Coffee production and marketing is one of the main global commercial activities, but crop yields depend on several factors, among which plant health. The objective of this study was to evaluate the efficiency of spray droplet deposition in coffee crops grown in a mountain region, associated to the efficacy of the control of fungal diseases. The application efficiency, using an unmanned aerial vehicle (UAV), and the efficacy of the products applied were tested. Water-sensitive paper tags were used to analyze the application efficiency; agronomic efficiency, vegetative vigor, yield, and physiological parameters were used to determine the fungicide efficacy. Droplet coverage in the upper canopy layer using a pneumatic sprayer (28.70%) was 4.11-fold higher than that found in the same layer for application using a UAV (6.98%) at the rate of 15 L ha−1. The highest droplet depositions by using a UAV were found for the rate of 15 L ha−1: 1.60, 1.04, and 0.43 µL cm−2 in the upper, middle, and lower layers, respectively; the deposition in the upper layer with application using a pneumatic sprayer was 42.67 µL cm−2, and therefore, a 26.7-fold higher deposition. The results denote that the control of fungal diseases through fungicide applications using a UAV is efficient for mountain coffee crops.
The efficiency of applications through spraying is connected to the capacity to minimize losses by endo-drift and exo-drift while ensuring adequate coverage and deposition on the target surface; the spray nozzles is the main factor connected to application quality. However, few researches focus on technology of application in black pepper crops. The objective of this work was to evaluate the coverage of droplets of simulated herbicide applications using different spray nozzles. The experiment was conducted in a commercial crop area of black pepper of the variety Bragantina, in a randomized block with a 2×2+1 factorial arrangement with four replications per treatment. The nozzles used were XR11002 VP, AI11002 VS, with and without protector (Chapéu de Napoleão) and an additional treatment using the manual backpack sprayer standard nozzle without protector. The results showed that, under these conditions, the nozzle AI11002 VS with protector resulted in adequate coverage and deposition of droplets between rows decreasing the risk of phytotoxicity to black pepper plants. The nozzle XR11002 VP presented higher coverage of droplets in the lower third of black pepper plants. The backpack sprayer standard nozzle resulted in the lowest coverage of droplets between rows.
Papaya production and export is increasingly expanding in the world market due to the nutritional importance of the fruit. Phytosanitary issues, labor shortages, and unevenness in land-based costal and motorized applications compromise crops, the environment, and humankind. The purpose of this study was to evaluate the efficiency of droplet distribution using an unmanned aerial vehicle, with different application rates (12.0, 15.0, and 18.0 L ha−1) and spray nozzles (XR110015 and MGA015) in the upper (UL), middle (ML), and lower (LL) layers, and on papaya fruit clusters (BF). Water-sensitive paper labels and artificial targets were used to assess the efficiency. Coverage, density, droplet distribution, and droplet diameter were influenced by the application rates in the following order: 18.0 > 15.0 > 12.0 L ha−1, showing concentrated droplet distribution in the respective layers: UL > ML > LL > BF. The 18.0 L ha−1 rate increased the variables examined, and the droplet coverage on the UL using the XR110015 nozzle was 6.56 times greater than that found on the LL and BF. The MGA015 nozzle presented better results in the LL and BF in all variables analyzed. The UAVs were efficient in applying to the papaya crop and further studies should be carried out in order to confirm the efficacy of plant protection products applied using this technology.
As pontas hidráulicas com indução de ar são amplamente utilizadas nas aplicações via pulverização, principalmente por diminuir o efeito da deriva primária. Entretanto, ainda há questionamentos quanto ao comportamento do espectro de gotas em determinadas pressões. Objetivou-se neste trabalho analisar o espectro de gotas da ponta com indução de ar TTI-110025 submetida às diferentes pressões de trabalho por meio de um analisador de partículas a laser em ambiente protegido. O experimento foi conduzido em delineamento inteiramente casualizado (DIC), representados pelas pressões 200, 300, 400, 500 e 600 kPa, com quatro repetições. As variáveis técnicas analisadas foram Dv0.1, DMV, Dv0.9, AR, % V < 100 μm e % V > 500 μm. A ponta TTI-110025 apresentou melhores resultados devido à diminuição das variáveis Dv0.1, DMV, Dv0.9 e % V > 500 μm à medida que aumentou a pressão de trabalho. O baixo valor da variável % V < 100 μm indicou baixo risco de deriva e o elevado valor % V > 500 μm sinalizou alto potencial de escorrimentos em aplicações pós-emergentes. Sugere-se operar a ponta TTI-110025 a pressão de 600 kPa.
The yield of coffee plants depends on several factors, and the leaf nutrition is one of the most important. The form of application of leaf fertilizers used is expensive considering the application efficacy and the efficacy of adherence and absorption of nutrients. The objective of this work was to evaluate the effect of configurations of operational parameters of centrifugal nozzle rotation and operational height on the application efficacy and efficacy of absorption of leaf fertilizers in Conilon coffee plants. The coverage, density, and deposition of spray droplets were efficacy parameters evaluated through water-sensitive paper tags and artificial targets. The efficacy of the macronutrients applied was confirmed through leaf analyses at 15 and 30 days after application. The application efficacy with a height of flight of 2.0 m and rotation of 10,000 rpm was the most adequate, with coverage of 12.4% and density of droplets of 127 droplets cm−2. The application of foliar fertilizers by UAV provided a distribution in newer leaves in which the absorption of macronutrients was greater, and the flight height of 2.0 m and rotation of the centrifugal nozzle of 10,000 rpm resulted in the best efficacy parameters.
In the conilon coffee tree, the stress caused by high light can reduce the photosynthetic rate, limit the development and also reduce the yield of beans. Considering that the quality of a sunscreen spray can influence photosynthetic performance, the goal was to understand the iterations between the quality of the spray and the variation of the chlorophyll a fluorescence when applying sunscreen on conilon coffee trees. The parameters coverage, volumetric median diameter, density, droplet deposition, and the variation of the chlorophyll a fluorescence were evaluated. The nozzle and application rate factors did not show direct effects in the physiological responses of the plants. Plants with no sunscreen application showed high values of energy dissipation flux. The photosystem II (PSII) performance index and PSII photochemical maximum efficiency indicate that the use of sunscreen for plants promotes better performance of photosynthetic activity and that it provides photoprotection against luminous stress, regardless of the application rate and spraying nozzle; however, we recommend using the application rate of 100 L ha−1 and the cone jet nozzle type because they provide lower risks of product loss due to runoff.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.