| Spodoptera frugiperda can migrate over long distances,has strong reproductive ability,and causes severe crop yield reduction.Spodoptera frugiperda invaded China in early 2019,causing food security problems for various crops such as corn.In this paper,chlorantraniliprole and indoxacarb were used as the objects to study the field control effect of Spodoptera frugiperda and their impact on corn yield under two application methods:knapsack electric spray and unmanned aerial vehicle spray.The effects of chlorantraniliprole and indoxacarb on the safety of maize under the 2application methods of knapsack electric spraying and drone spraying,the field control effect of maize Spodoptera frugiperda and their effects on maize yield.The main findings are as follows:1.Safety of different pesticides on maize under two kinds of foliar sprays.According to Pesticide-Guidelines for the Field Efficacy Trials were carried out on the control of Spodoptera frugiperda in corn by treating 3 kinds of test chemicals 200g/L chlorantraniliprole,150 g/L indoxacarb and 10%carbaryl indoxacarb.Observations were made 3,5,and 7 days after the treatments.All treatment plots under the 2 treatments showed normal growth and no phytotoxicity.2.Efficacy of different pesticides against corn Spodoptera frugiperda under the application method of knapsack electric sprayer.According to Pesticide-Guidelines for the Field Efficacy Trials on the test of different pesticides against Spodoptera frugiperda was carried out under the application method of the knapsack electric sprayer,and the occurrence of Spodoptera frugiperda in the experimental plot was investigated before and 3,5 and 7 days after the treatment.The results showed that the number of newly damaged leaves of maize and live insects of Spodoptera frugiperda larvae were significantly reduced after the use of pesticides,compared with the other 5 treatment areas,the control effect of damaged leaves and larvae in the treatment area of 10%Avid-Indoxacarb 40 g/667 m~2was lower.150 g/L indoxacarb has good quick-acting effect,and 200 g/L chlorantraniliprole has better lasting effect.On the whole,200 g/L chlorantraniliprole10 m L/667 m~2+150 g/L indoxacarb 12 m L/667 m~2 had the best treatment effect,and the control effect was the highest 10 days after the treatment,which were 95.37%and98.55%respectively.3.Efficacy of different pesticides against corn Spodoptera frugiperda under the application method of knapsack electric sprayer.According to Pesticide-Guidelines for the Field Efficacy Trials on the test of different pesticides against Spodoptera frugiperda was carried out under the application method of the knapsack electric sprayer,and the occurrence of Spodoptera frugiperda in the experimental plot was investigated before and 3,5 and 7 days after the treatment.The results showed that the number of newly damaged leaves of maize and live insects of Spodoptera frugiperda larvae were significantly reduced after the use of pesticides,compared with the other 5 treatment areas,the control effect of damaged leaves and larvae in the treatment area of 10%Avid-Indoxacarb 40 g/667 m~2was lower.150 g/L indoxacarb has good quick-acting effect,and 200 g/L chlorantraniliprole has better lasting effect.On the whole,200 g/L chlorantraniliprole10 m L/667 m~2+150 g/L indoxacarb 12 m L/667 m~2 had the best treatment effect,and the control effect was the highest 10 days after the treatment,which were 98.55%and94.69%,respectively.There was no significant difference in the effect of drone spraying on the control of corn flea armyworm and artificial spraying,and the effect of drone spraying was slightly better than that of artificial spraying in some treatments.4.The influences of different chemical control on corn yield under two kinds of foliar sprays.According to Pesticide-Guidelines for the Field Efficacy Trials on the yield of corn were carried out,theoretical yield measurement investigation of maize in experimental plot at 60 d after treatment.The results showed that there are differences in the number of effective panicles,effective panicle grains and thousand-grain weight in the 7 treatment areas.After artificial spray application,the effective panicle number,effective panicle number and thousand-grain weight per unit area of the 200g/L chlorantraniliprole 10 m L/667 m~2 compound 150 g/L Indoxacarb 12 m L/667 m~2treatment area slightly higher than the other 6 treatment areas,the theoretical rice yield per mu is also somewhat different from the other 6 treatment areas,which is526.31 kg,and the other 6 treatment areas are 511.73 kg,520.43 kg,505.86 kg,504.11 kg,480.66 kg and 467.06 kg respectively.After the drone is sprayed,the effective panicle number,effective panicle number and thousand-grain weight per unit area of the 200 g/L chlorantraniliprole 10 m L/667 m~2 compound 150 g/L Indoxacarb12 m L/667 m~2 treatment area slightly higher than the other 6 treatment areas,the theoretical rice yield per mu is also somewhat different from the other 6 treatment areas,which is 532.16 kg,and the other 6 treatment areas are 511.92 kg,527.05 kg,502.29 kg,513.89 kg,493.82 kg and 466.86 kg respectively.There was no significant difference in the effect of drone application on yield compared with manual spray application,and the yield of drone application was slightly better than that of manual spray application in some treatments. |
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