Viabilidade agronômica no uso de drone pulverizador visando o controle de doenças na cultura da soja

Abstract

Soybean is the main crop in Brazil and the country stands out for being the first in the ranking of the largest producers in the world. To maintain competitiveness and accelerate production, it is essential to control factors that negatively affect the culture. An important point is the increase in the efficiency of control methods and technologies for the application of agricultural defensives, among which Drones stand out. The use of spray drones is a recent practice for controlling pests, diseases and weeds in crops, and expansion is expected in the coming years. There are several advantages listed for spraying with drones, however, as it is a recent technology and under evaluation, the objective of this study was to evaluate in the field the agronomic efficiency of the drone sprayer compared to the self-propelled sprayer, to define whether the drone allows satisfactory control of the main diseases in the soybean crop and what is the adequate volume of syrup in the drone. The study was conducted in two stages for validation. The first test was carried out in TrêsCorações and the second in São Bento Abade, both located in the southern region of the state of Minas Gerais. The sprayings were carried out with a self-propelled sprayer with a conical and fan nozzle, at a flow rate of 150 L ha-1 (PQ150C and PQ150L) and with a drone sprayer with a conical and fan nozzle and a flow rate of 10 L ha-1 (Q10C and Q10L) and 15 L ha-1 (Q15C and Q15L). Equal agronomic managements were carried out in all spraying models and variables were evaluated: average volumetric diameter, droplet density, percentage of covered area, severity of the main diseases and productivity. The experiments were carried out in a DBC with four replications and analyzed with the SISVAR Software. The largest volumetric mean diameters and percentage of covered area were observed in PQ150L, PQ150C and Q10C. Regarding droplet density, the conical nozzle was more efficient. As for the severity of rust attack, the lowest flow rates (Q10C and Q10L) were the most inefficient, regardless of the nozzle used. In the control of white mold, the Q15C, Q15L and Q10C drones are efficient compared to the Q10L and did not differ from the self-propelled sprayers As already observed in the control of rust and white mold, only Q10L was not efficient in controlling end-of-cycle diseases. The results reflect the productivity that reached an average of 79 vs 84sc ha-1 in test 1; and 80 vs 90sc ha-1 in test 2. Therefore, it is concluded that the application with a drone presents different results and presents itself as an efficient technology for spraying. Spraying with a drone at a flow rate of 15 L ha-1, especially using the conical nozzle, culminates in similar results in several parameters to the self-propelled sprayer with a flow rate of 150 L ha-1, thus being an effective alternative for achieving success in phytosanitary management, providing satisfactory results in terms of productivity in addition to potentially reducing negative damage to the environment.