Nutrient Seed Priming Effects on Water Stress Tolerance and Nutrient Uptake of Chilies (<i>Capsicum annum</i> L.)

Nutrient seed priming is a promising technique for enhancing nutrient uptake and improving crop growth, especially under water stress conditions. This study investigated the effects of various priming treatments on water stress tolerance and the uptake of essential nutrients, including nitrogen (N), phosphorus (P), potassium (K), and zinc, in <i>Capsicum annuum</i> L. plants grown under varying moisture conditions (30% field capacity (FC), 50% FC, and 80% FC). Seed priming was conducted using two nutrient solutions: potassium nitrate (KnO₃) and zinc oxide (ZnO) with best-performing concentrations, i.e., ZnO 20 mg/L and KnO₃ 10 g/L and the best priming duration of 12 h obtained from a previous preliminary glasshouse experiment. The study examined the effectiveness of different priming solutions, zinc oxide, potassium nitrate (KnO₃), and water (H₂O), at various field capacities (30%, 50%, and 80%). The results demonstrated that nutrient priming significantly influenced nutrient uptake, with KnO₃ and H₂O priming showing the most pronounced effects on N, P, and K uptake. ZnO-primed seedlings absorbed 54.63% more nitrogen compared to the control and 25.7% more phosphorus. Zn uptake was significantly influenced by the interaction between priming treatment and moisture content, while ZnO priming generally resulted in 25.6% lower Zn uptake compared to the control and other treatments. The highest Zn concentrations of 32 mg/kg were observed in control plants grown under very low and optimum moisture conditions (30% and 80% field capacity). The results imply that the ideal absorption of Zn is influenced by both priming and moisture factors. Overall, this study highlights that nutrient seed priming, especially with KnO₃ and water, effectively enhances nitrogen, phosphorous, and potassium uptake in <i>Capsicum annuum</i> plants. Optimizing priming treatments, especially in conjunction with appropriate moisture management (50–80% FC), is crucial for maximizing nutrient acquisition and plant growth and development. The complex interaction between ZnO priming and moisture content highlights the species-specific nature of priming responses, particularly for Zn absorption.