Brazilian Semiarid Region Research Articles

The influence of vegetation covers on urban thermal comfort in a Brazilian semiarid region

The influence of vegetation covers on urban thermal comfort in a Brazilian semiarid region

Avaliação não destrutiva de atributos de qualidade em maçãs e peras usando espectroscopia no infravermelho próximo e quimiometria

Abstract The objective of this study was to evaluate the performance of a handheld NIR spectrometer for non-destructive quality analysis of apples and pears produced in the Brazilian Semi-arid region. NIR spectra were acquired with a portable spectrometer in the wavelength range of 750–1065 nm and reference analyses of dry matter content (DMC) and soluble solids content (SSC) were measured weekly during 10 weeks of storage at 0.5 °C. Spectra were pre-processed with standard normal variate and used to develop DMC and SSC models using partial least squares regression with full cross-validation. The models were validated using data not included in the calibration. Satisfactory prediction results were obtained for SSC in apples (R² = 0.58) and pears (R² = 0.55), and for DMC in apples (R² = 0.55) and pears (R² = 0.65). All prediction models showed a relative root mean square error of prediction lower than 8%. These findings indicate that the NIR spectrometer is a promising tool to be used for a rapid and non-destructive determination of internal quality traits in apples and pears.

Caracterização e organização dinâmica de dois sistemas agroflorestais no semiárido paraibano e sua contribuição para melhoria das condições socioeconômicas de famílias agricultoras

ABSTRACT: The socio-economic vulnerability of family farmers in Brazilian semi-arid regions, combined with the intense degradation of the Caatinga biome, entails the use of alternatives that allow people to remain in the countryside while recovering the environment. Are agroforestry systems (AFS), which are based on the ecological, economic, and social interactions existing in a production system, an alternative? The present study described the structure, organization, and floristic composition of two AFS and analyzed the soil fertility of the two AFSimplanted in the semi-arid region of Paraíba. This study revealed that the farmers consider the AFS to be less harmful to the environment as it provides greater protection to the soil and better-qualityfood. Thegreatest challenges wereobtaining water during drought season and the need foran extra workforce. Nevertheless, the produce from these systemswas sufficient to provide for the families. Several varieties of fruit species were found in both the AFS studied, and Malpighia emarginata (acerola) was the most predominant. The soils of the two AFS presented a practically neutral pH the and high percentage of base saturation,thereby falling under the category of eutrophic soil with high fertility, and are ideal for growingany type of crop.

Effects of corn straw on meat characteristics of lambs in the Brazilian semi-arid region

Effects of corn straw on meat characteristics of lambs in the Brazilian semi-arid region

Adubação potássica no cultivo de maracujazeiro-azedo sob estratégias de irrigação com água salobra

ABSTRACT In the Brazilian semiarid region, the occurrence of water sources with high salt concentrations stands out as a limiting factor for the production of most crops under irrigated conditions. This research was conducted to evaluate the physical and chemical quality of sour passion fruit as a function of brackish water irrigation strategies and potassium doses. The experiment was carried out under field conditions using a randomized block design in a 6 × 2 factorial scheme, consisting of six strategies of irrigation with brackish water (irrigation with water of 1.3 dS m-1 throughout the cycle - WS; irrigation with water of 4.0 dS m-1 in the vegetative stage - VE; flowering stage - FL; fruiting stage - FR; in the successive vegetative/flowering stages - VE/FL; vegetative/fruiting stages - VE/FR) and two potassium doses: 60 and 100% (345 g of K2O per plant per year) of recommendation, with four replicates and three plants per plot. Irrigation with water of 4.0 dS m-1 in the flowering stage or continuously in the vegetative and flowering stages reduced the yield and size of sour passion fruit. Fertilization with 60% of K is recommended for the production of sour passion fruits with greater polar diameter. It is feasible to cultivate sour passion fruit under irrigation with 4.0 dS m-1 of water in the flowering and fruiting stages and fertilization with 60% of the K recommendation without losses in ascorbic acid and total soluble sugars.

Mortality of the cotton boll weevil in drip and sprinkler irrigated cotton crops.

The cotton boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), is a key cotton crop pest in Brazil. Adverse climatic factors, such as high temperatures and low soil moisture, dehydrate oviposited cotton squares (bud flowers) on the ground and cause high mortality of its offspring within these plant structures. The objective of this research was to evaluate the mortality of the cotton boll weevil in drip and sprinkler irrigated cotton crops. The experimental design was in randomized blocks with two treatments: drip (T1) and sprinkler (T2, control) irrigated cotton crops with sixteen replications. Each parcel had one emergence cage, installed between two cotton rows per irrigation system, with 37 cotton squares with opened oviposition punctures and yellowish bracts, to capture adult cotton boll weevils. The average number of boll weevils that emerged from the cotton squares and the causes of mortality at different development stages were determined per treatment. Third-generation life tables of the boll weevil were prepared using the natural mortality data in drip and sprinkler irrigation treatments and plus actual, apparent and indispensable mortality rates and the lethality of each mortality cause. We conclude that the application of water directly to the root zone of the plants in a targeted manner, using the drip irrigation system, can cause high mortality of the cotton boll weevil immature stages inside cotton squares fallen on the ground. This is because the cotton squares fallen on the drier and hotter soil between the rows of drip-irrigated cotton dehydrates causing the boll weevils to die. This is important because it can reduce its population density of the pest and, consequently, the number of applications of chemical insecticides for its control. Thus, contributing to increase the viability of cotton production, mainly in areas of the Brazilian semiarid region where the cotton is cultivated in organic system.

Croton L. (Crotonoideae, Euphorbiaceae) em uma área protegida do Nordeste do Brasil

Abstract Croton is the largest genus of Crotonoideae Burmeist. (ca. 1200 species), with approximately 300 species distributed in all the phytogeographic domains in Brazil. The Chapada of Araripe Environmental Protection Area (CA-EPA) is one of the largest protected areas in northeastern Brazil and comprises many different types of vegetation. Considering the expressive representation of Croton in that northeastern region and its morphological complexity, we carried out a taxonomic study of the species occurring in the CA-EPA. The analysis of collections deposited in regional herbaria, together with field observations, revealed 18 Croton species, five of which had never been cited as occurring in the study area; seven of those taxa are endemic to the Brazilian semiarid region. Croton species were recorded in all of the vegetation types in the CA-EPA, especially in the “carrasco” and “caatinga” vegetation. The plants habits, the shapes of their stipules, extrafloral nectaries, indumenta, and staminate and pistillate sepals were important characteristics for their differentiation.

DIÁLOGO ENTRE A TEORIA E A PRÁTICA UTILIZANDO A FOTOGRAFIA E A PINTURA PARA O ESTUDO DAS PAISAGENS DO SEMIÁRIDO NORDESTINO

This paper proposal aims to add to the expansion of the debate on the use of didactic resources such as photography and painting in Geography teaching especially for the study of the northeastern semi-arid region, having as focus on its landscapes. Therefore, extradition project subject project/menu was prepared with the theme “semi-arid alive! Threatened Wealthiness”, which was presented and performed at EREM Carlos Pena Filho High School Reference, located in Salgueiro-PE municipality, with high school students as the target audience. Methodologically, bibliographic surveys were carried out on the central thematic of the research and theoretical and practical activities (photographs and paintings) as well as field activities in a Salgueiro-PE municipality tourist spot. The practices carried out stated the importance of the working with photographs for the study of landscape in Geography teaching besides reinforced the importance of studying the Brazilian semiarid region.

Weed spatial distribution as a function of soil properties in two distinct environments of the Brazilian semi-arid region

Weed spatial distribution as a function of soil properties in two distinct environments of the Brazilian semi-arid region

Molecular detection of Trypanosoma cruzi in equids in a semiarid zone of Pernambuco - Brazil

Trypanosoma cruzi is the etiological agent of Chagas disease, a neglected and frequently occurring zoonosis in Central and South American countries. Wild mammals and domestic dogs are the main reservoirs of the parasite in the wild and domestic cycles, respectively. The vectors have a wide variety of food sources that can influence transmission cycles. The aim of this study was to determine the prevalence of T. cruzi infection in donkeys (Equus asininos) and mules (Equus mulus) living in rural areas of the Brazilian semi-arid region. Whole-blood samples from 72 equids (65 donkeys and 7 mules) were analyzed by nested polymerase chain reaction (nested PCR). A total of 51.39% of the samples (37/72) were positive. Phylogenetic analysis identified discrete typing units TcI and TcII, which suggested the possibility that donkeys and mules might be participating in domestic/peridomestic and wild transmission cycles. This was the first report of T. cruzi infection in donkeys and mules in Brazil, with high prevalence of positive animals. This places these animals as potential reservoirs for the parasite and the particular features of these hosts, the presence of vectors and the socioeconomic characteristics of the population under semiarid conditions create interactions that may favor transmission and overlapping T. cruzi infection cycles.

Evaluating homogeneity and trends in extreme daily precipitation indices in a semiarid region of Brazil

A regional investigation of precipitation extremes could help the local authorities to develop strategies against potential climatic disasters, especially in regions of large climate vulnerability. In this context, this study focused on the homogeneity and trend analysis of eleven extreme precipitation indices from a daily rainfall dataset of rain gauges of the state of Ceará, located in the north of Northeast Brazil, from 1974 to 2018 at annual and seasonal time scales. The data were first submitted to gap-filling and quality control processes. Homogeneity, trend, and correlation coefficient were performed subsequently. Homogeneity results showed that most of the precipitation series were classified as “useful.” Significant break years in the series agreed well with moderate and very strong El Niño and La Niña events, suggesting a further investigation of this possible connection. Wet and dry day precipitation indices mainly indicated a decrease in the rainfall regime and an increase in dry days, mainly in the central-eastern, northwestern, and southern regions of the Ceará, especially during the annual time scale and the rainy season. The Locally Weighted Scatterplot Smoothing (LOWESS) curve showed changes in almost all series during the 1980s and 1990s, coinciding with the homogeneity breaks and years of severe droughts that strongly hit the region. Correlation coefficients were strong and significant between rainfall total index and the other precipitation indices.

Laticifer ontogenesis and the chemical constituents of Marsdenia zehntneri (Apocynaceae) latex in a semiarid environment.

Anastomosed laticifers with intrusive growth produce latex containing methyl comate and betulin with economic and ecological value in arid environments. Climatic factors influence laticifer development in the apical meristem and vascular cambium. Latex is a complex emulsion with high medicinal as well as ecological value related to plant survival. Marsdenia zehntneri is a shrubby plant that grows on limestone outcrops in the semiarid regions of Brazil. We sought to characterize the ontogenesis of the laticifers of this species and to relate that process to climatic seasonality and phenology through anatomical, ultrastructural, and micro-morphometric evaluations of the apical meristem and vascular cambium. The histochemistry of the secretory structure was investigated and the chemical composition of the latex was analyzed. Phenological assessments were performed by monitoring phenological events for 1 year. The laticifers network of M. zehntneri permeates the entire primary and secondary body of the plant, providing a wide distribution system of defensive compounds. Its laticifers, of a distinct mixed type (anastomosed, with intrusive growth), are numerous and voluminous in the apical meristem but scarce and minute in the secondary phloem. Latex secretion involves the participation of oleoplasts, polysomes, and dictyosomes. Methyl 2,3-dihydroxy-ursan-23-oate, methyl 3-hydroxy-ursan-23-oate, and betulin are encountered in high proportions in the latex and have ecological and medicinal functions. The development of primary laticifers is related to the resumption of apical meristem activity with increasing day length at the end of the austral winter. The development of secondary laticifers is related to high summer temperatures and rainfall that favor vascular cambium activity. The wide distribution of laticifers, their seasonal pattern of secretion, and their latex composition contribute to the adaptation of M. zehntneri to its natural environment.

Patterns associated with hunting with dogs in a semiarid region of northeastern Brazil

BackgroundHunting has been an important cultural and subsistence activity for the survival of the human population. In the Brazilian semiarid region (Caatinga), the extreme seasonal changes and socioeconomic conditions have made local people dependent on the natural resources available, including wildlife. Although hunting with dogs can result in higher efficiency for hunters, it can also have implications for game species conservation.MethodsUsing an ethnozoological approach (semi-structured questionnaires, free interviews, informal conversations, and free listing technique), this study aimed to analyze the patterns of hunting with dogs activities in a semiarid region of northeastern Brazil by characterizing hunters’ and hunting dogs’ profiles, investigating target and nontarget prey species, hunters’ practices, motivations, and perceptions regarding the efficiency of hunting with dogs.ResultsWe found that hunters that use dog assistance were mostly men, of different ages, with an occupation in agriculture, receiving less than a minimum wage, and with a low level of formal education. Hunters use two or more mixed-breed dogs with no clear preference regarding dogs’ sex. The motivations for hunting with dogs included mainly food, sport, and trade. Hunters cited twenty species captured by dogs without distinction between prey’s sex and age (14 mammals, 4 birds, and 2 reptiles). Only six of these were mentioned as being target prey when hunting with dogs. From nontarget species, eight carnivores are usually left at the site of kill, as they have no use to the hunters. Hunters perceived that hunting with dogs could be three times more efficient than hunting without dogs.ConclusionOverall, hunting with dogs represents a complex set of local variables, including characteristics of dogs and prey species, hunters’ motivations, and practices that should be considered according to each particular situation. Considering the human dependence on natural resources in the semiarid region, hunters should be included in wildlife management debates to mitigate the threat to game species while allowing sustainable hunting practices.

Temperatures and substrates on the germination and vigor of seeds of Pilosocereus catingicola subsp. salvadorensis in the Caatinga biome of Paraíba

The Caatinga biome is presented in the vegetation where the Brazilian semiarid region predominates, with a great variety of native species, and facheiro is one of the most important species because of its wide range in the semiarid region in northeastern Brazil. Therefore, the knowledge of the germinative behavior of the Caatinga species is essential to subsidize conservationist actions in this ecosystem. This study aimed to determine the effect of temperature and substrate on the germination and vigor of facheiro’s seeds. These seeds were obtained from ripe fruits collected in three localities of the Agreste of Paraíba: Arara, Bananeiras, and Boa Vista. After extraction, the seeds were placed to dry on paper for one week in a laboratory environment. Subsequently, the experiment was started by testing four temperatures: 20, 25, 30, and 20-30 °C. The germination test was conducted with four replications of 50 seeds distributed in “gerbox” boxes and placed in bio-oxygen demand (BOD) chambers using as a substrate the germitest paper, with a photoperiod of 12 hours. The statistical design was randomized in a 3 × 4 factorial arrangement (3 localities and 4 temperatures). A significant effect was observed for populations and substrates. The best substrate for germination was the germitest, while the substrate vermiculite presented a good performance, and the substrate soil presented low germination. Therefore, seeds presented the best vigor in the germitest paper, mainly with a temperature of 25 °C where the best performance for all localities was found. The vigor of seeds in the localities of Bananeiras and Boa Vista, temperatures of 25, 30, and 20-30 °C, and substrate germitest paper provided the highest vigor. The germitest substrate is the recommended substrate for the germination of the species, maximizing its physiological potential and being able to accelerate conservation projects for the species.

Integrated management of agronomic practices in the forage cactus: maximising productivity, biological efficiency and economic profitability

Forage cactus cropping systems that include a combination of agricultural practices (cloning, irrigation, mulching and/or intercropping) can increase forage production and economic return in semi-arid environments. This study evaluated the effect on productivity, biological efficiency and economic return of combining different practices with forage cactus cropping systems in the semi-arid region of Brazil. The research was conducted in four experimental areas, in a randomised block design with four replications, and included the following practices: 1) clones – irrigation - cover, 2) different irrigation depths, 3) intercropping - mulching, and 4) different levels of mulch. The treatments in experiment I consisted of three cactus clones (‘Orelha de Elefante Mexicana’—OEM; ‘Miúda’—MIU and ‘IPA-Sertânia’—IPA), two water regimes (rainfed and irrigated), and two levels of mulch (with and without mulch). Experiment II comprised four irrigation depths (0, 40, 80 and 120% of the crop evapotranspiration) and three cactus clones. In experiment III, three crop arrangements (single cactus, cactus intercropped with millet, and single millet) were evaluated under two levels of mulching (with and without mulching). In experiment IV, four levels of mulch were used (0, 5, 10 and 15 Mg ha-1). The total number of cladodes per plant, fresh matter yield (YFM), dry matter yield (YDM), and final plant density were obtained when harvesting. Economic viability was assessed using the profitability index (PI). The rainfed systems showed greater yield. The use of mulch afforded greater productivity. The OEM clone (YFM = 310.76 Mg ha-1 and YDM = 29.87 Mg ha-1) obtained a higher yield than did the IPA and MIU clones. The highest PI values were achieved under the rainfed systems. The MIU and IPA clones exhibited lower PI values. The cactus-millet intercrop achieved the best performance with the use of mulch. Cactus systems of 15.0 Mg ha-1 showed a greater PI value. It was concluded that the integrated management of such practices as intercropping, mulching and the adoption of the OEM clone can increase the supply of forage. These practices can promote the sustainable intensification of forage input in Livestock Production Systems in semi-arid environments.

Morphology of coat and skin of small ruminants reared in the Brazilian semi-arid region

The structure of the coat and integument of small ruminants reared in semi-arid regions have valuable characteristics that favor their adaptation to the region. The objective of this study was to evaluate the structural characteristics of the coat and integument and sweating capacity of goats and sheep in the Brazilian semi-arid region, using 20 animals, 10 of each breed, 5 males and 5 females of each species, grouped in a completely randomized design in a 2 x 2 factorial scheme (2 species and 2 genders) with 5 replicates. The animals were already being kept under the influence of high temperatures and levels of direct solar radiation before the day of the collections. At the time of the evaluations, ambient temperature was high, with low relative humidity. The pattern of epidermal thickness and sweat glands per body region was superior in sheep (P < 0.05), and the number of hair follicles and sweat rate were similar (P > 0.05) between the species. There was no difference (P > 0.05) in the evaluated characteristics between the genders, showing that they are not influenced by hormones. The morphology of the coat and skin of these animals showed a superiority of goats compared to sheep.

Jeans Processing and Water Reuse Systems in a Brazilian Semiarid Region

Purpose: This study aims to analyze the water reuse and technological innovation employed in industrial jeans processing activities in a dry region. Toritama in the Brazilian state of Pernambuco is a part of a ten-city agglomeration involved in garment production and processing. Laundries in Toritama carry out dyeing, wear, fading, and other interventions that add value to the jeans items. This activity uses large quantities of water, which is scarce in this region. Due to rising environmental concerns, the public control agencies passed legislation to ensure the laundries install a water treatment system to treat the effluents. Laundries view the requirement as a disadvantage as small non-formalized laundries are not obliged to implement reuse technology. Method/design/approach: This study used a combined quantitative and qualitative approach to understand the complexity of the social phenomenon. The research was carried out over 2018 and 2019 in formalized laundries. The use of water in the improvement processes and the stages involved were investigated, in addition to determining the cost impact of water reuse. Results and conclusion: the implementing an innovative water treatment system and reusing water plays a critical role in reducing environmental damage caused by industrial activities while also bringing down production costs. Research implications: thus, the study highlights that it is possible for enterprises to gain a competitive advantage while being mindful of the environment. Originality/value: our research fulfills the important role of clarifying the reality of organizations located in regions of peripheral economy that, despite suffering with their specificities, still have space for environmentally and socially sustainable actions.

Domestic Sewage Effluent Increases Plant Growth, Yield, and Fiber Quality of Cotton Cv. BRS 335

ABSTRACT Semi-arid regions have low water availability, and water reuse in irrigation is an alternative to enable satisfactory agricultural yields in the Brazilian semi-arid region. To evaluate the effects of irrigation with sewage effluent and phosphate fertilization on upland cotton (Gossypium hirsutum L. cv. BRS 335), we irrigated the cotton plant only with well water (control) or irrigated it with a solution containing 50 and 100% effluent sewage, in soil with and without pre-planting phosphate fertilization. For plant growth analysis, we considered time as the third factor. The experimental design consisted of randomized blocks, with six replicates, during two cotton cycles in the open field. Plant growth, yield, and fiber quality increased with the application of sewage effluent compared to the control. The control obtained cotton fiber yields of 740 and 741 kg ha−1 in the first and second cycles, using 50% sewage effluent outperformed 240 and 290% of the control and using 100% sewage effluent outperformed 235 and 300% of the control, respectively. Pre-planting phosphate fertilization failed in upland cotton cv. BRS 335. Irrigation using 100% sewage effluent promotes more significant plant growth, production, and quality of cotton fiber.

Two-Dimensional Modelling of the Mixing Patterns in a Tropical Semiarid Reservoir

Tropical semi-arid regions suffer with recurrent droughts and uncertain water availability, but a few research studies have been conducted to further understand those complexities and their relationships with reservoir hydrodynamics. This study assessed the hydrodynamic processes of a multiple-use reservoir located in the Brazilian semiarid region. The aim was to apply the CE-QUAL-W2 model to understand the lake’s thermal structure and its variabilities in time and space by using the Richardson’s number (Ri) as a reference. Meteorological patterns were also investigated. Results show that: (1) no significant changes were found by analysing the spatial variabilities of stratification; (2) seasonal changes were relevant as more robust stratification stability was observed in the wet period when water availability may be impacted by poor water quality; (3) from meteorological evaluations, rainfall showed a strong coefficient of determination with Ri (r² of 0.77); and (4) a threshold value of 60 mm in monthly precipitation was found as an indication of a stable stratification in the water column. Wind speed and water level partly influenced Ri’s variabilities, while low impact was noted for air temperature and inflow. These results can promote an improvement in water-resources management by linking rainfall regime and reservoir hydrodynamics.

Osmotic adjustment, production, and post-harvest quality of mini watermelon genotypes differing in salt tolerance

The mini watermelon is a crop with high yield potential in the Brazilian semiarid region; however, some problems, such as the salinity of irrigation water, can cause physiological and biochemical changes in the species, compromising production and post-harvest quality of the fruits. In the present study, two genotypes of mini watermelon (Citrullus lanatus L.) cultivated in a hydroponic system were evaluated for the effects of nutrient solution salinity on yield, fruit quality, and solutes content. The experimental design used was completely randomized, in a factorial scheme (5 × 2), with four replicates, each consisting of three plants. The mini watermelon genotypes ‘Champagne’ (CP) and ‘Fancy’ (FY) were cultivated in nutrient solutions with different electrical conductivity levels - ECsol (2.5 - control, 3.5, 4.5, 5.5, and 6.5 dS m−1). Production components, post-harvest variables of fruit quality and the contents of organic and inorganic solutes were evaluated. The increase in ECsol reduced the production variables, with the emphasis on the CP genotype, which stood out for comparatively mall production losses (45% - fruit mass); being considered tolerant to salt stress when compared to FY (57% - fruit mass). Fruit production showed a linear decrease, with a salinity threshold at 2.5 dS m−1 in both genotypes. The salinity increased the contents of total soluble solids (TSS) in both genotypes: for 9.5 to 10.6 °Brix (11.6%) in the CP genotype and from 9.7 to 12.1° Brix (24.7%) in the FY. Contents of organic and inorganic solutes, except proline, can act as indicator for the selection of salinity-tolerant mini watermelon genotypes. Despite the changes induced by salt stress in the physicochemical characteristics, the fruits remained within acceptable commercial standards for both genotypes. The FY genotype, though salt-sensitive is more suitable for hydroponic cultivation up to ECsol of 4.5 dS m−1, and both the genotypes can be used in systems up to with ECsol 6.5 dS m−1.