Effects of Different Nitrogen Rates on the Growth and Nitrogen and Nicotine Accumulation in Flue-Cured Tobacco

In a field experiment, flue-cured tobacco (Nicotiana tabacum) cultivar K 326 was selected to study the effects of different nitrogen application rates on the growth and the accumulation of nitrogen and nicotine in flue-cured tobacco. The results showed that the dry weight or nitrogen accumulation and nicotine accumulation of each leaf position and of the whole plant had an increasing trend as nitrogen application increased within certain ranges in Jinsha, and they remained basically unchanged when the nitrogen rate surpassed 97.5 kg/hm2. The effects of nitrogen application for increasing dry weight and nitrogen and nicotine accumulation of upper leaves mainly occurred at later growth stages of tobacco plants but those of middle and lower leaves occurred at earlier stages. Compared with the no-N control, nitrogen application treatments advanced the arrival of the highest rates of accumulation in dry weight and nitrogen accumulation and nicotine accumulation of the whole plant, and all the three increased with N rates. The highest rate of nitrogen accumulation of the whole plant occurred before that of nicotine accumulation and dry weight of the whole plant, which occurred after the removing the apex.