The spray nozzles are one of the most important components of pesticide hydraulic sprayers. This study aimed at evaluating the chemical control of the rust and the deposition of fungicide sprayed on soybean concerning different nozzles, and application volumes. A randomized complete-block design with four replications was used, in a factorial model (4 x 2) + 1: four spray nozzles (standard flat fan, pre-orifice flat fan, air induction flat fan and air induction twin flat fan), two spray volumes (115 and 160L ha-1) and the control (non-treated plot). Emgopa 313 soybean (long cycle) were sown. After the application of the fungicide tebuconazole, with the different nozzles and volume rates, the spray deposition in the plant canopy, the rust severity, and the yield were evaluated. The results showed that, despite the fact of the volume rate of 160L ha-1 and of the use of the standard flat fan nozzles have provided larger fungicide distribution uniformity in the plant canopy, there was not influence of the nozzle type neither of the application volume in the control of the rust as well as in the soybean yield. The fungicide has provided a good control of the rust, increasing the soybean yield, that was, on average, 41% superior to that obtained in the control.
application technology; spray nozzles; Glycine max L.; Phakopsora pachyrhizi
