Study On Calcium Uptaking And Distribution In Apple Tree And Related Effective Factors

Fuji apple trees were used to clarify the effects of the split application of calcium fertilizer on the absorption and distribution of different apple organs in Wanzikou horticultural garden of Penglai and Shandong Agriculture University in 2006 and 2007. The split fertilization was performed as follows: once in spring, twice in spring and summer, three times in spring, summer and autumn. Simultaneously, the pot experiment of young apple trees was carried out to study the effects of different rootstocks and calcium fertilizers on absorption and translocation dynamics of calcium in apple trees.1. Three-time fertilization could improve the total and exchangeable calcium in soil, and the correlation coefficients between them were significant (r= 0.9634 for the total calcium, and r=0.9799 for the exchangeable calcium). The concentration of calcium in apple root was raised with the increased amount of calcium fertilization, and the correlation coefficient between the calcium concentration in apple root and the exchangeable calcium in soil was significantly (r=0.8722). In comparison, the utilization efficiency of calcium was the highest by the application of calcium fertilizer in summer, while the next in spring and the lowest in autumn. The concentration of calcium in apple root was higher than that of the control by 23.27%, 46.07% and 32.79% in summer.2. The concentration of calcium in shoots and leaves increased gradually in the growing season. The concentration of calcium in different organs was significantly improved by the application of calcium fertilizer by split fertilization, and was paralleled with the calcium fertilizer amount. When fertilizer application in autumn, the concentration of calcium in the new shoots was the highest and was higher than control by 36.73%. The similar results were found in the change tendency of leaves and new shoots.3. The concentration of calcium in apple fruit decreased during fruit growth, whereas it could be significantly improved by calcium fertilizer application, especially fertilizer application in spring, with a 50%~82.1% higher calcium than the control. By one-off fertilization in spring, the concentration of calcium in young fruit was 1.75 times and 1.88 times of the control in 2006 and 2007, respectively. By fertilization in summer, the concentration of calcium in apple fruit was increased 37.3%~56.4%, compared with the control. The concentration of calcium in apple fruit could still be improved by fertilizer application in autumn (Ca-Ⅲ), which were 53.71% and 70.83% higher than control in 2006 and 2007, and were significantly higher than one-off fertilization in spring and fertilization in both spring and summer, the concentrations of calcium in apple fruit of treatment Ca-Ⅲwere 9% and 14% higher than that of treatment CaⅠand CaⅡafter fertilizer application for two years.4. The concentration of calcium kept increasing since calcium fertilizer application, and the total calcium in mature fruit of Ca-Ⅲwas higher than the control, Ca-Ⅰand Ca-Ⅱby 70.83%, 14% and 9%. Calcium absorption capacity of fruit varied in different periods, i.e., the young fruit could accumulate 46.8%～62.4% calcium of the mature fruit, the fruit of inflating stage could accumulate 33.85%～45.42% calcium of mature fruit. Long-term and adequate application of calcium fertilizer could improve the fruit calcium content and attenuate apple bitter pit disease incidence rate, down 45% and 16.2%, by one-off fertilization in spring, and down 9.3% by three-time fertilization in spring, summer and autumn, compared with the control.5. The concentrations of calcium in new shoot of pot 4-year-old apple trees were the highest of various organs with calcium fertilizer application in different seasons, next was the roots and leaves, main branches, main trunk and 1-year-old branches had small changes in calcium concentrations; The calcium content in the summer and autumn roots were the highest, cumulative accounts for 54% of the whole tree, main trunk of upland parts was the highest, followed by main branches and 1-year-old branches, the proportion of leaves and new shoots were only 1.34% and 2.5%.6. The abilitiy of calcium absorption is various for different types of rootstocks, and the differences increased with the amount of calcium fertilizer application (r=0.94). The calcium absorption ability of dwarf Malus hupehensis (Pamp) Rehd was higher than that of semi-dwarf and standard Malus hupehensis (Pamp) Rehd by 11.20% and 23.51%. The calcium absorption ability of Fuji apple trees grafted on different rootstocks were significantly different. The leaves of Fuji apple trees grafted on dwarf Malus hupehensis (Pamp) Rehd and Malus baccata (L.) Barkh were high, followed by semi-dwarf Malus hupehensis (Pamp) Rehd, Malus baccata (L.) Barkh and Malus sieversii, (and) standard Malus hupehensis (Pamp) Rehd and /M9/ Malus baccata (L.) Barkh were the lowest two.7. Ca(NO3)2 and CaCl2 were the best calcium fertilizer for apple tree, the concentration of calcium in roots reached 6.47g/kg and 6.22g/kg, respectively, followed by CaSiO4, calcium magnesium phosphate and single superphosphate (SSP), when fertilizer application by same Calcium amount. The concentration of calcium in roots of treatment with calcium cyanamide and gypsum were the lowest, only 3.16g/kg and2.17g/kg. The concentration of calcium in leaves had the same changing trend. Different sources of calcium fertilizer put different effects on apple tree growth, and Ca(NO3)2 could generate the best effects, followed by CaSiO4 and calcium magnesium phosphate. By contrast, the other sources of calcium fertilizer had the poor effects.