Effects Of Nitrogen Fertilizer Application On Growth And Quality Of Flue - Cured Tobacco In Longjiang 981

In order to promote the production of high-quality characteristic flue-cured tobacco production, taking flue-cured tobacco variety LJ 981 as material under field experiment, the effect of decreased-nitrogen fertilization on leaf photosynthetic characteristics,root morphological characteristics, leaf area coefficient, chemical composition, yield and quality of flue-cured tobacco varieties LJ981 in Longjiang, the effects of nitrogen fertilization on photosynthetic characteristics, root morphology, leaf area coefficient, chemical composition, yield and quality of flue-cured tobacco were studied.Results show:1. Decreased-nitrogen fertilization treatment decreased leaf chlorophyll SPAD value, transpiration rate, stomatal conductance, F value and Fm’ values, increased the photosynthetic rate, intercellular CO2 concentration and ΦPSⅡ of flue-cured tobacco leaf net photosynthesis, and accelerated the electron transfer rate. Combined application of foliar fertilizer treatment increased the chlorophyll SPAD value of the upper and lower leaves of Flue-cured tobacco. The treatment of 15kg/hm-2 nitrogen fertilization maintains relative high photosynthetic characteristics.2 The technology of decreased-nitrogen fertilization increased the root vitality of flue-cured tobacco, and inhibited the decrease of root activity. The vitality of root with a total 15kg/hm-2 nitrogen application was the highest. Decreased-nitrogen fertilization will reduce root length, surface area, volume, diameter and the number of root tips.3. Reduction of nitrogen fertilization technology is helpful to improve the middle and upper part of flue-cured tobacco nicotine(in addition to no fertilization), reduce the lower part of leaf total nitrogen and central leaf total nitrogen, reducing sugar, total sugar content. Lower, middle and upper parts of the leaf to reduce nitrogen fertilization treatment to reduce the ratio of nitrogen to nicotine, ratio of sugar to alkali, improve the ratio of potassium to chlorine. Finally, the total nitrogen application rate was 15kg/hm-2, which was the most coordinated and the highest evaluation score. Reduced nitrogen fertilizer treatment decreased the N content of tobacco plant, total nitrogen content for 15kg/hm-2 treatment can improve the tobacco plant P, K content, total nitrogen content more than 15kg/hm-2 treatment decreased in tobacco plant P, K content and effects of P and K absorbed properly. Reducing nitrogen fertilization, reducing the proportion of root and stem dry weight of the whole plant, increasing the proportion of the whole tobacco leaf.4. Decreased-nitrogen fertilization technology improved leaf number and plant height in resettling stage, as well as length, width and area of upper leaves in the growth period,and reducedlength, width, area of the middle leaves in the growth period of the flue-cured tobacco group tree. Decreased-nitrogen fertilization results in high incidence of plant diseases and insect pests. Combined application of foliar fertilizer treatment reduces the incidence of plant diseases and insect pests. Decreased-nitrogen fertilization improved the flue-cured tobacco’s per leaf weight, classy smoke rate, secondary smoke rate, orange smoke rate, yield, average price and production value.