Revista Brasileira de Engenharia Agrícola e Ambiental

(941 Artigos indexados)

Effect of excess soil water on the development of Bermuda grass (Cynodon spp.) - (2025)

Antônio A. do Nascimento Filho, Raimundo N. T. Costa, Carlos H. C. de Sousa, Caroline de M. D. Mateus, Kenya G. Nunes

Volume: 24 - Issue: 5

Resumo. ABSTRACT Soil drainage is an important technique in the construction of a sports lawn and information about the sensitivity of the crop to excess water influences the design of the project. Assuming that excess water affects the development of the grass and that the indices SEW30 (Sum of Excess Water above 0.30 m depth) and SDI (Stress-Day Index) are sensitive to the variables of development of the crop, the objective was to identify the sensitivity of Bermuda grass to the excess of water. The experimental design was completely randomized with five treatments and four repetitions. The treatments consisted of groundwater elevations: 0 cm d (at the level of the drains - control); 180 cm d (at 0.20 m from the soil surface); 270 cm d (at 0.15 m from the soil surface); 360 cm d (at 0.10 m from the soil surface); and 450 cm d (at 0.05 m from the soil surface), carried out fortnightly, lasting three days. The variables used to test the treatment were root length, photosynthesis rate, dry mass of roots, stolons, rhizomes, culms and leaves and dry mass of grass clippings. Stress caused by excess water near the soil surface reduced root length, dry mass of culms and leaves, and photosynthesis rate; Bermuda grass was more sensitive to excess water in its initial vegetative stage, which occurs until 42 days after planting; and the photosynthesis rate in the treatment with highest stress level decreased by approximately by 2/3 when compared to the condition of no water table.

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Photochemical efficiency of basil cultivars fertigated with salinized nutrient solutions - (2025)

Sandy T. dos Santos, Francisco de A. de Oliveira, Giordanio B. S. Oliveira, Francisco V. da S. Sá, Jessilanne P. B. de M. Costa, Pedro D. Fernandes

Volume: 24 - Issue: 5

Resumo. ABSTRACT Reduction in plant growth under salt stress is due, among other factors, to changes in photochemical efficiency and, consequently, in photosynthesis. The objective of this study was to evaluate the effect of salt stress on the chlorophyll fluorescence variables in cultivars of basil (Ocimum basilicum L.). The experiment was conducted in a greenhouse, using a randomized block design in a 5 x 3 factorial scheme, corresponding to five basil cultivars (‘Grecco a Palla’, ‘Alfavaca Basilicão’, ‘Alfavaca Verde’, ‘Lemoncino’ and ‘Roxo’) and three salinity of the nutrient solution (2.0, 3.5 and 5.0 dS m-1), with three repetitions, and the experimental plot was represented by three pots containing 3.0 dm3 of coconut fiber. At the full flowering stage, plants were evaluated for chlorophyll fluorescence, when adapted to the dark, as well as under saturating light conditions. In general, there were changes in fluorescence variables only at salinity above 3.5 dS m-1. Fertigation using high-salinity water promotes strong changes in the chlorophyll a fluorescence of sensitive basil cultivars. The cultivars ‘Grecco a Palla’ and ‘Alfavaca Verde’ were little affected by the increase of salinity, being the most tolerant to salt stress. In the cultivars ‘Alfavaca Basilicão’, ‘Lemoncino’ and ‘Roxo’, chlorophyll fluorescence was strongly affected by salinity, being the most sensitive. The tolerance ranking based on chlorophyll fluorescence is: ‘Grecco a Palla’ = ‘Alfavaca Verde’ > ‘Alfavaca Basilicão’ > ‘Lemoncino’ > ‘Roxo’.

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Production of Bambusa vulgaris seedlings from rhizomes under brackish water irrigation - (2025)

Lourenço M. C. Branco, Claudivan F. de Lacerda, Albanise B. Marinho, Carlos H. C. de Sousa, Amanda S. F. Calvet, Erasto G. de Oliveira

Volume: 24 - Issue: 5

Resumo. ABSTRACT The objective of this study was to evaluate the influence of irrigation with brackish water on the production of bamboo seedlings (Bambusa vulgaris). The experiment was carried out at the Fazenda Experimental Piroás, in the municipality of Redenção, CE, Brazil (4° 14’ 53” S, 38° 45’ 10” W, and altitude of 230 m), in a completely randomized design with five treatments and six repetitions. The treatments consisted of five irrigation water electrical conductivity (ECw): 0.5 (control); 1.5; 2.5; 3.5 and 4.5 dS m-1. At 120 days after the beginning of the application of the treatments the leaf gas exchange, relative chlorophyll index (RCI), plant height (H), shoot dry matter (SDM), H/SDM ratio, and the concentrations of Na+ and K+ in stems and leaves were evaluated. Salt tolerance indexes were calculated based on SDM, H, photosynthesis rate and RCI. The increase in the ECw reduced leaf gas exchange, and the reduction in the photosynthesis rate was caused by stomatal and non-stomatal effects. The salinity affected negatively the growth and quality of bamboo seedlings, with the greatest effects being with ECw equal to or greater than 2.5 dS m-1. Bamboo seedlings present Na+ retention in the stems and low Na+/K+ ratio in the leaves. Bamboo seedlings are tolerant to salinity up to 1.5 dS m-1, indicating that waters with this salinity can be used for seedling production of this species, without loss of growth and quality.

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Trickle irrigation systems affect spatial distribution of roots of banana crop - (2025)

Edvaldo B. Santana Junior, Eugênio F. Coelho, Jailson L. Cruz, João B. R. da S. Reis, Diego M. de Mello, Bruno L. da S. Pereira

Volume: 24 - Issue: 5

Resumo. ABSTRACT Trickle irrigation has been largely used for banana in Brazil, mainly due to the increase in water and fertilizer use efficiency. These irrigation systems have different options concerning number, type and flow rate of emitters as well as for hydraulics, number and location of lateral lines. The small area of soil wetted by these systems limits root spatial distribution of crops. This study aimed to evaluate the effect of different trickle irrigation systems on the root spatial growth and root spatial distribution of banana cv. Prata Gorutuba. Root length density and root length were evaluated in soil profiles of three micro-sprinkler systems, with emitter flow rates of 35, 53 and 70 L h-1 and of two drip irrigation systems, with one and two lateral lines per crop row. Trickle irrigation systems influence root spatial distribution, favoring a greater or smaller distribution of roots at different depth and distance from the plant according to micro-sprinkler flow rate and to the number of lateral lines per crop row. The effect on root spatial distribution is more accentuated for micro-sprinkler systems than for drip systems. The majority of the total root length (80%) was observed in the soil profiles from 0.33 to 0.57 m depth and at distances from the plants of 0.75 to 0.83 m.

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Water potential, biochemical indicators and yield of sugarcane irrigated with brackish water and leaching - (2025)

Anízio H. Godoi Neto, Ênio F. de F. e Silva, José E. F. de Morais, Larissa G. L. de Andrade, Weliston de O. Cutrim, Claudivan F. de Lacerda

Volume: 24 - Issue: 5

Resumo. ABSTRACT Knowledge on the water relations and biochemical responses of plants has been pointed out as important for selecting genotypes that are tolerant to abiotic stresses, such as drought and salinity. Thus, the objective of this study was to evaluate the leaf water potential, enzymatic activity and yield of sugarcane (RB 92579) irrigated with brackish waters and leaching fractions. The study was conducted from November 2016 to November 2017 in Recife, PE, Brazil. The experimental design was completely randomized, in a 5 x 2 factorial scheme, with four repetitions. Treatments consisted of five irrigation water salinity (0.5; 2.0; 4.0; 6.0 and 8.0 dS m-1) and two leaching fractions (0 and 0.17), corresponding to 100 and 120% of crop evapotranspiration. The values of irrigation water salinity were obtained by adding NaCl and CaCl2 at molar proportion of 1:1 (Ca:Na) to water from the local supply (ECw = 0.5 dS m-1). Readings of leaf water potential (Ψw) were taken at predawn, and +3 leaves were collected for the determination of catalase and ascorbate peroxidase activity at 90, 150, 210 and 270 days after planting. Yield was determined at 365 days after planting. Increase in water salinity reduced leaf water potential and yield, and increased the activity of catalase and ascorbate peroxidase, and the leaching fraction of 0.17 was able to reduce the deleterious effects of salts on plants.

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Impacts of climatic changes on the vegetative development of olive cultivars - (2025)

Gabriel W. L. Florêncio, Fabrina B. Martins, Mábele de C. Ferreira, Rodolfo A. de A. Pereira

Volume: 23 - Issue: 9

Resumo. ABSTRACT The aim of this study was to simulate the vegetative development of the olive cultivars Arbequina and MGS ASC315 cultivated in Maria da Fé, MG, Brazil (22° 18’ 29” S, 45° 22’ 31” W, 1.276 m of altitude). The development of these cultivars was simulated in nine transplanting dates, considering three distinct scenarios for three periods (2011-2040, 2041-2070 and 2071-2100). Climate changes influence the olive crop management. The increase in air temperature modifies the development rate and the duration of the seedling phase of the cultivars Arbequina and MGSASC315. In colder months, there is accelerated vegetative development and shorter seedling phase duration. Conversely, in warmer months, there is delayed development with longer seedling phase duration.

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Modeling and thermodynamic properties of ‘bacaba’ pulp drying - (2025)

Maria F. de Morais, José R. O. dos Santos, Marisângela P. dos Santos, Dyego da C. Santos, Tiago N. da Costa, Joel B. Lima

Volume: 23 - Issue: 9

Resumo. ABSTRACT This study aimed to dry ‘bacaba’ (Oenocarpus bacaba Mart.) pulp under different thermal conditions, fit different mathematical models to the dehydration curves, and calculate the diffusion coefficients, activation energy and thermodynamic properties of the process. ‘Bacaba’ fruits were meshed to obtain the pulp, which was dried at temperatures of 40, 50 and 60 °C and with thickness of 1.0 cm. Increase in drying temperature reduced the dehydration times, as well as the equilibrium moisture contents, and drying rates of 0.65, 1.04 and 1.25 kg kg min-1 were recorded at the beginning of the process for temperatures of 40, 50 and 60 °C, respectively. The Midilli’s equation was selected as the most appropriate to predict the drying phenomenon, showing the highest R2, lowest values of mean square deviation (MSD) and χ2 under most thermal conditions, and random distribution of residuals under all experimental conditions. The effective diffusion coefficients increased with increasing temperature, with magnitudes of the order of 10-9 m2 s-1, being satisfactorily described by the Arrhenius equation, which showed activation energy (Ea) of 37.01 kJ mol-1. The drying process was characterized as endergonic, in which enthalpy (ΔH) and entropy (ΔS) reduced with the increment of temperature, while Gibbs free energy (ΔG) was increased.

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Nutrient contents and growth of corn fertigated with human urine and cassava wastewater - (2025)

Narcísio C. de Araújo, Vera L. A. de Lima, Geovani S. de Lima, Elysson M. G. Andrade, Jailton G. Ramos, Suenildo J. C. Oliveira

Volume: 23 - Issue: 9

Resumo. ABSTRACT This study aimed to evaluate the contents of macronutrients (NPK and S) and the growth of ‘Potiguar’ corn fertigated with human urine, cassava wastewater and their associations with NPK. The experiment was set up in greenhouse located on Campus I of Universidade Federal de Campina Grande. A completely randomized experimental design was used, consisting of eight treatments, corresponding to fertigation with mineral fertilizer NPK formula; organic, composed of yellow water, cassava wastewater and human urine associated with cassava wastewater; organomineral, composed of human urine associated with phosphorus and potassium, cassava wastewater associated with nitrogen and phosphorus and human urine associated with cassava wastewater and phosphorus, with five repetitions. At 50 days after sowing (DAS), plants were evaluated for the leaf NPK and S concentrations and growth variables: number of leaves, plant height, stem diameter, leaf area, fresh and dry mass of leaves, mass of stem and shoots. Nitrogen and phosphorus concentrations and the growth variables number of leaves, plant height, fresh and dry mass of leaves, mass of stem and of shoot were influenced by fertigation with human urine, cassava wastewater concentrations and their associations with NPK. In the leaves of corn cultivar Potiguar the accumulated concentrations of N, P and K, at 50 DAS, varied in the sequence N > K > P. Human urine has potential as source of N in fertigation of corn and cassava wastewater can be used if associated with other sources of nutrients.

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Soil physical and hydraulic properties in the Donato stream basin, RS, Brazil. Part 1: Spatial variability - (2025)

Tirzah M. Siqueira, José A. S. Louzada, Olavo C. Pedrollo, Nilza M. dos R. Castro, Marquis H. C. de Oliveira

Volume: 23 - Issue: 9

Resumo. ABSTRACT The processes of water flow and water storage in the soil are directly associated with its hydraulic properties, which may vary significantly in space. Therefore, this study aimed to perform a spatial analysis of saturated hydraulic conductivity and the parameters of the soil water retention curve in the Donato basin, located in the municipality of Pejuçara, in the northwest region of the state of Rio Grande do Sul, Brazil, with geographic coordinates between 28º 25’ 34” S and 53º 40’ 30” W, and 28º 24’ 50” S and 53º 41’ 30” W, 590 m of altitude. Undisturbed soil samples (total of 55) were collected from August to November of 2012. The results have demonstrated larger variability for hydraulic conductivity and for the parameter α of the retention curve, and allowed identifying that the high spatial heterogeneity of the studied variables could be associated with factors such as climate, land use and land cover, sampling errors, sampling grid density and also the level of soil compaction.

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Sediment production and soil water infiltration under different simulated rainfall characteristics - (2025)

Wilk S. de Almeida, Daniel F. de Carvalho, Fernandes A. C. Pereira, Janaína R. C. Rouws

Volume: 23 - Issue: 8

Resumo. ABSTRACT The study was carried out to evaluate sediment production, water infiltration and surface runoff in an Ultisol under simulated rainfalls with similar erosivity, but different combinations of intensity (Int) and duration (Dur). The rainfalls were applied after soil tillage in the period from August to September 2017, in Seropédica, RJ State, Brazil. Using a computer program, the treatments were defined from the erosivity calculated for a rainfall with intensity of 60 mm h-1 and duration of 60 min, resulting in the other combinations of Int and Dur: 44.5 mm h-1 and 106 min; 53.5 mm h-1 and 78 min; 66.9 mm h-1 and 48 min; and 76.5 mm h-1 and 38 min, in a completely randomized design with five repetitions. Sediment production varied from 2.17 to 6.11 g m-2, respectively, in the treatments with Int 53.5 mm h-1 and Dur 78 min and Int 44.5 mm h-1 and Dur 106 min. Stable infiltration rate (mm h-1) were 21.6, 37.7, 31.4, 29.5, and 22.4, respectively, in the treatments Int 44.5 mm h-1 and Dur 106 min; Int 53.5 mm h-1 and Dur 78 min; Int 60.4 mm h-1 and Dur 60 min; Int 66.9 mm h-1 and Dur 48 min; and Int 76.5 mm h-1 and Dur 38 min. The different combinations of intensity and duration of rainfalls with similar erosivity change sediment production, but do not significantly influence surface runoff and water infiltration in the soil.

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Sprouting of pre-sprouted sugarcane seedlings and micrometeorological variables under photo-selective nets - (2025)

José J. F. Cordeiro Júnior, Cristiane Guiselini, Héliton Pandorfi, Alex S. Moraes, Dimas Menezes, Luiz A. de Almeida Neto

Volume: 23 - Issue: 8

Resumo. ABSTRACT Sugarcane is a grass species that stands out worldwide in the production of ethanol. Brazil is the world’s largest producer and leader in exports, responsible for more than 50% of the products that are marketed worldwide. The objective of this study was to investigate the effect of photo-selective nets on micrometeorological variables and on sprouting of pre-sprouted sugarcane seedlings. The experiment was carried out in a protected environment at Universidade Federal Rural de Pernambuco - UFRPE, in a completely randomized design. Seedlings of cultivar RB92579 were obtained by the technique of production of pre-sprouted seedlings. The protected environment was divided into four modules corresponding to the treatments: covered with anti-UV low-density polyethylene plastic: + Solpack® red ultranet net, + Solpack® white net, + Solpack® freshnet net and without shade net. Micrometeorological data of air temperature and substrate temperature were recorded in each module. The first count of emergence, sprouting speed index and sprouting percentage were calculated. Principal component analysis was used to verify the association between the cultivation modules and the micrometeorological and sprouting variables of the seedlings. Air temperature in the protected environment was 8.7% higher than that in the external environment. The white net led to sprouting of 78.93%. The substrate temperature above 30.4 °C favored seedling sprouting. The modules with white net and red ultranet net favored seedling sprouting.

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Agronomic performance of beet cultivars as a function of phosphorus fertilization - (2025)

Gerlani A. Silva, Leilson C. Grangeiro, Valdivia de F. L. Sousa, Luiz R. R. Silva, Priscila M. M. Jesus, Jorge L. A. Silva

Volume: 23 - Issue: 7

Resumo. ABSTRACT The lack of phosphorus in soil affects the development and productivity of plants; however, in order for them to express the full potential, it is necessary to supply this nutrient. The objective of this study was to define adequate doses of phosphorus, which maximize the productivity and quality of four beet cultivars, and to identify among them the most efficient use of phosphorus. The experiment was carried out at the Rafael Fernandes Experimental Farm, of the Federal Rural Semi-Arid University, Mossoró, RN state, Brazil, from July to October 2016. The experimental design was a randomized block in a 4 x 4 factorial scheme with four repetitions, corresponding to four beet cultivars (Early Wonder, Fortuna, Kestrel and Cabernet) and four doses of phosphorus (0, 90, 180 and 270 kg ha-1 of P2O5). The dose that maximized commercial productivity was 186 kg ha-1 of P2O5 for the cultivars Early Wonder (21.71 t ha-1) and Kestrel (22.59 t ha-1), 180 kg ha-1 of P2O5 for Carbenet (25.82 t ha-1) and 183 kg ha-1 of P2O5 for Fortuna (25.40 t ha-1). The Cabernet and Fortuna cultivars were classified as not efficient but responsive, whereas Early Wonder and Kestrel were efficient but not responsive. Phosphorus did not influence content of soluble solids and percentage of white rings at the root.

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Characterization of venturi injector using dimensional analysis - (2025)

Luiz R. Sobenko, José A. Frizzone, Antonio P. de Camargo, Ezequiel Saretta, Hermes S. da Rocha

Volume: 23 - Issue: 7

Resumo. ABSTRACT Venturi injectors are commonly employed for fertigation purposes in agriculture, in which they draw fertilizer from a tank into the irrigation pipeline. The knowledge of the amount of liquid injected by this device is used to ensure an adequate fertigation operation and management. The objectives of this research were (1) to carry out functional tests of Venturi injectors following requirements stated by ISO 15873; and (2) to model the injection rate using dimensional analysis by the Buckingham Pi theorem. Four models of Venturi injectors were submitted to functional tests using clean water as motive and injected fluid. A general model for predicting injection flow rate was proposed and validated. In this model, the injection flow rate depends on the fluid properties, operating hydraulic conditions and geometrical characteristics of the Venturi injector. Another model for estimating motive flow rate as a function of inlet pressure and differential pressure was adjusted and validated for each size of Venturi injector. Finally, an example of an application was presented. The Venturi injector size was selected to fulfill the requirements of the application and the operating conditions were estimated using the proposed models.

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Sources and doses of aluminum in experiments with rice in nutrient solution - (2025)

Lucas B. de Freitas, Dirceu M. Fernandes, Suelen C. M. Maia, Arianne Moniz, Beatriz G. Mazziero, Fábio Steiner

Volume: 23 - Issue: 7

Resumo. ABSTRACT The aluminum source to produce toxicity in upland rice in nutrient solution experiments is not yet well established, althought the aluminum potassium sulfate has been utilized source to produce aluminum toxicity. However, in recent studies have used aluminum chloride. The aim of this study was to evaluate the capacity of aluminum sources and doses to produce toxicity in upland rice plants grown in nutrient solution. The experiment was arranged in a block randomized design, in a 2 x 5 factorial scheme and four repetitions. The treatments were two aluminum sources (aluminum potassium sulfate - AlK(SO4)2.12H2O and aluminum chloride - AlCl3.6H2O) and five aluminum doses in nutrient solution (0, 370, 740, 1100 and 1480 μmol L-1). The experiment was conducted in a greenhouse in Botucatu city, São Paulo state, Brazil, starting in April 2012, and was carried out for 56 days from transplanting of the seedlings. Using aluminum chloride, the rice plants show lower production of root and total dry weight, area and root volume, medium and thick root length, potassium and sulfur contents and accumulations. Using aluminum potassium sulfate, there are lower aluminum activity and availability, besides the formation of large amount of aluminum compounds non-toxic to the plants (aluminum sulfate) in the nutrient solution. The aluminum doses between 1100 to 1480 µmol L-1, corresponding to aluminum activity of 336.8 to 429.0 µmol L-1 of aluminum chloride as source, are more effective to produce aluminum toxicity in upland rice plants grown in nutrient solution.

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Gas exchanges and growth of cotton cultivars under water salinity - (2025)

André A. R. da Silva, Luana L. de S. A. Veloso, Ronaldo do Nascimento, Elka C. S. Nascimento, Carlos V. de C. Bezerra, Márcia C. de A. Pereira

Volume: 23 - Issue: 6

Resumo. ABSTRACT Indication of salt-tolerant cotton cultivars can make the agricultural exploitation with saline water irrigation feasible in the Brazilian semi-arid region. Thus, this study aimed to evaluate the gas exchanges and growth of cotton cultivars irrigated with saline water. The study was conducted in pots adapted as drainage lysimeters under greenhouse conditions, using a sandy loam Entisols as substrate. Treatments were distributed in completely randomized design, in 5 x 2 factorial arrangement, relative to five levels of irrigation water electrical conductivity - ECw (1.5, 3.0, 4.5, 6.0 and 7.5 dS m-1) and two cotton cultivars (BRS 368 RF and BRS Safira). Increase in irrigation water salinity inhibits the vegetative growth and gas exchanges of the cotton cultivars BRS Safira and BRS 368 RF. Leaf area and instantaneous carboxylation efficiency are the most affected variables. Physiological and growth performance of the cultivar BRS Safira in response to water salinity was higher than that of BRS 368 RF.

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Irrigation levels and use of hydro retainer polymer in greenhouse lettuce production - (2025)

Welcio R. da Silva, Leandro C. Salomão, Débora R. M. Pereira, Henrique F. E. de Oliveira, Alexandre I. de A. Pereira, Fernando S. Cantuario

Volume: 23 - Issue: 6

Resumo. ABSTRACT One of the potential alternatives to improve the use of water resources is the use of hydro retainer polymer applied to the soil. The objective of this study was to evaluate how irrigation levels and doses of hydro retainer polymer interfere in the production of ’Vanda’ lettuce. The experiment was carried out from December 2017 to January 2018 under protected environment in the Instituto Federal Goiano, Urutaí Campus, Goiás State, GO, Brazil (17º 29’ 10” S of latitude, 48º 12’ 38” W of longitude and 697 m of altitude). The work tested four irrigation levels of 50, 75, 100 and 125% of the evaporation obtained daily by the hook micrometer and five doses of hydrogel polymer (0, 50, 100, 150 and 200 g plant-1). The experimental design was a randomized block design in a scheme of split-plot and four blocks. Canopy fresh and dry mass, plant height, number of leaves and productivity were evaluated. There was 29.24% increase in the dry mass comparing the hydro retainer polymer doses of 0 and 169.28 g and an increase of 14.36% of the height of plants when compared with the irrigation levels of 50 and 125%. The use of a hydro retainer polymer provided a significant increase in all the evaluated productive variables. The irrigation levels influence the fresh mass from aerial part, plant height and productivity. The productivity increased 18.42% for the irrigation levels used and the highest estimated values were presented in the dose of 157.49 g (14.46 t ha-1) hydro retainer polymer.

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Growth and production components of West Indian cherry cultivated with saline waters and potassium fertilization - (2025)

Geovani S. de Lima, Francisco W. A. Pinheiro, Adaan S. Dias, Hans R. Gheyi, Lauriane A. dos A. Soares, Saulo S. da Silva

Volume: 23 - Issue: 4

Resumo. ABSTRACT Due to water limitations in terms of both quantity and quality in the semi-arid region of northeastern Brazil, the use of waters with high concentrations of salts become necessary in irrigated agriculture. Thus, this study aimed to evaluate the growth and production of grafted West Indian cherry under saline water irrigation and potassium fertilization. The experiment was carried out in drainage lysimeters under protected environment conditions, using a Regolithic Neosol with sandy loam texture. Treatments resulted from the combination of two levels of electrical conductivity - ECw (0.8 and 3.8 dS m-1) of irrigation water and four doses of potassium (50, 75, 100 and 125% of the recommendation of Musser), arranged in a randomized block design, with three replicates. Irrigation water salinity of 3.8 dS m-1 markedly inhibited the growth in stem diameter and mean fruit weight of West Indian cherry. Potassium fertilization mitigated the deleterious effects of salt stress on the relative growth in stem diameter of the rootstock, total number of fruits and total fresh mass of fruits of West Indian cherry, with highest values in plants irrigated with water of lowest level of salinity associated with the highest dose of K2O.

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Nutritional deficiency symptoms of young ‘cedro doce’ plants grown under macronutrient omission - (2025)

Simone T. M. de Aquino, Reila F. dos Santos, Karine D. Batista

Volume: 23 - Issue: 4

Resumo. ABSTRACT ‘Cedro doce’ [Pochota fendleri (Seem) Alverson & Duarte] is a native forest species in Amazon with great ecological and economic importance. Understanding nutritional requirements of the species allows cultivating Pochota fendleri with more efficient fertilization practices since its initial growth, as a seedling. Thus, this research aimed to evaluate the symptoms of nutritional deficiency of young ‘cedro doce’ plants. The experiment was carried out from September to December 2016, under greenhouse conditions, at Embrapa Roraima, in Boa Vista, RR, Brazil. The experiment was a randomized complete block design with seven treatments [complete solution and individual omission of the macronutrients (N, -P, -K, -Ca, -Mg, -S)] and three replications. Each experimental plot corresponded to a pot with one plant, corresponding to 21 plots. At 77 days after transplanting the seedlings to the pots, the plants were evaluated for symptoms of nutritional deficiency: total height, collar diameter, leaf number, chlorophyll a and b, chlorophyll a/b index ratio, shoot and root dry mass, and root/shoot ratio. The macronutrients omission caused nutritional deficiency symptoms in all ‘cedro doce’ plants. In general, P and N omission caused the least development of plants. This result is an indicative that ‘cedro doce’ is a high demanding species for both nutrients, especially phosphorus.

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Salt stress and exogenous application of hydrogen peroxide on photosynthetic parameters of soursop - (2025)

André A. R. da Silva, Geovani S. de Lima, Carlos A. V. de Azevedo, Luana L. de S. A. Veloso, Hans R. Gheyi, Lauriane A. dos A. Soares

Volume: 23 - Issue: 4

Resumo. ABSTRACT This study aimed to evaluate the gas exchanges and photosynthetic pigments of soursop seedlings cv. ‘Morada Nova’ irrigated with saline waters and subjected to exogenous application of hydrogen peroxide by seed soaking and foliar spraying. The study was carried out using plastic bags under greenhouse conditions at the Center of Technology and Natural Resources of the Federal University of Campina Grande, PB, Brazil, using a eutrophic Regolithic Neosol of sandy loam texture. Treatments were arranged in a randomized block design, in 5 x 5 factorial scheme, which consisted of five levels of electrical conductivity – ECw (0.7; 1.4; 2.1; 2.8 and 3.5 dS m-1) of irrigation water and five concentrations of hydrogen peroxide - H2O2 (0, 25, 50, 75 and 100 µM), with four replicates and three plants per plot. As the salt stress increased, there were reductions in internal CO2 concentration, instantaneous carboxylation efficiency and water use efficiency, and instantaneous carboxylation efficiency was the most sensitive variable. Hydrogen peroxide at concentrations of 25 and 50 µM attenuated the deleterious effects of water salinity on stomatal conductance, CO2 assimilation rate and chlorophyll a content, and the concentration of 25 µM was the most efficient. The content of chlorophyll b and carotenoids of soursop cv. ‘Morada Nova’ had the deleterious effects caused by the salinity of irrigation water mitigated by the exogenous application of hydrogen peroxide in the concentration of 25 μM.

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Sowing operation direction and population densities in corn growing - (2025)

Rafael D. G. Corrêa, Carlos E. A. Furlani, Cristiano Zerbato, Danilo T. de Oliveira, Rafael H. de F. Noronha, Newton K. Warikoda

Volume: 23 - Issue: 3

Resumo. ABSTRACT Among the factors that may influence corn yield are sowing operation direction and plant population, since they alter the shade index between crop rows, and consequently the efficiency of interception of the photosynthetically active radiation by the leaves of plants. The aim of this study was to evaluate the influence of sowing direction and plant populations on P2830VYH hybrid corn yield. The experiment was conducted at the facilities of FCAV-UNESP, latitude 21º 14’ S and longitude 48º 16’ W in Jaboticabal (SP). The treatments were composed of three sowing directions (North-South, Northeast-Southwest, and East-West) and three population densities (40,000, 60,000 and 80,000 plants ha-1). The treatment with 80,000 plants ha-1 had the lowest cost per sack of corn and profitability 21% higher than that of the treatment with 60,000 plants ha-1, and 45% higher than that of the treatment with 40,000 plants ha-1. Sowing direction had no influence on grain yield when environmental conditions were favorable to the development of the crop. Lower plant densities lead to higher individual results in relation to the number of cobs, length of cobs and number of grains per row.

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Thermal environment of masonry-walled poultry house in the initial life stage of broilers - (2025)

Diogo J. de R. Coelho, Ilda F. F. Tinôco, Cecília F. Souza, Fátima J. F. Baptista, Matteo Barbari, Kelle P. Oliveira

Volume: 23 - Issue: 3

Resumo. ABSTRACT The aim of this study was to monitor and evaluate the thermal environment and undertake a complete mapping of the variables air temperature, air relative humidity, and temperature-humidity index for broilers. The research was conducted during the winter, in Brazil, in a commercial poultry house fully walled with concrete-block masonry, equipped with a full-time negative-pressure mechanized ventilation system and indoor-environment air heating by a wood-burning furnace located outside the facility. The shed was fully automated and housed 30,000 birds at a density of 15 birds m-2. Thermal-environment data analysis revealed that the masonry-wall model did not ensure homogeneous thermal distribution within the poultry house, with the central region showing the highest air temperature and lowest air relative humidity values. The indoor environment did not provide thermal comfort to the housed birds, which were under thermal discomfort in certain situations in some internal regions of the shed.

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Agronomic performance of lettuce subjected to green manure with different leguminous species - (2025)

José J. A. Sarmento, José J. F. dos Santos, Caciana C. Costa, Marinês P. Bomfim

Volume: 23 - Issue: 2

Resumo. ABSTRACT Green manure is the practice of cultivation and incorporation of plants to the soil, mainly leguminous species, produced or not in situ, for the purpose of preserving and/or restoring soil organic matter and soil nutrients. To compare the effects of incorporating leguminous species in the pre-planting green manure on lettuce production, seven treatments were tested: mineral fertilization; crotalaria (Crotalaria juncea); cowpea (Vigna unguiculata); common bean (Phaseolus vulgaris); lablab bean (Dolichos lablab); pigeon pea (Cajanus cajan) and spontaneous plants. The treatments were arranged in the randomized blocks, with five repetitions. The experiment was conducted in the experimental area of the CCTA/UFCG, in the period from April to December 2016. At 30 days after transplanting, the following variables were analyzed: number of leaves, head diameter, shoot height, root volume, fresh weight of shoots and roots, dry weight of shoots and roots, total fresh weight of shoots and roots, total dry weight of shoots and roots and yield. The results were subjected to analysis of variance and, when significant, Tukey test at 0.05 probability level was applied to compare the means. The results showed that, among the leguminous species, the use of lablab bean led to greater development and yield of lettuce.

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Biophysical controls of evapotranspiration in cowpea cultivation under different water regimes - (2025)

Daniely F. S. de Souza, João V. de N. Pinto, Deborah L. P. Costa, Igor C. de O. Vieira, Thieres G. F. da Silva, Paulo J. de O. P. de Souza

Volume: 23 - Issue: 10

Resumo. ABSTRACT The objective of this study was to analyze the variations of the decoupling factor and the aerodynamic and stomatal conductances for cowpea subjected to different levels of water availability during the reproductive phenological stages of the crop. The study was conducted in the municipality of Castanhal located in the northeast of the state of Pará, Brazil, in an area planted with cowpea, in 2013, 2014 and 2015 with four irrigation treatments: T100 - replacement of 100% of the crop evapotranspiration (ETc); T50 - replacement of 50% ETc; T25 - replacement of 25% ETc; and T0 - without any replacement (without irrigation). The interaction between the crop and the atmosphere in water vapor exchange was estimated through the decoupling factor (Ω), which was between 0.5 and 1, except for the treatment without irrigation, indicating a moderate to high decoupling between the crop and the atmosphere, so that the water vapor exchange process was controlled by the energy supply, instead of stomatal control.

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Growth, production and water and nitrogen use efficiency of maize under water depths and nitrogen fertilization - (2025)

David H. Campelo, Adunias dos S. Teixeira, Luis C. J. Moreira, Claudivan F. de Lacerda

Volume: 23 - Issue: 10

Resumo. ABSTRACT The objective of this study was to evaluate the growth, the production components and the water (WUE) and nitrogen use efficiency (NUE) in maize (Zea mays L.), as function of water depths and nitrogen doses. The experimental design was randomized blocks in a split-plot scheme with four repetitions. The irrigation treatments applied in the plots were composed of four water depths: 80, 90, 100 and 110% of the water requirement, based on the soil field capacity, while the N doses, distributed in the subplots, were 0, 60, 120 and 180 kg ha-1. Increases in water depths and in N doses promote linear increases in plant height and leaf area index. For cycle I (2015) the maximum yield (16,778.3 kg ha-1) was reached with the irrigation depth of 538.1 mm and nitrogen dose of 180 kg ha-1; and for cycle II (2016), the maximum yield was reached with the irrigation depth corresponding to 505 mm and N dose of 180 kg ha-1, yielding 17,819.5 kg ha-1. The highest values of WUE (4.1 and 3.8 kg m-3) were estimated in cycle I (2015) for 432.7 mm and in cycle II (2016) for 359.6 mm, respectively; while the highest values of NUE (67.5 and 65.3 kg kg-1) were estimated in cycle I (2015), for the water depth of 555.7 mm and nitrogen dose of 113.3 kg ha-1, and in cycle II (2016), for the water depth of 506 mm and nitrogen dose of 107.7 kg ha-1.

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Operational and energy performance of the tractor-scarifier assembly: Tires, ballasting and soil cover - (2025)

José E. L. Lopes, Carlos A. Chioderoli, Leonardo de A. Monteiro, Mara A. M. dos Santos, Eric H. C. B. van Cleef, Elivânia M. S. Nascimento

Volume: 23 - Issue: 10

Resumo. ABSTRACT The heights of tire claws, tractor ballasting and soil cover can influence the operational and energy performance of the tractor-scarifier assembly. The objective of this study was to analyze the operational and energy performance of the tractor-scarifier assembly as a function of the heights of the tire claws, ballasting and rolling surface. The experiment was conducted at the experimental area of the Fazenda Experimental do Vale do Curu of the Universidade Federal do Ceará in Pentecoste municipality, CE, Brazil. The experiment was carried out in a randomized block in a 2 × 2 × 2 factorial arrangement with four repetitions. The treatments comprised two tire claw heights (T1-28% and T2-100%), two ballasts (B1-100% of solid and 75% liquid weights and B2 - 0% of solid and liquid weights), and two soil surfaces (S1 - soil with 4200 kg of straw ha-1 and S2 - mobilized soil). Worn tires provided a lower bar force (12.88 kN) and power requirement (20.06 kW) and a greater effective and operative field capacity of the tractor-scarifier assembly. The lowest slippage of the front wheels of the tractor was recorded for the worn tires (4.81%).For the rear wheels, slippages were found on the new tires (10.96%), and a higher speed of displacement was found for worn tires (5.54 km h-1). Lower specific fuel consumption was found for the mobilized soil (534.68 g kWh-1); furthermore, the hourly consumption of fuel and the consumption per area were not significantly affected by the treatments analyzed.

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