Revista Brasileira de Engenharia de Biossistemas

Eucalyptus and Ipomoea nil phytotoxicity after herbicide application

Thu, 16 Feb 2023 00:00:00 +0000

The presence of weeds in forest estates is considered one of the biggest problems in the implantation, maintenance, and renovation of eucalyptus plantations. This research aims to evaluate the phytotoxicity of herbicides on eucalyptus and I. nil. The experiment was installed inside a greenhouse in a completely randomized design with five replications. The treatments consisted of the application of 0.2% (v/v) adjuvant with the herbicides: atrazine (2250 g i.a. ha^-1), clomazone (720 g i.a. ha^-1), sulfentrazone (600 g i.a. ha^-1), glyphosate (1440 g i.a. ha^-1), and control. The following variables were analyzed: electron transport rate (ETR), water consumption, and plant phytotoxicity. For I. nil plants treated with atrazine, it was possible to detect phytotoxicity previous to the appearance of symptoms in the visual analysis, due to the inhibition of ETR at 24 hours after application (HAA). The highest levels of phytotoxicity for eucalyptus and I. nil were obtained by glyphosate and sulfentrazone, respectively.

The The use of activated charcoal from corn cobs as adsorbent of heavy metals from groundwater

Ermadani, Amalia Viviani, Yasdi, Shally Yanopa, Suryanto, Arsyad, Ar, Sarman — Tue, 05 Sep 2023 00:00:00 +0000

Iron (Fe) and manganese (Mn) are heavy metals which are found in high concentration in highly weathered soils, especially in the tropics, resulting in high content of them in groundwater. These metals cause a distinctive odor, reddish brown, yellowish color, and high sediment. This condition could cause health problems when it is used as a source of drinking water. This study was aimed to evaluate the efficiency of activated carbon from corn cobs in reducing the concentrations of Fe and Mn from groundwater adsorption. The adsorption process was performed by applying activated carbon with varying doses of 0.1 g, 0.2 g, 0.3 g, 0.4 g, 0.5 g, 1 g, 1.5 g and 2 g into 100 ml groundwater. Variations of pH were pH 2, pH 3, pH 4, pH 5, pH 6, pH 7 and pH 8, and variations in contact time of 10, 30, 45, 60, 90 and 120 minutes. The results showed that the optimum doses to reduce Fe and Mn concentration from groundwater were 1 g and 0.5 g with the adsorption efficiency of 70.14% and 41.60% respectively. The optimum pH for both Fe and Mn was pH 4 with an adsorption efficiency of 75.44% and 56.52% respectively, while the optimum contact times were 60 and 30 minutes with an adsorption efficiency of 75.44 dan 59.29% respectively.

Distance of brachiaria management in between the rows of coffee trees

Mon, 27 Feb 2023 00:00:00 +0000

Brazil is the world's largest coffee producer, but with the changes in climate that have occurred in recent years, the concern with soil management with cover crops has become important, since it configures a strategy that can contribute to the improvement of production systems. Brachiaria is one of the main species used in intercropping in coffee production to generate biomass and soil cover. The objective of this research was to evaluate the effect of the distance of brachiaria management in between rows of coffee trees. The research was carried out from 2016 to 2022 in a coffee plantation implanted in 2016 with the cultivar Catuai Amarelo IAC 62 associated with Brachiaria ruziziensis, in a randomized block design, with 6 treatments and 4 replications: T1- without brachiaria between the rows (control), T2 - management of brachiaria up to the projection of the coffee tree crown, T3 - management with 25 cm distance from the projection of the crown of the coffee tree, T4 - management with 50 cm away from the projection of the coffee tree crown, T5 - management with 75 cm distance from the projection of the coffee tree crown, T6 - management with 100 cm distance from the projection of the coffee tree crown. The evaluated parameters were: setting and establishment of coffee seedlings, height of the orthotropic branches, length of the plagiotropic branches, number of internodes, and productivity. The intercropping of the coffee tree with brachiaria must be managed at 50 cm from the projection of the plagiotropic branch of the coffee tree, aiming at non-competition and better development of the crop.

Effect of glucose on germination performance in two soybean cultivars

Pedro Henrique Gorni, Denis Wesley Polimeno — Thu, 11 May 2023 00:00:00 +0000

Glucose promotes increases in physiological processes related to plant growth and induces cell division and can also act in seed germination. The present investigation has been carried out on the influence of various concentrations of glucose on the germination performance of soybeans seeds of cv. BMX and 66i68. Seeds of soybeans (Glycine max (L.) Merrill) were treated with three concentrations of the glucose (0.05, 0.10 and 0.20 mmol L^-1), and a control with distilled water. Tests of seed germination and vigor were carried out: it was calculated the germination percentage (first and final counting), percentage of normal seedlings; and speed of germination, length of the primary root and the aerial part of seedlings were recorded. The experiment was arranged in a completely randomized design with three treatments and five repetitions depending on the test. Increasing doses of the plant growth regulator influence the germination and can increase the speed of germination. The use of glucose in the treatment of soybean seeds, increases the rate of germination and emergence speed, growth of the root system and medium of seedlings. Soybean cultivar BMX seeds showed an increase in physiological performance with increasing glucose dosage.

Fuzzy modeling of coffee productivity under different irrigation depths, water deficit and temperature

Thu, 14 Sep 2023 00:00:00 +0000

The coffee culture has great economic importance on the world stage, especially for Brazil. Considered one of the most traded commodities on the world's trading exchanges. Thus, the main objective of this study was to develop a system based on fuzzy rules to evaluate coffee productivity, using irrigation, soil water deficit and ambient temperature as the main production factors. The research was developed from searches of scientific data on the main variables for coffee production. The work was divided into two stages: the first in the scientific search for data collection and the second in the development of the fuzzy model. With this, it was parameterized that the input variables would be the temperature, the irrigation depth, and the water deficit of the soil and for the output variable the coffee productivity. Based on the model prediction, the fuzzy system showed which variable values are necessary for the best coffee productivity, by a set of rules involving the variation of water deficit (60%), temperature (30°C) and irrigation (300 mm), for a productivity of 24 sc ha^-1. The performance of the fuzzy system was tested by comparing it with articles on the subject that relate coffee production with irrigation, water deficit and temperature of the environment and in almost all cases the model was efficient, reinforcing the assessment of the strength of the scheme, the analysis was extended to several scenarios relating the same three input variables.

The economic importance of the peanuts production chain

Thu, 11 May 2023 00:00:00 +0000

The importance and economic representativeness of the peanut production chain has grown exponentially in recent years, tending to gain more market share. Background: The study had as its theme the question: What is the economic, technological, social and environmental relevance of the peanut production chain for Brazil? Objective: Conduct a survey of information and data that allow inferring the economic, social and environmental importance of the peanut production chain for Brazil in the global scenario. Methods: The methodology applied was exploratory research "ad hoc" in exploratory theoretical essay of qualitative approach, and analytical descriptive in the report of the findings. Results: Exports grow on a logarithmic scale, in 2020 it had revenues of US$ 427.8 million. The sector generates 42 thousand jobs, and the culture makes it possible to meet social and environmental demands. Conclusions: The adoption of technologies and the improvement of production methods are essential for the continuous progress of the sector with the creation of jobs and the adhesion of new producers, with an increasingly sustainable production, with less environmental impact and reduction of fertilizer waste, with expansion of the productive capacity per planted bushel.

Cotton nitrogen doses in the edaphoclimatical conditions of northeastern Brazil

Thu, 11 May 2023 00:00:00 +0000

The study of cotton plant responses to nitrogen fertilization in different climate and soil conditions is essential for the correct management of nitrogen in this crop. Therefore, the objective of the present study was to evaluate the responses of cotton plants to nitrogen fertilization in the edaphoclimatic conditions of the Cariri region, located in the northeastern State of Ceará, Brazil. The experiment was conducted in an experimental area at the CENTEC (Centre for Technological Education) School of Technology (FATEC - Cariri campus), located in the city of Juazeiro do Norte, Ceará State. The statistical design adopted was Completely Randomized Design (CRD). The treatments were composed from the combination of four doses of nitrogen (0, 60, 120, and 180 kg ha^-1 of N, equivalent to 0, 50, 100, and 150% of the N recommendation for the crop) with four replications. Urea was used as a nitrogen source. At 42 days after sowing, the plants were collected. Plant height, number of leaves, stem diameter, leaf area, absolute growth rate, shoot and root dry matter, total and nitrogen use efficiency were evaluated. The different doses of nitrogen significantly influenced all the analysed variables. In general, nitrogen doses greater than 120 kg ha^-1 of N were shown to impair the growth and dry matter production of the cotton plant in the climate and soil conditions of the Cariri region, northeastern Brazil. In addition, excessive nitrogen fertilization was shown to reduce the efficiency of nitrogen use by the cotton crop.

Spatial variability of physical attributes of a Oxisol related to garlic productivity

Thu, 10 Aug 2023 00:00:00 +0000

Garlic is a product with high demand in Brazil and worldwide, being highly valued in the cuisine of several countries and is a culture with high added economic value. In 2018, this work was carried out in the irrigation and drainage area of the Federal University of Viçosa, in Viçosa, Minas Gerais State, Brazil, in a Oxisol. The objective was to characterize the structure and magnitude of the spatial distribution of physical attributes of a Oxisol, perform the mapping, and evaluate the spatial correlation between garlic bulb yield, lateral shoot growing and soil characteristics. The attributes studied were garlic bulb yield, lateral shoot growing, soil moisture on a dry basis, soil moisture on a humid basis, volumetric soil moisture, particle density, free soil porosity, sampled in a 90-georeferenced grid. Data analysis using statistical techniques and geostatistics made it possible to verify that the garlic yield and other soil physical attributes studied showed spatial dependence. There was an emphasis on the spatial correlation between garlic bulb yield and free-soil porosity. The lateral shoot growing of garlic has a direct and positive relationship with free soil porosity, soil moisture on a dry basis and soil moisture on a humid basis.

Distribution and spatial autocorrelation of physical-water attributes of an Oxisol

Mon, 17 Jul 2023 00:00:00 +0000

Spatial autocorrelation, which in this work was calculated using Moran's bivariate analysis, can be defined as the coincidence of similar values in nearby locations, or the absence of randomness of a variable due to its spatial distribution. Therefore, the objective of this study is to analyze the distribution and spatial autocorrelation of physical attributes of an Oxisol. The experiment was carried out in the irrigation and drainage area of the Universidade Federal de Viçosa, in Viçosa, Minas Gerais, Brazil. The soil in which the experimental meshes were installed was classified as a sandy clayey Oxisol. The attributes were determined: soil moisture on a dry basis, % (DB), soil moisture on a wet basis, % (WB), volumetric soil moisture, % (VS), particle density, g cm-1 (PD), sampled at different depths and within a grid of 90 georeferenced points. For spatial autocorrelation, the global Moran and local Moran indexes (LISA) were used as statistical tools. Bivariate analysis revealed that soil volumetric moisture is closely related to wet and dry basis moisture. It was also found that the surface particle density is related to the deeper layers of the soil, thus reinforcing that the solid fraction of a soil sample, without considering porosity, tends to remain constant. This happens because the predominant mineral constituents in soils are quartz, feldspars, and colloidal aluminum silicates, whose particle densities are around 2.65 g cm^-3.