Uso de aeronave remotamente pilotada para aplicação de inibidores de florescimento de cana-de-açúcar

Abstract

The use of remotely piloted aircraft (RPAs) in agricultural spraying has been increasing due to their advantages, such as efficient water use and application flexibility. However, further research is necessary to understand the dynamics of this equipment under different working conditions, in order to generate recommendations that improve the quality and safety in the use of this new tool. The aim of this study was to evaluate the quality of the application of flowering inhibitors (florpyrauxifen-benzyl at 0.20 and 0.30 L ha⁻¹ and ethephon at 0.66 L ha⁻¹) using RPAs in sugarcane crops at two application rates (10 and 15 L ha⁻¹), resulting in six treatments and one additional untreated control, all with four replications. The trial was repeated in six locations, of which in two, spray deposition (by detecting a tracer through spectrophotometry) and droplet spectrum (by analyzing water- sensitive paper) were evaluated. In all trials, crop injury symptoms and productivity were assessed. Raw material quality (soluble solid content – BRIX and recoverable sugar – ATR) was also evaluated in three locations, along with the physical-chemical properties of the spray solutions. It was concluded that the choice of product greatly influenced the physical-chemical characteristics of the spray solution. Florpyrauxifen- benzyl led to a greater reduction in surface tension and contact angle of the droplet, indicators directly related to increased spreading and coverage potential on the target surface. However, it also resulted in a smaller volumetric median diameter (VMD), an indicator related to greater risk of drift. Ethephon resulted in higher deposition, possibly related to less interference from drift or volatilization. The use of RPA for the application of flowering inhibitors and the tested application rates were technically viable and safe for sugarcane cultivation, with the observed injuries related to the sensitivity of variety RB96 6928 and not to the application technology itself.