Qualidade da aplicação em trigo conforme reduções da taxa aplicada em associação com diferentes pontas de pulverização

Abstract

Nowadays there is a trend of become the operational of agrochemicals spray faster. Then, it may cause a direct impact on the spray quality of a given product, influencing even directly the effectiveness of it control. The present study investigated the feature of application as reduced spray rates in combination with different spray nozzles in two wheat cultivars. Field experiment was conducted in the winter of 2011 at Institute Phytus experimental field, on Itaara, central region of Rio Grande do Sul. It was test rates of 180, 140, 100 and 60 L/ha applied with the nozzles XR 11001, TT 11001 and TT 110015 on Fundacep 52 and Quartzo wheat cultivars, on three times: during the stem elongation, in head emission and in full flowering. For collection of drops of dye was used application on Contact paper cards, which were placed in exactly the same position and with the same format that the leaves if desired look. In each application was performed to characterize the quality as this: volume median diameter (VMD), SPAN (RA), number of droplets per square centimeters and percentage of coverage. Common to both cultivars, the DMV was conditioned only by the nozzles, being always smaller for XR 11001, and AR did not vary in any situation. The interaction between spray rates and spray nozzles was more decisive in droplet deposition on the cultivar Fundacep 52 than cultivar Quartzo, and on number of droplet per square centimeters than percentage of coverage. The nozzle XR 11001 tended to result in the greatest number of droplets per square centimeter, while the TT 11001 tended to generate the highest percentage of coverage. Reductions in spray rate normally produce more regular decreases in deposits when were used the TT nozzles regarding XR nozzle.