| The occurrence of diseases and pesticides presents new characteristics of installment vegetable plants in China,and the abuses of chemical pesticides,low efficiency use or excessive use occur.In order to screen out new pesticide applicators suitable for greenhouse tomato disease and pest control,we provide guidance for scientific use of pesticides in tomato production.In this paper,four different spray mode were tested under the rated spray pressure,the safety test of the electrostatic spray on tomatoes,the test of pesticide utilization by the manual and the electrostatic spray,and the deposition of 2h,4h,6h,8h and 24 h on the upper,middle and lower leaves of the tomato after the application of diphenyl permethrin in the positive and reverse sides of the leaves and the loss of the ground.Under the conditions of 0%,40%,60% and 80%,the comparison test of diphenyl pyrethrin with four spray mode in the leaf deposition test and the field efficacy test for the control of tomato whitefly.The main research results are as followsThe results of the four sprayers in the nozzle flow are electric spray > manual spray > Non-electrostatical spray > electrostatic spray.From the point of flow stability,the results show completely opposite results.Therefore,the nozzle volume of electrostatic spray mode is smaller,the droplet is thinner and the flow rate of sprinkler is more stable.From the flow rate of the electrostatic spray mode in the non-electrostatic and electrostatic mode,there is little difference between the two.The electrostatic sprayer applied the pesticide to tomato and used the high registered dose to prevent and control the pesticide of tomato diseases and insect pests.When the amount of liquid was 8.3 L,3 d,7 d and 10 d after the application,there was no significant difference in the deciduous and drop rate of the treated chemicals,the deciduous rate and the falling fruit rate of the water control.The results showed that the rate of fallen leaves and fruit dropping were the same as those of the contrast.Using 100g/L biphenyl pyrethrin EC,the effective ingredient was 7.5 g(a.i.)/ha.The deposition of electrostatic spray in tomato plants increased by 68%,the utilization rate of pesticides increased by 114.7%,and the utilization rate of pesticides in leaves,stems and fruits increased respectively by 114.7%,106% and 137.2%.For tomato seedlings,the deposition of electrostatic spray was increased by 75.2% than that of manual spray and the utilization rate of pesticides increased 92.8%.Therefore,electrostatic spray can increase the utilization rate of tomato adult plants and seedlings compared with manual spray even more than 90%.The electrostatic spray has a faster deposition rate than the manual spray.After the electrostatic spray,the amount of deposition will not increase after 2 h,and the manual spray can deposit completely at about 4 h.Electrostatic spray can increase the amount of biphenyl pyrethrin on the positive and negative sides of tomato leaves.By comparison,it is found that the deposition of the electrostatic spray on the upper part of the blade is increased by 72%,55% in the middle and 36% in the lower part.The deposition rate of the electrostatic sprayer increased by 38% compared with the manual spray on the upper side of the blade,increased by 42% in the middle and increased by 63% in the lower part.Therefore,electrostatic spray can increase the deposition of pesticides on the front and the opposite sides of tomato leaves,which can make the tomato more uniform than manual sprayers.The results showed that the 4 spray mode showed the same rule for the deposition and efficacy of bifenthrin in tomato leaves.At 0%,the deposition of electrostatic spray mode is higher than that of non-static,manual and electric spray.When the antistatic spray is reduced by 40%,the electrostatic sprayer is equal to the control effect of manual and electric spray model when the electrostatic model is deposited at 0%.Therefore,the electrostatic spray mode has good deposition rate and can reach the deposition level of conventional spray mode.The deposition of 60% and 80% decreased significantly compared with 0% and 40% respectively.In the field of efficacy,the use of diphenyl pyrethrin to prevent and control tomato whitefly by 4 kinds of spray mode showed that the electrostatic spray mode had better control effect at the same time as the conventional manual and electrostatic spray,and the control effect was equal to the conventional spray when the amount of water was reduced by 40% and the water consumption was 8.3 L.Therefore,field control of tomato whitefly can be carried out with electrostatic spray.In conclusion,electrostatic spray can increase the sedimentation rate and the amount of deposition in tomato leaves,reduce soil loss,increase the utilization rate of pesticides,improve the control effect and reduce the 40% dosage of pesticide.Therefore,in greenhouse tomato production,electrostatic spray mode can be used as a substitute for manual and electric spray,and it is more economical and environmentally friendly. |
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