Lentil is an important grain legume crop which is mostly grown on marginal soils that hamper its productivity. Improvement of salt tolerance in lentils is considered to be a useful strategy of utilizing salt-affected lands in an economic manner. This study was conducted to evaluate the effectiveness of seed priming using silicic acid and humic acid both seperately and in combination to improve salt stress tolerance among three different lentil varieties: IPL-316 (tolerant), PSL-9, and PDL-1 (susceptible). The concentrations and durations of treatments were standardized under the normal condition and the salinity stress condition. Salt stress hindered seedling emergence and biomass production and accelerated Na⁺ toxicity and oxidative damage at the seedling stage in untreated seeds. Nevertheless, chemical priming improved early seedling emergence, increased root length, shoot length, and seed vigor index I and II, and reduced the mean germination time. A significant quantitative change in biochemical parameters under normal and salinity stress conditions was observed in IPL-316,viz. Specifically, for IPL-316, the following parameters were observed (values under the normal condition and values under salt stress conditions, respectively): chlorophyll-a (16 and 13 mg/g Fw), chlorophyll-b (25 and 16 mg/g FW), total chlorophyll content (42 and 30 mg/g FW), relative leaf water content (92% and 82%), total soluble sugars (26 and 33 ug/g FW), free amino acid (10 and 7 mg/g FW), total phenol (26 and 24 mg of GAE/g FW), total protein (35 and 29 mg/g FW), carbohydrate (208 and 173 mg/g FW), superoxide dismutase (SOD) (29 and 35 unit/min./g FW), proline (0.28 and 0.32 u mol/g FW), catalase (CAT) (84 and 196 unit/mL/g FW), and peroxidase (POX) (217 and 738 unit/mL/g FW). Furthermore, histochemical analysis of H₂O₂ and O²⁻, micronutrients, and macronutrients also increased, while malondialdehyde (MDA) (0.31 and 0.47 nmol/mL FW) content decreased using silicic and humic acid priming under salt stress conditions. The combination of silicic and humic acids improved seedling growth and reduced oxidative damage in lentil plants under salt stress conditions. The combination of silicic and humic acid priming hastened seedling emergence, seed quality parameters, and biochemical parameters under salt stress over respective control. To the best of our knowledge, this is the first report of integrated chemical priming in lentils for salinity stress. In conclusion, chemical priming using a combination of silicic and humic acid performed better in terms of seed quality due to enhanced antioxidant machinery, better membrane stability and osmolyte protection, and enhanced nutrient uptake under salt stress conditions.

Background: Lentil is second most important nutritionally dense pulse crop of India due to its ability to fix nitrogen, helps to maintain soil fertility and increase yield of other crops grown in rotations. Seed priming is a good innovative technology for improvement of emergence and plant stand under various stress conditions and also could enhance various defense mechanisms in seeds against biotic and abiotic stresses. The present study aimed to examine the effect of seed priming with silicic acid (3 mM @18 hr), humic acid (600 ppm @18 hr) and combination of humic and silicic acid (100 ppm + 1 mM @ 16 hr), that may reduce harmful effect of stress at seedling stage and improve early seedling vigor. Methods: In this field-laboratory investigation during 2022-2023, seed quality and yield quality attributing parameters i.e. germination percentage, seed vigor index-I and II, total chlorophyll, emergence percentage, final plant stand, final plant stand emergence, plant height, secondary branches, tertiary branches, number of pod per plant, average number of pod per plant, pod cluster, seed yield per plot and yield per plot were recorded in both laboratory and field conditions. Result: The results demonstrated a positive effect of seed priming on seed quality parameters against the stress. The highest seed quality and yield quality attributing parameter was recorded in treatment (T5) combination of humic and silicic acid as compare to control. The chemical priming with combination of humic and silicic acid was found to be most effective treatment to enhance plant stand establishment against stress.