Determination And Evaluation Model Of Pesticide Deposition Rate For Utilization By Folia Spray In Rice Field

The pesticide deposition rate for utilization is an important factor to reveal the application level of pesticide.In this paper,a mathematical model for evaluating the pesticide deposition rate for utilization by folia spray in rice field was established by comprehensive consideration of the ratio of different plant protection machinery applied in Chinese rice paddy fields,the operational level of the applicators,application level of the pesticide and other factors.This model has great theoretical significance and applicable value to evaluate the development of spray application equipment,operator skill level and application level of pesticide scientifically and rationally.Specific conclusions are as follows:(1)Technical methodology of determining pesticide depos ition rate for utilization by folia Spray in field crop was established,and the stability and precision of the method were verified by determining pesticide deposition rate for utilization of different rice-producing region,different growth period of rice and different spray methods applied in rice field.(2)The mathematical model of pesticide deposition rate for utilization is established according to the main factors that affected the pesticide deposition rate for utilization in rice field,including spray method,chemical and physical properties of spray liquid,application level of pesticide use and the operational level of the applicators.PE_j:Pesticide deposition rate for utilizationa:Synergistic coefficient of pesticide formulations after optimized?:Operational level impact factorX:Type of spray method,1,2,3……Si:The area of pest control on rice by a certain spray methodS:Total spray area of rice(?):The measured value of pesticide deposition rate for utilization in rice by a certain spraying method(3)The pesticide deposition rate for utilization in rice fields in China in 2018 was calculated and evaluated by this mathematical model.Pesticide deposition rate for utilization of Knapsack manual or electric spray method,Knapsack type motorized low volume,stretcher type or vehicle-mounted power spray gun spray method,boom spray method,aviation spray method,is 35.0%?46.2%?25.8%?40.3%and 46.7%respectively.A total of 17.39 million hm~2 of rice control area was investigated,including9.637 million hm~2 of farmers'self-protection and 7.753 million hm~2 of unified control.The weights of the above five spray methods were 0.3437,0.0517,0.0559,0.2614,and 0.2774,respectively.According to the pesticide formulation registered in China and the application of adjuvant sprays in rice field,the synergistic coefficient of pesticide formulation is calculated to be 1.11 after optimized.On this basis,in the light of the mathematical model,the pesticide deposition for utilization with spray technology in the rice field was 36.2%in China in 2018.