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.

ABSTRACT 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. | RESUMO 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.

ABSTRACT 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. | RESUMO 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.

RESUMO 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. | ABSTRACT 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.

The use of wastewater has emerged as alternative to control environmental pollution and a viable option to improved water availability in the arid and semiarid zones. In this study, the effects of irrigation solution with domestic sewage effluent and, of growing substrate on growth of Aroeira seedlings was examined in a greenhouse experiment. The effects of five irrigation solution (Public-supply water, PSW, domestic sewage effluent, DSE and the mixtures of 75% DSE + 25% PSW, 50% DSE + 50% PSW and 25% DSE + 75% PSW) and two growing substrate (75% soil + 25% bovine manure and, 75% soil + 25% coconut fiber) were used in a completely randomized block design, arranged as split plots with three replications for each treatment. The evaluations were made at 30, 60, 90 and 150 days after planting, and the parameters following were measured: stem diameter, shoot height, relationship between height and diameter, shoot/root dry matter ratio, dry matter of the root, shoot and total and, Dickson index. The analysis results indicated that the irrigation solution composed by raw sewage effluent or mixed with Public-supply water increased the growth and improved morphological index of Aroeira seedlings, being the better development found when plant of Aroeira were grown in bovine manure + soil substrate under irrigation with solution containing 100% domestic sewage effluent.

ABSTRACT The use of wastewater has emerged as alternative to control environmental pollution and a viable option to improved water availability in the arid and semiarid zones. In this study, the effects of irrigation solution with domestic sewage effluent and, of growing substrate on growth of Aroeira seedlings was examined in a greenhouse experiment. The effects of five irrigation solution (Public-supply water, PSW, domestic sewage effluent, DSE and the mixtures of 75% DSE + 25% PSW, 50% DSE + 50% PSW and 25% DSE + 75% PSW) and two growing substrate (75% soil + 25% bovine manure and, 75% soil + 25% coconut fiber) were used in a completely randomized block design, arranged as split plots with three replications for each treatment. The evaluations were made at 30, 60, 90 and 150 days after planting, and the parameters following were measured: stem diameter, shoot height, relationship between height and diameter, shoot/root dry matter ratio, dry matter of the root, shoot and total and, Dickson index. The analysis results indicated that the irrigation solution composed by raw sewage effluent or mixed with Public-supply water increased the growth and improved morphological index of Aroeira seedlings, being the better development found when plant of Aroeira were grown in bovine manure + soil substrate under irrigation with solution containing 100% domestic sewage effluent. | RESUMO O uso das águas residuais tem despontado como uma alternativa para o controle da poluição ambiental e uma opção viável para aumentar a disponibilidade hídrica nas regiões áridas e semiáridas. Neste estudo, os efeitos da água de irrigação com efluente de esgoto doméstico e do substrato de cultivo sob o crescimento de mudas de Aroeira foram estudados em um experimento em condições de ambiente protegido. Foram testados cinco soluções de irrigação (Água de abastecimento - AA, Efluente de esgoto doméstico bruto - ED e as misturas de 75% ED + 25% AA, 50% ED + 50% AA e 25% ED + 75% AA) e dois substratos de cultivos (75% solo + 25% esterco de bovinos e 75% solo + 25% fibra de coco) utilizando o delineamento estatístico inteiramente casualizado, arranjadas em parcelas subdivididas com três repetições com três repetições por tratamento. As avaliações de crescimento e desenvolvimento foram realizadas aos 30; 60; 90 e 150 dias após o plantio e determinaram-se as variáveis diâmetro do colo, altura de parte aérea, relação entre altura e o diâmetro, relação matéria seca da parte aérea/matéria seca da raiz, matérias secas do sistema radicular, da parte aérea, total, e o índice de Dickson. As análises dos resultados indicaram que a irrigação com efluente de esgoto aumentou o crescimento e o índice morfológico das mudas de aroeira, sendo o melhor desenvolvimento encontrado quando as plântulas de Aroeira foram cultivadas em substrato de esterco bovino + solo e irrigadas com solução contendo 100% efluente de esgoto doméstico tratado.

To understand the production cycle of a particular cultivar in a given region, it is necessary to obtain information related to its phenology and the accumulated degree days. The purpose of this study was to evaluate the phenological cycle of citrus species grafted onto two rootstocks and grown in the Low-Middle Region of the São Francisco River Basin, in particular with respect to accumulated degree days. The experiment was conducted using ‘Rubi’ and ‘Pera D-12’ oranges and ‘Page’ mandarins. Two rootstocks were used, namely ‘Cravo’ and ‘Volkameriano’ lemon species that were drip irrigated in the Campo Experimental de Bebedouro, an experimental field owned by Embrapa Semiárido. ‘Page’ mandarins with ‘Cravo’ or ‘Volkameriano’ rootstocks exhibited a subperiod (0-10) of 183.32 and 181.24 days, respectively. Meanwhile, ‘Pera D-12’ and ‘Rubi’ oranges with ‘Cravo’ rootstocks had values of 249.57 and 178.58 days, respectively, while those with ‘Volkameriano’ rootstocks had values of 226.35 and 200.41 days, respectively. The accumulated degree days were measured from the initial sprouting to harvesting, which took place when the fruits presented a soluble solids/titratable acidity ratio equal to or greater than 12. ‘Page’ mandarins required 2,720 degree days, whereas ‘Pera D-12’ and ‘Rubi’ oranges required approximately 3,390 and 2,280 degree days, respectively. Finally, ‘Pera D-12’ and ‘Rubi’ oranges with either rootstock presented cycles characterized as mid-season and precocious, respectively, while ‘Page’ mandarins had precocious cycles.

ABSTRACT To understand the production cycle of a particular cultivar in a given region, it is necessary to obtain information related to its phenology and the accumulated degree days. The purpose of this study was to evaluate the phenological cycle of citrus species grafted onto two rootstocks and grown in the Low-Middle Region of the São Francisco River Basin, in particular with respect to accumulated degree days. The experiment was conducted using ‘Rubi’ and ‘Pera D-12’ oranges and ‘Page’ mandarins. Two rootstocks were used, namely ‘Cravo’ and ‘Volkameriano’ lemon species that were drip irrigated in the Campo Experimental de Bebedouro, an experimental field owned by Embrapa Semiárido. ‘Page’ mandarins with ‘Cravo’ or ‘Volkameriano’ rootstocks exhibited a subperiod (0-10) of 183.32 and 181.24 days, respectively. Meanwhile, ‘Pera D-12’ and ‘Rubi’ oranges with ‘Cravo’ rootstocks had values of 249.57 and 178.58 days, respectively, while those with ‘Volkameriano’ rootstocks had values of 226.35 and 200.41 days, respectively. The accumulated degree days were measured from the initial sprouting to harvesting, which took place when the fruits presented a soluble solids/titratable acidity ratio equal to or greater than 12. ‘Page’ mandarins required 2,720 degree days, whereas ‘Pera D-12’ and ‘Rubi’ oranges required approximately 3,390 and 2,280 degree days, respectively. Finally, ‘Pera D-12’ and ‘Rubi’ oranges with either rootstock presented cycles characterized as mid-season and precocious, respectively, while ‘Page’ mandarins had precocious cycles. | RESUMO Para definir o ciclo de produção de uma cultivar em uma determinada região são necessárias informações relacionadas à fenologia e ao acúmulo de graus-dia para a sua produção. O objetivo deste trabalho foi avaliar o ciclo fenológico de espécies cítricas, enxertadas sobre dois Porta- enxertos em função do acúmulo de graus-dias nas condições do Submédio São Francisco. O experimento foi conduzido com duas laranjeiras ‘Rubi’ e ‘Pera D-12’ e uma tangerineira ‘Page’, sobre dois porta-enxertos: limoeiros ‘Cravo’ e limoeiro ‘Volkameriano’, irrigadas por gotejamento, no Campo Experimental de Bebedouro, pertencente à Embrapa Semiárido. Para a tangerineira ‘Page’ nos porta-enxertos ‘Cravo’ e ‘Volkameriano’, o subperíodo (0-10) foi de 183,32 dias e 181,24 dias, respectivamente; para as laranjeiras ‘Pera D-12’ e ‘Rubi’, sobre o porta-enxerto ‘Cravo’, foi de 249,57 dias e 178,58 dias e, para o ‘Volkameriano’, foi de 226,35 dias e 200,41dias, respectivamente. Desde a emissão da brotação até a colheita, fase em que os frutos apresentaram valor de “ratio” igual ou superior a 12, para a tangerineira ‘Page’ foram necessários aproximadamente 2.720 graus-dias, e para as laranjeiras ‘Pera D12’ e ‘Rubi’, aproximadamente 3.390 e 2.280 graus-dias, respectivamente. As laranjeiras ‘Pera D-12’ e ‘Rubi’, enxertadas sobre os dois porta-enxertos apresentaram ciclos caracterizados como sendo de meia-estação e precoce, respectivamente, e a tangerineira ‘Page’, ciclo precoce.

This study aimed to characterize three natural populations of mangabeira (Hancornia speciosa) located in parts of the Cerrado in the region of Porto Nacional, State of Tocantins, as well as to evaluate phenotypic variability in individual plants based on the physicochemical properties of their fruits. Ten genotypes were selected from each population, and 20 fruits of each genotype were collected for analysis. Fruits were analyzed for transverse and longitudinal diameters, total mass, pulp mass and yield, and number and fresh mass of seeds. Two seeds were taken from each fruit for the measurement of longitudinal and transverse diameter and thickness. Furthermore, pH and soluble solids were measured in the total pulp of each genotype. Descriptive statistics were performed on the data from morphological characterization, and populations were compared by the Kruskal-Wallis test, followed by Dunn's test at 5% probability level. The relationship between variables was estimated by the Spearman’s correlation coefficient. Phenotypic variability was verified using the principal component analysis. All three natural populations of mangabeira investigated here exhibited similar characteristics regarding fruit morphology and pH. Significant differences were detected only in the transverse diameter of the seed (Canaã had the highest value) and for total soluble solids content (Providência had the highest value). Significant correlations were found for corresponding morphological variables and pH in each population, except for several negative correlations that were observed in the Canaã population, which produced more homogeneous fruit. The Providência population presented the largest and most massive fruit. The greatest phenotypic variabilities were observed in the São Judas Tadeu and Providência populations.

RESUMO O presente estudo teve como objetivo caracterizar três populações naturais de mangabeira (Hancornia speciosa Gomes) localizadas em áreas de Cerrado na região de Porto Nacional-TO e estudar a variabilidade fenotípica através de atributos físico-químicos de frutos. Foram selecionados dez genótipos em cada população e coletados vinte frutos de cada genótipo para análise. Nos frutos foram mensurados: o diâmetro transversal e longitudinal, a massa total, a massa e o rendimento de polpa, o número de sementes e a massa fresca das sementes. De cada fruto foram retiradas duas sementes e mensurados o diâmetro longitudinal, transversal e espessura. Da polpa total de cada genótipo foram mensurados o pH e sólidos solúveis. Para caracterização morfológica foi realizada estatística descritiva, a comparação entre as populações foi realizada através do teste de Kruskal-Wallis seguido do teste de Dunn a 5% de probabilidade. A relação entre as variáveis foi estimada pelo coeficiente de correlação de Spearman. Para o estudo da variabilidade fenotípica foi realizada a análise de componentes principais. As populações naturais de mangabeira estudadas apresentam características semelhantes quanto à morfologia do fruto e pH, sendo encontrado diferenças significativas apenas para o diâmetro transversal da semente, com maior valor para Canaã e sólidos solúveis totais, com maior valor para Providência. As correlações significativas em cada população ocorrem para as mesmas variáveis morfológicas e pH, com exceção das correlações negativas que ocorreram na população Canaã que se destacou por apresentar frutos mais homogêneos. Providência apresentou frutos maiores e com maior massa. Nas populações São Judas Tadeu e Providência foram observadas maiores variabilidades fenotípicas. | ABSTRACT This study aimed to characterize three natural populations of mangabeira (Hancornia speciosa) located in parts of the Cerrado in the region of Porto Nacional, State of Tocantins, as well as to evaluate phenotypic variability in individual plants based on the physicochemical properties of their fruits. Ten genotypes were selected from each population, and 20 fruits of each genotype were collected for analysis. Fruits were analyzed for transverse and longitudinal diameters, total mass, pulp mass and yield, and number and fresh mass of seeds. Two seeds were taken from each fruit for the measurement of longitudinal and transverse diameter and thickness. Furthermore, pH and soluble solids were measured in the total pulp of each genotype. Descriptive statistics were performed on the data from morphological characterization, and populations were compared by the Kruskal-Wallis test, followed by Dunn's test at 5% probability level. The relationship between variables was estimated by the Spearman’s correlation coefficient. Phenotypic variability was verified using the principal component analysis. All three natural populations of mangabeira investigated here exhibited similar characteristics regarding fruit morphology and pH. Significant differences were detected only in the transverse diameter of the seed (Canaã had the highest value) and for total soluble solids content (Providência had the highest value). Significant correlations were found for corresponding morphological variables and pH in each population, except for several negative correlations that were observed in the Canaã population, which produced more homogeneous fruit. The Providência population presented the largest and most massive fruit. The greatest phenotypic variabilities were observed in the São Judas Tadeu and Providência populations.

The semi-arid region accounts for about 70% of the surface area of the Brazilian northeast, and the most important forage resource is the Caatinga, covering approximately 54% of this region. However, about 40% of this vegetation is in secondary succession. The areas in the process of degradation range from low to severe intensity, and total more than 20 million hectares, reflecting the intense use of the land, such as the overgrazing. The objective of this study was to evaluate the influence of different doses of phosphorus (0, 50 and 100 kg P2O5 ha-1 year-1) on the dynamics of herbaceous vegetation at different times of the year, in a Caatinga area manipulated without grazing for four years. The experiment was conducted at the Serra Talhada-UFRPE Academic Unit during the years 2015 and 2016. We used a randomised block design with three blocks and four replicates per block. Phosphate fertilisation in grazing exclusion areas promoted an increase in forage mass of the enriched Caatinga herbaceous stratum at all evaluation times, especially in the dry season of 2016, which showed values above the average of 7950 kg DM ha-1. In addition, it promoted an increase in the participation of buffelgrass in the floristic composition, increasing its involvement in the area to around 74% at the maximum dose of phosphorus used. Thus, phosphate fertilisation at up to 100 kg of P2O5 ha-1 year-1, together with grazing exclusion, can help to recover the Caatinga enriched with buffelgrass and optimise its use by reducing the formation of new grazing areas in the Caatinga.

RESUMO O semiárido representa cerca de 70% da superfície do Nordeste brasileiro e o recurso forrageiro de maior expressão é a Caatinga, cobrindo aproximadamente 54% desta região. Porém, cerca de 40% dessa vegetação encontra-se em sucessão secundária e as áreas em processo de degradação de intensidade baixa a severa, já somam mais de 20 milhões de hectares, reflexo do uso intenso da terra, dentre elas o superpastejo. Objetivou-se avaliar a influência de diferentes doses de fósforo (0, 50 e 100 kg de P2O5 ha-1 ano), em área de Caatinga manipulada, sem pastejo por quatro anos, sobre a dinâmica da vegetação herbácea em diferentes épocas do ano. O experimento foi conduzido na Unidade Acadêmica de Serra Talhada-UFRPE, durante os anos de 2015 a 2016. Foi utilizado delineamento em blocos casualizados, com três blocos e quatro repetições por bloco. A adubação fosfatada em áreas de exclusão ao pastejo promoveu aumento da massa de forragem do estrato herbáceo da Caatinga enriquecida, em todas as épocas de avaliação, com destaque para a época seca de 2016, que obeteve valores acima da média de 7950 kg de MS ha-1. Promoveu aumento da participação do capim-buffel na composição florística, elevando sua participação na área em torno de 74% para a dose máxima de fósforo utilizada. Neste sentido, a adubação fosfatada até 100 kg de P2O5 ha-1 ano, juntamente com a exclusão ao pastejo, pode ajudar na recuperação da Caatinga enriquecida com capim-buffel e otimizar a sua utilização diminuindo a formação de novas áreas de pastejo na Caatinga. | ABSTRACT The semi-arid region accounts for about 70% of the surface area of the Brazilian northeast, and the most important forage resource is the Caatinga, covering approximately 54% of this region. However, about 40% of this vegetation is in secondary succession. The areas in the process of degradation range from low to severe intensity, and total more than 20 million hectares, reflecting the intense use of the land, such as the overgrazing. The objective of this study was to evaluate the influence of different doses of phosphorus (0, 50 and 100 kg P2O5 ha-1 year-1) on the dynamics of herbaceous vegetation at different times of the year, in a Caatinga area manipulated without grazing for four years. The experiment was conducted at the Serra Talhada-UFRPE Academic Unit during the years 2015 and 2016. We used a randomised block design with three blocks and four replicates per block. Phosphate fertilisation in grazing exclusion areas promoted an increase in forage mass of the enriched Caatinga herbaceous stratum at all evaluation times, especially in the dry season of 2016, which showed values above the average of 7950 kg DM ha-1. In addition, it promoted an increase in the participation of buffelgrass in the floristic composition, increasing its involvement in the area to around 74% at the maximum dose of phosphorus used. Thus, phosphate fertilisation at up to 100 kg of P2O5 ha-1 year-1, together with grazing exclusion, can help to recover the Caatinga enriched with buffelgrass and optimise its use by reducing the formation of new grazing areas in the Caatinga.

This study was conducted to evaluate the use of Curcuma longa (Linnaeus) extract in the in vitro control of Bipolaris oryzae (Breda de Haan) and to characterize the effect of this extract on rice seed germination. A completely randomized arranged in a factorial experimental design was used: three isolates of B. oryzae from rice seed from different rice-growing regions of Rio Grande do Sul (Fronteira Oeste, Campanha, and Sul) were tested with three concentrations (20, 40, and 80 mg/mL) of C. longa plus a control treatment (0 mg/mL). Each reaction was repeated in quadruplicate. The effect of the extract upon the disease development was evaluated based on mycelial growth (PMG) and spore production; rice seed germination was evaluated using a germination test (Germitest®). The PMG results demonstrate that the treatments were effective in reducing PMG, with a stronger response observed as the concentration of the extract increased. An average inhibition of 84% of sporulation was observed for the tested strains compared with the control treatment. There were, however, no significant differences in terms of seed germination test with the different C. longa concentrations. Therefore, treatment of rice seeds with C. longa extract does not affect seed germination but positively inhibits mycelial growth and sporulation, affecting the in vitro sporulation of the different isolates of B. oryzae.

ABSTRACT This study was conducted to evaluate the use of Curcuma longa (Linnaeus) extract in the in vitro control of Bipolaris oryzae (Breda de Haan) and to characterize the effect of this extract on rice seed germination. A completely randomized arranged in a factorial experimental design was used: three isolates of B. oryzae from rice seed from different rice-growing regions of Rio Grande do Sul (Fronteira Oeste, Campanha, and Sul) were tested with three concentrations (20, 40, and 80 mg/mL) of C. longa plus a control treatment (0 mg/mL). Each reaction was repeated in quadruplicate. The effect of the extract upon the disease development was evaluated based on mycelial growth (PMG) and spore production; rice seed germination was evaluated using a germination test (Germitest®). The PMG results demonstrate that the treatments were effective in reducing PMG, with a stronger response observed as the concentration of the extract increased. An average inhibition of 84% of sporulation was observed for the tested strains compared with the control treatment. There were, however, no significant differences in terms of seed germination test with the different C. longa concentrations. Therefore, treatment of rice seeds with C. longa extract does not affect seed germination but positively inhibits mycelial growth and sporulation, affecting the in vitro sporulation of the different isolates of B. oryzae. | RESUMO Objetivou-se avaliar o uso do extrato de Curcuma longa (Linnaeus) no controle de Bipolaris oryzae (Breda de Haan) in vitro, bem como conhecer o seu efeito sobre a germinação de sementes de arroz. O delineamento experimental foi inteiramente casualizado arranjado em um sistema fatorial: três isolados de B. oryzae de sementes de arroz, oriundas de três regiões orizícolas do Rio Grande do Sul (fronteira oeste; campanha e sul) x três concentrações (20; 40 e 80 mg/mL) de C. longa, mais um tratamento controle (0 mg/mL), com quatro repetições. O efeito do extrato sobre o desenvolvimento do patógeno foi avaliado a partir do crescimento micelial (CMC) e produção de esporos, para a germinação das sementes de arroz foi avaliado através do teste de germinação em papel toalha (Germitest®). Os resultados para o CMC demonstram que os tratamentos foram efetivos, reduzindo o CMC conforme aumentava-se as concentrações do extrato. Em relação a esporulação, ocorreu a inibição média de 84% para os isolados testados, quando comparado ao tratamento controle. Já para o teste de germinação de sementes, não houve diferença significativa entre as diferentes concentrações. Dessa forma, conclui-se que o extrato de C. longa quando em contato com a semente de arroz, não interfere na sua germinação e que age positivamente inibindo o crescimento micelial e afetando a esporulação dos diferentes isolados de B. oryzae in vitro.

Sugarcane is one of the most affected crops by water scarcity. The efficient use of the irrigation water is an alternative to minimize this problem. The objective of this work was to evaluate biometric parameters, yield, and technological quality of sugarcane plants subjected to different controlled water deficit regimes in the sub-middle São Francisco Valley, Brazil. The experiment was conducted in a randomized block design, in two crop cycles, with three replications, with ten treatments consisted of three controlled water deficits (15%, 30%, and 45% of the crop evapotranspiration - ETc), applied at three development stages of the plant - sprouting and tillering (Stage I), grand growth (Stage II), and maturation (Stage III) - and a control with 100% of the ETc throughout the entire crop cycle. The controlled water deficit did not affect the technological quality of the sugarcane in any development stage. The sugarcane yield was higher when using a controlled water deficit of 30% of ETc in the sprouting and tillering stages of the plants. The water deficit of 15% of ETc is recommended for the grand growth, or maturation stages of the sugarcane plants for a greater water use efficiency of the production system.

RESUMO A cana-de-açúcar é uma das culturas que mais sofrem com a escassez hídrica e, para minimizar esse problema, uma das alternativas é o uso eficiente da água de irrigação. Objetivou-se com este trabalho avaliar os parâmetros biométricos, produtividade e qualidade tecnológica da cana-de-açúcar submetida a diferentes regimes de deficit hídrico controlado, na região do Submédio do Vale do São Francisco. O delineamento experimental utilizado foi em blocos casualizados, com 10 tratamentos e três repetições, sendo três deficits hídricos controlados (15; 30; e 45% da evapotranspiração da cultura - ETc), aplicados nas três fases de desenvolvimento da planta (Fase I - brotação e perfilhamento, Fase II - desenvolvimento e Fase III - maturação) e tratamento controle com 100% da ETc, realizados em dois ciclos de cultivo. A qualidade tecnológica da cana-de-açúcar não foi alterada em função do deficit hídrico controlado nas diferentes fases de desenvolvimento. A produtividade da cana-de-açúcar foi maior utilizando-se deficit hídrico controlado de 30% da ETc na fase de brotação e perfilhamento de desenvolvimento da cultura da cana-de-açúcar. A fim de se garantir maior eficiência do uso da água pelo sistema produtivo, recomenda-se a aplicação de uma lâmina com deficit hídrico de 15% da ETc, nas fases de maior desenvolvimento ou maturação do ciclo da cultura. | ABSTRACT Sugarcane is one of the most affected crops by water scarcity. The efficient use of the irrigation water is an alternative to minimize this problem. The objective of this work was to evaluate biometric parameters, yield, and technological quality of sugarcane plants subjected to different controlled water deficit regimes in the sub-middle São Francisco Valley, Brazil. The experiment was conducted in a randomized block design, in two crop cycles, with three replications, with ten treatments consisted of three controlled water deficits (15%, 30%, and 45% of the crop evapotranspiration - ETc), applied at three development stages of the plant - sprouting and tillering (Stage I), grand growth (Stage II), and maturation (Stage III) - and a control with 100% of the ETc throughout the entire crop cycle. The controlled water deficit did not affect the technological quality of the sugarcane in any development stage. The sugarcane yield was higher when using a controlled water deficit of 30% of ETc in the sprouting and tillering stages of the plants. The water deficit of 15% of ETc is recommended for the grand growth, or maturation stages of the sugarcane plants for a greater water use efficiency of the production system.

Plasma technology is a fast, cost-effective, and pollution-free method that can be used in place of conventional methods to overcome seed dormancy. The goal of the present study was to determine the effect of different application times of atmospheric plasma on soaking and germination of Hybanthus calceolaria seeds in order to accelerate these processes. Helium plasma jet produced by dielectric barrier discharge was used to treat H. calceolaria seeds with applications of 1, 5, and 10 minutes. The treated seeds were characterized considering their weight variation during soaking, changes in electrical conductivity, and pH. It was found that germination depended on the plasma application time. The treatment of H. calceolaria seeds with atmospheric plasma for 1 minute provided 3.5 times greater germination in comparison to untreated seeds. Atmospheric plasma technology obtained by dielectric barrier discharge had potential of being used as a germination accelerant in H. calceolaria seeds. The treatment of H. calceolaria seeds using atmospheric plasma for 1 minute favored germination.

ABSTRACT Plasma technology is a fast, cost-effective, and pollution-free method that can be used in place of conventional methods to overcome seed dormancy. The goal of the present study was to determine the effect of different application times of atmospheric plasma on soaking and germination of Hybanthus calceolaria seeds in order to accelerate these processes. Helium plasma jet produced by dielectric barrier discharge was used to treat H. calceolaria seeds with applications of 1, 5, and 10 minutes. The treated seeds were characterized considering their weight variation during soaking, changes in electrical conductivity, and pH. It was found that germination depended on the plasma application time. The treatment of H. calceolaria seeds with atmospheric plasma for 1 minute provided 3.5 times greater germination in comparison to untreated seeds. Atmospheric plasma technology obtained by dielectric barrier discharge had potential of being used as a germination accelerant in H. calceolaria seeds. The treatment of H. calceolaria seeds using atmospheric plasma for 1 minute favored germination. | RESUMO A tecnologia de plasma constitui-se em um método rápido, econômico e livre de poluição que pode ser utilizada na superação de dormência de sementes em substituição aos métodos convencionais. O objetivo com esse estudo foi verificar o efeito do tempo de aplicação de plasma atmosférico sobre a embebição e germinação de sementes de Hybanthus calceolaria visando à aceleração destes processos. Jato de plasma de gás hélio, produzido por descarga em barreira dielétrica (DBD), foi utilizado para tratar as sementes de H. calceolaria por 1, 5 e 10 minutos de aplicação. As sementes tratadas foram caracterizadas quanto à variação de peso durante a embebição, variações da condutividade elétrica e pH. Verificou-se que a germinação depende do tempo de aplicação do plasma. O tratamento de sementes de H. calceolaria com plasma atmosférico por 1 min. proporcionou incremento na germinação de 3,5 vezes em comparação com as não tratadas. A tecnologia de plasma atmosférico, obtido por barreira dielétrica, apresenta potencial de utilização como acelerador da germinação de sementes de H. calceolaria. O tratamento de sementes de H. calceolaria à plasma atmosférico durante 1 minuto favorece a germinação.