Deposição de calda na aplicação aérea e terrestre de fitossanitário na cultura da batata

Abstract

RESUMO:O objetivo deste trabalho foi avaliar a deposição de calda pulverizada na cultura da batata e o espectro de gotas promovidos pela aplicação aérea e terrestre. O experimento foi repetido em duas épocas, em lavouras comerciais de batata, no delineamento inteiramente casualizado, em esquema fatorial 6 x 2, sendo seis formas de aplicação (aérea, a 15 e 30 L ha -1 com atomizador rotativo, e terrestre, a 200 e 400 L ha -1 , com pontas de jato plano duplo, com indução de ar e jato cônico vazio); e duas composições de calda (água e água mais o adjuvante fosfatidilcoline + ácido propiônico). Avaliaram-se deposição de calda no dossel da cultura, perdas para o solo e deriva, pela técnica da adição de traçador para quantificação por espectrofotometria, e espectro de gotas, por meio da análise de papéis hidrossensíveis. A adição do adjuvante, de forma geral, proporcionou maior retenção de calda nas folhas inferiores e superiores. A diminuição do volume de aplicação proporcionou boa deposição de calda no alvo, sendo uma alternativa para aumento da capacidade operacional. A aplicação aérea mostrou-se tão eficiente quanto as aplicações terrestres na deposição de calda no alvo. A utilização do adjuvante não interferiu no diâmetro da mediana volumétrica e na percentagem do volume de gotas pulverizadas menores que 100 μm. PALAVRAS-CHAVE:aviação agrícola, deriva, ponta de pulverização, espectro de gotas. SPRAY LIQUID DEPOSITION IN AERIAL AND GROUND PESTICIDE APPLICATION IN POTATO CROPABSTRACT: The aim of this study was to evaluate the sprayed liquid deposition in potato crop and the droplet spectrum, promoted by aerial and ground applications. The experiment was conducted in duplicate, in commercial potato crops, in completely randomized design, in a factorial model 6 x 2: six application methods (aerial, with rotative atomizer at 15 and 30 L ha -1 , and ground, at 200 and 400 L ha -1 with air induction twin flat-fan and hollow-cone nozzles) and with two spray liquid compositions (water and water plus phosphatydilcoline + propionic acid adjuvant). It was evaluated spray liquid deposition in the crop canopy, run-off and drift, by addition of a tracer for quantification by spectrophotometry technique and the droplet spectrum by image analysis of watersensitive papers. In general, the adjuvant addition provided a better spray liquid retention into lower and upper leaves. The decrease of spray volume provided a good spray liquid deposition on target that was contribute for an increase of the operational capacity. The aerial application was as efficient as the ground applications on the spray liquid deposition on the target. The use of adjuvant did not modify the volume median diameter and the percentage of spray volume in droplets smaller than 100 µm diameter.

Effect of Nozzles, Application Rates, and Adjuvants on Spray Deposition in Wheat Crops

“…These results are in line with those of Bueno et al (2013), who used different application rates in potato crops and found that losses to the environment were higher with higher application rates in the absence of adjuvants. Therefore, the analysis of the physicochemical properties of the evaluated adjuvants indicated their ability to reduce surface tension and their anti-drift and adhesive spreading properties, with a potential improvement in spray cover and leaf wetness.…”

Droplets size in the phytosanitary control of potato

“…Therefore, research on more efficient methods of pest, disease, and weed control is necessary. The successful control is directly linked to the technology used to apply phytosanitary products, which can reduce costs and environmental risks (BUENO et al, 2013).…”

“…Terrestrial application rates between 200 and 400 L ha -1 are commonly used in potato crops. Thus, studies aimed at reducing these application rates are necessary, as long as they do not impair the efficiency of the control (BUENO et al, 2013). Several farmers are have been reducing the application rate to increase operational field capacity, aiming at minimizing costs and increasing the service life of mechanized assemblies (CAMOLESE and BAIO, 2016).…”

“…The efficiency of the application of phytosanitary products and its result in the control of the target are directly related to the choice of nozzles and droplets sizes, the adjustment of application rate, the droplets coverage on the target, favorable environmental conditions for spray deposition, and the ideal application time (GRAZIANO, C. E. et al, 2017). Fine droplets are commonly used potato crops in the application of phytosanitary products (BUENO et al, 2013). Over the applications, the droplets spectrum must be homogeneous, that is, it must have a similar volume median diameter (VMD).…”

“…The potato crop has a vigorous plant mass under its canopy, which hinders the penetration of spray droplets, requiring several applications during the crop cycle (DAMMER et al, 2016). The higher the plant mass, the more difficult the droplets penetration and deposition on the lower third of the leaves (BAIO et al, 2018) Thus, fine droplets spray are still used in potato crop to overcome this problem (BUENO et al, 2013). However, fine droplets are more prone to drift, and they evaporate faster, which hinders the control of the target (JIA and ZHU, 2015;GRAZIANO, C. E. et al, 2017).…”