Effects Of Different Amounts Of Chlorine Fertilizer On Growth And Yield And Quality Of Flue-Cured Tobacco And The Research Of Chlorine Absorption Kinetics

The field experiment was carried out to study the effects of different treatments of chlorine on the agronomic traits?physiological indexes,economic characters?physical characters?coordination of chemical composition of flue-cured tobacco variety K326,and soil chlorine nutrient contents,and compared the contents of chlorine in five kinds of flue-cured tobacco varieties,including K326?Hongda?Xiangyan3?Zhongyan90?Yuanyan87?In order to reveal the rules of chlorine absorption and utilization in flue-cured tobacco,hydroponic experiment were carried out to explore the absorption kinetics of flue-cured tobacco varieties K326 and Xiangyan 5 at the different chlorine concentration gradients of Hoagland's nutrient solution.1The field experimental results showed that:?1?The growth of tobacco plant has a good develop trend with the increaseing amount of chlorine fertilizer.Different treatments have little effects on the agronomic indexes in the early.In the middle and later periods,the appearance of plant height?leaf length?leaf width?stem girth and the effective number of leaves on the amount of chlorine fertilizer was 45kg·hm^-22 which are best,and became worse at 60 kg·hm^-2,and following had a significant decrease at 75kg·hm^-2.The proper amount of chlorine fertilizer can meet the nutrient need of flue-cured tobacco growth,and also improve the soil water-soluble chlorine content.?2?Photosynthetic parameters with the increasing amount of chlorine fertilizer after an initial increase had a downward trend.Photosynthetic rate?Stomatal conductance?CO₂concentration?Transpiration rate?SPAD indexes were highest on the amount of chlorine fertilizer was 45kg·hm^-2,the variation tendency of enzyme activity is consistent with the Photosynthetic parameters.?3?The amount of chlorine fertilizer less than 45kg·hm^-22 not only boost the yield and output value,but has positive effects on the physical characters and coordination of chemical composition of flue-cured tobacco leaves,however,excessive is adverse.?4?Chlorine content in different flue-cured tobacco varieties shows that:HongDa>K326>Xiangyan3>Yunyan87>Zhongyan90,but the difference of chlorine absorption among varieties are shows that HongDa>K326>Yuanyan87>Zhongyan90>Xiangyan3.And the amount of chlorine fertilize is more than 60kg·hm^-2,the content of chlorine of each type of flue-cured tobacco leaves beyond the appropriate range.2 The hydroponic experiment results showed that:?1?The chlorine absorption rate rose with the chlorine concentration increased.At the low to moderate chlorine level?0⁰.8mmol/L?,the relation between the chlorine absorption rate of root and chlorine concentration was conformed to the model of enzyme inhibition kinetics.Xiangyan5 and K326 had high affinity and higher absorption rate at the low to moderate chlorine level?0⁰.8mmol/L?,means Xiangyan5 and K326 were more adaptable to nutrient uptake at low chlorine level.The kinetic parameters of chlorine absorption shows that the chlorine concentration of 0.4mmol/L is optimum.?2?At the same chlorine level,The chlorine absorption rate gradually became slower with time.the absorption potential of tobacco plants with low chlorine content was greater than those with high content.?3?The chlorine absorption rate with the change of growth period after an initial increase had a downward trend,and the gap of the chlorine absorption rate in different treatments were decreased in the later period.The maximum chlorine absorption rate.appeared in the period of 40d,and the rate was minimum after 25d.