Caracterização físico-química, espectro de gotas e deposição de calda de pulverização com uso de adjuvantes na cultura da soja

Abstract

The spray nozzles and physico-chemical properties of the spray determine their functions and their interaction with the environment. In this context, the objective was to evaluate the physicochemical characteristics, droplet spectrum and spray deposition with the use of adjuvants in the 'Monsoy 7739 IPRO' soybean crop. The laboratory analyzes were carried out in the Laboratorie of the State University of Goiás and the field in a rural area of soybean cultivation in the municipality of Anápolis - GO. The experiment to evaluate the physico-chemical properties of the spray was conducted in a completely randomized design, with a factorial scheme 4 x 2 + 1 (adjuvants x concentrations + control), with four replicates. The treatments consisted of four adjuvants (Break-Thru®, Haiten®, Iharaguen-S® and Orix®) added to the spray combined with two adjuvant concentrations (100 and 150%) and the control (water + fungicide) without the addition of adjuvant. The experiment to evaluate the droplet spectrum was conducted in a completely randomized design, with a factorial scheme 2 x 4 x 2 + 2 (nozzles x adjuvants x concentrations + controls), with four replicates. The treatments consisted of two nozzles (CVI 11002 - standard flat spray and TVI 800075 - empty air induction conical jet) and four adjuvants (Break-Thru®, Haiten®, Iharaguen-S® and Orix®) added to the combined spray with two adjuvant concentrations (100 and 150%) and the control (water + fungicide) without addition of adjuvant, applied with the different nozzles. For the field experiment the design was conducted in randomized blocks, with a factorial scheme 2 x 4 x 2 + 2 (nozzles x adjuvants x concentrations + control), with four replicates. The treatments consisted of two nozzles (CVI 11002 and TVI 800075), four adjuvants (Break-Thru®, Haiten®, Iharaguen-S® and Orix®), two adjuvant concentrations (100 and 150%) and control (Water + Fungicide) without the addition of adjuvant, applied with the different nozzles. The following characteristics were evaluated in the laboratory experiments: surface tension, density, pH and electric conductivity of the spray, size and uniformity of droplets. In the field experiment the droplet spectrum, the deposition of the spray. The data originated from the analyzes were submitted to analysis of variance (P <0.05), and when significant, the Tukey test (P <0.05). Statistical analyzes were performed using software R and SISVAR 5.6. All the boils with addition of the adjuvants reduced the values of surface tension, relative to the control (Water + Fungicide). The spray nozzle CVI 11002, under laboratory conditions, xiv presented DMV suitable for the application of systemic fungicide and safety against drift, with medium droplets and also presented a more homogeneous droplet spectrum. Addition of adjuvants decreased the droplet spectrum and increased droplet homogeneity. Addition of adjuvants did not change the droplet spectrum. In the field, the nozzle TVI 800075 generated droplets of smaller size and more uniform. Increasing the concentration of the adjuvants to the slurry did not increase the deposition and the spray with the Break-Thru® adjuvant increased the DMV at the top of the plant. The adjuvants added to the spray improved coverage on the top of the plant.