Effects Of Different Nitrogen Forms On Curing Characteristics In Flue-cured Tobacco

In order toexplore the effect of different forms of nitrogen supply on flue-cured tobacco ’s curing mechanism and quality,the flue-cured tobacco variety K326 was used as the test material,and five treatments with different nitrogen forms were set,with five different forms of nitrogen supply that N1(100% nitrate nitrogen),N2(30% ammonia nitrogen + 70% nitrate nitrogen),N3(50% ammonia nitrogen + 50% nitrate nitrogen),N4(70% ammonia nitrogen + 30% nitrate nitrogen)and N5(100% ammonia nitrogen),In 2015 ~ 2016 in Shixing County,Shaoguan C ity,Guangdong Province.The effects of different nitrogen forms on the baking characteristics and quality of flue-cured tobacco were studied by studying the water loss characteristics,yellowing characteristics,fixing characteristic s,main chemical composition and the economic shape of the flue-cured tobacco leaves.And the intensive curing process optimization and improvement provides a basis for enriching the smoke modulation technology theory.The main results of the five treatments were as follows:(1)The water loss of different tobacco leaves in the process of curing was characterized by slow,medium and late water loss.In the whole curing process,the water loss of 30% ammonia nitrogen + 70% nitrate nitrogen and 50% ammonia nitrogen + 50% nitrate nitrogen fertilizer was larger,and the water loss rate of tobacco leaves was,The coordination and the water loss rate were balanced;100% nitrate nitrogen and nitrogen fertilizer in the curing process of water loss,water lo ss rate and the water loss coordination of each stage is better than 70% ammonia nitrogen + 30% nitric nitrogen nitrogen ratio Treatment and 100% ammonia nitrogen treatment ratio of tobacco leaves;70% ammonia nitrogen + 30% nitrate nitrogen nitrogen treat ment and 100% ammonia nitrogen nitrogen ratio of tobacco treatment in the curing process,the tobacco leaves in the change Yellow before the middle of the water loss rate is small,in the late yellowing and fixed color loss rate suddenly increased,increas ing the chance of browning.(2)Chlorophyll and carotenoids in different nitrogen supply forms were degraded during the curing process.The chlorophyll degradation rate of 30% ammonia nitrogen + 70% nitrate nitrogen was the highest,and the chlorophyll degradation rate in the middle and middle leaves was 85 %,About 91%,to bake for 72 h,the chlorophyll degradation was more than 90%,and the leaf was the most easily yellowing in the black box test.50% ammonia nitrogen + 50% nitrate nitrogen nitrogen fertilizer 100% nitrate nitrogen nitrogen fertilizer chlorophyll degradation The rate of chlorophyll degradation was less than that of 70% ammonia nitrogen + 30% nitrate nitrogen application and 100% ammonia nitrogen application rate.The yellowing was longer and the yellowing was not ideal.(3)The activity of polyphenol oxidase in the tobacco leaves with different nitrogen supply during the curing process showed that the activity of polyphenol oxidase decreased first and then decreased.N itrate nitrogen fertilizer ratio of fresh tobacco leaves and in the curing process of polyphenol oxidase activity is high,easy to fix color;100% nitrate nitrogen nitrogen ratio and 50% ammonia nitrogen + 50% nitrate nitrogen Nitrogen ratio of polyphenol oxidase activity was moderate;and 30% ammonia nitrogen + 70% nitric nitrogen nitrogen fertilizer ratio of tobacco leaf polyphenol oxidase activity was weak,significantly less than other treatment activity,easy to color characteristics.(4)Different forms of nitrogen supply affect the quality of the flue-cured tobacco leaves by affecting the water loss characteristics,the yellowing characteristics,the fixing characteristics and the chemical composition changes in the tobacco curing process.The quality of the tobacco leaves determines the economy of the tobacco leaves benefit.In this experiment,30% ammonia nitrogen + 70% nitric nitrogen fertilizer ratio of the tobacco in the intensive curing process has a faster water loss rate,yellowing rate,especially water and yellow coordination and good,The enzyme activity and the ratio of sugar to nicotine at the appropriate level,the best tobacco curing characteristics,which can get the highest economic benefits.