Investigating the Effect of Ammonium Sulfate and Potassium Sulfate Application on seed and Oil Yields of Camelina (Camelina sativa L.) under Late-Season Drought Stress

A two-year experiment was carried out in Karaj to investigate the effect of potassium sulfate and ammonium sulfate fertilizers on agronomic traits, seed yield, oil content and yield of camelina under drought stress conditions.  

The experimental design was split plot-factorial in an RCBD with three replications. Irrigation regimes as full irrigation, irrigation interruptions from silicle formation and flowering stages in the main plots and combine of potassium sulfate (0, 25, 50, and 75 kg.ha-1) and ammonium sulfate (0, 25, 50, and 75 kg.ha-1) fertilizers in the sub plots.  

The number of silicle/plant, silicle length, number of seed/silicle, 1000-seed weight, biological yield, seed yield, harvest index, and oil content and yield were affected by a three-way interaction between irrigation regime × potassium sulfate × ammonium sulfate. When compared with full irrigation regime, the seed yield, oil content, and oil yield were decreased by 46, 8.5, and 51.2% in the irrigation interruption from the silicle formation stage, and by 51, 7.18, and 78.7% in the irrigation interruption from the flowering stage, respectively. The highest seed yield, oil content, and oil yield among the fertilizer treatments belonged to the application of 75 kg.ha-1 potassium sulfate+75 kg.ha-1 ammonium sulfate fertilizer treatment with an average of 1950 kg.ha-1, 31.8%, and 643 kg.ha-1, respectively.  

In general, camelina should be cultivated in the full irrigation conditions and treated with the potassium sulfate (75 kg.ha-1) + ammonium sulfate (75 kg.ha-1) fertilizers for achieving the maximum seed and oil yields.