The Fruit Quality Analysis And Balance Fertilization Research On Pear Leading Cultivars

In order to study the fruit quality and mineral elements distribution in pear cultivarsand provide evidence for the establishment of balanced fertilization scheme in pear orchard,The119fruit samples of40cultivars from19Experiment Stations of China Pear ResearchSystem （ESCPRS）,112branches samples of34cultivars from16ESCPRS,78samples ofirrigation water from14ESCPRS, and the leaf, root, soil samples of5leading cultivarsfrom there ESCPRS were collected as experimental materials.The fruit weight, soluble solids, soluble sugar, vitamin C, stone cells, titrated acidwere measured; the synthetic valuation and the principal component analysis of fruit traitswere done by using of fuzzy math method. The content of11mineral elements in fruit,branch, leaf, root and soil were assaied by using ICP-OES （Inductively CoupledPlasma-Optical Emission Spectrometry）, the difference of mineral element in fruit, branchand irrigation water, and the correlation between them were analyzed by the SPSS programversion11.0for Windows. The balanced fertilization scheme of the five leading cultivarshad been established.The main results achieved were as follows:1. The fruit quality of all cultivars tested can be divided into8groups according to thevalue of synthetic valuation （VSV）. There were12samples fell into the first group, theVSV was lager than0.60. The second group covered14samples and its VSV was from0.55to0.60. The third and the fourth group all included23samples; the VSV was0.50-0.55and0.45-0.50, respectively. There were18samples in the fifth group; its VSVwas0.40and0.45. The sixth group had13samples; the VSV was0.35-0.40. The seventhgroup,9samples, the VSV0.30-0.35; the eighth group,7samples, the VSV less than0.30.2. The mean of fruit weight, soluble solids, soluble sugar, vitamin C, stone cell andtitrated acid of all the tested samples was242.17g,12.30%,8.84%,10.80mg·kg^-1,0.52%and0.26%respectively. There was negative significant correlation between fruit weightand soluble sugar, and titrated acid; but there was positive significant correlation betweensoluble solids and soluble sugar, and stone cell content. There was positive significantcorrelation between soluble sugar and titrated acid. It shows that soluble sugar, solublesolids and titrated acid were in the first component in pear fruit economic characteristics bythe principal component analysis.3. The average content of N, P, K, Ca, Mg, S element in fruit was902.71,135.64,1465.50,68.58,100.75and56.91mg·kg^-1, respectively. The average content of Fe, Mn, Cu, Zn and B element in fruit was9.98,1.09,1.34,0.89and3.01mg·kg^-1, respectively.There was negative significant correlation between fruit weight and content of N, Ca, Mgand Mn element; there was positive significant correlation between soluble solids andcontent of N, K element; there was negative significant correlation between soluble solidsand content of Cu element; there was positive significant correlation between content ofvitamin C and Zn element; and there was positive significant between titrated acid andcontent of N, K, Ca and Mn element.4. The average content of N, P, K, Ca, Mg, S element in one-year-old branch of pearplant was4223.82,687.80,3221.12,4061.31,762.86and300.72mg·kg^-1; and theaverage content of Fe, Mn, Cu, Zn and B element was42.47,12.71,4.2,11.97and7.69mg·kg^-1, respectively.5. The average pH value of irrigation water was7.74by testing of the78samples, inwhich the acidic irrigation water, pH value less than6.0, accounted for1.28%, the faintlyacidic ones, pH value from6.0to6.5, accounted for1.28%, the near neutral ones, pH6.5-7.5, accounted for21.79%, the weakly alkaline irrigation water, pH7.5-8.0, accountedfor38.46%, and the alkaline ones, pH value higher than8.0, accounted for37.18%. Therewas negative significant correlation between the pH value and Cu content in irrigationwater; but there was positive significant correlation between NO₃^-and Ca²⁺, between K+and Ca²⁺, Mg²⁺and SO₄^2-, between Ca²⁺and Mg²⁺and SO₄^2-, and between Mg²⁺and SO₄^2-content in irrigation water.6. According to the scheme of balanced fertilization established in this experiment tokeep high yield and good fruit quality, the HuangGuan pear orchard in Changli ExperimentStation, CPRS should supplement N12.56kg, Mn2.34kg, Cu5.46kg and B0.05kg ineach area of667m²; and its YaLi pear orchard should added N7.25kg, Fe1.16kg, Mn2.57kg, B0.04kg in each area of667m². However, the FengShui pear orchard in theXuZhou Experiment Station, CPRS only needed a complement of Mn0.79kg, Cu5.81kgin each area of667m². DangShanSuli pear orchard in the TaiAn Experiment Station,CPRS should fertilize Mg57.87kg, Fe2.27kg, Mn2.35kg, Cu3.91kg, Zn0.65kg and B0.14kg in each area of667m². Nevertheless, the Bartlett pear orchard in the YanTaiExperiment Station, CPRS should complement K7.61kg, Ca370.84kg, Mg28.22kg andB0.15kg in each area of667m².