| This study has been completed in the Old Town of Luochuan County, Shaanxi Province from March 2008 to October 2008. 12-year-old apple (Malus pumila cv. FuJi) tree in the full fruit was taken as the material in this experiment, and was fertilized with the N P K before germination.. In order to reduce the scale of the experiment, we used an optimized design with Quadratic regression orthogonal in which there were three factors, five levels, a total of 15 treatments. Taking the largest yield as the expectations, the nutrient elements carried out ratio by fruit from the soil was calculated out. The best fertilizer amount for the theory was that elements carrying out divided by the utilization of each one. We take this amount as the middle level of the experiment. A statistical software was used to design experiment and gave corresponding parameters. The physiological relationship and indexes of different N P K ratio were studied in this experiment. Using a professional software, a set of fertilizer response models were established, and then a optimum N P and K fertilizer ratio corresponding with best quality and yield was suggested for the apple production in the area. The main results were as follows:1 Different combination of N P K fertilizer could affect growth of the apple tree, the quality and the yield of apple, and the optimum combination of the three fertilizer elements was shown to be different for each physiological index.2 The relative physiological index of the apple leaves was shown that three factors N P Keffecting the chlorophyll of apple leaves was in series as P＞N＞K, the maximum chlorophyll content of apple leaves was 3.01 mg/g, and the corresponding N P K fertilizer combination was 0kg /667m~2, 28.66kg/667m~2, 50.03kg/667m~2. The N P K effecting the soluble sugar of apple leaves by degrees was in series as N＞P＞K, the maximum soluble sugar content was 3.85%, and the corresponding N P K fertilizer combination was 17.02kg/667m~2,0kg /667m~2,0kg /667m~2. The factors effecting the soluble protein of apple leaves was in series as K＞P＞N, the maximum soluble sugar content was 4.82%, and the corresponding NPK fertilizer combination was 48.0kg /667m~2 ,0kg/667m~2 and 0kg/667m~2.3 Apple quality effected by fertilizer was shown that three factors NPK effecting the soluble sugar content of apple was in series as N＞K＞P, the maximum soluble sugar content was 18.60%, and the corresponding NPK fertilizer combination was 17.49kg /667m~2,60.0kg/667m~2 and 64.0kg/667m~2. Three factors N P K effecting the titratable acid content of apple was in series as N＞K＞P, the maximum titratable acid content was 0.41%, and the corresponding NPK fertilizer combination was 23.07kg/667m~2,0kg/667m~2 and 0kg/667m~2.Three factors N P K affecting the acid-sugar ratio of apple was in series as K＞P＞N, the maximum acid-sugar ratio was 0.4085%, and the corresponding N P K fertilizer combination was 48.0kg /667m~2,0kg /667m~2 and 64.0kg /667m~2.Aroma components contained in Fuji apples were analyzed by gas chromatography-mass spectrometry. A total of 49- components were identified, including 23- esters, 1-Butanol, 2-methyl-, acetate Acetic acid, butyl ester 1-Butanol, 2-methyl- Acetic acid, hexyl ester were the chief components; 13-alcohols, 1-Butanol 1-Hexanol were the chief components; 5-aldehydes, Hexanal 2-Hexenal were the chief components. The results indicate that different fertilizer proportion can effect aroma components of Fuji apple. According to professional software, a maximum aroma components content.could be gotten when the corresponding NPK fertilizer combination was 33.27kg/667m~2 20.76kg/667m~2 37.33kg /667m~2.Three factors N P K effecting the firmness of apple fruit by degrees was in series as K > P > N, the maximum firmness of fruit was 10.27kg/cm~2, and the corresponding N P K fertilizer combination was 0kg /667m~2,0kg /667m~2 and 64.0kg/667m~2.5 Three factors N P K effecting the yield of single tree by degrees was in series as K > P > N, the maximum yield of single tree was 49.62kg per tree, and the corresponding NPK fertilizer combination was 48.0kg/667m~2,60.0kg/667m~2 64.0kg/667m~2. |
