叶面喷施不同配比氮、钾元素对富士苹果叶片性状及果实品质的影响

研究采用两因素三水平叶面喷肥不同比例的N/K试验，为苹果生产合理施肥提供参考。试验选用尿素和氯化钾对7年生红富士进行叶面喷肥，采用两因素三水平，2 因素为尿素 (C) 和氯化钾 (K) ，尿素与氯化钾各设置3个水平浓度〕，试验共设置9 个处理，设置3 次重复，测定叶片和果实相关指标。叶施氮肥、钾肥均可促进果实产量、单果重、果型指数，叶施氮肥增加了果实可滴定酸含量，叶施钾肥对果实硬度、色泽、可溶性固形物有促进作用，当喷施氮肥浓度大于等于2.5 g·L^-2时对果实硬度、色泽、可溶性固形物有抑制作用；氮钾配施对叶绿素含量影响不显著，对类胡萝卜素影响显著，氮肥与钾肥均可以促进叶比重、叶绿素含量、叶面积、百叶重。喷施适宜浓度氮肥钾肥对苹果产提质均具有促进作用，但浓度过大则会产生负效应。当喷施氮肥浓度小于等于2.5 g·L^-2，喷施钾肥浓度小于或等于1.82 g·L^-2时，苹果产量和品质均随着钾肥浓度的增加而提高；而当氮肥喷施浓度大于2.5 g·L^-2小于5 g·L^-2时，喷施钾肥浓度大于1.82 g·L^-2小于5 g·L^-2时，则会抑制苹果叶片生长，降低果实品质。氮钾肥用量过多，不仅增加了经济投入，而且对提高苹果产量与品质不利。

Effect of Foliar Spraying with Different Ratios of Nitrogen and Potassium on Leaf Characters and Fruit Quality in Fuji Apple

In this study, two factors and three levels of foliar fertilizer spraying with different ratios of N/K test were used to provide references for rational fertilizer application in apple production.In this experiment, urea and potassium chloride were used to spray fertilizer on the leaves of 7A green red Fuji apple. Two factors of urea (C) and potassium chloride (K) and three levels were used were set for urea and potassium chloride respectively. A total of nine treatments and three repeated treatments were set, and related indexes of leaves and fruits were determined. Leaf nitrogen and potash fertilizer could promote the fruit yield, fruit weight, fruit shape index.Leaf nitrogen increased fruit titratable acid content, leaf potassium application affected the fruit hardness, colour and lustre, soluble solids; When spraying of nitrogen concentration was less than or equal to 2.5 g·L^-2, the application of potassium fertilizer concentration was greater than 1.82 g·L^-2, the quality and yield of apple increased with increase of application of potassium fertilizer;When the spraying of nitrogen concentration was greater than 2.5 g·L^-2 and less than 5 g·L^-2, the application of potassium fertilizer concentration was greater than 1.82 g·L^-2 and less than 5 g·L^-2 , and the growth of apple leaves was inhibited, the quality of apple fruit was increased. Spraying of proper concentration of nitrogen fertilizer and potassium fertilizer can promote the yield and quality of apple, but high concentration will have negative effect.