Effects Of Foliar Application Of Fertilizers And GA₃ On Dongzao Fruit Quality And Preliminary Study On Leaf Analysis Standard Of Dongzao (Zizyphus Jujuba Mill.)

Dong Zao (Zizyphus jujuba Mill. Cv. Dong Zao) is the best fresh jujube cultivar with the largest cultivation area in our country now. But because of the wrong use of fertilizers and hormones, the Dong Zao yield became unstable and the fruit quality decreased. It affected famers'benefit and positive, hindered the healthy development of the Dong Zao industry, so improving fruit quality became a problem to be solved. In this paper the effects of foliar application of fertilizers and GA3 on Dongzao fruit quality were studied and the mineral nutrient contents in leaves of diferrent orchard production were determined to study the effect of GA3 and foliar fertilizer on fruit quality, and provide theoretical basis for fertilization on leaf analysis guide. The main results are as follows:1 Boron and calcium were sprayed as foliar fertilization on'Dongzao', both of them have 2 concentrations of 0.2% and 0.4% , the concentrations of Ca(NO3)2 and Na2B4O7 in 7 treatments combined by these 2 concentrations was: W1(0%, 0%); W2( 0%, 0.4%);W3(0.2%, 0.2%);W4(0.2%, 0.4%);W5(0.4%, 0%);W6(0.4%, 0.2%);W7(0.4%, 0.4%). The results showed that boron and calcium effectively improved the photosynthetic efficiency of jujube leaves, increased the soluble solids and reducing sugar content, increased the sweetness, improved fruit quality. The W7 treatment had the most obvious effect, the soluble solids content increased 12.6% and 12.3% compared to the control in both orchards. The reducing sugar content increased 44% and 52% compared to the control. Boron and calcium reduced titratable acid content, the W4 treatment had the most obvious effect. The chlorophyll content, single fruit weight, fruit longitudinal and traverse diameter, edible rate, fruit shape index and Vc Content etc had no significant changes. The optimal concentrations of boron and calcium were W7 treatment, W4 treatment was the next.2 The rare earth foliar fertilization experiment showed that it had no obvious effect on photosynthetic efficiency of jujube leaves, but the soluble solids content and reducing sugar content had trend of increase. The X3(300mg/L) treatment had the most obvious effect, the soluble solids content and reducing sugar content increased 2.6% and 10.2% compared to the control. The rare earth foliar fertilization decreased fruit acidity, the X3 and X5 (300mg/L, packed by aluminium foil bag) treatment had better effects. The X5 treatment had significant effect. The best rare earth foliar fertilization concentration was 300mg/L. .3 The gibberellic acid test had 3 treatments with the concentrations of 0.20mg/kg, 40mg/kg. GA3 treatment increased single fruit weight and fruit longitudinal and traverse diameter. The single fruit weight increased 53% and 47% compared to the control in the two orchards. After the 20mg/kg, 40 mg/kg GA3 treatments, the soluble solids content decreased 24.1%,31.1%, and reducing sugar content decreased 8.7%,14% in Lvlou orchard, and in Liguanzhuang orchard the soluble solids content decreased 18.3%,20.1%, and reducing sugar content decreased 11.4%,15.8%,the higher concentration made the bigger decrease. And also GA3 made the fruit spots clearer,less crisp. Spraying GA3 at young fruit stage decreased the fruit sweetness,affected the nutrition accumulation,changed the flavor,decreased the fruit quality.4. To provide theoretical basis for increasing quality ,yield and optimizing fertilization, high yield Leaf nutritional diagnosis was conducted in high yield trees, and nutritional ranges of Dong zao were determined, N was (2.49±0.43%), P was (0.47%±0.06%),K was (2.04±0.42%),Ca was(1.58±0.20%),Mg was(0.24±0.08%),Fe was(230.94±20.16 mg/kg),Mn was(55.66±19.57 mg/kg),Cu was(6.35±1.18 mg/kg),Zn was (53.58±11.26mg/kg).5.Nine mineral nutrients (N, P, K, Ca, Mg, Fe, Mn, Cu, Zn) contents of Dongzao leaves in Cangzhou were determined and their correlation was analyzed, The results showed that Mg content had the most significant change, the coefficient of variation was 29%. According to the munber of coefficient of variation, the major elements were put in the order of Mg> P> K> N> Ca, and the trace elements were put in the order of Cu> Mn> Zn> Fe. Cu content had the biggest coefficient of variation with 43.49%, which may be caused by the spraying of Bordeaux mixture.