Foliar Application of Silicon Alleviates Drought Stress in Chickpea (Cicer arietinum L.) by Improving Growth, Photosynthetic and Antioxidant Metabolism

Purpose: The purpose of this study is to evaluate the impact of silicon (Si) on increasing drought tolerance in chickpeas (Cicer arietinum L.) by improving biochemical and physiological responses. In changing climate scenarios, drought is common, resulting in decreased crop yield. Methods: The chickpea variety NOOR 2013 was sown, and pots were subjected to three levels of water irrigation, i.e. 100% of water holding capacity (WHC) as control, 75% WHC, and 50% of WHC as drought treatment using complete randomized design (CRD). Foliar application of Si (Source: Silica gel: SiO₂) was done at the rate of 50 mgL^-1 at the pre-flowering stage. The data related to antioxidants (superoxide dismutase (SOD), catalase (CAT), proline, and malondialdehyde (MDA)), physiological (relative water content (RWC), excise leaf water loss (ELWL), and SPAD chlorophyll), morphological, and yield parameters were collected. Results: Results showed that the drought significantly decreases the yield of chickpea by reducing the RWC (36%), SPAD chlorophyll (44%), plant height (10%), pods plant^-1 (23%), seeds pod^-1 (39%), shoot weight (17%), root weight (16%), number of nodules (31%), nodule weight (20%), and seed yield plant^-1 (55%) in comparison to control. However, Si application significantly improved chickpea yield by increasing the proline (25%), CAT (37%), SOD (46%), RWC (26%), SPAD chlorophyll (31%), plant height (20%), pods plant^-1 (41%), seeds pod^-1 (35%), shoot weight (21%), root weight plant^-1 (9%), number of nodules (18%), nodule weight (11%), and seed yield plant^-1 (40%). Conclusions: Si is beneficial in reducing the negative effects of drought by increasing antioxidant activity and augmenting chickpea morphological, physiological, and yield characteristics. Further study should explore Si’s efficacy under varying stress intensities, field conditions, and interactions with other agronomic practices to optimize its practical application.