Effects Of Different Nitrogen Forms On Fusarium Wilt Of Cucumber

Cucumber(Cucumis sativus L.) is one of the main vegetables are facilities large area of cultivation. In recent years, with the development of vegetable production, facility cultivation has become one of the world’s most important agricultural production mode.Facility vegetable cultivation of special ecological environment and excessive, abuse of chemical fertilizer phenomenon led to the soil secondary salinization in facilities, nutrient imbalance, soil environmental degradation and other issues, the serious influence the quality and the quality of the vegetables, has become an important factor of restricting the sustainable development of vegetable production..Therefore, how to use fertilizer reasonably and improve the utilization rate of fertilizer has become a problem to be solved.This paper with different nitrogen processing cucumber blight pathogen as the research object, combined with the pathogen growth and development, research the different ratio of nitrogen forms on cucumber blight pathogen spores germination, spore production quantity and the influence of the hyphae length. By different nitrogen treatment under the condition of cucumber seedling root zone soil microbial community structure, quantity, soil enzyme activity and incidence of, intends to find out different form and proportion of nitrogen in cucumber blight pathogen growth and soil ecological environment. Try to explore the reasonable ratio of nitrogen, so as to create a good ecological environment of soil and formulate reasonable fertilization system provides theory basis. By studying the following conclusions:1. Ammonium nitrogen than nitrate as10:0,5:5significantly inhibited the cucumber blight pathogen spores germination rate; Ammonium nitrogen than nitrate as10:0,5:5, when the ratio of3:7pathogen spores quantity minimum significantly;Cucumber blight pathogen colony diameter in2-5d than ammonium nitrogen nitrate as10:0, the colony diameter was significantly lower than in other treatment5:5proportion,6d than ammonium nitrogen nitrate as the ratio of5:5colony diameter was significantly higher than that of ammonium nitrogen than nitrate as10:0.2. Ammonium nitrogen than nitrate to5:5and the ratio of3:7, the lowest incidence of cucumber seedling blight were31.67%,38.33%, disease index were14.17%,17.92%, effectively inhibit the incidence of cucumber fusarium wilt, reduce the disease index.3. Ratio of different forms of nitrogen are promoted the growth of cucumber seedlings, and improved the cucumber root zone soil urease, neutral phosphatase activity, reduce the activity of catalase.And improved the cucumber root zone soil urease, neutral phosphatase activity, reduce the activity of catalase.When points after seedling,21,28d than ammonium nitrogen nitrat10:0, ratio of7:3urease activity;Ammonium nitrogen as the ratio of7:3than nitrate in points i seedling, at21d14highest soil neutral phosphatase activity significantly, after points miao than ammonium nitrogen nitrate as10:0, therefore, the ratio of5:5the highest soil nei phosphatase activity;Cucumber root zone soil catalase activity were significantly lower control in the three sampling period, among them with ammonium nitrogen than the minir ratio of nitrate nitrogen for10:0activity;Ammonium nitrogen than nitrate as7:3and5:5and of3:7in cucumber seedlings after21and28root zone soil dehydrogenase activity significantly higher than that of control, of which the ratio of5:5the highest activity, the rati3:7.4. Cucumber seedlings points after seedling,21,28d than ammonium nitrogen nitrate tc cucumber root area, the ratio of3:7higher soil microbial total,28d, ammonium nitrogen nitrate to5:5cucumber root area, the ratio of3:7number of soil bacteria and actinomyc significantly higher10:0and contrast, and the ratio of5:5cucumber root zone soil fungi qua minimum, and significantly lower than other treatment and control.5. Under different ratio of nitrogen form processing, no cucumber root zone soil inocul cucumber blight pathogen bacteria community structure in14,21d, ammonium nitrogen nitrate and processing for cucumber root zone under the number of bacteria community struc belt, Shannon Wiener index and evenness index is the largest,28d when the difference betv the groups was not significant;14d after inoculation, ammonium nitrogen than nitrate is processing cucumber root zone bacteria Shannon Wiener index and evenness index significant the largest, most significantly, while21d but nitrate nitrogen and ammonium nitrogen ratio o processing difference was not significant,28d than ammonium nitrogen nitrate is3:7proces cucumber root zone community structure of Shannon Wiener index and evenness index, lo other differences between the groups was not significant.Ammonium nitrogen than nitrate a; processing, unvaccinated cucumber root zone soil fungal pathogen colony structure Shann Wiener index and evenness index in14,28d is significantly higher than other treatment;In th d after inoculation is significantly higher than other processing.T o sum up:Different Forms of Nitrogen Fertilizer changed the soil environment, ammoi nitrate cucumber root area ratio is the ratio5:5,3:7and soil microbial activity occurred in number and diversity change, changing the soil environment, increasing the number abundance of soil microbes to promote the growth of cucumber seedlings, reducing the incid of cucumber wilt disease, in which ammonium nitrate ratio of5:5ratio is more approp cultivation of cucumber production facilities.