Effect Of Plant Compounding Agents On Continuous Cropping Flue-cured Tobacco And Planting Tobacco Soil

In order to improve the diseases and insect pests of flue-cured tobacco caused by continuous cropping and to realize the sustainable development of flue-cured tobacco industry,pot experiments and field experiments of plant compounding agents and chemical agent were carried out in the tobacco experiment base of Zhangshu village,Guangchang county,Jiangxi province,to provide scientific basis for the sustainable development of local flue-cured tobacco.1 Pot experimentThe pot experiment was carried out by setting up 4 treatments: T1 plant compound agent,T2 chemical agent,T3 two kinds of medicament(T1T2)and T4 water treatment.Use of plant compounding agents and chemical pesticides can significantly promote the accumulation of dry and fresh weight of flue-cured tobacco in each growth period,When combined with traditional chemical agents,the promotion of flue-cured tobacco was more obvious.The growth stage from the long term to the late maturity,the dry matter accumulation of T1、T2、T3 treated flue-cured tobacco was 9.6%,11.7% and 28.2% higher than that of T4,fresh weight was 21.7%,25.1% and 34.7% higher than T4.But for the whole growth period,organic material had a positive role in improving fresh dry weight of tobacco.Application of plant compounding agents increased the p H of continuous dryland purple soil,it also increases the content of organic matter in soil,over the whole growth period of flue-cured tobacco T1 、 T3 it was 10.4% and 12.4% higher than the average organic matter content in T4,using plant compounding agents can increase the utilization rate of flue-cured tobacco for soil nutrient nitrogen,phosphorus,potassium,etc.The use of plant compounding agents agents can increase the main activity of sucrase,acid phosphatase,urinary enzyme in soil,traditional chemical pesticides alone decreased the activity of enzymes in soil compared with the blank control,however,the synergistic effect of the combined use of the two agents on soil enzyme activity was more obvious.Use of plant compounding agents to treat flue-cured tobacco,increase microbial population of tobacco-planting soil in different degrees and enrich soil ecosystem biodiversity when compared with the group T4,T1 and T3 increase the number of bacteria in tobacco-plant soils by 43.6 %and 53.6 % in long-term,increased the number of fungi in soil by 46.6% and 52.1%,respectively.The effect of plant compounding agents agent combined with chemical pesticide is more better.2 Field experimentThe field experiment was carried out by setting up 6 treatments: P1 plant compound agent 3 times,P2 plant compound agent 5 times,P3 chemical agent 3 times,P4 chemical agent 5 times,combined treatment of two agents 3 times,P6 two agents combined 5 times.Spraying plant compounding agents can significantly increase plant height,effective number of green leaves and leaf length and width of flue-cured tobacco.The more times applied,the better,and it better with chemicals pesticides.The effect of combined application of five pairs of plant compound agent and chemical pesticide in each treatment on the promotion of flue-cured tobacco is best,the agronomic characters of flue-cured tobacco sprayed only with plant compound agent were slightly worse than those sprayed only with chemical.Spraying plant compounding agents can obviously reduce the content of nicotine in cured tobacco leaves,increase in total sugar and reducing sugar,it also can improve the ratio of sugar-nicotine and potassium to chlorine,the more times used,the more obvious.On nicotine,the combined use of plant compound agent and chemical pesticide for 5 times is the best,compared with the control group,the P3 of nicotine in the upper and middle leaves were reduced 9.97% and 26.5%,with regard to total sugar,the total sugar content in the upper and middle leaves of flue-cured tobacco treated by P6 increased by 34.3% and46.3% respectively compared with the group P3.It is lowest incidence of flue-cured tobacco pests when plant compounding agent and chemical pesticide combined treatment 5 times,compared with P3 treatment,it decreased by 8.54% and decreased the species of pests.The control effect of flue-cured tobacco with plant compound agent is weaker than that with chemical agent.combined treatment of plant compound agent and chemical pesticide has the best control effect on flue-cured tobacco disease,and the more times it was sprayed,the better,P6 lowest incidence of flue-cured tobacco,black shank and PMV,9.93% and 9.83% lower than P3,the effect on both diseases was over 75%.Spraying plant compound can improve the yield,output value and proportion of upper and middle-grade flue-cured tobacco,the more you use,the more effective it is,combined use with chemical pesticides plays a synergistic role.the treatment P1 reduced the yield by11.01% and the output value by 14.1% compared with the group P3;P2、P4、P5、P6 can increase output by 3.05%,9.94%,7.3%,19.8%,respectively,and increase output by4.1%,11.7%,13.3%,14.5%,the effect of combined spraying of two kinds of medicament on the yield,output value and the proportion of upper and middle tobacco was the most significant.