agricultural sustainability. A field experiment was conducted at the Agricultural Research Farm of Lovely Professional University during the rabi seasons of 2021–22 and 2022–23 to evaluate the performance of various sulphur sources in conjunction with salicylic acid and hydrogel treatment. The experiment utilized a split-plot design featuring 24 treatments, incorporating gypsum, bentonite sulphur, and elemental sulphur as distinct sulphur sources, alongside the application of hydrogel and salicylic acid during the blooming and pod development stages. The application of gypsum, among various sulphur sources, resulted in notable enhancements in growth and yield parameters, including plant height (175.74 cm), number of branches per plant (23.10), dry matter production (250.21 g), root length (8.83 cm), root dry weight (63.17 g), leaf area index (6.47), 1000-seed weight (4.38 g), siliqua length (5.42 cm), and siliquae per plant (354.07) compared to all other treatments. The treatment involving the application of hydrogel (2.5 kg/ha) and salicylic acid (150 ppm) at both 50% flowering and 50% pod formation phases demonstrates the most favorable outcomes for growth and yield parameters. The blend of gypsum and hydrogel at 2.5 kg/ha, combined with salicylic acid at 150 ppm during 50% flowering and 50% pod formation, demonstrates superior outcomes for both growth and yield parameters observed in the study.