Semi-arid Region Of Northeast Brazil Research Articles

Hematological referential interval of clinically healthy canines in the semi-arid region of Northeast Brazil

Hematological referential interval of clinically healthy canines in the semi-arid region of Northeast Brazil

Attenuation of salt stress on the physiology and production of bell peppers by treatment with salicylic acid

The use of saline water for irrigation in semi-arid regions has become a reality due to the water scarcity that occurs in most of the year. In this scenario, exogenous application of salicylic acid may be a strategy to mitigate the deleterious effects of salt stress on plants and ensure the production of socioeconomically important crops in the semiarid region of Northeast Brazil, such as bell pepper. Thus, this study examines the osmoprotective effect of salicylic acid on gas exchanges, chloroplast pigments and production components of ‘All Big’ bell pepper plants irrigated with water with different saline levels. The experiment was carried out in greenhouse conditions in Campina Grande - PB, Brazil. Treatments consisted of four levels of electrical conductivity on the irrigation water (0.8, 1.6, 2.4 and 3.2 dS m-1) and four concentrations of salicylic acid (0, 1.2, 2.4 and 3.6 mM), which were distributed in a 4 × 4 factorial arrangement in a randomized block design with three replicates. Increases in irrigation water salinity from 0.8 dS m-1 resulted in changes in gas exchange and total chlorophyll levels of ‘All Big’ bell pepper plants. The estimated salicylic acid concentration of 1.7 mM reduced the effects of salinity on stomatal conductance, transpiration, CO2 assimilation rate, instantaneous carboxylation efficiency, total chlorophyll and fruit diameters. Irrigation with water of 1.8, 0.8 and 1.6 dS m-1 salinity associated with the estimated salicylic acid concentration of 1.6 mM increased the biosynthesis of chlorophylls a and b and the number of fruits, respectively, in bell pepper plants.

Obtaining the daily actual evapotranspiration through remote sensing techniques application in Brazilian Semiarid

Large volumes of water are released to the atmosphere through evaporation from soil and transpiration from vegetation, constituting evapotranspiration (ET). Estimating the water consumption in vegetated areas is important for the management and rational use of this resource. For this study were processed orbital images which correspond to Quixeré-CE, with interest at the Frutacor Farm, where there is predominance the banana crop. The main objective of this study was to assess the accuracy and applicability of S-SEBI and SSEB algorithms with regard to SEBAL to estimate the actual daily evapotranspiration ETa) of a semi-arid region of Northeast Brazil, containing areas of banana orchard, native vegetation (caatinga) and bare soil. S-SEBI. The SSEB and SSEB algorithms showed strong correlation (r > 0.93) with statistical significance of 5%. The S-SEBI exhibited errors less than 12% in the orchard and caatinga and SSEB exhibited greater errors at 22%, though for the bare soil, both models showed large discrepancies when compared with SEBAL, with errors greater than 36%. Therefore, among the two algorithms compared with SEBAL, S-SEBI had a better performance in ETa estimation with lower deviations.

Obtaining the daily actual evapotranspiration through remote sensing techniques application in Brazilian Semiarid

Large volumes of water are released to the atmosphere through evaporation from soil and transpiration from vegetation, constituting evapotranspiration ( ET ). Estimating the water consumption in vegetated areas is important for the management and rational use of this resource. For this study were processed orbital images which correspond to Quixere-CE, with interest at the Frutacor Farm, where there is predominance the banana crop. The main objective of this study was to assess the accuracy and applicability of S-SEBI and SSEB algorithms with regard to SEBAL to estimate the actual daily evapotranspiration ET a ) of a semi-arid region of Northeast Brazil, containing areas of banana orchard, native vegetation (caatinga) and bare soil. S-SEBI. The SSEB and SSEB algorithms showed strong correlation ( r > 0.93) with statistical significance of 5%. The S-SEBI exhibited errors less than 12% in the orchard and caatinga and SSEB exhibited greater errors at 22%, though for the bare soil, both models showed large discrepancies when compared with SEBAL, with errors greater than 36%. Therefore, among the two algorithms compared with SEBAL, S-SEBI had a better performance in ET a estimation with lower deviations.

IDENTIFICAÇÃO DE TENDÊNCIAS NAS SÉRIES TEMPORAIS DE PRECIPITAÇÃO NA MICRORREGIÃO DO ALTO SERTÃO PARAIBANO

The development of the semi-arid region of Northeast Brazil (NEB), mainly in the State of Paraiba , is strongly dependent on its rainfall index. Precipitation variations can cause economic and social damage to the population of the state. The activities of agriculture and breeding, as well as the human supply, are of great importance in the economics of the NEB, and, in particular, for the microregion of the Alto Sertao Paraibano. This study promotes the exploration of the Alto Sertao Paraibano microregion pluviometric time series characteristics, with the objective of investigating circumstantial changes in the precipitation distribution. For the identification of trends in time series of precipitation, the non-parametric methods of Mann-Kendall and Pettitt and the parametric method of Linear Regression were applied to 15 rain stations. At the data organization, it was possible to notice that the microregion rainy season, composed of the months of February to May, is responsible for more than 70% of the total annual precipitation, thus having a graphical oscillation consistent with the yearly average precipitation distribution. The trend identification methods were efficient and comprehensible in time series analysis of rainfall. Both analysis of annual rainfall and the rainy season, although with signs of positive and negative trends, did not become significant. The dry season shows a negative trend in the first ten years studied, but there is no evidence of a recent significant trend.

Cytogenetic analysis of nuclear abnormalities in the erythrocytes of gecko lizards (Phyllopezus periosus) collected in a semi-arid region of northeast Brazil: Possible effects of natural background radioactivity

High natural-background radioactivity levels occur in the semi-arid region of the State of Rio Grande do Norte, northeastern Brazil. We have studied the lizard Phyllopezus periosus, an endemic species of the Brazilian caatinga with saxicolous habitat, as a bioindicator of environmental quality. Specimens were collected in three areas, an environmental protection area and two areas recognized as having high natural background radiation, one of these being a mining area. Level of metals and gamma radiation emitters present in the water sources potentially used by the lizards were measured. The biological endpoints assessed were micronuclei and nuclear abnormalities in blood samples. Significant differences in background radioactivity levels were found among the assessed areas. Statistically significant differences in micronuclei and nuclear abnormality frequencies were seen, among the study areas and a relationship between radioactivity level and genetic damage was observed.

Influence of the structure on the collapse potential and shear strength of a residual soil in the semiarid region of Northeast Brazil

In the last decades, several engineering works have been developed in the Northeast of Brazil, a region marked by the occurrence of collapsible and expansive soils. This work aimed to characterize and study the behavior of two samples of residual soils collected in the municipality of Salgueiro-PE regarding their collapse potentials and shear strength parameters, in natural and disturbed conditions, evaluating the influence of the applied vertical stresses and the structural arrangement in these properties. The results obtained showed that the two samples analyzed show collapsible behavior, however, the observed potential for collapse was lower after the original structure arrangement was undone. From the direct shear strength tests, the strength parameters of the two soils were obtained, which pointed effective friction angle close to 30° and cohesive intercept close to 0 kPa. The destructuring of the samples did not cause a considerable variation in these parameters. Thus, it was possible to conclude that for these samples the microstructure has a predominant influence on the occurrence of collapsibility, but does not have the same relevance on the shear strength, such that the material’s destructuring can be considered as an effective measure to reduce the potential collapse.

The Piancó-Piranhas-Açu Hydrographic Basin Face to the 2012-2020 Drought Event / A Bacia Hidrográfica dos Rios Piancó-Piranhas-Açu Frente ao Evento de Seca 2012-2020

The semiarid region of Northeast Brazil experienced during the years 2012 to 2020 one of its worst periods of severe drought. This was largely due to the conditions of the El Niño phenomenon in the Pacific Ocean and the oceanographic and atmospheric conditions of the Atlantic Ocean. In this article, it was intended to address the aspects of water management due to this extreme drought, both from the supply and demand side, in a typical hydrographic basin in the Brazilian semiarid, the Piancó-Piranhas-Açu river basin. With the reduction of rainfall and the consequent tax flow to the main reservoirs in the region, the operation of the reservoirs responsible for the main uses of the region's water resources is shown to be of fundamental importance: irrigated agriculture (with an estimated area of around 50 hectares in the basin); aquaculture; human and industrial supply, among others. Actions aimed at the rational use of water, monitoring and negotiated water allocation mechanisms, as well as communication were also carried out.

Selectivity of Pre and Postemergence Herbicides in Single or Combined Applications in Castor Crop

One of the main challenges in castor crop (Ricinus communis L.) production is efficient weed management mainly due to limited options of selective herbicides. This study evaluated the selectivity of herbicides applied alone or in combination in pre- and postemergence applications in castor crop. Two field experiments were carried out under irrigation conditions in a semi-arid region of Northeast Brazil. It was found that the visual symptoms of phytointoxication of the herbicides used on castor were mild in both experiments. Consequently, there were no significant interferences on plant height, number of racemes, and grain (seed) yield. Pre-emergence applications (g ha−1) of trifluralin (1800), pendimethalin (1500), clomazone (750), clomazone + trifluralin (750 + 1800), and clomazone + pendimethalin (750 + 1500) followed by chlorimuron-ethyl in postemergence (15 g ha−1) are selective to castor. The application (g ha−1) of pendimethalin + clomazone (1000 + 500) in pre-emergence, associated with chlorimuron-ethyl (10 and 15), metamitron (2800 and 4200), ethoxysulfuron (60 and 80), or halosulfuron-methyl (75 and 112.5) in one or two applications in postemergence, as single or split applications, in an interval of 14 days, are selective to castor crop.

Grandes projetos, pequenas escolhas: notas sobre a desmobilização em contextos camponeses no semiárido potiguar

Mediante a retórica do desenvolvimento, se instalam no semiárido nordestino grandes projetos que provocam profundas alterações e reordenamentos no sentido de vida compartilhado por populações locais. Este artigo busca compreender a questão da desmobilização enquanto um fenômeno produzido no contexto de dois conflitos socioambientais no RN: o primeiro é referente à chegada da revolução verde, cujo marco é a construção da barragem Armando Ribeiro Gonçalves, até hoje a maior do estado; e o segundo é relativo ao caso contemporâneo de instalação de parques de energia eólica na chamada Costa Branca, litoral norte. O cenário desses conflitos está inscrito na região oeste do estado, que concentra as principais atividades da economia primária e está altamente integrada ao mercado de commodities. Os dados trabalhados neste estudo são referentes à percepção dos estudantes do curso de Licenciatura Interdisciplinar em Educação do Campo da Universidade Federal Rural do Semiárido (Ledoc/Ufersa) que, sendo oriundos das comunidades rurais diretamente impactadas por esses projetos, estimam perdas, inconvenientes e constrangimentos mediante considerações pouco recorrentes nos estudos sobre o tema.

Biological activity of geopropolis produced by Partamona cupira (Meliponinae, Apidae) in the semiarid of the Brazilian northeast

Research on the chemical composition and pharmacological activities of geopropolis produced by stingless bees (Hymenoptera, Apidae, Meliponini) may contribute to expand its use of propolis-based formulations in the clinical context. Thus he study aimed to evaluate the chemical composition and biological activity of the hydroethanolic extract (HEG) of the geopropolis of Partamona cupira, obtained in the semiarid region of northeast Brazil. Chemical analyses of HEG were carried out using HPLC-DADESI-MS/MS. The antioxidant activity of extracts was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay method and cytotoxic activity by the in vitro MTT method [brometo de 3- (4.5dimetiltiazol-2-il)-2.5-difeniltetrazolio]. The antibacterial activity of the HEG was evaluated through the disc-diffusion test on agar and measurement of the promoted by the extract in different concentrations. The genoprotective potential of the HEG was evaluated through the comet assay on fibroblasts of L929, co-treated with the extract and submitted to genotoxicity induction with H2O2. We also investigated the healing effect of the cream containing geopropolis (10%) on experimental skin wounds in Wistar rats. The HEG presented in its composition phenolic compounds of high biological activity, as well as revealed high antioxidant activity and promoted genoprotective effect by reducing DNA damage from L929 fibroblasts. The HEG presented antimicrobial activity promoting inhibition of S. aureus, S. pyogenes, E. coli and E. aerogenes. The topical use of the cream containing geopropolis promoted wound closure and faster reepithelialization in relation to the control group, in addition to a less intense inflammatory reaction, increased fibroblastic proliferation and collagen deposition.

EFFECT OF GREEN MANURING WITH MERREMIA AEGYPTIA ON AGRO-ECONOMIC EFFICIENCY OF RADISH PRODUCTION

ABSTRACT The introduction of new crops in northeastern Brazil, associated with the use of the green manure, can become an alternative for family farmers. Thus, the objective of this work was to determine the effect of green manuring with M. aegyptia L. on the agro-economic efficiency of radish production. The experimental design was a randomised complete block with four treatments and five replicates; the treatments were composed of four doses of M. aegyptia (20, 35, 50 and 65 t ha-1 on a dry basis) incorporated into the soil in three cropping periods. In radish plants, we evaluated plant height, fresh and dry mass of shoots, total and commercial productivity of roots, productivity of scrap roots, dry mass of roots and root diameter. The economic indicators gross income, net income, rate of return and profit margin were used to evaluate the agro-economic efficiency of the system. The maximum agronomic efficiency was reached with a commercial root productivity of 7.86 t ha-1 and the addition of 49.29 t ha-1 of green manure. The maximum economic efficiency was obtained with a net income of 11,955.46 R$ ha-1 when a green manure dose of 46.00 t ha-1 was added. The use of M. aegyptia as green manure is economically viable in the production of radish in the semi-arid region of Northeast Brazil.

Effects of topography and climate on Neotropical mountain forests structure in the semiarid region

AbstractQuestionWe aimed to analyze how the topography, temperature and rainfall influence the floristic distribution in three different topographic areas and their surrounding vegetation. We addressed three main questions: (i) How is the distribution of species among the topographic areas? (ii) Which abiotic variable is driving this distribution? and (iii) What is the difference among the mountain forests and between mountain forests and the Caatinga vegetation?LocationThe Maranguape mountain forest were divided into three topographic categories: windward (600–800 m, WMA), leeward (600–800 m, LMA) and top (above 800 m, TMA). We also considered another six areas of mountain forests and four Caatinga areas in Ceará State.MethodsWe calculated different structural parameters and the floristic diversity of each category. A Principal Correspondence Analysis was performed to analyze the indirect ordination of forest sites by species abundance. A Canonical Correspondence Analysis was conducted to evaluate which variables were driving species distribution. We used non‐metric multidimensional scaling distance and the average linkage method to investigate the similarity among mountain forests and Caatinga.ResultsA total of 1,536 individuals belonging to 144 tree species distributed in 44 families and 93 genera were recorded. Myrtaceae, Fabaceae and Rubiaceae were the most species‐rich families. Myrcia splendens had the highest importance value followed by Guapira nitida and Mollinedia ovata. The leeward slope showed the highest richness and diversity index, whereas the windward showed the highest density and the top showed the highest basal area. The ordination indicated a greater similarity between TMA and WMA than LMA.ConclusionOur results suggest that temperature, precipitation and slope angle are the abiotic factors driving species distribution in Maranguape. Those mountains are heavily anthropized and continuously explored, therefore these outcomes will be useful for conservation and restoration purposes in the poorly known semiarid region of Northeast Brazil.

Stable isotopes of C and N as dietary indicators of Nile tilapia (Oreochromis niloticus) cultivated in net cages in a tropical reservoir

The relative contribution of natural feed sources and commercial diets to the nutrition of Nile tilapia (Oreochromis nilloticus) was evaluated in a net cage production carried out in a reservoir in the semi-arid northeast region of Brazil. The present study tested the hypothesis that tilapia uses natural sources of feed for growth, even when confined in cages and artificial feed resources are available. The fish and various feed sources (commercial feed, seston and periphyton) were sampled and the water quality was monitored during the cultivation, which was carried out for 120 days. The fish were fed three times daily with two commercial feeds of 40 and 32 % crude protein, both of which used fish meal as a protein source. Stable isotopes analyses were carried out by measuring the 13C and 15N of fish muscle tissue and the feed items using the MixSIAR mixing model to determine the relative contribution of the nutrient sources to fish growth. The tilapia showed adequate weight gains with the total contributions of the feed items: periphyton (14.4 %), seston (51.2 %) and commercial feed (34.4 %) throughout the 120 days of culture. It can be concluded that the natural feed sources of seston and periphyton contributed more to the growth of the Nile tilapia than the commercial feed when cultivated in net cages, changing the notion that the commercial feed contributes predominantly to the intensive farming of this species in cages. The results of the present study suggest a more sustainable feed management in the farming of Nile tilapia in net cages.

Reproductive and productive characteristics of hair sheep raised in the tropical region grassland of Brazil

We aimed to characterize the energetic profile of hair sheep (Ovis aries) raised on pasture in a tropical climate country and verify it is influence on productive and reproductive parameters. A total of 68 non-pregnant adult ewes were randomly distributed into four genetic groups (GGs) according to coat color (Red-coated Santa Inês GG – 17, Black-coated Santa Inês GG – 13, White-coated Morada Nova GG – 28 and Red-coated Morada Nova GG – 10). We collected blood samples at the beginning and at the end of the breeding season. The reproductive efficiency of the ewes was evaluated by fertility, prolificacy, lamb survival rate, and lamb body weight at birth and weaning. We performed statistical analyses using the package PROC GLM and the chi-square (χ2) test from SAS software. The genetic group influenced serum glucose and β-hydroxybutyrate concentrations, prolificacy, and lamb body weight. Male lambs were heavier than female lambs at birth and weaning. Twin lambs were lighter at birth and at weaning than were single lambs. The genetic group, lamb birth rank, and sex influenced the lamb body weight at birth and weaning. This study presents important information on the reproductive efficiency of these hair sheep that are relevant to tropical climate countries. The blood parameters found in this research show that there are important metabolic differences between hair sheep in the semi-arid region of Northeast Brazil. Morada Nova sheep with independent white coat color, higher reproductive performance in tropical conditions.

Gas exchanges, growth and production of okra cultivated with saline water and silicon fertilization

Excess salts in water and/or soil are a critical factor that adversely affects the physiology and growth, besides limiting the production of crops in the semiarid region of Northeast Brazil. One way to reduce the effect of salt stress on plants is by using silicon (Si) fertilization. In this context, the objective of this study was to evaluate the gas exchange, growth, and production of okra cv. Valença as a function of irrigation with saline water and Si doses. The experiment was conducted in a greenhouse in the municipality of Pombal - PB, Brazil. The experimental design adopted was randomized blocks in a 5 × 2 factorial scheme corresponding to five levels of electrical conductivity of water ECw (0.3, 1.0, 1.7, 2.4, and 3.1 dS m-1) and two doses of Si fertilization (100 and 200 g of Si per plant), with four replicates. Salt stress increased the intercellular concentration of CO2 in the substomatal chamber and reduced the CO2 assimilation rate, instantaneous carboxylation efficiency, growth, and production of okra plants. Intrinsic water use efficiency and average weights of okra fruits were not influenced by irrigation with saline water and Si doses. The supply of 200 g Si per plant reduced the deleterious effect of salt stress on stomatal conductance and leaf area of okra, at 45 days after sowing but did not increase production.

Bactérias diazotropicas no crescimento inicial e alterações bioquímicas de Vigna unguiculata sob deficit hídrico

O cultivo do feijão caupi vem se destacando por ser uma cultura adaptável para a região árida e semi-árida do Nordeste brasileiro. Dentre os fatores que reduzem a sua produção, o déficit hídrico e a adubação, tem destaque. Devido a sua capacidade de realizar simbiose com bactérias noduladoras, poderá optimizar a fixação do N2 atmosférico dependendo da combinação e compatibilidade das estirpes envolvidas. O objetivo do trabalho foi avaliar a resposta de plantas de feijão-caupi (cultivar BRS Marataoã) sob déficit hídrico inoculadas e coinoculadas com bactérias fixadoras de nitrogênio. O delineamento experimental utilizado foi o inteiramente casualizado em esquema de parcelas subdivididas com dois fatores (4x5), composto por: T1: BR3264 (A); T2: BR85 (B); T3: BR3264+BR85 (C); T4: controle nitrogenado (CN); T5: controle absoluto (CA), associado com as lâminas de água nas seguintes proporções: 100 %, 80%, 60% e 40% da evapotranspiração da cultura (ETc). As análises foram realizadas aos 45 dias após a emergência (DAE) e compostas de parâmetros filotécnicos (número de folhas, altura da planta, diâmetro do caule, clorofila a, b e total) e bioquímicos (teores de açúcares solúveis totais, açúcares redutores, e prolina). Os resultados obtidos demonstraram que o déficit hídrico ocasionou influência negativa no número de folhas, no diâmetro do caule, na altura das plantas, na clorofila A, na massa seca da parte aérea e na inoculação. A inoculação das cepas de rizóbio é reduzida quando submetida a plantas com estresse hídrico, se sobressaindo cepas nativas. Sendo que a inoculação cruzada favorece a inoculação nessas condições.

Root biomass and production of cotton cultivars subjected to saline water irrigation

Water scarcity and high levels of salinity in irrigation water limit irrigated cotton cultivation in the semiarid region of Northeast Brazil. So, it is necessary to adopt cultivation strategies that make the production system feasible. In this context, the present study aimed to evaluate the biomass and production of cotton cultivars subjected to different levels of saline water irrigation. The experiment was carried out under greenhouse conditions, with treatments distributed in a completely randomized design, in a 5 x 2 factorial arrangement, corresponding 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), with 4 replicates. Treatment effects were measured by the number of bolls per plant, lint weight, number of seeds per plant, total weight of seeds and dry and fresh biomass of stem, roots and leaves. Irrigation using water with electrical conductivity from 1.5 dS m-1 negatively affects the production of the cotton cultivars BRS SAFIRA and BRS 368 RF, causing reductions in all production variables analyzed. The cultivar BRS Safira has better production performance than BRS 368 RF when exposed to water salinity.

Assessing drought in the drylands of northeast Brazil under regional warming exceeding 4 °C

Historically, during periods of extreme drought, food security in the drylands of the semiarid region of Northeast Brazil (NEB) is under severe risk due to agricultural collapse. The drought that started in 2012 continues to highlight the vulnerability of this region, and arid conditions have been detected during the last years mainly in the central semiarid region, covering almost 2% of the NEB. Climate projections show an increase in the area under water stress condition, covering 49% and 54% of the NEB region by 2700 and 2100, respectively, with a higher likelihood with warming above 4 °C. The projections of vegetative stress conditions derived from the empirical model for Vegetation Health Index (VHI) are consistent with projections from vegetation models, where semi-desert types typical of arid conditions would replace the current semiarid bushland vegetation (“caatinga”) by 2100. Due to the impacts of the 2012–2017 drought, public policies have been implemented to reduce social and economic vulnerability for small farmers but are not enough as poor population continues to be affected. In the long term, to make the semiarid less vulnerable to drought, strengthened integrated water resources management and a proactive drought policy are needed to restructure the economy. Integrating drought monitoring and seasonal climate forecasting provides means of assessing impacts of climate variability and change, leading to disaster risk reduction through early warning. Lastly, there is an urgent need for integrated assessments because the possibility that under permanent drought conditions with warming above 4 °C, arid conditions would prevail in NEB since 2060.

Wound healing activity and chemical composition of geopropolis from Melipona subnitida

Geopropolis collected by stingless bees is a product widely used in the semiarid Northeast region of Brazil. The wound healing activity, palynological analysis, free-radical scavenging activities, and the chemical composition of the hydroalcoholic extract of six samples from jandaira geopropolis were determined. The wound healing activity was evaluated using 10% geopropolis hydroalcoholic extract added to the formulation incorporated into a base of Lannette cream, and the chemical composition of six samples was determinate by ultra-performance liquid chromatography coupled with diode array and quadrupole time-of-flight mass spectrometry. The detected compounds in the five samples (1–5) were classified as flavonoid aglycones (flavonols, flavanonols, flavonones, flavones, and chalcones). In sample 6, flavonoids, phenylpropanoids, and hydrolysable tannins were identified. Analysis of the pollen types in geopropolis showed that pollen from Leguminosae was predominant, indicating the visit of bees in the species of this family. This sample (6), with the highest content of phenolic compounds and high free-scavenging activity, was tested to evaluate the wound healing potential. The topical application of geopropolis (10%) increased the wound healing rate and re-epithelialization of wounds in rats. Our data indicate that the mixture of phenolic components in the geopropolis may contribute to the activities of free-radical scavenging and wound healing.