Quantification of self-propelled sprayers turn compensation feature utilization and advantages during on-farm applications

Abstract

Agricultural sprayers are utilized in applying pesticides to control pests and diseases in crops. The increase in machine size and a better control system have been associated with increased productivity, improved efficiency and minimized the impact of the chemical on the environment. However, wider booms may contribute to application error due to the difference in speed between the inner and outer boom section when applying in curvilinear passes. Field tests were conducted in three irregular shaped fields with varying terrain using a 36.6-m self-propelled sprayer with a turn compensation technology. The results showed that turning occurred near the grassed waterways, boundaries and end of headlands. The product was applied during turning to 19.0% of Field 1, 17.8% of Field 2 and 22.5% of Field 3. These could have been the percentage of field areas that may receive more or less product if the sprayer was not equipped with turn compensation technology. As expected, the speed difference between the inner and outer boom increases as the radius of turn decreases. The speed difference could translate to an under-application on the outer boom section where the speed is much faster and over-application on the inner boom section where the speed is slower. The application errors from such speed differential could vary from − 48.2 to + 1058.0%, depending on the turning radius. However, the pulse width modulation system implemented duty cycles based on turning speeds, which resulted to a 90.0% application rate uniformity across the field regardless of the travel path during operation.