Control Effect of UAV Low Volume Spray Technology on Thrips and Tomato Spotted Wilt Virus in Tobacco Field

[Objectives]The paper was to explore the influence of unmanned aerial vehicle(UAV)low volume spray technology on the control effect of viruliferous thrips and tomato spotted wilt virus(TSWV)under different pesticide concentrations,and to explore the effective control nodes and methods of thrips and TSWV.[Methods]According to the occurrence characteristics of thrips and TSWV,the field control effects of 4 pesticides on thrips and TSWV were tested by UAV with the thrips number and disease index as indicators,following the principle of regional and periodic control trials.[Results]In the groups of UAV and artificial prevention and control,4 agents were used alternatively,including 1%emamectin benzoate ME,1.7%abamectin imidacloprid ME,5%emamectin benzoate WDG,and 30%pyriproxyfen dinotefuran SL.There was no significant difference in the control effect of thrips and TSWV among treatment 1(recommended dosage of UAV agent),treatment 2(reduction of recommended dosage of UAV agent by 25%)and treatment 4(recommended dosage of artificial control agent),and the control effects on thrips were more than 83.16%in the 3 treatments.The disease index of TSWV in the 3 treatments decreased from 8.64±1.37 in the blank control group to less than 3,which reached the prevention and control threshold.But treatment 3(reduction of recommended dosage of UAV agent by 50%)did not reach the prevention and control threshold.The disease index of TSWV in the blank control area increased with the increase of the number of live nymphs of thrips,and there was a significant positive correlation,with good fitness.[Conclusions]UAV has a significant impact on the control effect of thrips and TSWV under different pesticide concentrations.In the actual flight control application,it is recommended that the amount of the pesticides is about 3/4 and not less than 1/2 of that of the artificial application.The control area should be extended to 100 m of the ridge of the tobacco field,and UAV is used periodically to control thrips and TSWV for 5 times from pre-transplanting stage to pre-squaring stage of flue-cured tobacco.The control effect is significantly different from the traditional artificial application.

A Preliminary Study on the Regularity of Outbreak of Thrips in Asparagus-bean Interplanting Fields

[Objectives]This study was conducted to clarify the composition and occurrence regularity of thrips in asparagus-soybean intercropping fields.[Methods]The species and occurrence dynamics of thrips in asparagus-bean intercropping fields in Luquan District of Shijiazhuang were investigated.[Results]There were 7 species of thrips in this area,namely,tobacco thrips[Thrips alliorum(Priesner)],western flower thrips[Frankliniella occidentalis(Pergande)],Scolothrips takahashii Priesner,Megalurothrips usitatus(Bagrall),Sussericothrips melilotus Han and Aeolothrips fasciatus.As the dominant species,tobacco thrips had two peak outbreaks in late June and late September,and maintained a high quantity level for a long time.Other thrips had fewer population and different occurrence time,but were greatly affected by temperature,humidity and host crop species.[Conclusions]This study provides a theoretical basis for the forecast and comprehensive control of thrips in North China.