DROPLET DISTRIBUTION AS A FUNCTION OF COTTON INTERROW SPACING AND ANGLES OF SPRAYER DISPLACEMENT

ABSTRACT Application technology factors may be influenced by changes in plant architecture, such as height and leaf area. This study aimed to evaluate which angle of sprayer displacement in the application of pesticides in relation to the direction of cotton sowing, cultivated in the ultra-narrow row, narrow row, and conventional systems, provides the best application quality characteristics in the different thirds of plants. The experiment was installed in a split-plot design with four replications in the 3 × 4 factorial scheme, composed of three cotton cultivation systems and four angles of sprayer displacement in relation to the direction of the sowing rows. The evaluated characteristics were mean volumetric diameter, density and coverage of droplets, number of droplets, and open area in the interrows without leaf. The upper third presented the highest values of mean volumetric diameter, number of droplets, and density and coverage of droplets for all interrow spacing and application angles. The angle of displacement of 30° in relation to the sowing row presented the best results in relation to the number and density of droplets. The spacing of 0.90 m in the interrows increased the number of droplets, droplet density, and coverage in the lower third of plants.摘要 施药技术参数可能受株型（如株高、叶面积）变化的影响。本研究旨在评估：针对超窄行、窄行及常规种植系统下的棉花，采用何种喷雾机相对于播种行方向的偏移角度，可在植株不同三分之一段实现最优的施药质量指标。本实验采用裂区设计，设置3×4因子方案并开展4次重复，因子组成为3种棉花种植系统与4种喷雾机相对于播种行方向的偏移角度。本次测定的指标包括：雾滴平均体积粒径、雾滴密度、雾滴覆盖率、雾滴数量，以及无叶行间的裸露面积。无论行间间距与施药角度如何，植株上部三分之一段的雾滴平均体积粒径、雾滴数量、雾滴密度与覆盖率均达到最高水平。相对于播种行偏移30°的角度，在雾滴数量与雾滴密度方面表现最优。行间间距为0.90m时，可提升植株下部三分之一段的雾滴数量、雾滴密度与覆盖率。