Evaluation of Remotely Piloted Aircraft for Agricultural Spraying in Corn Cultivation in the Brazilian Savannah

This study aimed to evaluate the quality of application using both RPA and ground techniques in corn cultivation using different spray nozzles in Brazilian savannah (Cerrado). The experiment was conducted using a completely randomized design, with four treatments and eight repetitions. The treatments involved two methods of application- aerial (RPA, 10 L ha-1) and ground (backpack sprayer, 100 L ha-1); and two types of nozzles- the standard flat fan nozzle XR 11001 and the air induction flat fan nozzle AirMix 11001. To study the quality of the application, the deposition was evaluated using a tracer and spectrophotometry, and the droplet spectrum, evaluated through the analysis of water-sensitive paper. Furthermore, a study on application quality was conducted using the Statistical Process Control methodology. The results demonstrated that with RPA, the deposition was higher, and the AirMix 11001 nozzle also stood out in this variable. No non-random behavior was observed in the deposition. Ground application showed the best performance in terms of target coverage and droplet density. The XR 11001 nozzle resulted in a higher droplet density. Overall, the XR11001 nozzle and the RPA application showed smaller volume median diameters (VMDs), indicating a higher potential for drift, which should be taken into account. Given the results obtained, it can be stated that the use of RPAs for agricultural spraying is viable for application.