Information about the response of onion to different potassium doses may contribute to optimizing the use of fertilizers and, consequently, make the activity more profitable and environmentally sustainable. In this context, the aim of this study was to evaluate the effects of doses of potassium on onion yields. Two field experiments were carried out in the periods of September to December 2012 and April to July 2013. The experimental design used was completely randomized blocks with four replications. The treatments corresponded to the potassium doses (0, 36, 72, 108, 144 and 180 kg ha-1 of K2O). Potassium fertilization promoted an increase in the content of K in the leaf, commercial and total yield, with the maximum obtained in the dose of 180 kg ha-1 of K2O. The maximum overall and commercial yields were respectively 54.69 and 54.12 t ha-1 in the experiment of September to December 2012 and 47.39 and 46.39 t ha-1 in that of April to July 2013.

Information about the response of onion to different potassium doses may contribute to optimizing the use of fertilizers and, consequently, make the activity more profitable and environmentally sustainable. In this context, the aim of this study was to evaluate the effects of doses of potassium on onion yields. Two field experiments were carried out in the periods of September to December 2012 and April to July 2013. The experimental design used was completely randomized blocks with four replications. The treatments corresponded to the potassium doses (0, 36, 72, 108, 144 and 180 kg ha-1 of K2O). Potassium fertilization promoted an increase in the content of K in the leaf, commercial and total yield, with the maximum obtained in the dose of 180 kg ha-1 of K2O. The maximum overall and commercial yields were respectively 54.69 and 54.12 t ha-1 in the experiment of September to December 2012 and 47.39 and 46.39 t ha-1 in that of April to July 2013. | Informações sobre a reposta da cebola a diferentes doses de potássio podem contribuir para a otimização do uso de fertilizantes e, consequentemente, tornar a atividade mais rentável e ambientalmente sustentável. Nesse contexto, o objetivo do trabalho foi avaliar os efeitos de doses de potássio na produtividade da cebola. Para isso dois experimentos de campo foram realizados nos períodos de setembro a dezembro de 2012 e abril a julho de 2013 O delineamento experimental foi em blocos casualizados completos com quatro repetições. Os tratamentos corresponderam às doses de potássio (0, 36, 72, 108, 144 e 180 kg ha-1 de K2O). A adubação potássica promoveu aumento do teor de K na folha, produtividade comercial total, com o máximo obtido na dose de 180 kg ha-1 de K2O. As produtividades máximas totais e comerciais foram respectivamente de 54,69 e 54,12 t ha-1 no experimento de setembro a dezembro de 2012 e 47,39 e 46,39 t ha-1 de abril a julho de 2013.

Cassava is mostly planted in sandy soils which are usually of low fertility, thereby making it necessary to perform beneficial associations with microorganisms that can promote their growth. In this perspective, the possibility of selecting bacterial isolates efficient in promoting the growth of the culture is evident, which can provide subsidies for future inoculants. The objective of this study was to isolate, identify, select and evaluate the genetic diversity of endophytic bacteria in roots and stems of cassava grown in Garanhuns - PE, with features involved in promoting plant growth. The isolation was performed on culture medium semisolid LGI-P. The selected isolates were evaluated for the potential to fix N2, as the ability to produce indole acetic acid, for their ability to solubilize inorganic phosphate and produce exopolysaccharides. Some bacterial isolates had their 16S rRNA gene sequenced by the Sanger method. A total of 52 endophytic bacteria isolates were obtained from cassava. Regarding the potential to fix N2, 15% of the isolates were positive. As for the production of IAA, 78% of the isolates produced this phytohormone in a medium with increased L-tryptophan. Approximately 31% of the isolates were able to solubilize inorganic phosphate and 60% had exopolysaccharide. The identification of 19 isolates allowed the grouping into six bacterial genera, namely: Achromobacter, Bacillus, Burkholderia, Enterobacter, Pantoea and Pseudomonas. Cassava plants grown in Garanhuns - PE present interaction with different groups of endophytic bacteria and there are bacterial groups with several characteristics involved in promoting plant growth.

Cassava is mostly planted in sandy soils which are usually of low fertility, thereby making it necessary to perform beneficial associations with microorganisms that can promote their growth. In this perspective, the possibility of selecting bacterial isolates efficient in promoting the growth of the culture is evident, which can provide subsidies for future inoculants. The objective of this study was to isolate, identify, select and evaluate the genetic diversity of endophytic bacteria in roots and stems of cassava grown in Garanhuns - PE, with features involved in promoting plant growth. The isolation was performed on culture medium semisolid LGI-P. The selected isolates were evaluated for the potential to fix N2, as the ability to produce indole acetic acid, for their ability to solubilize inorganic phosphate and produce exopolysaccharides. Some bacterial isolates had their 16S rRNA gene sequenced by the Sanger method. A total of 52 endophytic bacteria isolates were obtained from cassava. Regarding the potential to fix N2, 15% of the isolates were positive. As for the production of IAA, 78% of the isolates produced this phytohormone in a medium with increased L-tryptophan. Approximately 31% of the isolates were able to solubilize inorganic phosphate and 60% had exopolysaccharide. The identification of 19 isolates allowed the grouping into six bacterial genera, namely: Achromobacter, Bacillus, Burkholderia, Enterobacter, Pantoea and Pseudomonas. Cassava plants grown in Garanhuns - PE present interaction with different groups of endophytic bacteria and there are bacterial groups with several characteristics involved in promoting plant growth. | A mandioca é, geralmente, plantada em solos arenosos e de baixa fertilidade, tornando eminente a necessidade da mesma em realizar associações benéficas com micro-organismos que possam auxiliar seu crescimento. Nessa ótica, é evidente a possibilidade de seleção de isolados bacterianos eficientes em promover o crescimento da cultura, os quais podem fornecer subsídios para futuros inoculantes. O objetivo deste trabalho foi isolar, identificar, selecionar e avaliar a diversidade genética de bactérias endofíticas de raízes e caules de mandioca, cultivada em Garanhuns - PE, com características envolvidas na promoção de crescimento vegetal. O isolamento foi realizado em meio de cultura semissólido LGI-P. Os isolados selecionados foram avaliados quanto ao potencial de fixar N2, quanto à capacidade de produzir ácido indol acético, quanto à capacidade de solubilizar fosfato inorgânico e produzir exopolissacarídeos. Alguns isolados bacterianos tiveram o gene 16S rRNA sequenciados pelo método de Sanger. No total, foram obtidos 52 isolados de bactérias endofíticas de mandioca. Em relação ao potencial para fixar N2, 15% dos isolados foram positivos. Quanto à produção de AIA, 78% dos isolados produziram este fitohormônio em meio com o acréscimo de L-triptofano. Cerca de 31% dos isolados foram capazes de solubilizar fosfato inorgânico e 60% apresentaram produção de exopolissacarídeos. A identificação de 19 isolados possibilitou o agrupamento em seis gêneros bacterianos, sendo eles: Achromobacter, Bacillus, Burkholderia, Enterobacter, Pantoea e Pseudomonas. Plantas de mandioca cultivadas em Garanhuns - PE apresentam interação com diferentes grupos de bactérias endofíticas e há grupos bacterianos com diversas características envolvidas na promoção de crescimento vegetal.

Nitisols are livelihood sources of agricultural and socio-economic development in several underdeveloped countries worldwide, including Brazil. Brazilian Nitisols are usually associated with basaltic rocks found in the Southern and Southeastern regions of the country. However, Nitisols derived from basalt also occur on the southern coast of Pernambuco state, a region under full urban, agricultural, and industrial development. Aiming to understand the relationship between climate and attributes of Nitisols from the southern coast of Pernambuco, we performed morphological descriptions, physical and chemical analyzes, iron selective extraction, and soil mineralogy (sand, silt, and clay) for three basaltic soil profiles along a land slope. The results suggest a strong weathering of the profiles due to climate conditions, besides a great loss of basic cations and xanthization process, resulting in the natural genesis of acric Nitisols with yellowish coloration, which has not been yet cataloged for this soil order in the Brazilian taxonomic system. In addition, there is a variation for physical attributes of Nitisols along the slope.

Nitisols are livelihood sources of agricultural and socio-economic development in several underdeveloped countries worldwide, including Brazil. Brazilian Nitisols are usually associated with basaltic rocks found in the Southern and Southeastern regions of the country. However, Nitisols derived from basalt also occur on the southern coast of Pernambuco state, a region under full urban, agricultural, and industrial development. Aiming to understand the relationship between climate and attributes of Nitisols from the southern coast of Pernambuco, we performed morphological descriptions, physical and chemical analyzes, iron selective extraction, and soil mineralogy (sand, silt, and clay) for three basaltic soil profiles along a land slope. The results suggest a strong weathering of the profiles due to climate conditions, besides a great loss of basic cations and xanthization process, resulting in the natural genesis of acric Nitisols with yellowish coloration, which has not been yet cataloged for this soil order in the Brazilian taxonomic system. In addition, there is a variation for physical attributes of Nitisols along the slope. Os Nitossolos dão suporte ao desenvolvimento agrícola e socioeconômico de muitos países subdesenvolvidos do mundo, incluindo o Brasil. Os Nitossolos brasileiros estão geralmente associados às rochas basálticas das regiões Sul e Sudeste. Entretanto, Nitossolos derivado de basalto também ocorrem na costa sul de Pernambuco, uma região em pleno desenvolvimento urbano, agrícola e industrial. Objetivando compreender as relações entre o clima e os atributos dos Nitossolos da costa sul de Pernambuco, foram realizadas descrições morfológicas, análises físicas e químicas, extrações seletivas de ferro e a determinação da mineralogia das frações areia, silte e argila de três perfis derivados de basalto ao longo de uma vertente. Os resultados demonstram que o clima da região implica em forte intemperização dos perfis, em grande perda de bases e favorece o processo de xantização, resultando na singular gênese de Nitossolos com matizes amarelados e caráter ácrico, fato que até o momento ainda não foi catalogado para esta ordem no sistema taxonômico brasileiro. Os resultados também demonstram a variação dos atributos físicos dos Nitossolos ao longo da vertente.

This study aimed to establish an adequate tetrazolium test procedure to estimate okra seed viability. Initially, seeds from four okra lots were immersed in alcohol (98%) for 60 minutes, followed by an 18-h soak in distilled water at 25 °C. Then, the seeds were longitudinally sectioned, immersed in 0.025, 0.050 and 0.075% tetrazolium solutions for 60, 90 and 120 minutes and maintained in an oven at 35 and 40 °C. Subsequently, the seeds were evaluated for viability, based on tissue color (bright red, pink or dark Carmine red). Simultaneously, a germination test was conducted, and its results were used as a reference for the tetrazolium test. The experiment was carried out in a completely randomized design, in a 3 x 3 + 1 factorial scheme (three concentrations of tetrazolium salt x three immersion periods, plus the control) in four replicates of 50 seeds for each treatment. The tetrazolium test to estimate okra seed viability should be conducted in 0.075% tetrazolium solution, for 90 minutes, at 35 °C.

This study aimed to establish an adequate tetrazolium test procedure to estimate okra seed viability. Initially, seeds from four okra lots were immersed in alcohol (98%) for 60 minutes, followed by an  18-h soak in distilled water at 25 °C. Then, the seeds were longitudinally sectioned, immersed in 0.025, 0.050 and 0.075% tetrazolium solutions for 60, 90 and 120 minutes and maintained in an oven at 35 and 40 °C. Subsequently, the seeds were evaluated for viability, based on tissue color (bright red, pink or dark Carmine red). Simultaneously, a germination test was conducted, and its results were used as a reference for the tetrazolium test. The experiment was carried out in a completely randomized design, in a 3 x 3 + 1 factorial scheme (three concentrations of tetrazolium salt x three immersion periods, plus the control) in four replicates of 50 seeds for each treatment. The tetrazolium test to estimate okra seed viability should be conducted in 0.075% tetrazolium solution, for 90 minutes, at 35 °C. | Objetivou-se estabelecer o procedimento adequado do teste de tetrazólio para estimar a viabilidade em sementes de quiabo. Inicialmente, as sementes de quatro lotes de quiabo foram imersas em álcool (98%) por 60 minutos e seguida de 18 horas de embebição em água destilada a 25 ºC. Após este período, as sementes foram seccionadas longitudinalmente, imersas em soluções de tetrazólio de 0,025; 0,050 e 0,075% por 60, 90 e 120 minutos e mantidas em estufa a 35 e 40 °C. Posteriormente, as sementes foram avaliadas quanto à viabilidade, tendo como indicação a coloração dos tecidos (vermelho brilhante rosa ou vermelho carmim forte). Paralelamente, foi instalado o teste de germinação, cujos resultados serviram como referência para o teste de tetrazólio. O experimento foi conduzido em delineamento inteiramente casualisado, em esquema fatorial 3 x 3 + 1, (três concentrações do sal de tetrazólio x três períodos de imersão e a testemunha) em quatro repetições de 50 sementes para cada tratamento. O teste de tetrazólio para estimar a viabilidade em sementes de quiabo deve ser realizado em solução de tetrazólio de 0,075%, por 90 minutos, a 35 °C.

Intercropping is a cropping system that involves cultivating two or more crops in the same area with different cycles and vegetative architectures. One of the ways to increase productivity and efficiency in this cropping system is through green manuring and by properly considering crop combinations, cultivation timing, and planting configuration of the component crops. Thus, the aim of this study was to evaluate the productive performance of carrot and lettuce intercropping systems under different amounts of rooster tree biomass incorporated into the soil and under different spatial arrangements. The study was conducted at the experimental farm Rafael Fernandes, RN, Brazil, in the period from September 2012 to January 2013, in an experimental design of randomized complete blocks in a 4 x 3 factorial scheme, with twelve treatments and 3 replicates. The treatments consisted of the combination of four rooster tree biomass amounts incorporated into the soil (10, 25, 40 and 55 t ha-1 on a dry basis) with three predetermined spatial arrangements between the component crops (2:2, 3:3 and 4:4), which correspond to the rows of carrot alternating with the rows of lettuce. The agronomic performance of the carrot and lettuce intercropping system was optimized in the amount of approximately 46.36 t ha-1 of rooster tree incorporated into the soil. There was no influence of the spatial arrangements on the agronomic efficiency of the carrot and lettuce intercropping. The use of rooster tree as green manure is agronomically viable in intercropped systems of carrot and lettuce.

Intercropping is a cropping system that involves cultivating two or more crops in the same area with different cycles and vegetative architectures. One of the ways to increase productivity and efficiency in this cropping system is through green manuring and by properly considering crop combinations, cultivation timing, and planting configuration of the component crops. Thus, the aim of this study was to evaluate the productive performance of carrot and lettuce intercropping systems under different amounts of rooster tree biomass incorporated into the soil and under different spatial arrangements. The study was conducted at the experimental farm Rafael Fernandes, RN, Brazil, in the period from September 2012 to January 2013, in an experimental design of randomized complete blocks in a 4 x 3 factorial scheme, with twelve treatments and 3 replicates. The treatments consisted of the combination of four rooster tree biomass amounts incorporated into the soil (10, 25, 40 and 55 t ha-1 on a dry basis) with three predetermined spatial arrangements between the component crops (2:2, 3:3 and 4:4), which correspond to the rows of carrot alternating with the rows of lettuce. The agronomic performance of the carrot and lettuce intercropping system was optimized in the amount of approximately 46.36 t ha-1 of rooster tree incorporated into the soil. There was no influence of the spatial arrangements on the agronomic efficiency of the carrot and lettuce intercropping. The use of rooster tree as green manure is agronomically viable in intercropped systems of carrot and lettuce. | A consorciação de culturas é um sistema de cultivo que envolve o cultivo de duas ou mais culturas na mesma área com diferentes ciclos e arquiteturas vegetativas. Uma das maneiras de aumentar a produtividade e a eficiência neste sistema de cultivo é através de adubação verde e considerando adequadamente as combinações de culturas, o tempo e a configuração de plantio das culturas componentes. Assim, o objetivo deste estudo foi avaliar o desempenho produtivo de sistemas consorciados de cenoura e alface em diferentes quantidades de biomassa de flor-de-seda incorporadas no solo e em diferentes arranjos espaciais. O estudo foi realizado na fazenda experimental Rafael Fernandes, RN, Brasil, no período de setembro de 2012 a janeiro de 2013, em um delineamento experimental de blocos completos casualizados, em esquema fatorial 4 x 3, com doze tratamentos e 3 repetições. Os tratamentos consistiram da combinação de quatro quantidades de biomassa de flor-de-seda incorporadas no solo (10, 25, 40 e 55 t ha-1 em base seca) com quatro arranjos espaciais predeterminados entre as culturas componentes (2:2, 3:3 e 4:4), que correspondem às fileiras de cenoura alternadas com as fileiras de alface. O desempenho agronômico do sistema de consórcio de cenoura e alface foi otimizado na quantidade de aproximadamente 46.36 t ha-1 de flor-de-seda incorporada no solo. Não houve influência dos arranjos espaciais sobre a eficiência agronômica do consórcio de cenoura e alface. O uso da flor-de-seda como adubo verde é agronomicamente viável em sistemas consorciados de cenoura e alface.

The accelerated aging test consists of evaluating the vigor of the seeds under conditions of high temperature and humidity, with the purpose of identifying the physiological quality of lots with similar germination. The objective of this study was to evaluate the efficiency of the accelerated aging test for classifying seed lots of P. moniliformis at different levels of vigor. Initially, the seed lots were assessed by means of seedling emergence, life velocity index, shoot length and root length, total dry mass of seedlings and determination of water content, before and after each period of aging. The experimental design for the whole world was based on a 3 × 4 factorial scheme (three seed lots and four periods of 24, 48, 72 and 96 h duration), with separate evaluations at temperatures of 38 °C and 41 °C. The accelerated aging test conducted at a temperature of 41 °C for 24 h was a more suitable combination for separating batches of P. moniliformis according to different levels of vigour, and made it possible to obtain results similar to the classification of lots in relation to the initial quality.

The accelerated aging test consists of evaluating the vigor of the seeds under conditions of high temperature and humidity, with the purpose of identifying the physiological quality of lots with similar germination. The objective of this study was to evaluate the efficiency of the accelerated aging test for classifying seed lots of P. moniliformis at different levels of vigor. Initially, the seed lots were assessed by means of seedling emergence, life velocity index, shoot length and root length, total dry mass of seedlings and determination of water content, before and after each period of aging. The experimental design for the whole world was based on a 3 × 4 factorial scheme (three seed lots and four periods of 24, 48, 72 and 96 h duration), with separate evaluations at temperatures of 38 °C and 41 °C. The accelerated aging test conducted at a temperature of 41 °C for 24 h was a more suitable combination for separating batches of P. moniliformis according to different levels of vigour, and made it possible to obtain results similar to the classification of lots in relation to the initial quality. | O teste de envelhecimento acelerado consiste em avaliar o vigor das sementes em condições de elevada temperatura e umidade, com a finalidade de identificar diferenças na qualidade fisiológica de lotes com germinação semelhante. Dessa forma, objetivou-se avaliar a eficiência do teste de envelhecimento acelerado para classificar os lotes de sementes de P. moniliformis em diferentes níveis de vigor. Inicialmente os lotes de sementes foram avaliados por meio da emergência de plântulas, índice de velocidade de emergência, comprimento da parte aérea e da raiz, além da massa seca total de plântulas, além da determinação do grau de umidade, antes e após cada período de envelhecimento das sementes. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 3 x 4 (três lotes de sementes e quatro períodos de 24, 48, 72 e 96 horas), e avaliado separadamente nas temperaturas de 38 e 41 °C. O teste de envelhecimento acelerado conduzido sob a temperatura de 41 °C durante 24 horas é a combinação mais adequada para separar os lotes de P. moniliformis em diferentes níveis de vigor, pois possibilitou a obtenção de resultados semelhantes à classificação dos lotes em relação à qualidade inicial.

Genome-wide selection (GWS) uses simultaneously the effect of the thousands markers covering the entire genome to predict genomic breeding values for individuals under selection. The possible benefits of GWS are the reduction of the breeding cycle, increase in gains per unit of time, and decrease of costs. However, the success of the GWS is dependent on the choice of the method to predict the effects of markers. Thus, the objective of this work was to predict genomic breeding values (GEBV) through artificial neural networks (ANN), based on the estimation of the effect of the markers, compared to the Ridge Regression-Best Linear Unbiased Predictor/Genome Wide Selection (RR-BLUP/GWS). Simulations were performed by software R to provide correlations concerning ANN and RR-BLUP/GWS. The prediction methods were evaluated using correlations between phenotypic and genotypic values and predicted GEBV. The results showed the superiority of the ANN in predicting GEBV in simulations with higher and lower marker densities, with higher levels of linkage disequilibrium and heritability.

Genome-wide selection (GWS) uses simultaneously the effect of the thousands markers covering the entire genome to predict genomic breeding values for individuals under selection. The possible benefits of GWS are the reduction of the breeding cycle, increase in gains per unit of time, and decrease of costs. However, the success of the GWS is dependent on the choice of the method to predict the effects of markers. Thus, the objective of this work was to predict genomic breeding values (GEBV) through artificial neural networks (ANN), based on the estimation of the effect of the markers, compared to the Ridge Regression-Best Linear Unbiased Predictor/Genome Wide Selection (RR-BLUP/GWS). Simulations were performed by software R to provide correlations concerning ANN and RR-BLUP/GWS. The prediction methods were evaluated using correlations between phenotypic and genotypic values and predicted GEBV. The results showed the superiority of the ANN in predicting GEBV in simulations with higher and lower marker densities, with higher levels of linkage disequilibrium and heritability. | A seleção genômica ampla (Genome Wide Selection - GWS) utiliza simultaneamente o efeito de milhares de marcadores cobrindo todo o genoma para predizer o valor genético genômico dos indivíduos no processo de seleção. Os possíveis benefícios de seu uso são a redução do ciclo de melhoramento, propiciando maior ganho por unidade de tempo e diminuição de custos. O sucesso da GWS está atrelado a escolha do método de predição dos efeitos dos marcadores. Assim, neste trabalho, visou-se aplicar as redes neurais artificiais (Artificial Neural Networks - ANNs), com a finalidade de predizer os valores genéticos genômicos (Genomic Breeding Values - GEBVs) baseado na estimação dos efeitos dos marcadores comparados a regressão de cumeeira – melhor preditor não viesado/seleção genômica ampla (Ridge Regression – Best Linear Unbiased Predictor/Genome Wide Selection – RR-BLUP/GWS). Foram efetuadas simulações por meio do software R, fornecendo as correlações referentes às ANNs e a RR-BLUP/GWS. Os métodos de predição foram avaliados utilizando correlações entre o valor fenotípico e valor genotípico com o valor genético genômico predito. Os resultados demonstraram superioridade das ANNs na predição dos GEBVs nos cenários com maior e menor densidade de marcadores, paralelo a níveis mais altos de desequilíbrio de ligação e maior herdabilidade.

Reliable information on vegetation cover and its dynamics over time is essential for managing life, resources, and supporting policies. Although many related initiatives have been undertaken in Brazil since the 1980s, knowledge about its dry forests is still limited. In this study, we address the drivers of deforestation and their threat to the Brazilian dry forest called Caatinga. We evaluated the land cover dynamics and landscape metrics in the watershed of the Pontal River, as it has become one of the most socially and environmentally important areas in Brazil. The overall process consists of a systematic sampling grid of hydrological samples, where Landsat images (1975 to 2013) combined with the FRAGSTATS package were used to evaluate landscape metrics indices for the Caatinga. Data showed that the relative area (RA) decreased from 90.25% to 60.98% over the 38-year period, while fragmentation (PD) presented an increasing bias. In addition, the spatial distribution of both indices became more heterogeneous and clustered in the north. We suggest that appropriateness of land for farming was the leading cause of deforestation; rainfall is 112% more intense in the north of the watershed than in the south. Therefore, the northern fauna and flora have been significantly altered and reduced. The relationship between deforestation and time shows an increasing threat. Further studies evaluating these causes are needed to improve our understanding of the vegetation dynamics in this region.

Reliable information on vegetation cover and its dynamics over time is essential for managing life, resources, and supporting policies. Although many related initiatives have been undertaken in Brazil since the 1980s, knowledge about its dry forests is still limited. In this study, we address the drivers of deforestation and their threat to the Brazilian dry forest called Caatinga. We evaluated the land cover dynamics and landscape metrics in the watershed of the Pontal River, as it has become one of the most socially and environmentally important areas in Brazil. The overall process consists of a systematic sampling grid of hydrological samples, where Landsat images (1975 to 2013) combined with the FRAGSTATS package were used to evaluate landscape metrics indices for the Caatinga. Data showed that the relative area (RA) decreased from 90.25% to 60.98% over the 38-year period, while fragmentation (PD) presented an increasing bias. In addition, the spatial distribution of both indices became more heterogeneous and clustered in the north. We suggest that appropriateness of land for farming was the leading cause of deforestation; rainfall is 112% more intense in the north of the watershed than in the south. Therefore, the northern fauna and flora have been significantly altered and reduced. The relationship between deforestation and time shows an increasing threat. Further studies evaluating these causes are needed to improve our understanding of the vegetation dynamics in this region. | Informações confiáveis sobre a cobertura vegetal e sua dinâmica ao longo do tempo são essenciais para a gestão de vidas, recursos, e apoio a políticas. Embora muitas iniciativas tenham sido realizadas no Brasil desde a década de 1980, o conhecimento sobre suas florestas secas ainda é limitado. Neste estudo, abordamos os moduladores do desmatamento e sua ameaça à floresta seca brasileira chamada Caatinga. Avaliamos a dinâmica da cobertura da terra e métricas de paisagem na bacia do rio Pontal, a qual se tornou uma das áreas mais socialmente e ambientalmente importantes do Brasil. O processo em geral consiste em uma amostragem sistemática baseada em características hidrológicas, onde imagens Landsat (1975 a 2013) combinadas com o software FRAGSTATS foram utilizadas para avaliar índices de métricas de paisagem para a Caatinga. Os dados mostraram que a área relativa (RA) diminuiu de 90,25% para 60,98% ao longo do período de 38 anos, enquanto que a fragmentação (PD) apresentou uma tendência crescente. Além disso, a distribuição espacial de ambos os índices se tornou mais heterogênea e agrupada ao norte. Sugerimos que a aptidão da terra para a agricultura foi a principal causa do desmatamento. A chuva é 112% mais intensa no norte da bacia do que no sul. Portanto a fauna e flora ao norte foram significativamente alteradas e reduzidas. A relação entre desmatamento e tempo mostrou uma ameaça crescente. Outros estudos que avaliem essas causas são necessários para melhorar a compreensão da dinâmica da vegetação nesta região.

Reliable information on vegetation cover and its dynamics over time is essential for managing life, resources, and supporting policies. Although many related initiatives have been undertaken in Brazil since the 1980s, knowledge about its dry forests is still limited. In this study, we address the drivers of deforestation and their threat to the Brazilian dry forest called Caatinga. We evaluated the land cover dynamics and landscape metrics in the watershed of the Pontal River, as it has become one of the most socially and environmentally important areas in Brazil. The overall process consists of a systematic sampling grid of hydrological samples, where Landsat images (1975 to 2013) combined with the FRAGSTATS package were used to evaluate landscape metrics indices for the Caatinga. Data showed that the relative area (RA) decreased from 90.25% to 60.98% over the 38-year period, while fragmentation (PD) presented an increasing bias. In addition, the spatial distribution of both indices became more heterogeneous and clustered in the north. We suggest that appropriateness of land for farming was the leading cause of deforestation; rainfall is 112% more intense in the north of the watershed than in the south. Therefore, the northern fauna and flora have been significantly altered and reduced. The relationship between deforestation and time shows an increasing threat. Further studies evaluating these causes are needed to improve our understanding of the vegetation dynamics in this region.

Plant growth promoter microorganisms have been studied as important tools for increasing crop production. Lettuce is the most consumed hardwood crop in the world. Numerous microorganisms are capable of acting in a beneficial way in the growth of this culture. The objective of the present study was to evaluate the efficacy of Trichoderma and Pseudomonas on the microbial biomass, enzymatic activities in sandy soil and lettuce production. The experimental design was completely randomized with ten replicates and treatments: CONT (absolute control); CM (control with cattle manure fertilization); CMB (with fertilization and Pseudomonas sp.); CMF (with fertilization and T. aureoviride) and CMBF (with fertilization and the two microorganisms combined). The fertilizer used was organic with cattle manure in a dose recommended for the culture. This study evaluated the production of lettuce, microbial biomass and the enzymatic activity of acid phosphatase, alkaline phosphatase and urease. The combined application of CMBF was efficient in increasing lettuce production, because it increased 85% of the cv. Veronica cultivated on sandy soil. The combined use of plant growth promoting microorganisms resulted to an increase in microbial biomass. In lettuce crops, it is recommended to use T. aureoviride URM 5158 and Pseudomonas sp. UAGF 14 in lettuce crops, because improved lettuce production, improves the biochemical quality of soils measured by absolute and specific enzymatic activities per unit of microbial biomass.

Plant growth promoter microorganisms have been studied as important tools for increasing crop production. Lettuce is the most consumed hardwood crop in the world. Numerous microorganisms are capable of acting in a beneficial way in the growth of this culture. The objective of the present study was to evaluate the efficacy of Trichoderma and Pseudomonas on the microbial biomass, enzymatic activities in sandy soil and lettuce production. The experimental design was completely randomized with ten replicates and treatments: CONT (absolute control); CM (control with cattle manure fertilization); CMB (with fertilization and Pseudomonas sp.); CMF (with fertilization and T. aureoviride) and CMBF (with fertilization and the two microorganisms combined). The fertilizer used was organic with cattle manure in a dose recommended for the culture. This study evaluated the production of lettuce, microbial biomass and the enzymatic activity of acid phosphatase, alkaline phosphatase and urease. The combined application of CMBF was efficient in increasing lettuce production, because it increased 85% of the cv. Veronica cultivated on sandy soil. The combined use of plant growth promoting microorganisms resulted to an increase in microbial biomass. In lettuce crops, it is recommended to use T. aureoviride URM 5158 and Pseudomonas sp. UAGF 14 in lettuce crops, because improved lettuce production, improves the biochemical quality of soils measured by absolute and specific enzymatic activities per unit of microbial biomass. | Os micro-organismos promotores do crescimento de plantas vêm sendo estudados como uma importante ferramenta para o aumento da produção agrícola. Lactuca sativa (alface) é a hortaliça folhosa mais consumida em todo mundo. Inúmeros micro-organismos podem atuar de forma benéfica no crescimento desta cultura. O objetivo do presente trabalho foi avaliar a eficácia de isolados de Trichoderma e Pseudomonas sp. na biomassa microbiana, atividades enzimáticas em solo arenoso e produção da alface cultivada com alface. O experimento foi conduzido em delineamento experimental inteiramente casualizado com dez repetições, sendo os tratamentos: CONT (controle absoluto); CM (controle apenas com a fertilização); CMB (com fertilização e Pseudomonas sp.); CMF (com fertilização e T. aureoviride) e CMBF (com fertilização e os dois micro-organismos combinados). A fertilização utilizada foi a orgânica pela adição de esterco bovino em dose recomendada para a cultura. Avaliou-se a produção de alface, a biomassa microbiana e a atividade enzimática da fostafase ácida, fosfatase alcalina e urease. A aplicação CMBF foi eficiente para o aumento na produção de alface, pois incrementou 85% da produção da cv. Verônica em solo arenoso. O uso combinado de micro-organismos promotores de crescimento de plantas incrementam a biomassa microbiana. Recomenda-se o uso de T. aureoviride URM 5158 e Pseudomonas sp. UAGF 14 no cultivo de alface, pois além de melhorar a produção, melhora a qualidade bioquímica dos solos mensurados por atividades enzimáticas absolutas e específicas por unidade de biomassa microbiana.

Plant growth promoter microorganisms have been studied as important tools for increasing crop production. Lettuce is the most consumed hardwood crop in the world. Numerous microorganisms are capable of acting in a beneficial way in the growth of this culture. The objective of the present study was to evaluate the efficacy of Trichoderma and Pseudomonas on the microbial biomass, enzymatic activities in sandy soil and lettuce production. The experimental design was completely randomized with ten replicates and treatments: CONT (absolute control); CM (control with cattle manure fertilization); CMB (with fertilization and Pseudomonas sp.); CMF (with fertilization and T. aureoviride) and CMBF (with fertilization and the two microorganisms combined). The fertilizer used was organic with cattle manure in a dose recommended for the culture. This study evaluated the production of lettuce, microbial biomass and the enzymatic activity of acid phosphatase, alkaline phosphatase and urease. The combined application of CMBF was efficient in increasing lettuce production, because it increased 85% of the cv. Veronica cultivated on sandy soil. The combined use of plant growth promoting microorganisms resulted to an increase in microbial biomass. In lettuce crops, it is recommended to use T. aureoviride URM 5158 and Pseudomonas sp. UAGF 14 in lettuce crops, because improved lettuce production, improves the biochemical quality of soils measured by absolute and specific enzymatic activities per unit of microbial biomass. | Os micro-organismos promotores do crescimento de plantas vêm sendo estudados como uma importante ferramenta para o aumento da produção agrícola. Lactuca sativa (alface) é a hortaliça folhosa mais consumida em todo mundo. Inúmeros micro-organismos podem atuar de forma benéfica no crescimento desta cultura. O objetivo do presente trabalho foi avaliar a eficácia de isolados de Trichoderma e Pseudomonas sp. na biomassa microbiana, atividades enzimáticas em solo arenoso e produção da alface cultivada com alface. O experimento foi conduzido em delineamento experimental inteiramente casualizado com dez repetições, sendo os tratamentos: CONT (controle absoluto); CM (controle apenas com a fertilização); CMB (com fertilização e Pseudomonas sp.); CMF (com fertilização e T. aureoviride) e CMBF (com fertilização e os dois micro-organismos combinados). A fertilização utilizada foi a orgânica pela adição de esterco bovino em dose recomendada para a cultura. Avaliou-se a produção de alface, a biomassa microbiana e a atividade enzimática da fostafase ácida, fosfatase alcalina e urease. A aplicação CMBF foi eficiente para o aumento na produção de alface, pois incrementou 85% da produção da cv. Verônica em solo arenoso. O uso combinado de micro-organismos promotores de crescimento de plantas incrementam a biomassa microbiana. Recomenda-se o uso de   T. aureoviride URM 5158 e Pseudomonas sp. UAGF 14 no cultivo de alface, pois além de melhorar a produção, melhora a qualidade bioquímica dos solos mensurados por atividades enzimáticas absolutas e específicas por unidade de biomassa microbiana.

The objective of this study was to quantify the necromass stock in a Mixed Ombrophilous Forest (MOF) fragment in the National Forest of Irati, State of Paraná, Brazil. Two sampling methods were tested: FA1, consisting of a fixed area (FA) approach with sample units measuring 2,500 m2 (50 m × 50 m); and FA2, consisting of fixed area sampling units measuring 500 m2 (10 m × 50 m) and line intercept sampling (LI) using 50 m lines. Data were collected on permanent sample plots installed in the area, consisting of 25 square blocks of 1 ha. Fallen dead wood pieces with a diameter = 10 cm were used in the analysis. The dead wood was classified into three degrees of decomposition, and masses were calculated as the corresponding density at each class. The tested sampling methods were evaluated using coefficient of variation and relative sampling error, and the nonparametric Kruskal-Wallis test was used to compare the results between the methods. Volume size of fallen dead wood did not statistically differ between the methods, but variation in necromass volume was lower in the FA1 method, whereas the FA2 method had a smaller sampling error. Overall sampling error ranged from 23.4-27.92%; lowering the sampling error to 15% would require a high sampling intensity (FA1: 42 area units a.u., FA2: 99 a.u., and LI: 236 a.u.). Total necromass weights amounted to 4.67 Mg.ha-1 (FA1); 5.16 Mg.ha-1 (FA2) and 4.58 Mg.ha-1 (IL), and carbon stock estimates were 2.00 Mg.C.ha-1 (FA1); 2.20 Mg.C.ha-1 (FA2) and 1.96 Mg.C.ha-1 (IL).

The objective of this study was to quantify the necromass stock in a Mixed Ombrophilous Forest (MOF) fragment in the National Forest of Irati, State of Paraná, Brazil. Two sampling methods were tested: FA1, consisting of a fixed area (FA) approach with sample units measuring 2,500 m2 (50 m × 50 m); and FA2, consisting of fixed area sampling units measuring 500 m2 (10 m × 50 m) and line intercept sampling (LI) using 50 m lines. Data were collected on permanent sample plots installed in the area, consisting of 25 square blocks of 1 ha. Fallen dead wood pieces with a diameter ≥ 10 cm were used in the analysis. The dead wood was classified into three degrees of decomposition, and masses were calculated as the corresponding density at each class. The tested sampling methods were evaluated using coefficient of variation and relative sampling error, and the nonparametric Kruskal-Wallis test was used to compare the results between the methods. Volume size of fallen dead wood did not statistically differ between the methods, but variation in necromass volume was lower in the FA1 method, whereas the FA2 method had a smaller sampling error. Overall sampling error ranged from 23.4–27.92%; lowering the sampling error to 15% would require a high sampling intensity (FA1: 42 area units [a.u.], FA2: 99 a.u., and LI: 236 a.u.). Total necromass weights amounted to 4.67 Mg.ha-1 (FA1); 5.16 Mg.ha-1 (FA2) and 4.58 Mg.ha-1 (IL), and carbon stock estimates were 2.00 Mg.C.ha-1 (FA1); 2.20 Mg.C.ha-1 (FA2) and 1.96 Mg.C.ha-1 (IL). | O estudo teve por objetivo quantificar o estoque de necromassa, em um fragmento de Floresta Ombrófila Mista, na Floresta Nacional de Irati, estado do Paraná. Dois métodos de amostragem foram testados, sendo área fixa (AF) com unidades amostrais de 2500 m2 (50 m x 50 m) -AF1; área fixa com unidades amostrais de 500 m2 (10 m x 50 m) – AF2 e método de amostragem por Linha Interceptadora (LI), com linhas de 50 m. Os dados foram coletados em parcelas permanentes instaladas na área, constituídas por 25 blocos quadrados de 1 ha. Foram medidas peças de madeira morta caída com diâmetro ≥ 10 cm. A madeira morta foi classificada em três graus de decomposição e a massa foi calculada conforme a densidade correspondente a cada classe. Os métodos de amostragem testados foram avaliados por meio do Coeficiente de Variação e do Erro de Amostragem Relativo. Para comparações dos resultados entre os métodos utilizou-se o teste não paramétrico de Kruskal-Wallis. Os volumes para madeira morta caída não diferiram estatisticamente entre os métodos, porém o método AF1 teve menor variação do volume de necromassa e o método AF2 apresentou menor erro de amostragem. O erro amostral variou de 23,4 % a 27,92 % entre os métodos. Para atingir um erro de amostragem de 15% seria necessária uma elevada intensidade amostral (AF1: 42 unidades de área [u.a.], AF2: 99 u.a., e LI: 236 u.a.). O peso total de necromassa foi de 4,67 Mg.ha-1 (AF1); 5,16 Mg.ha-1 (AF2), e 4,58 Mg.ha-1 (LI) e o estoque de carbono foi de 2,00 Mg.C.ha-1(AF1); 2,20 Mg.C.ha-1 (AF2), e 1,96 Mg.C.ha-1 (LI).