ABSTRACT Information on the different species that compose a weed community is essential for plant protection managements in production systems, which should include not only flora identification and diversity assessments, but morphological and ecophysiological aspects that can to show the potential effect of the agrosystem and guide the conduction of weed control strategies. Therefore, the objective of this work was to conduct a floristic and phytosociological surveying to identify the grouping patterns of weed populations in vineyards in the Petrolina-Juazeiro irrigated perimeter, in the Sub-Mid São Francisco River Valley, Brazil. The absolute and relative values of weed frequency, density, abundance, importance value index, population distribution level, and similarity between areas were evaluated in five properties. A high diversity of species of the families Poaceae, Malvaceae, and Asteraceae were found. The most important species found were Commelina benghalensis, Euphorbia hirta, and Cyperus aggregatus. The distribution of populations was mainly in aggregate and highly aggregate forms. | RESUMO O conhecimento sobre as diferentes espécies que compõem uma comunidade infestante torna-se fundamental no manejo fitossanitário dos sistemas de produção vegetal, não somente pela identificação da flora e diagnóstico da diversidade, mas também pelos aspectos morfológicos e ecofisiológicos, o que pode revelar o potencial de interferência ao agrossistema e nortear a condução das estratégias de controle. Neste sentido, o objetivo deste trabalho foi realizar o levantamento florístico e estudo fitossociológico, assim como conhecer o padrão de agrupamento das populações infestantes em áreas de videira no perímetro irrigado do polo Petrolina -PE/Juazeiro-BA, submédio do Vale do Rio São Francisco. As avaliações ocorreram em cinco propriedades, sendo analisados os parâmetros de: frequência, densidade, abundância e índice de valor de importância absolutos e relativos, assim como o grau de distribuição das populações e a similaridade entre as propriedades. As famílias Poaceae, Malvaceae e Asteraceae apresentaram maior diversidade de espécies. E as espécies com maiores níveis de importância foram Commelina benghalensis, Euphorbia hirta e Cyperus aggregatus. De maneira majoritária, a distribuição das populações apresentou-se de forma agregada ou altamente agregada.

ABSTRACT The soils of the Semiarid region of Brazil lack studies regarding sorption processes and availability of phosphorus (P). Therefore, the objective of this work was to quantify the sorption of P in ten soils representative of the Semiarid region of Brazil and correlate them with the soil phosphorus storage capacity. The P concentrations in the equilibrium solutions used to model the sorption isotherms were: 0, 5, 10, 15, 20, 30, 40, 55, 70, and 80 mg L-1 for the soils Typic Quartzipsamment (Neossolo Quartzarenico), Typic Hapludox (Latossolo Vermelho Amarelo), Typic Hapludult (Argissolo Vermelho Amarelo), Typic Quartzipsamment (Neossolo Flúvico), and Typic Dystrudept (Cambissolo Haplico); and 0, 10, 15, 25, 40, 55, 80, 100, 130, and 150 mg L-1 for the soils Typic Calciudolls (Chernossolo Rendzico), Typic Dystrudept (Cambissolo Haplico), Typic Dystrudept (Cambissolo Haplico), Typic Hapludult (Argissolo Vermelho Amarelo), and Typic Hapludert (Vertissolo Haplico). The Langmuir and Freundlich sorption isotherms were fitted to non-linear regression models and the values of the model parameters were estimated. The sorption isotherms were adequate to quantify the sorption of P in the soils of the Semiarid region of Brazil, with maximum P sorption capacity varying from 50.4 mg kg-1 to 883.5 mg kg-1. The sorption of P was higher in soils with more clayey textures, alkaline, and rich in iron and calcium, denoting the importance of evaluating the effect of these characteristics on the sorption of P in these soils. | RESUMO Os solos do semiárido brasileiro ainda não foram suficientemente estudados quanto aos processos de sorção e de disponibilidade de fósforo (P). Nesse sentido objetivou-se com este trabalho quantificar a sorção de P em dez solos representativos da região semiárida e correlacioná-las com o Fator Capacidade de Fósforo do Solo (FCP). As concentrações de P das soluções de equilíbrio utilizadas para o ajuste dessas isotermas corresponderam a 0; 5; 10; 15; 20; 30; 40; 55; 70 e 80 mg L-1 de P para os solos Neossolo Quartzarênico (Entisol), Latossolo Vermelho Amarelo (Oxisol), Argissolo Vermelho Amarelo (Ultisol), Neossolo Flúvico (Entisol) e Cambissolo Háplico (Inceptsol); e a 0; 10; 15; 25; 40; 55; 80; 100; 130 e 150 mg L-1 para os solos Chernossolo Rêndzico (Mollisol), Cambissolo Háplico (Inceptsol), Cambissolo Háplico (Inceptsol), Argissolo Vermelho Amarelo (Ultisol) e Vertissolo Háplico (Vertisol). As isotermas de Langmuir e de Freundlich foram ajustadas por meio da técnica de regressão não-linear e estimados os valores dos parâmetros desses modelos. As isotermas mostraram-se adequadas para quantificar a sorção de P nos solos do semiárido, com valores de capacidade máxima de sorção de P (CMSP) variando de 50,4 mg kg-1 a 883,5 mg kg-1. O P foi sorvido em maior quantidade nos solos mais argilosos, alcalinos e ricos em ferro e cálcio, evidenciando a importância da avaliação dessas características na sorção de P nesses solos.

ABSTRACT The Brazilian Northeast region suffers from some abiotic stresses that are responsible for the loss of agricultural production, such as long drought periods and high evapotranspiration, associated with the quality of the water, which induces the use of saline water as an alternative for the expansion of irrigated areas, and silicate fertilization contributes to reduce the effects of salinity under the Northeastern semi -arid conditions. The objective of this study was to evaluate the osmotic potential and physiological indices of yellow passion fruit seedlings under irrigation water salinity and silicate fertilization. The experiment was carried out under greenhouse conditions at the Federal University of Campina Grande, Pombal -PB, Brazil, in a randomized block design in a 5 x 5 factorial scheme, relative to five levels of electrical conductivity of irrigation water - ECw (0.3; 1.0; 1.7; 2.4 and 3.1 dS m-1) and five doses of silicate fertilization (0; 25; 50; 75 and 100 g silicon per plant) in four replicates and two plants per plot. The application of 50, 75 and 100 g silicon per plant reduced the osmotic potential in the leaf tissues of ‘Gigante Amarelo’ passion fruit plants. Water salinity lower than 1.3 dS m-1 resulted in an increase in chlorophyll b content; increase in carotenoid content was observed in plants subjected to silicon doses of 25 and 100 g per plant. Salinity levels above 1.1 dS m-1 compromised the performance of photosystem II of passion fruit plants when subjected to silicon doses. | RESUMO O Nordeste brasileiro sofre com alguns estresses abióticos que são responsáveis pela perda de produção agrícola, como os longos períodos de estiagem e elevada evapotranspiração, associado à qualidade das águas que induz ao uso de águas salinas como alternativa para expansão das áreas irrigadas, com isto a adubação silicatada contribui para redução dos efeitos da salinidade nas condições de semiárido nordestino. Objetivou-se avaliar o potencial osmótico e os índices fisiológicos de mudas de maracujazeiro amarelo sob salinidade da água de irrigação e adubação silicatada. O experimento foi desenvolvido em condições de casa de vegetação na Universidade Federal de Campina Grande, Pombal-PB, em delineamento de blocos ao acaso em esquema fatorial 5 x 5, relativo a cinco níveis de condutividade elétrica da água de irrigação - CEa (0,3; 1,0; 1,7; 2,4 e 3,1 dS m-1) e cinco doses de adubação silicatada (0; 25; 50; 75 e 100 g de silício por planta) em quatro repetições e duas plantas por parcela. A aplicação de 50, 75 e 100 g por planta de silício reduziu o potencial osmótico nos tecidos foliares das plantas de maracujazeiro ‘Gigante Amarelo’. A salinidade da água menor que 1,3 dS m-1 resultou em incremento no conteúdo de clorofila b; aumento nos teores de carotenoides foi verificado nas plantas submetidas as doses de 25 e 100 g de silício. Níveis salinos acima de 1,1 dS m-1 comprometeram o desempenho do fotossistema II das plantas de maracujazeiro quando submetidas as doses de silício.

RESUMO O objetivo deste estudo foi avaliar o efeito da substituição do feno de Tifton 85 pelo feno de maniçoba em dietas à base de palma forrageira sobre a ingestão e digestibilidade de nutrientes, comportamento ingestivo e parâmetros ruminais de ovinos confinados. Foram utilizados oito ovinos machos com cânula ruminal, distribuídos em quatro níveis (0, 333, 666 e 1.000 g kg-1 de matéria seca) de substituição do feno de Tifton 85 por feno de maniçoba em delineamento quadrado latino. Os animais permaneceram confinados por 60 dias divididos em quatro períodos de 15 dias. A substituição do feno de Tifton 85 por feno de maniçoba não influenciou no consumo ou digestibilidade de matéria seca. No entanto, influenciou de forma linear negativa na digestibilidade da fibra insolúvel em detergente neutro e proteína bruta. O nitrogênio amoniacal e proteína bruta ruminal diminuiu linearmente com a substituição do feno de Tifton 85 por feno de maniçoba. Não houve efeito da substituição do feno na produção de ácidos graxos voláteis ou no biofilme microbiano. A substituição total de Tifton 85 por feno de maniçoba em rações de palma forrageira para ovinos não influenciou o consumo de nutrientes digestíveis totais, a produção de ácidos graxos voláteis ou biofilme, mas afetou a digestibilidade da proteína bruta, nitrogênio amoniacal e teor de proteína bruta no rúmen. Portanto, o feno de maniçoba pode substituir até 300 g kg-1 de feno de capim em dietas de palma forrageira para ovinos, sem comprometer o consumo e os parâmetros ruminais. | ABSTRACT The objective of this study was to evaluate the effect of replacing Tifton 85 hay with maniçoba hay in diets based on spineless cactus on the nutrient intake and digestibility, ingestive behaviour and ruminal parameters of confined sheep. In order to do this, eight male sheep with ruminal cannulae were used, distributed across four levels (0, 333, 666 and 1.000 g kg-1 of dry matter) of replacement of Tifton 85 hay with maniçoba hay in a double Latin square experimental design. The animals were confined for 60 days divided into four periods of 15 days. The replacement of Tifton 85 hay with maniçoba hay did not influence the dry matter intake or digestibility. However, it influenced in a positive linear fashion the intake of non-fibrous carbohydrates and in a linear negative fashion the digestibility of insoluble fibre in neutral detergent and crude protein. The ruminal ammonia-nitrogen and the crude protein ruminal content decreased linearly with the replacement of Tifton 85 hay with maniçoba hay. There was no effect of hay replacement on the production of volatile fatty acids or the microbial biofilm. The total replacement Tifton 85 by maniçoba hay in spineless cactus diets for sheep did not influence total digestible nutrient intake, volatile fatty acid production or biofilm, but did affect crude protein digestibility, ammonia-nitrogen and crude protein content in the rumen. Therefore, maniçoba hay can replace 300 g kg-1 grass hay in spineless cactus diets for sheep without compromising intake and ruminal parameters.

RESUMO O trabalho teve por objetivo caracterizar, por meio de índices faunísticos, as populações de moscas-das-frutas no Brejo Paraibano, e analisar se essas populações são similares entre si. A pesquisa foi desenvolvida em oito municípios situados na Mesorregião do Agreste Paraibano e Microrregião do Brejo Paraibano, nos quais foram selecionadas duas propriedades rurais de cada município, georreferenciadas, identificadas segundo o critério de diversidade de espécies frutíferas. Cada município foi considerado como tendo uma população das moscas-das-frutas com características próprias, determinadas pelos índices faunísticos de frequência, constância, dominância, índices de diversidade de Shannon-Wiener e de Margalef, além de equitabilidade. Foram capturados 3.159 espécimes de moscas-das-frutas, dos quais 85,57% pertenciam ao gênero Anastrepha e 14,43% o gênero Ceratitis. Foram capturadas onze espécies de moscas-das-frutas nas armadilhas. Anastrepha fraterculus foi a espécie mais frequente, dominante e constante, estando presente em todas as localidades; seguida das espécies A. obliqua, A. sororcula e Ceratitis capitata. Os municípios estudados apresentam similaridade de 54%, o que indica alta semelhança entre as áreas. A maioria das espécies capturadas no presente estudo ocorre em baixa frequência populacional. | ABSTRACT The objective of this study was to characterize, through faunistic indices, the populations of fruit flies in the Brejo Paraibano microregion and analyze whether these populations are similar to one another. The study was conducted in eight municipalities located in the Agreste Paraibano mesoregion and Brejo Paraibano microregion, Paraíba state, Brazil, where two rural properties of each municipality were selected, georeferenced and identified according to the diversity criterion of fruit species. Each municipality was assumed to have a population of fruit flies with its own characteristics, determined by the faunistic indices of frequency, constancy, dominance, Shannon-Wiener and Margalef diversity indices, as well as evenness. 3.159 specimens of fruit flies were captured, of which 85.57% belonged to the genus Anastrepha and 14.43% to the genus Ceratitis. 11 species of fruit flies were captured in the traps. Anastrepha fraterculus was the most frequent, dominant and constant species, being present in all locations; followed by A. obliqua, A. sororcula and Ceratitis capitata. The studied municipalities have a similarity of 54%, which indicates a high similarity between the areas. Most species captured in the present study occur at low population frequency.

ABSTRACT Technologies that use rhizobacteria to promote plant growth are increasing in agriculture, results have shown improvements in soil quality, increases in productivity, and decreases in the use of synthetic inputs, The objective of work was to characterize bacterial isolates regarding their biological activity and growth promotion of soybean plants grown in a controlled environment. Fifteen bacteria were isolated from soils with continuous use of biological fertilizer. They were evaluated for enzymes production (amylase and protease), nitrogen fixation, antagonistic activity to phytopathogenic fungi, and indoleacetic acid (IAA) production, Soybean seeds were inoculated with bacterial isolates in a greenhouse and evaluated for plant development and soil chemical attributes. The results showed that 8 of the 15 isolates presented production of amylase, protease, or both and 4 isolates presented nitrogen-fixing capacity. The percentage of isolates with high or moderate inhibitory action against the fungi Sclerotinia sclerotiorum, Macrophomina phaseolina, and Fusarium solani were 73.3%, 66.6%, and 73.3%, respectively. The IAA production varied from 8.56 to 31.33 µg mL-1 (5 isolates had low, 6 had moderate, and 4 had high production). The soybean development was significantly higher in 80% of the treatments with inoculation with bacterial isolates. Five bacterial isolates effectively present all characteristics for use as inoculant (biofertilizer) to promote the development of soybean plants.

ABSTRACT Stress caused by soil water deficit has been one of the main factors that inhibit plant growth. The knowledge of the factors related to the behavior of weed species under water stress conditions can contribute to the elaboration of effective control strategies. Two experiments were carried out to evaluate the effects of the degree and duration of water deficit on physiological and growth indicators of two weed species (Bidens pilosa L. and Bidens subalternans DC.). The stress degree was simulated by four soil moisture: 100, 75, 50, 25% of total soil capacity. The water deficit duration was evaluated by five intervals of water supply: 0, 1, 2, 3, 4, 5, and 6 days. The experiments were carried out in a randomized complete block design with six replicates. The evaluated variables were: the photosynthetic rate (A; μmol CO2 m-2), stomatal conductance (gs; μmol H2O m-2 s-1), transpiration (E; mmol H2O m-2 s-1), number of leaves per plant, and dry matter of the roots, stems, leaves, and total. The results showed that the species of B. pilosa and B. subalternans tolerate low water availability conditions. Low stomatal opening and loss of leaves are mechanisms that ensure the survival of Bidens plants to the water deficit. However, water stress close to 25% of field capacity caused the death of species. The B. subalternans had higher sensitivity to the water deficit, showing a lower dry matter of leaf, stem, and root than B. pilosa.

ABSTRACT Cenostigma pyramidale, a pioneer species presents in all different successional stage (early, intermediate and late) of fifteen natural regeneration areas of Caatinga after land used changed and abandonment was used to investigates the morphological and physiological attributes that are very important to xeromorphic conditions as against herbivories. Leaf samples were collected to evaluate the percentage of the herbivory and index of sclerophylly. Anatomy, histochemistry, total phenolic content, epicuticular wax load, and n-alkanes profile were also performed. The results showed an inverse relationship between the percentage of herbivory and the index of sclerophylly. The leaves showed typical morphological and anatomical characteristics of xeric environments plants such as uniseriate epidermis and trichomes. Furthermore, it was also noticed a decrease in the overall thickness and the tissues according to the advancement of the successional stages. The histochemical revealed the presence of lipidic substances coating the epidermal layers, phenolics compounds stored in secretory structures, and starch in the mesophyll. The concentration of phenolics compounds indicating the difference from health leaves of plants between different stages of regeneration, but no difference when they were herbivored. The amount of cuticle wax did not change significantly with the successional stage. The profile of n-alkanes was characterized by the predominance of nonacosane (C29) and hentriacontane (C31). The C29 content decreases with the advancement of the successional stage, while the C31 content increases. All those attributes have a role to protect the plants to acclimate to the various environmental conditions of Caatinga.

ABSTRACT Using organic filters produced in local communities with low financial cost can reduce the environmental impacts caused by the disposal of untreated wastewater into receiving water bodies. In this study, the objective was to evaluate the efficiency of the filtration of swine wastewater (SWW) using banana stalk as an alternative material in an organic filter. SWW was applied to the organic filter and the filtered volume was converted into pore volume. Analyses of total solids, turbidity, color, total phosphorus, and total nitrogen were performed in the filter feed solution and effluent to evaluate treatment efficiency. Regression analyses were used to obtain equations in the estimation of the filtration performance in removing these variables from wastewater, with pore volume as an independent variable. The banana stalk filter did not remove total solids and color from the feed solution applied. Removal of 10–50% of SWW turbidity were obtained by the banana stalk. Banana stalk was highly efficient in removing nitrogen and phosphorus from SWW, reaching mean removals of 67% and 62%, respectively. In general, a banana stalk filter can be considered a promising alternative in the primary treatment of SWW.

ABSTRACT The lack of knowledge of the genetic parameters and the type of gene action results in difficulties to obtain varieties that combine agronomic and functional characteristics. The objective of this study was to determine the type of gene action associated with the contents of chlorophyll and agronomic characteristics in lettuce populations. The research was conducted at the Experimental Station of Vegetables, Monte Carmelo, Brazil. To perform the crosses and obtain the generations P1, P2, F1, F2, Bc1 and Bc2 the genotypes UFU-Albina#2, UFU-Albina#3, UFU-Lisa124#2#1, UFU-Crespa199#1#1 and UFU-Lisa217#5#2 were used as parents. The generations were evaluated for three characteristics: number of leaves, plant diameter and chlorophyll content. The parameters: genetic, phenotypic, environmental and additive variance, the dominance in F2, heritability in the broad and narrow-sense, the average degree of dominance based on averages, number of genes, the measure of the dominance deviations, additive effects and all interactions of ‘additive x additive’, ‘additive x dominant’ and ‘dominant x dominant’ type, were evaluated. Chlorophyll content was the most influenced by the environment. Plant diameter had the highest narrow-sense heritability for the cross UFU-Lisa-124#2#1 x UFU-Albina#3 (82.1%). The number of genes for the number of leaves varied from inconclusive to a minimum of 9 genes. The gene interactions for number of leaves were of overdominance type, while for plant diameter and for chlorophyll content the gene interactions were of partial dominance. The characteristics are suggested as being of polygenic or oligogenic nature.