|
The area of the’Housui’Pear cultivation in China has expanded each year, studying the actual needs of fertilization is necessary. There is no domestic production of fertilizer pear tree phased in accordance with the law need fertilizer, but excessive application of nitrogen common to the phenomenon of decline in fruit quality. This paper is aimed to discuss the effects of different rates of nitrogen fertilizer application on the physiologic characteristic of leaf and quality of fruit during Fruit Expanding Period of’Housui’Pear in the old course of Yellow River. As well as the effect bio-organic manure, providing a theoretical basis for the production of high-quality and pollution-free green pear. The major results are as follows:1 Rational application of nitrogen fertilizer could increase the leaf NR activity, total nitrogen, soluble protein content; Also could increase chlorophyll a, chlorophyll b and carotenoid. Net photosynthetic rate(Pn), transpiration rate(Tr), stomatal conductance(Gs), stomatal limitation value(Ls)was significantly increased, Intercellular CO2 concentration(Ci) decreased, photosynthetic carbon assimilation capacity of benefit enhancements; Soluble sugar in the leaves increased firstly and then decreased with the increasing of nitrogen fertilizer’s application during the harvest stage. Compared with the control, with the increase o-f nitrogen in leaves of N, the content of N and Ca first increased and then decreased, Mg, Fe, Mn and Cu Corresponding increase in levels, P and K elements decreased, the element Zn did not change significantly.2 (1) Rational application of nitrogen fertilizer could improve fruit quality, With the increase of nitrogen, fruit weight, soluble solids and total soluble sugar first increases and then decrease; fruit firmness decreased; Titratable acid content increased; fruit shape index, VC and stone cells showed no significant change. (2) during the development of’Housui’ Pear fruit to accumulate mainly fructose, sucrose, glucose second, and sorbitol were the lowest; amount of nitrogen can increase the total soluble sugar content of fruit, But overuse of nitrogen reduce the concentration of fructose and glucose, which reducing the total sugar content of soluble sugar. (3) nitrogen can increase the acid content of fruit, with the increase of nitrogen within the malic acid and citric acid content increased; nitrogen levels has a Greater impact on early fruit development of higher malic acid content, While with little significant on post-treatments.3 application of nitrogen fertilizer can enhance the quality of flowers, flower quality and reducing excess nitrogen fertilizer. (1) nitrogen could increase the rate of tree flowering and increase the number of inflorescences per plant, number of flowers per inflorescence, While high N treatment reduced; (2) Nitrogen treatment increased the amount of pollen anthers, each flower pollen number and quantity; (3) Effects of nitrogen fertilizer can increase the germination rate of pollen, and in a certain range with the increase of nitrogen, pollen germination rate will Reduce with excess nitrogen.4 Application of chemical fertilizer combining with organic fertilizer was able to increase the contents of soil’s organic matter, total nitrogen and rapidly available phosphorus, and decrease the soil pH value, and also increase fruit hardness and sugar-acid ratio, although with the little decreasing of single fruit weight. Chemical fertilizer combining organic fertilizer had the perfect proportion that was five to five.
|