Physiological And Ecological Effects Of VAM Agent On Several Fruit Trees Including Cherry In Yantai

The physiological and ecological effects of the application of VAM (Vesicular-Arbuscularmycorrhiza) agents on the colonization of three different fruit trees (Yantai Cherry, Hongfushiapple and pear) and their rhizosphere (soil microbial formations, soil enzyme activity and soilnutrient status), and on growth (tree growth and fruit quality) were investigated in this study,the results are listed as follows:1. The infection rate of VA mycorrhiza fungi in the roots of all the three kinds of treesinoculated with VAM agents increased by68.3%，27.7%and31.4%compared with thecontrol, respectively, i.e., the application of VA mycorrhiza agents significantly promoted theinfection rate of VA mycorrhizal fungi, indicating that VA mycorrhiza fungi and tree roots arewell symbioni-ed with the best symbionts formed between VA mycorrhizafungi and apple roots.2. In the rhizosphere of fruit trees inoculated with VA mycorrhiza, the number of microbes(fungi, bacteria and actinomycetes) all showed significant rise; the urease activity increasedsignificantly, while no evident difference was seen in the activity of phosphatase and sucrase;soil pH lowered but electric conductivity increased; The content of organic matter wasreduced significantly; Effective content of N and P in the soil was elevated significantly, butthe result of K was opposite. The application of VA mycorrhiza agents promoted transforma-tion of the total nutrients in the soil into effective contents, thus provided the plants with moreavailable nutrients and faciliated the nutrient absorption in tree roots, raised the nutrientcontent in leaves.3. Compared with the control, the relative water content in leaves of fruit trees (apple,cherry, pear) inoculated with VAM agents increased by2.4%、2.2%and2.8%，the chlorophyllcontent increased by12.8%、13.3%and4.5%, respectively. The sugar content in fruits ofapple and pear trees inoculated with VA mycorrhiza agents increased by21.5%and12.4%,the VC content increased by20.6%and44.2%，ash content increased by13.9%and8.6%,while the acidity declined by21.2%and10.8%, respectively, compared with the control. Thecontent of nutrients like Cu, Fe and Zn in the inoculated trees also exhibited increasecompared with the control. It was evidenced that the application of VA mycorrhiza agentsresulted in the increase of sugar, VC, nutrition, and ash content, but decrease in acidity in fruits, leading to an improvement of the fruit quality and a promotion of the fruit nutrition.