The uniformity and droplet size produced during the spraying as well the correct deposition of these in the target, contribute directly to the success of a pesticide application. The objective of the present study was to characterize the ejected spray in the aerial and terrestrial spraying of pumpkin crops, with the use of adjuvants in a liquid solution. The experiment was carried out in two commercial plantations, in an entirely randomized design, employing a 6 × 2 factorial scheme, with six forms of application and two liquid compositions. The droplet spectrum was assessed employing water-sensitive card imaging. Smaller drop sizes and relative amplitudes were produced by aerial applications. In turn, the largest droplet diameters and the lowest percentage of drops smaller than 100 μm were obtained when using air induction twin flat spray nozzles. The adjuvant did not interfere in the numerical and volumetric median diameters, the relative amplitude, or the volume rate of droplets smaller than 100 μm.
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.
Inadequate soil management is one of the primary causes of pasture degradation, aggravated by the replacement of natural forest environments with cultivated pastures. Thus, the objective of the present study was to quantify the flux of CO2 and organic carbon of the soil in grasslands undergoing intensive and extensive management, and in a native forest. The experiment was conducted in a randomized block design, with three treatments: intensive management system (IMS), extensive management system (EMS), and native vegetation (NV). The collected soil variables consisted of CO2 flux, organic carbon, temperature, and humidity. The CO2 flux quantification was obtained using LI-COR 8100-A equipment, chamber model 103. Carbon determination was performed according to EMBRAPA methodology, and soil temperature and humidity were plotted using a model 5TM Decagon Devices® sensor. The respective mean CO2 flux values for the IMS, EMS, and NV were 2.18; 4.04, and 1.69 μmol CO2 m-2 s-1, and the values found for organic carbon content were 32.9; 24.3, and 14.9 g kg-1, respectively. The intensive management system exhibited higher CO2 flux from the soil to the atmosphere, and the soil containing native vegetation displayed greater values of organic carbon content.
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