Abstract: 【Objective】 To investigate the effects of nitrogen（N）,phosphorus（P）and potassium（K）fertilizer on grain-filling and oil accumulation of confectionary sunflower.【Methods】 The experiment was carried out in Wuchuan,Inner Mongolia,and five treatment groups were set：FP（farmers used to apply fertilizer）,NE（nutrient experts recommended fertilization）,NE-N（no nitrogen fertilizer）,NE-P（no phosphate fertilizer）and NE-K（no potassium fertilizer）. The dry matter accumulation,crude fat content and fatty acid components in the seeds of confectionary sunflower were determined by regular sampling after flowering.【Results】 The dry matter accumulation in confectionary sunflower seeds showed an S-shaped curve,and reached the maximum at 19-20 days after flowering,then decreased gradually. The dry matter accumulation in NE treatment was higher than that in NE-N,NE-P and NE-K treatment,and the dry matter accumulation at inflection points of NE-N,NE-P and NE-K treatment was 89%,90% and 91% compared with NE treatment. The crude fat content in seeds also showed an S-shaped curve. The crude fat content in seeds under NE treatment was the highest,and the accumulation amount of crude fat at inflection points in NE-N,NE-P and NE-K treatment was 99%,94% and 93% compared with NE treatment. The changes of palmitic acid content and stearic acid content in seeds showed a power curve. Palmitic acid content tended to be stable at 37 days after flowering,accounting for 7%-8% of the total fatty acid content. The stearic acid content tended to be stable 29 days after flowering,accounting for 0.3%-0.5% of the total fatty acid content. Oleic acid content in seeds was low at the beginning of grain-filling,and peaked at 22 days after flowering. Oleic acid content in seeds accounted for 13%-17% of total fatty acid content at harvest time. The linoleic acid content increased from about 50% at the early stage of grain-filling,and accounted for 75%-80% of the total fatty acid content at harvest time.【Conclusion】 The dry matter accumulation and crude fat content of confectionary sunflower seeds showed an S-shaped curve,and the dry matter and crude fat accumulation of confectionary sunflower seeds reached the maximum at 19-20 days and 28-30 days after flowering,respectively. The main component of fatty acids in seeds was linoleic acid,and fertilization had little effect on the fatty acid components.

Key words: Confectionary sunflower, Nitrogen,phosphorus and potassium, Grain-filling, Oil accumulation, Fatty acid components