Evaluation of potassium nano-fertilizer, fulvic acid, and chitosan application on quantitative traits of sesame (Sesamum indicum L.) in different irrigation regimes

The present study was conducted to evaluate the impact of potassium nano-fertilizers, fulvic acid, and chitosan on quantitative traits of sesame under different irrigation regimes. A field experiment was conducted in Semnan Agricultural and Natural Resources Research Center as a factorial split-plot based on randomized complete block design with three replications in 2019. In this experiment irrigation regimes (full irrigation: non-stress, irrigation cut off at the beginning of seed formation inside the capsule: moderate stress and the beginning of flower structure formation: severe stress) as the main plot, and potassium nano-fertilizer (0, 1.5, and 2.5 per thousand) and foliar application of chitosan (five g.ha-1) and fulvic acid (two kg.ha-1) in four levels were tested as sub-plots. The application of potassium nano-fertilizer along with fulvic acid and chitosan increased the photosynthetic pigments, seed yield, and oil and protein content, which was a significant increase under severe drought stress. Application of 1.5 per thousand potassium nano-fertilizer with chitosan under non-stress conditions resulted in the highest number of capsules per plant, seed yield, biological yield, oil yield, and protein yield. The highest oil and protein content (48.79 and 25.12%, respectively) were obtained using a combination of chitosan and fulvic acid under non-stress conditions. The highest seed yield (2249.2 kg.ha-1) was achieved in the application of chitosan along with 1.5 per thousand potassium nano-fertilizer under non-stress conditions.