Influência De Diferentes Pontas De Aplicação De Bioinsumos E Populações De Plantas Na Deposição De Gotas Na Cultura Da Soja (Glycine Max L.)

The efficiency of bioinput application in soybean is directly related to spray application technology, particularly nozzle characteristics, crop growth stage, and canopy architecture. This study aimed to evaluate the quality of bioinput application at different soybean growth stages, considering spray nozzles, plant populations, and deposition positions within the canopy. The experiment was arranged in a randomized complete block design with a split-split-plot scheme: two plant populations (160,000 and 240,000 plants ha⁻¹) in the main plots; four flat-fan nozzles (TT110.04, TT110.015, TT110.02, and TT110.03) in the subplots; and two sampling positions (upper and lower canopy) and three growth stages (V10, R1, and R5) in the sub-subplots, evaluated as repeated measures. The number of droplets, spray coverage, volume median diameter (VMD), relative span, and deposited spray volume were determined on water-sensitive papers using Gotas® software. Data were analyzed using a Gamma generalized linear model, and means were compared by Fisher’s least significant difference (LSD) test (p ≤ 0.05). The number of droplets was affected by the nozzle × plant population × growth stage interaction. The TT110.02 nozzle provided the highest deposition, coverage, and spray volume at V10 and R5, whereas the TT110.015 stood out for the number of droplets at R1. Deposition and coverage were higher in the upper canopy, indicating reduced droplet penetration at more advanced growth stages. The TT110.04 showed the highest VMD and span values, without resulting in greater deposition. In conclusion, application efficiency depends on the interaction among nozzle, growth stage, and canopy architecture, with the TT110.02 standing out at V10 and R5 and the TT110.015 at R1.