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Physical and hydrological characteristics and modelling of the soil water retention curve in the brazilian semi-arid region
Get PDFSemiarid regions are characterised by water scarcity, a limiting factor on plant growth and development. The Sertão Canal was built in the semiarid region of Brazil, more specifically in the state of Alagoas, with the aim of making year-round irrigation possible. However, for the best water management, a physical and hydrological knowledge of the soils is necessary. As such, the aim of this study was to determine the physical and hydrological characteristics of three different types of soil (Argisol, Quartzarenic Neossol and Regolithic Neossol) under native vegetation (Caatinga) and agricultural systems in the semiarid region of Alagoas, as well as to adjust the soil water retention characteristic curves. Soil samples were collected at depths of 0-10, 10-20 and 20-30 cm in the municipalities of Inhapi, Delmiro Gouveia and Pariconha, in the state of Alagoas. The points of the moisture characteristic curve were determined by the Richards method, at pressures of 33, 100, 500, 1000 and 1500 kPa. Retention curves were modelled using the exponential decay equation and compared using the van Genuchten equation, modelled with the help of the RETC computer software. Particle size varied according to the textural classification of the different soils, from Sand to a Sandy Clay Loam. The retention curve fluctuated due to the particle size of the soil, with the Red-Yellow Argisol (Inhapi) having a greater capacity for water retention. Extremely sandy soils, such as those in the Delmiro Gouveia region, had a low capacity for retaining water. For each soil sample, the exponential decay equation gave the best fit, with values for R2adjust of greater than 0.93. When the measured soil moisture levels were compared with the levels estimated by the RETC model, some of the treatments were unable to estimate accurately the moisture levels obtained with the soil water retention curves
DIVERGÊNCIA GENÉTICA ENTRE ACESSOS DE ABÓBORA PARA CARACTERES MORFOAGRONÔMICOS
No full textThe objective of this work was to evaluate the diversity between accessions of Cucurbita moschata from the Northeast of Brazil and preserved at the Universidade Federal Rural do Semi-Árido (UFERSA) in Mossoró-RN. The experiment was carried out in complete randomized blocks, with two replications and three plants per plot. The treatments consisted of 51 accessions of C. moschata Duch and a commercial cultivar of Cucurbita maximum Duch. After ripening, the fruits were harvested (one fruit per plant) and evaluated for morpho-agronomic descriptors. Univariate and multivariate variance analyzes were performed. From the dissimilarity matrices, accessions were hierarchically grouped by the UPGMA method. The relative contribution of quantitative characters to the divergence was also estimated. There was an effect of accessions (p <0.01 or p <0.05) for all characters in univariate analyzes, indicating that there is heterogeneity between the accessions evaluated. Considering the quantitative descriptors, the accessions formed eight groups and for the qualitative six groups. When considering the two sets of descriptors, the accessions were distributed in eight groups but presenting a greater distribution of accessions. The descriptors that most contributed to the discrimination of accessions were the firmness of the pulp and the length of the fruit.O trabalho teve como objetivo avaliar a diversidade entre acessos de Cucurbita moschata provenientes do Nordeste brasileiro e conservados na Universidade Federal Rural do Semi-Árido (UFERSA) em Mossoró-RN. O experimento foi conduzido em blocos casualizados completos, com duas repetições e três plantas por parcela. Os tratamentos consistiram de 51 acessos de C. moschata Duch e uma cultivar comercial de Cucurbita máxima Duch. Após a maturação, os frutos foram colhidos (um fruto por planta) e avaliados para descritores morfoagronômicos. Foram efetuadas as análises de variâncias uni e multivariada. A partir das matrizes de dissimilaridade, agrupou-se hierarquicamente os acessos pelo método UPGMA. Também se estimou a contribuição relativa dos caracteres quantitativos para a divergência. Observou-se efeito de acessos (p<0,01 ou p<0,05) para todos os caracteres nas análises univariadas, indicando que existe heterogeneidade entre os acessos avaliados. Considerando os descritores quantitativos, os acessos formaram oito grupos e para os qualitativos seis grupos. Quando considerados os dois conjuntos de descritores os acessos foram distribuídos em oito grupos, porém apresentando uma maior distribuição dos acessos. Os descritores que mais contribuíram para a discriminação dos acessos foram a firmeza de polpa e comprimento do fruto
Qualidade do solo ATRIBUTOS FISICOS E MATERIA ORGANICA EM PASTAGENS DE Brachiaria brizantha EM DIFERENTES NÍVEIS DE DEGRADAÇÃO
No full textPastures cover, in Brazil, around 165 million ha, most of them are at some degradation level. Recovering these pastures is essential. The objective of this study was to evaluate the sensibility of soil organic matter (SOM) and its physical attributes in pasture soil at different degradation levels (1 to 4), Capoeiras (1 and 2) and secondary Forest (Control). Samples were collected at four depths (0.00-0.05, 0.05-0.10, 0.10-0.20 and 0.20-0.40 m). We verified higher values for SOM and hydraulic conductivity (Ko) in Forest, especially in the most superficial layer (0.00-0.05). We noted low values for macroporosity in this area. In all areas under Pastures lower values for Ko were observed in the superficial layer (0.00-0.05 m) when compared to layers 0.05-0.10 and 0.10-0.20 m, which indicates that the pasture management and cattle trampling negatively affect the physical quality of the pastures. For field capacity and wilting point the average values were observed in Pasture 4 (more degraded), which caused higher values for water availability. According to the principal components analysis, except for SOM at 0.20-0.40 m, all variables studied presented correlation above 0.6. From grouping analysis, we separated 3 groups: Forest; Capoeiras 1 and Capoeira 2 and Pastures 1 to 4.As pastagens no Brasil cobrem cerca 165 milhões de ha. Grande parte delas encontram-se em algum nível de degradação. Recupera-las é imprescindível para a eficiência agropecuária e prestação de serviços ambientais, mas para isso diferentes estratégias podem ser usadas. O objetivo deste trabalho foi avaliar a sensibilidade da matéria orgânica do solo (MOS) e dos atributos fisicos do solo, macroporosidade (Ma), condutividade hidraulica (Ko), capacidade de campo (CC), ponto de murcha (PM) e água disponivel (AD) do solo sob diferentes níveis de degração de pastagens (classificadas de 1 a 4, em ordem cresente de degradação), duas Capoeiras (1 e 2) em diferentes estagios de regenerção natural, e uma área de Mata secundária (controle). Para tanto, amostras em quatro profundidades (0,00-0,05, 0,05-0,10, 0,10-0,20 e 0,20-0,40 m) foram tomadas, visando verificar sensibilidade dos indicadores nessas diferentes camadas e separar niveis de degradação de pastagens. Verificaram-se valores de MOS e Ko mais elevados na área de Mata, sobretudo na camada superficial (0,00-0,05m), no entanto na Mata foram notadas baixos valores de Ma, sendo condição contrária verificada nas demais áreas. Em todas as áreas sob Pastagens (1 a 4) foram observados valores mais baixos de Ko na camada superficial (0,00-0,05 m) comparado às camadas 0,05-0,10 e 0,10-0,20 m indicando que o manejo da pastagem e o pisoteio afetam negativamente a qualidade física das pastagens, mesmo àquelas com maior cobertura do solo, como o Pasto 1 e Pasto 2. Para a CC, PM os maiores valores médios foram observados na área de Pasto 4 (mais degradada) que levaram à maiores valores de AD. De acordo com a análise de componentes principais,com exceção da MOS na profundidade 0,20-0,40 cm, todos as variáveis estudadas apresentaram correlação superior a 0,6 (%), demostrando que as variáveis escolhidas explicam em grande parte a variabilidade das diferentes áreas estudadas. E a partir da análise de agrupamento foi possível separar três grupos: Mata com as profundidades 0,00-0,05, 0,05-0,10 e 0,10-0,20 m; Capoeiras 1 e 2 e Pastagens 1 a 4 nas profundidades 0,00-0,05, 0,05-0,10, 0,10-0,20 e 0,20-0,40 m; e Mata na profundidade 0,20-0,40 m
Influência da distribuição de tensão no desenvolvimento de lesões cervicais não cariosas com diferentes níveis de inserção óssea
No full textThis study aimed to evaluate the influence of different bone attachment levels and occlusal loads on the stress distribution pattern of maxillary premolars with or without non-carious cervical lesion (NCCL), before and after restoration with composite resin by three-dimensional (3D) finite element analysis. From the healthy model, NCCL models were produced and the cavity was restored with composite resin. Models with vertical and horizontal bone loss were also made. For each model, three types of occlusal loads were simulated (100 N): vertical load (VL), buccal load (BL), and palatal load (PL). After processing the models, the data were obtained in MPa for the criteria of Maximum Principal Stress (for all structures) and Minimum Principal Stress (for cortical and medullary bones). Stress values were collected for a node on the cervical buccal surface (Maximum Principal Stress) and the buccal crestal bone (Minimum Principal Stress). As a result, the different bone attachment levels did not affect stress distribution at the amelodentinal junction. The buccal load promoted a higher concentration of compressive stress on the buccal bone surface and the palatal load resulted in greater tensile stress in the buccal cervical third of the tooth. The concentration of tensile stress in the buccal cervical third was exacerbated by the presence of NCCL and it was similar to the healthy and restored models. It can be concluded that stress concentration at the bone level does not depend on the presence or absence of NCCL and the restoration procedure but it is related to the type of occlusal load. However, the presence of NCCL promoted a higher stress concentration in the cervical region, especially when combined with oblique occlusal loads.O objetivo deste estudo foi avaliar a influência do padrão de distribuição do estresse nos pré-molares superiores com lesões cervicais não cariosas (LCNCs), com diferentes níveis de inserção óssea, anterior e posteriormente ao procedimento restaurador da LCNC. Para esta análise, foram gerados modelos tridimensionais de pré-molares superiores. A partir do modelo hígido, foi gerado um modelo com LCNC. Para esses modelos foram gerados três modelos com perda óssea: nível ósseo normal, perda óssea vertical e perda óssea horizontal. A restauração de resina composta do modelo com LCNC foi simulada. Para cada modelo foram aplicadas três cargas diferentes com 100 N: carregamento axial (VL), carregamento vestibular (BL) e carregamento palatino (PL). Os dados foram obtidos em MPa, os valores de tensão foram obtidos pelo critério de tensão máxima principal em um nó da superfície vestibular e o valor da tensão mínima principal foi obtido em um nó para análises da crista óssea vestibular. Para os resultados de tensão máxima principal, a perda óssea não influenciou na distribuição de tensão ao nível da junção amelo-dentinária; para o critério de tensão mínima principal. O carregamento vestibular promoveu maior tensão compressiva na superfície óssea vestibular. A concentração de tensão ao nível ósseo independe da presença ou ausência de LCNC e do procedimento de restauração. O tipo de contato oclusal é fator chave para o desenvolvimento da perda óssea e origem e progressão da LCNC
Multiline aiming at phenotypic stability and rice blast resistance
Get PDFThis study aimed to verify the efficiency of multilines in reducing blast progress and their potential benefits to phenotypic stability in rice. The experiments were conducted in the 2016/17 and 2017/18 agricultural years. A randomized block design was performed with three replications, evaluating 12 lines and a multiline, which consisted of five lines from the Cultivation and Use Value (CUV) test. The multiline presented an estimated grain yield above the average of experiments of around seven bags ha-1 and superior performance in early flowering, justifying the high phenotypic stability for these characters. In this case, the line selection for composing the multiline was favorable and efficient, highlighted by a higher agronomic performance than most lines of the CUV test. The multiline is an adequate strategy to provide higher phenotypic stability and reduce blast progress in the field
EFICÁCIA DE HERBICIDAS NO MANEJO OUTONAL DE Richardia brasiliensis, Commelina benghalensis, Conyza sumatrensis E Digitaria insularis
No full textOther herbicides, alone or in combination with glyphosate, may be effective in controlling Richardia brasiliensis, Commelina benghalensis, Conyza sumatrensis e Digitaria insularis. Therefore, the aim of this study was to evaluate the efficacy of herbicides, alone or in combination, in the control of these weeds in the off-season. Three composite experiments were conducted by applying herbicides, alone or in combinations. Experiments 1 and 2 were conducted in Palotina, State of Paraná (PR), Brazil. Experiment 3 in Iporã, PR, Brazil. The three during fall 2017 in fallow areas after soybean harvest. The experiment was a randomized complete block design with 4 replications and weed control at 7, 14, 21, 28, 35, and 42 days after application (DAA). The control of R. brasiliensis and C. benghalensis was evaluated in the three experiments, the control of C. sumatrensis, in experiments 1 and 2, while the control of D. insularis was evaluated only in experiment 3. Data were subjected to analysis of variance and F-test (p < 0.05). The treatment means values of experiments 1 and 2 were compared by Tukey’s test (p < 0.05), and the treatment mean values of experiment 3 were grouped by the Scott and Knott test (p < 0.05). Some herbicide combinations were effective in controlling R. brasiliensis, C. benghalensis, in a single or sequential application. Herbicide combinations were effective in controlling C. sumatrensis with sequential application. Herbicide combinations in a single application did not provide satisfactory final control (≥ 80%) for D. insularis.Outros herbicidas, isolados ou em associações com glyphosate, podem ser eficazes no controle de Richardia brasiliensis, Commelina benghalensis, Conyza sumatrensis e Digitaria insularis. Portanto, o objetivo deste estudo foi avaliar o a eficácia de herbicidas, isolados e em associações, no controle destas plantas daninhas no período de entressafra. Foram conduzidos três experimentos compostos pela aplicação de herbicidas, isolados ou em associações. Os experimentos 1 e 2 foram conduzidos em Palotina, estado do Paraná (PR), Brasil. O experimento 3 em Iporã, PR, Brasil. Os três durante o outono de 2017 após a colheita da soja. O delineamento experimental utilizado foi em blocos casualizados com 4 repetições, foi avaliado o controle de plantas daninhas aos 7, 14, 21, 28, 35 e 42 dias após a aplicação (DAA). Foi avaliado o controle de R. brasiliensis e C. benghalensis nos três experimentos, o controle de C. sumatrensis nos experimentos 1 e 2, enquanto D. insularis apenas no experimento 3. Os dados foram submetidos a análise de variância e teste F (p < 0,05). As médias dos tratamentos dos experimentos 1 e 2 foram comparadas pelo teste de Tukey (p < 0,05), e as médias dos tratamentos do experimento 3 foram agrupadas pelo teste de Scott e Knott (p < 0,05). As associações de herbicidas foram eficazes no controle de R. brasiliensis, C. benghalensis, em aplicação única ou com aplicação sequencial. As associações de herbicidas foram eficazes no controle de C. sumatrensis, com aplicação sequencial. As associações de herbicidas, em aplicação única, não proporcionaram controle final satisfatório (≥ 80%) para D. insularis
Characterization of highly stable extracellular lipase from the extremely halophilic archaeon Halolamina sp.
Get PDFEnzymes of the archaea living in extreme environments are resistant to the challenging conditions. Lipase is among the important enzymes used in the industry and agriculture. In this study, the extracellular lipase from extremely halophilic archaeon Halolamina sp. was characterized for the first time. Optimum temperature for the enzyme activity was determined as 70oC, optimum pH was 7.0, and the optimum salt concentration was 3.6 M. Additionally, more than 70% of the enzyme activity was remained between pH 3.0-10.0 for 48 h as well as incubation of the enzyme at 70oC for 30 min increased its activity for 44%, and no activity loss was observed after incubation at 80oC. Also, presence of the metals increased the enzyme activity up to 88%. The enzyme was highly resistant to the organic solvents acetone, methanol, and DMSO while strong inhibition was caused by n-butanol. Among the detergents, the enzyme kept its activity substantially in the presence of SDS; however, other detergents caused inhibition of the enzyme activity. This characterization study showed that the lipase from the haloarchaeon Halolamina sp. is highly stable at the wide ranges of temperature and pH values as well as in the presence of diverse inhibitors. This enzyme is promising to be used in biotechnological applications
PROMOÇÃO DE CRESCIMENTO DE Schizolobium parahyba var. amazonicum COM A APLICAÇÃO DE Trichoderma spp. SOB DOSES DE BORO
No full textBrazil has many important native species, which includes Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby, however, the growth of this species is inhibited in soils with low boron contents, or excess boron, which causes phytotoxicity. Applications of strains of Trichoderma spp. increase the plants\u27 tolerance to abiotic stresses, including tolerance to low or excess levels of nutrients such as boron (B). Thus, the objective of this work was to evaluate plant development and the effect of strains of Trichoderma spp. in Schizolobium parahyba var. amazonicum seedlings grown under different boron rates. A randomized block experimental design was used, with a 4×5 factorial scheme, consisting of 4 strains of Trichoderma spp. and 5 B rates (0, 0.5, 1.0, 1.5, and 2.0 mg dm-3), with seven replications, in greenhouse. Plant height, stem diameter, fresh and dry mass, leaf, stem and total were evaluated at 120 days after emergence. The stains of Trichoderma spp. and B rates presented significant interaction for all evaluated variables, decreasing phytotoxicity. The strain IBLF006WP (T. harzianum) showed a higher capacity of increasing the plants\u27 tolerance to boron, followed by URM5911 (T. asperellum). However, the beneficial effect of increasing this tolerance with the application of these strains is only feasible for soils with high contents of this micronutrient in the soil.Existe um elevado número de espécies nativas de importância no Brasil, entre as espécies está o paricá (Schizolobium parahyba var. amazonicum), entretanto seu crescimento inibido pela falta de boro (B) ou pelo excesso, causando fitotoxidez. Entre os benefícios relatados atualmente pelo Trichoderma spp. está o aumento da tolerância a estresses bióticos, inclusive aumento na tolerância a nutrientes como o Boro. Assim, o objetivo deste trabalho foi avaliar o desenvolvimento e a promoção do Trichoderma spp. em mudas de paricá com a aplicação de doses de boro. O delineamento utilizado foi o de blocos casualizados, em esquema fatorial 4 x 5 (cepas de Trichoderma spp. e doses de boro), com sete repetições, sendo as doses 0, 0.5, 1.0, 1.5 e 2.0 g m-3 de B. Foram avaliadas as variáveis de altura de planta, diâmetro do coleto, massa fresca e seca foliar, caulinar e total, após 120 dias. Existe interação entre as cepas de Trichoderma spp. e doses de boro, neste caso, para a diminuição da fitoxidez. A cepa T. Harzianum IBLF 006 WP apresenta maior capacidade de aumentar a tolerância ao boro, seguido do T. asperellum URM 5911. Entretanto, o efeito benéfico no aumento da tolerância promovido por estas cepas, somente é viável para solos com altos conteúdos de boro no solo
IMPACTO DAS ÉPOCAS DE SEMEADURA NA EFICIÊNCIA PRODUTIVA DE CULTIVARES DE ARROZ DE TERRAS ALTAS
No full textThe choice of cultivars adapted to different regions and the determination of the best sowing dates are indispensable tools for crop development. This allows the installation of the crop in times favorable to its development, as well as cultivars that manage to reach their maximum yield potential. The objective of this study was to determine the best sowing dates and the cultivars that can adapt to the low-altitude Cerrado region and have the best development and yield efficiency. The experiment was conducted on a typical clayey dystrophic Red Latosol soil. The experimental design was in randomized blocks in a factorial scheme, comprised by four sowing dates during the spring/summer season (October, November, December, and February) and in each sowing date there were eight upland rice cultivars (BRS Esmeralda, ANa 6005, ANa 5015, IPR 117, IAC 203, IAC 500, ANa 7211 and BRSGO Serra Dourada) with four replicates. Sowing in October and November benefited the aerial dry mass and the spikelets fertility however, sowing in November provided higher plant height, which caused lodging in plants. Sowing in December caused the incidence of scald, mainly affecting the cultivar ANa 7211. For all cultivars, sowing in October favored the yield efficiency of upland rice in the low-altitude Cerrado, followed by sowing in November. The cultivars which demonstrated higher yield efficiency in the conditions of the region were BRS Esmeralda and ANa 5015.A escolha de cultivares adaptadas a diferentes regiões e a determinação das melhores datas de semeadura são ferramentas indispensáveis para o desenvolvimento das culturas. Isso permite a instalação da lavoura em épocas favoráveis ao seu desenvolvimento, bem como cultivares que consigam atingir seu máximo potencial produtivo. O objetivo deste estudo foi identificar as melhores épocas de semeadura e as cultivares que podem se adaptar à região do Cerrado de baixa altitude e ter a melhor desenvolvimento e eficiência produtiva. O experimento foi conduzido em um solo típico de Latossolo Vermelho distrófico argiloso. O delineamento experimental foi em blocos casualizados, em esquema fatorial, com quatro épocas de semeadura durante a primavera/verão (outubro, novembro, dezembro e fevereiro), cada uma com oito cultivares de arroz de terras altas (BRS Esmeralda, ANa 5015, ANa 6005, IPR 117 , IAC 500, IAC 203, BRSGO Serra Dourada e ANa 7211) e quatro repetições. A semeadura em outubro e novembro beneficiou a massa seca da parte aérea e a fertilidade das espiguetas, entretanto, a semeadura em novembro proporcionou maior altura das plantas, o que causou o acamamento de plantas. A semeadura em dezembro causou incidência de escaldadura, afetando principalmente a cultivar ANa 7211. Para todas as cultivares, a semeadura em outubro favoreceu a eficiência produtiva do arroz de terras altas no Cerrado de baixa altitude, seguido pela semeadura em novembro. As cultivares que demonstraram maior eficiência de produção nas condições da região foram BRS Esmeralda e ANa 5015
PHENOL COMPOUND CONTENT AND ANTIBACTERIAL CHARACTERISTICS OF GAHARU LEAF EXTRACT PRODUCTS (Aquilaria malaccensi
No full textGaharu leaf extract produces yield extraction, phenol compound, and antibacterial activity in diverse quantities. The purpose of this research was to investigate the influence of the extraction method and type of solvent on the extractability of the polyphenol component and the antibacterial activity of gaharu leaves. Extraction was done through maceration and Soxhlet methods by using solvents of hexane, ethyl acetate, and ethanol. The extraction result showed that the highest yield value of 18.4% was found on the treatment of a combination of ethanol solvent and Soxhlet method. The total content of phenol and tannin of gaharu leaf extract was in the range of 11.2 to 18.62mg. mL-1 and 12.82 to 13.41%, respectively. Antibacterial activity of gaharu leaf extract on the Gram-positive test of Staphylococcus aureus was higher than that of the Gram-negative test of Escherichia coli having a value of zone of inhibition in the range of 5.33 to 6.33 mm and 4.00 to 5.00 mm, respectively