Effect of different K fertilizers on fruit flavor quality of 'Xinli No.7' pears

Abstract：【Objective】The experiment was performed to investigate the effect of different potasium fertilizers on fruit flavor quality of'Xinli No.7'pears.【Methods】Three treatments of potassium chloride (T1) , potassium sulfate (T2) and potassium nitrate (T3) , were applied in the soil during the growing season, with no K fertilizer for comparison (CK) .【Results】The results showed that sugar contents of in the fruit with different types of K fertilizer treatments were significantly higher than the control, fruits of T2 potassium sulfate had the highest total sugar content, which increased by 34.55%, compared to the control, followed by T3 potassium nitrate, and T1 potassium chloride treatment.Fructose, glucose and sucrose contents of fruits treated with potassium sulfate were 15.96%, 27.32%, 52.81%, and were higher than those of potassium chloride treatment, respectively, and were 11.36%, 27.75% and 27.75% higher than potassium nitrate treatment.Total acid contents of the fruit treated with different types of potasium were higher than those of the control, total acid content in fruits treated with T3 potassium nitrate was the highest, 103.68% higher than the control, followed by T2 potassium sulfate treatment, and again for T1 potassium chloride treatment.Malic acid content was the highest in CK and potassium-treated pear fruits.Except the fumaric acid content in the fruit treated with potassium chloride was the lowest, the content of tartaric acids with the rest treatments was the lowest.The effects of different types of K fertilizer treatments on organic acid contents of'Xinli No.7'pear fruits varied with different varieties, and the content of aroma volatile with K fertilizer treated fruits were significantly higher than the control.The change of fruit aroma volatile with different types of K fertilizer treatment was different, among them the types of aroma volatile materials in the fruit treated with potassium chloride were up to 78, and the total content of fruit aroma volatile with potassium sulphate treatment was up to 746.8 ng·g-1.【Conclusion】The K fertilizer treatment improves the sugar and acid contents as well as aroma flavor quantity of'Xinli No.7'pear fruits, and the potassium sulfate treatment is the most reasonable.