Adjuvant efficiency in spray syrup applied by self-propelled spray

Abstract

The present work aimed to evaluate the efficiency of two adjuvants, commercial and sugar, considering mainly the droplet deposition and coverage parameters. The test was carried out at Capelari Farm in Paragominas, Pará. A self-propelled John Deere model 4730 spray was used. The spray tips on the spray were of model M380 Magnojet®, empty cone nozzle; 90º opening angle. Working pressure from 2 to 6.2 bar. An adjunct methyl ester of soybean oil (commercial Aureo®) at a dose of 0.2 L ha-1, recommended by the manufacturer. And sugar at a dose of 0.2 kg ha-1, a dose recommended by expert advice, in addition to a control treatment employing only water. A volume of syrup of 50 2 L ha-1 was used to obtain the deposition, water-sensitive papers positioned 0.5 m from the soil were placed. The parameters dispersion factor, droplet density, coverage percentage and volumetric average diameter were evaluated. The treatments were submitted to a completely randomized design, with the means compared by the Scott-Knott test at 0.05 probability. The results obtained were: the dispersion factor varied with means from 1.50 (control) to 1.67 (sugar), coverage from 32.44% (control) to 36.90% (sugar) the average volumetric diameter from 1913.10 µm (sugar) to 2092.60 µm (water), where there was no significant difference between any of the treatments. Comparing the results of droplet density, it was observed that there was a significant difference of the two adjuvants compared to the control treatment.  The main conclusions of the work are that the adjuvants, commercial and sugar, increased the number of drops per area, providing better spraying efficiency and that, from an economic point of view, the use of sugar as an adjuvant is recommended.