The Dynamics Of Tobacco With Bacterial Wilt In Wenshan Prefecture

The research on tobacco infection of Ralstonia solanaceanm and pathogenesis dynamics in Wenshan was systematically processed by roots digging investigation and ELASA detection at fixed location and periods.The results are as follows:1.The results of digging investigation and detection in every week indicated that Ralstonia solanaceanm was detected in the roots firstly in the fifth week after transplanted,and some tobacco roots were affected by black necrosis;About 50%of roots were affected by Ralstonia solanaceanm and black necrosis appeared on several tobacco stems in the seventh week after transplanted;the picks out rate of Ralstonia solanaceanm in stems and roots all raised up to 80% when the tobacco plants were transplanted in the twelfth week.The interval between positive detection in the roots and symptoms appeared on the stems was about 21 days.Based on that, the positive detection and root black necrosis could be taken as the first and second periods to be application time respectively.2.Base on the result of investigation,the field experiment was developed with different applications time.The results indicated that the control efficacy of the disposal to irrigate roots with 100mL of Streptomycin sulfate(200U) and 500mL of Quicklime solution(20×) after transplanted in 10 days was notable and 60.25%of the tobacco plants were protected.The control efficacy was only 30.21%when application after 30 days transplanted.However,it was not obvious control efficacy to Ralstonia solanaceanm after 50 days transplanted.According to the experiments,the suitable application time was the key to protect and cure tobaccos with bacterial wilt besides of choosing the effective medicaments.In conclusion,10 days after transplant was the best time to application.