Study On Optimizing Liquid Pesticide Application Technology

Pesticide application study includes equipment development and operating parameter r optimization. This dissertation put the emphasis on the effect analysis and regularity research of affecting factors on spray quality through a number of tests on different sprayers. Regression models were used in the study to find out the relative extent of different affecting factors against spray quality indices and determine the weights of these factors in the equations that spray quality indices were target functions. The purpose of the regression analysis was to pick out the main affecting factors and to optimize their values, The whole study included six parts, which were analysis on spray quality and affecting factors, analysis on liquid atomizing forms and droplet characteristics, study on nozzles and spray patterns, droplet distribution experiments, spray drift measurements and optimization of spray parameters. Droplet distribution uniformity, drift and coverage ratio are main indices of appraising spray quality. On the basis of rendering the concept of spray quality indices, the effect of meteorological and technical factors on spray quality was synthetically analysed. Liquid pesticide spray is the main form of pesticide application. The liquid atomization is the key process of spray. Starting from discussing the droplet atomizing patterns, the dissertation discussed the effect of the droplet releasing forms on droplet size, initial droplet speed and spray patterns in space for knowing the fitness of different atomizing ways to different types of spray targets and spray conditions. The atomizing principles of typical nozzles, droplet movement and energy balance were fully studied by both theory analysis and case study. The spray quality, on a great extent, depended on the carefiul selection of nozzle types and nozzle quality. The research on the working principles, characteristics, spray patterns, volumeime effect, classify and selection of flat fan nozzles, cone nozzles and spinning discs were important contents of the dissertation. For different spray targets, such as field crops, trees and tiny vertical targets, author designed different test models to measure the distribution uniformity and drift potential under different spray conditions. By test data analysis, the effect of affecting factors on spray quality indices was traced. These affecting factors included nozzle types, sizes, liquid pressures, nozzle heights, spacing, angles and meteorological factors, such as wind speed, temperature and relative humidity. The purpose of this tests was to determine the extent, trend and regularity of these factors affecting spray quality, which provided a prerequisite for further spray technical optimization. By the combination of field tests and wind tunnel experiments, comparisons was conducted on different anti- drift nozzles. The classification of spinning discs in terms of drift potential has been taken into the reference standards of nozzle classification of British Crop Protection Council. Basing on the test data, the author figured out the relative extent of affecting factors on spray quality and determined the weights of these factors against spray quality indices. At the last part of the dissertation, the spray quality indices were listed in order according to their importance to different spray works, such as spraying insecticides, fungicides, herb...