Indoor toxicity of oxathiapiprolin against Phytophthora nicotiana and its control effect against tobacco black shank
Tobacco black shank is a soil-borne fungal disease caused by tobacco blight,which poses a serious hazard to tobacco production.To investigate effect of oxathiapiprolin on control of tobacco black shank,the inhibition of mycelial growth and sporulation of Phytophthora nicotiana was measured under in vitro conditions,and control effect of oxathiapiprolin on tobacco black shank and its impact on the safety of tobacco was evaluated in indoor pot and field trials.The results showed that oxathiapiprolin was effective in inhibiting mycelial growth and sporocyst formation of tobacco pathogens in all regions,with EC50 value of 0.000 5 mg/L and 0.000 4 mg/L,respectively,compared to other control agents.Indoor pot test showed that the efficacy of oxathiapiprolin 10％oil dispersion 4 000 times against tobacco black shank was 84.33％,while the efficacy of 2 000 times reached 96.00％,which was significantly different from the control agent.Field trials showed that the efficacy of oxathiapiprolin 10％oil dispersion at 2 000,3 000 and 4 000 times of solution reached 93.82％,90.18％and 83.27％,respectively,while that of dimethomorph 80％water dispersible granule 2 500 times and mancozeb 80％wettable powder 600 times were 77.82％and 75.27％,respectively.In addition,compared to the control agent,oxathiapiprolin showed better promotion in plant height,effective leaf number,leaf length,leaf width and photosynthetic rate.The above results showed that oxathiapiprolin was effective in controlling tobacco black shank and could improve tobacco yield and quality to a certain extent.
tobacco black shankoxathiapiprolinindoor toxicitycontrol efficacy
万方数据
维普
