Innovative sprayer with optimized sensor-based gap detection for precision application of plant protection products

For fruit growing, plant protection products (PPP) are required to maintain yield and to fulfill high quality standards. In vertical crops the application of PPP is made by active air support, which can result in unwanted displacement of PPP into the environment. These amounts rise when trees are bare and gaps in the canopy are larger. In densely populated regions and those with a high density of ditches, the reduction of these amounts and drift mitigation are important sociopolitical goals. Modern sensor systems offer the possibility for precise target and gap detection and can ensure an appropriate switching of single nozzles. This innovative system allows a high saving potential of PPP and a precise application onto the target area in each tree. In the present project, a concept of an optimal combination of sensors and nozzles for gap detection was further developed. Different sprayers were equipped with a high number of new optical infrared-sensors to optimize the scanning field in the orchard. In comparison with previous sensor systems, the new sensors detect single bare branches without focusing a second tree row and neglect branches in the immediate area. In 2014, field experiments in Jork have shown that a precise application can reduce the output quantity of PPP, as much as 40% in a ten-year-old apple orchard. The efficiency was significantly influenced by software-supported switch-on and switch-off of the nozzles. The evaluation of the losses in the gap showed lower values compared to conventional full application, which could also result in a drift reduction and more efficient application onto the target area. The aim of the project is to develop marketable sprayers with different fan types as well as a retrofitting kit for sprayers in use, which fulfill the requirements for a high PPP usage efficiency.