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Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Cientifica is the property of Fundacao de Apoio a Pesquisa e Extensao and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Bioscience Journal is the property of Bioscience Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nativa is the property of Revista Nativa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The salinity of irrigation water is one of modern agriculture's major obstacles, as it can damage the plants metabolism and, consequently, its development. Currently there is a great demand for substances that may mitigate such effects, such as salicylic acid. Thus, this study aimed to evaluate the effects of salicylic acid application on watermelon plants (Citrullus lanatus L.) under salinity stress. The experimental design was a randomized block design, in an incomplete factorial scheme, with four replications and two plants per replicate. The treatments resulted from the combination of five concentrations of salicylic acid (0.00, 0.15, 0.50, 0.85 and 1.00 mM) and five electrical conductivities of the irrigation water (0.50, 1.01, 2.25, 3.49 and 4.00 dS m-1). The development, gas exchange, chlorophyll index and fluorescence were evaluated 30 days after transplanting. This data was submitted to analysis of variance and then confidence bands (confbands) and Pearson correlation were produced. The application of salicylic acid (up to 0.85 mM) promotes beneficial effects for the watermelon plants morphophysiology, while the increase in electrical conductivity of the irrigation water is harmful. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this study was to evaluate the photosynthetic and productive responses of the soybean inoculated with A. brasilense, via seed and foliar spray application of foliar spray application of plant regulators, submitted to severe drought. For this we used a randomized block design with five treatments and five replications: irrigated control, drought control, A. brasilense seed with drought, foliar spray A. brasilense with drought and foliar spray plant regulators (auxin, gibberellin and cytokinin - AX+GA+CK) with drought. The evaluations performed daily and after rehydration consisted of: relative water content (RWC), soil gravimetric moisture (Ug) and gas exchange. In severe drought the chlorophyll a fluorescence was evaluated, and at the moment of maturation, the number of pods per plant and grains per pod, mass of 100 grains and production. RWC and Ug did not show variations between treatments maintained in drought. In the gas exchanges the foliar spray application of A. brasilense assisted in the maintenance of CO2 assimilation and increased the water use efficiency. In relation to the production the foliar spray application of A. brasilense or AX + GA + CK softens the losses in drought conditions. It is concluded that the use of A. brasilense foliar or plant regulators alleviates losses in production when the incidence of drought in the flowering period. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Ciência Florestal (01039954) is the property of Ciencia Florestal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista IRRIGA - Brazilian Journal of Irrigation & Drainage is the property of Revista IRRIGA (Brazilian Journal of Irrigation & Drainage) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Basil (Ocimum basilicum L.) is one of the world's most widely cultivated medicinal herbs, but its physiological processes are affected by salinity. Therefore, mitigation strategies against the harmful effects of salt on plants have been increasingly on demand, including the use of salicylic acid. Thus, the effect of salicylic acid on the ecophysiology of basil plants grown under saline stress was evaluated in two different periods. The experimental design was the randomized complete block design using the Box Central Composite matrix with five irrigation water electrical conductivities (0.5, 1.3, 3.25, 5.2, 6.0 and dS m-1) and five doses of salicylic acid (0.0, 0.29, 1.0, 1.71 and 2.0 mM), with five replicates. Gaseous exchanges, fluorescence and chlorophyll content were evaluated at 30 and 60 days after irrigation with saline water started. Data were evaluated by analysis of variance and regression and by correlation analysis. The water electrical conductivity negatively affected the analyzed variables, while the salicylic acid had a positive effect. The highest correlation between the variables was obtained at 30 days after the irrigation with saline water started. Salicylic acid treatment up to the dose of 1.0 mM has a beneficial effect on basil plants. [ABSTRACT FROM AUTHOR]

Copyright of Revista IRRIGA - Brazilian Journal of Irrigation & Drainage is the property of Revista IRRIGA (Brazilian Journal of Irrigation & Drainage) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT Germination and seed vigor may be influenced by several factors, such as water stress during production, which affect crops differently according to the phenological stage of the plant. The aim of this study therefore was to evaluate the physiological quality of sesame seeds from plants subjected to water stress at different phenological stages. To this end, sesame plants were subjected to water stress at the following stages: I - germination to the start of vegetative growth (T1); II - vegetative growth to flowering (T2); III - flowering to pod formation (T3); IV - fruit maturation (T4); also for stress at all stages (T5) and full irrigation (T6). By weighing and daily irrigation of the containers, levels were kept at 50% of pot capacity (CV) for treatments with water deficit, and at 100% CV for treatments with no deficit. At 90 days after planting, the plants were harvested. The seeds were evaluated by germination test, first germination count, germination speed index, mean germination time, accelerated aging, electrical conductivity, seedling emergence, emergence speed index, mean time of emergence, seedling length and seedling dry weight. Sesame seeds from plants grown under water deficit display lower physiological quality. Between germination and the start of vegetative growth, and between flowering and fruit formation, the sesame is more sensitive to water stress, so that water limitation during these periods results in the production of seeds of low physiological quality.

Changes in spacing within rows may alter the morphology of the coffee plant by affecting the physiological constituents of its productivity. Even though some common plant responses to crop spacing variation are known, there is yet no scientific evidence that elucidates the effects of decreased spacing on the sourcesink relation in plagiotropic branches and, its association with both productivity and eco-physiological aspects of coffee leaves, mainly for new coffee cultivars in the Brazilian savannah. The aim of this work was to characterize the morphophysiological responses of Coffea arabica L. cultivars subjected to different spacing between plants within rows. Four Arabica coffee cultivars (Catuaí Vermelho IAC 144, Catuaí Amarelo IAC 62, Catuaí Amarelo IAC 32, and Tupi RN IAC 1669-13) were transplanted in January 2010. A row spacing of 0.40, 0.50, 0.60, 0.70, and 0.80 m was adopted between plants, maintaining a 3.80-m constant between rows. A randomized block design with four replicates was applied. During the experimental period, several morphophysiological characteristics of plagiotropic fruiting branches were evaluated in the months of April and December in 2013 and, in April 2014. The evaluation was conducted based on two canopy positions; canopy toward the rows, representing low exposure to light or toward the inter-row spacing, representing high light exposure. Leaf gas exchange, chlorophyll fluorescence, and photosynthetic pigments levels were minimally or not at all affected by changing either the coffee cultivars or plant spacing. During the first evaluation, the leaf-to-fruitratio linearly increased, regardless of the cultivar. Light-exposed branches showed higher content of carotenoids and chlorophyll a in leaves and lower leaf-to-fruit-ratio as compared to those within the plant canopy. A major reduction in the number of fruits per branch was observed which was closely related to a parallel decrease in the number of fruits per node but not in the number of fruiting nodes per branch. Although this response was largely cultivar-dependent, it also changed according to the branch position in the hedgerow. Our results suggest that all tested cultivars exhibit high morphophysiological plasticity and have the potential to grow under different plant spacing within rows.

Resumo: O objetivo deste trabalho foi caracterizar as variáveis fisiológicas e produtivas da videira 'Niágara Rosada' (Vitis labrusca) nos sistemas de condução em espaldeira e em Y, nos dois primeiros anos de produção. Nos ciclos produtivos de 2014 e 2015, avaliaram-se os seguintes parâmetros: índice de área foliar, fotossíntese, transpiração, condutância estomática, área de superfície foliar, variáveis de produção e qualidade do fruto. No primeiro ano de produção, houve diferenças entre os sistemas de condução quanto às variáveis ecofisiológicas influenciadas pela área de superfície foliar dos dosséis. No segundo ano de produção, não houve diferenças entre as variáveis ecofisiológicas. O número de cachos por área de superfície foliar, a massa do cacho, o número de bagas por cacho e a produção por planta não apresentaram diferenças entre os sistemas de condução. Videiras do primeiro e do segundo ano de produção não apresentaram diferenças entre os sistemas de condução, quanto às relações entre área de superfície foliar e produção; porém, a produtividade foi superior no sistema em espaldeira, em função do maior número de plantas por hectare. Frutos produzidos no sistema em Y apresentaram maior quantidade de pigmentos, como antocianinas e flavonóis, do que aqueles no sistema em espaldeira, com a mesma a quantidade de sólidos solúveis totais.

O rabanete (Raphanus sativus L.) é uma cultura de ciclo curto, que proporciona rápido retorno econômico ao produtor. Para seu cultivo qualificado, a definição de aspectos relacionados à implantação no campo, à escolha do espaçamento ideal de cultivo e da densidade de plantas por cova e ao entendimento de seus efeitos sobre a fisiologia da cultura ajudam na obtenção da máxima eficiência produtiva. Assim, o presente trabalho teve por objetivo avaliar o desempenho fisiológico do rabanete submetido a diferentes espaçamentos e densidades de plantas por cova. Para isso, realizou-se um experimento em delineamento em blocos ao acaso, com quatro repetições, em esquema fatorial 4 × 2. O primeiro fator foi composto por quatro diferentes espaçamentos entre plantas (0,05; 0,10; 0,15; 0,20 m) e o segundo, por duas densidades de plantas por cova de cultivo (uma e duas plantas por cova). Avaliou-se concentração interna de CO2, transpiração, condutância estomática, fotossíntese líquida, razão entre a concentração interna de CO2 e a ambiente, eficiência instantânea de carboxilação, fotossíntese bruta, clorofilas e área foliar. A densidade de duas plantas por cova combinada com maiores espaçamentos foram os fatores que proporcionaram os maiores valores de fotossíntese líquida e clorofila para as plantas. A densidade de uma planta por cova, combinada com espaçamentos de 0,05 a 0,15 m entre plantas, possibilitou a obtenção dos maiores valores de fotossíntese bruta e massa fresca de túberas. A densidade de uma planta por cova e o espaçamento de 0,05 m, por ter possibilitado maiores médias de produtividade, é a mais indicada para cultivo do rabanete.

Abstract Eugenia dysenterica DC is a fruiting species endemic to the Brazilian Cerrado, belonging to the Myrtaceae family and popularly known as Cagaiteira. It has medicinal and antifungal properties, and has an important function in the ecosystem. Nevertheless, there are few studies about the maintenance of this species. The aim of this study was to evaluate the growth, nutrition, quality and physiology of E. dysenterica seedlings grown in fine vermiculite and rice husk-based substrates in the following combinations: 1:0, 3:1, 1:1, and 1:3, in addition to Trimix® commercial substrate and vermiculite only. The physical attributes of substrates (dry and moist densities, available water, remaining water, aeration space and total porosity), seedling emergence percentage, emergence speed index, gas exchange, chlorophyll a fluorescence, relative seedling water content, relative substrate moisture content, plant biometric growth characteristics, accumulated dry weight and nutritional status were evaluated through leaf macronutrient content 128 days after emergence. The increase in the proportion of rice husk mixed with vermiculite resulted in reduction of the dry and moist densities of substrates, available water, remaining water, total porosity and moisture content, and increased the aeration space in substrates. The fine vermiculite substrate promoted the highest Dickson’s quality index and the greatest stem diameter of plants. Seedlings grown on vermiculite substrate presented higher N and K content in leaves, and those grown in Trimix® substrate showed higher leaf Mg content. Substrates did not alter the physiological attributes of seedlings.

Este estudo teve o objetivo de avaliar as respostas ecofisiológicas do juazeiro (Ziziphus joazeiro Martius) em condições de campo em duas ecorregiões do estado de Sergipe, Brasil, em diferentes períodos sazonais. Para isto, avaliou-se: fotossíntese líquida (A), condutância estomática (gs), transpiração (E) e a fluorescência da clorofila a. A taxa de fotossíntese (A) foi maior na ecorregião Agreste no período chuvoso e menor no Sertão no período de estiagem. A gs foi maior nos horários que o déficit de pressão de vapor (VPD) foi menor, mantendo a taxa de assimilação do CO2 e evitando a perda excessiva de água pela transpiração (E). Em relação à fluorescência da clorofila a, verificou-se que os indivíduos apresentaram valores dentro do normal, não indicando condição de estresse, embora no período seco no Sertão tenha havido diminuição na eficiência do fotossistema II, com consequente diminuição no Índice de performance e no pool de elétrons transportados pelo centro de reação do PSII. Esta espécie apresenta estratégias de sobrevivência, mantendo seu aparato fotossintético funcionando mesmo durante períodos de estiagem.

ABSTRACT Sorghum arundinaceum (Desv.) Stapf is a weed that belongs to the Poaceae family and is widespread throughout Brazil. Despite the frequent occurrence, infesting cultivated areas, there is little research concerning the biology and physiology of this species. The objective of this research was to evaluate the growth, carbon partitioning and physiological characteristics of the weed Sorghum arundinaceum in greenhouse. Plants were collected at regular intervals of seven days, from 22 to 113 days after transplanting (DAT). In each sample, we determined plant height, root volume, leaf area and dry matter, and subsequently we perfomed the growth analysis, we have determined the dry matter partitioning among organs, the accumulation of dry matter, the specific leaf area, the relative growth rate and leaf weight ratio. At 36, 78 and 113 DAT, the photosynthetic and transpiration rates, stomatal conductance, CO2 concentration and chlorophyll fluorescence were evaluated. The Sorghum arundinaceum reached 1.91 in height, with slow initial growth and allocated much of the biomass in the roots. The photosynthetic rate and the maximum quantum yield of FSII are similar throughout the growth cycle. At maturity the Sorghum arundinaceum presents higher values of transpiration rate, stomatal conductance and non-photochemical quenching coefficient (NPQ).

Eucalyptus requires large amounts of nitrogen (N); however, it responds in diverse manners to the application of this nutrient. The aim of this study was to evaluate the differential performance in growth, mineral nutrition, and gas exchanges of N-fertilized Eucalyptus clones. The treatments consisted of two Eucalyptus clones (VM-01 and I-144) and six N application rates (0, 0.74, 2.93, 4.39, 5.85, and 8 mmol L-1 NH4NO3) arranged in a randomized complete block design with five replications. VM-01 had greater plant height and greater height/collar diameter ratio, as well as higher leaf concentrations of all macronutrients and of Cu, Fe, Mo, and Zn. In terms of total and root dry matter production, root/shoot ratio, and collar diameter, as well as stomatal conductance and transpiration, I-144 performed better. The performance of the clones was clearly differentiated, and the growth of I-144, despite lower leaf N concentration, was in general better than VM-01.

Copyright of Revista Ambiente e Água is the property of Revista Ambiente e Agua and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The cv. Bordô grapevine (Vitis labrusca L.) is characterized by rusticity and greater resistance to fungal diseases, good adaptability to climatic changes and good aptitude for the production of juices and wines. However, many of these characteristics can also be influenced by the rootstock. Thus, this work aimed to evaluate the effect of diurnal and rootstock variation on the photosynthetic capacity and stomatal conductance of Bordô vine. The experiment was carried out in a randomized complete block design, in a factorial arrangement with time subdivided plots, the IAC 572, IAC 766 and 1103 Paulsen rootstocks were used in the period from 08:00 to 16:00 h with intervals of 2 h in 2 evaluation periods, the months of April and May, using three replicates and four plants per experimental unit. The rate of liquid photosynthesis (Pn), leaf stomatal conductance (gs), vapor pressure deficit and photosynthesis were evaluated. The rootstocks IAC 572 Jales, IAC 766 Campinas and 1103 Paulsen, did not alter the net photosynthesis rate and leaf stomatal conductance of cv. Bordô, in both periods evaluation. The period of greatest photosynthetic rate and higher stomatal conductance of leaves is given in the morning. However, both decreases as the air temperature and vapor pressure deficit increase, as well as the reduction of the relative humidity of the air. The best time interval for evaluating the net photosynthesis rate for cv. Bordô is between 9 h and 11 h, since the conditions in this time frame are more suitable for photosynthesis. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Agricultura Irrigada - RBAI is the property of Revista Brasileira de Agricultura Irrigada - RBAI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Agricultura Irrigada - RBAI is the property of Revista Brasileira de Agricultura Irrigada - RBAI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Photosynthesis of species of Anibae in response to the exposure to contrasting light environments. Ecophysiological traits and the light environment have implications for the establishment of forest plantations. The aim of this study was to investigate the photosynthetic activity of Aniba canelilla and A. rosaeodora in response to changes in the availability of light in the field. Gas exchange, content of chlorophylls (ICC) and photochemical performance (FV/FM) were measured in leaves acclimated in the shade during 300 days, after in the full sun (28 days) and again in the shade by 28 days. The photosynthesis, ICC and FV/FM of A. canelilla and A. rosaeodora were negatively affected in full sunlight, but the plants recovered when submitted to shade. Photosynthesis, ICC and FV/FM were twice as high in shade plants. Aniba rosaeodora presented photosynthetic performance twice higher than A. canelilla. Differences in photosynthetic responses to light suggest that species could occupy different succession “niches” in enrichment plantation, and plasticity (recovery-mediated) implies acclimatization under variable light environments. The fact that the studied species of Anibae have differences in plasticity for light should be viewed with caution to suggest conventional plantations, but it reinforce the indication for enrichment plantations in forest sites with variations in the availability of light. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Agricultura Irrigada - RBAI is the property of Revista Brasileira de Agricultura Irrigada - RBAI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Agricultura Irrigada - RBAI is the property of Revista Brasileira de Agricultura Irrigada - RBAI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

O objetivo deste trabalho foi avaliar o efeito de diferentes períodos de imposição do deficit hídrico sobre a concentração da florada do cafeeiro (Coffea arabica), bem como sobre as trocas gasosas, a produtividade, a maturação e a qualidade dos grãos. As cultivares Catuaí Vermelho IAC 144 e Bourbon Amarelo J9 foram avaliadas conforme os seguintes tratamentos: não irrigado (NI), irrigado continuamente (IC), e suspensão da irrigação em 1/7/2010 (D1) e em 1/8/2010 (D2), com retorno desta em 24/9/2010. Cerca de três dias após a retomada da irrigação, registrou-se a ocorrência de uma "chuva de florada", com precipitação de 69 mm. O potencial hídrico foliar de antemanhã (Ψam) nas cultivares Catuaí Vermelho IAC 144 e Bourbon Amarelo J9, em 22/9, foi de -0,59 e -0,82 MPa, -0,53 e -0,79 MPa, e -0,34 e -0,49 MPa, para os tratamentos NI, D1 e D2, respectivamente. O percentual máximo de botões florais no estádio E4, imediatamente antes da ocorrência da chuva, não foi afetado pelos níveis de deficit impostos durante o inverno, independentemente das cultivares. Os níveis moderados de deficit hídrico impostos pelos tratamentos (Ψam ~ -0,80 MPa) produziram pouco ou nenhum efeito sobre as trocas gasosas, a taxa de florescimento ou a uniformidade de maturação - percentagem de cerejas de 66% -, e a produtividade e a classificação dos grãos, de ambas as cultivares. O efeito dos diferentes tratamentos sobre o status hídrico dos botões florais não se sobrepõe ao efeito da chuva de florada, que foi determinante para sua abertura.

A interferência das plantas daninhas, afeta os parâmetros de fisiológicos da cultura do feijão-caupi, com reflexo direto no crescimento e na produtividade. Assim, objetivou-se avaliar a atuação de métodos de controle das plantas daninhas na cultura do feijão-caupi, identificando o mais eficiente, por meio do acompanhamento dos componentes de crescimento, sendo estes compostos de altura (cm), número de folhas, diâmetro do caule (mm) e os aspectos fisiológicos da cultura, pela coleta de dados da taxa de assimilação de CO2 (μmol m-2 s-1), transpiração (mmol de H2O m-2 s-1), condutância estomática (mol de H2O m-2 s-1) e concentração interna de CO2, com um analisador de gás infravermelho . O experimento foi realizado em condições de campo no Centro de Ciências e Tecnologia Agroalimentar da Universidade Federal de Campina Grande, Campus Pombal, Paraíba. O delineamento experimental utilizado foi o de blocos ao acaso com oito tratamentos e quatro repetições em esquema fatorial 2 x 4, sendo os fatores: dois cultivares de feijão-caupi (BRS Marataoã e BRS Rouxinol) e quatro manejos das plantas daninhas (mecânico, químico, físico e sem controle). Os manejos químico, mecânico e físico, mostram-se superiores nos componentes de crescimento, não afetando tais características, sendo as trocas gasosas severamente afetadas. Physiological performance and growth of cowpea under weed management Abstract: The interference of weeds affects the physiological parameters of cowpea culture, with direct reflection on growth and productivity. The objective of this study was to evaluate the performance of different weed control methods in cowpea culture in order to identify the most efficient by monitoring the growth components, being these compounds of height (cm), number of leaves and diameter of the stem (mm) and the physiological aspects of the culture, by collecting data: CO2 assimilation rate (μmol m-2 s-1), transpiration (mmol H2O m-2 s-1), Stomatal conductance (mol of H2O m-2 s-1) and internal CO2 concentration, with an infrared gas analyzer. The experiment was accomplished under field conditions at the Center for Agro-Food Science and Technology of the Federal University of Campina Grande, Campus Pombal, Paraíba . The experimental design was a randomized complete block design with eight treatments and four replications in a 2 x 4 factorial scheme, being these factors: two cultivars of cowpea (BRS Marataoã and BRS Rouxinol) and four weed management (mechanical, chemical , Physical and uncontrolled). Chemical, mechanical and physical management are shown to be superior in the growth components, not affecting these characteristics, being the gas exchanges severely affected.

O objetivo deste estudo foi investigar o efeito do magnésio (Mg) sobre os parâmetros de trocas gasosas da fotossíntese [assimilação líquida de CO2 (A), condutância estomática (gs) e concentração interna de CO2 (Ci)], dos parâmetros de fluorescência da clorofila (Chl) a {fluorescência mínima (F0), fluorescência máxima (Fm), rendimento quântico do fotossistema II (Fv/Fm), coeficiente de extinção fotoquímica (qp), rendimento da fotoquímica [Y(II)], rendimento de dissipação de energia regulado [Y(NPQ)] e o rendimento das perdas de dissipação não reguladas [Y(NO)]}, bem como sobre as concentrações de pigmentos cloroplastídicos em plantas de arroz cultivadas em solução nutritiva contendo 0,5 ou 1,5 mM de Mg (-Mg ou +Mg nas plantas, respectivamente). As plantas com + Mg apresentaram aumento do desempenho fotossintético em relação as plantas com - Mg. O aumento do desempenho fotossintético promovido por + Mg esteve associado aos incrementos nos pigmentos cloroplastídicos, no aumento de A e do rendimento quântico fotoquímico da fotossíntese, demonstrado por qp e Y(II).

O objetivo deste estudo foi investigar as respostas fotossintéticas em folhas de café arábica submetido ao déficit hídrico, utilizando para isso, os parâmetros de trocas gasosas da fotossíntese [assimilação líquida de CO2 (A), condutância estomática (gs), taxa de transpiração (E) e concentração interna de CO2 (Ci)], as concentrações de pigmentos cloroplastídicos e o extravasamento de eletrólitos (EE) em folhas de plantas cultivadas a 30, 60 e 100% de água disponível (AD) no substrato. De acordo com os resultados obtidos foi verificado que os déficits hídricos afetaram negativamente a fotossíntese das plantas, ocasionando decréscimos significativos em gs, os quais, estiveram associados a diminuição nos valores de A. À medida que se intensificou o déficit hídrico foi encontrado redução nos teores das clorofilas e danos as membranas celulares.

Natural ventilation system facilitates gaseous exchanges in in vitro plants promoting changes in the leaf tissue, which can be evaluated through the leaf anatomy, and it allows a cultivation closer to the photoautrophic micropropagation. The objective of this work was to evaluate the effects on in vitro growth and on the leaf anatomy of Cattleya walkeriana grown in natural and conventional ventilation system with different concentrations of sucrose (0; 15; 30 and 45 L-1) combined with different cultivation systems (conventional micropropagation and natural ventilation system). The culture medium was composed of MS salts, solidified with 7 g L-1 of agar and pH adjusted to 5.8. Forty milliliters of culture medium were distributed in 250 mL flasks, autoclaved at 120 ºC for 20 minutes. The greater plant growth, as well as the greater thickness of the mesophyll was observed with the use of 20 g L-1 sucrose in natural ventilation system. Plants grown in natural ventilation system showed a thicker leaf mesophyll, which is directly related to photoautotrophic crops. The natural ventilation system induced more elliptical stomata and probably more functional formats.

This study aimed to evaluate the phytotoxicity of the mesotrione herbicide in the initial development of maize inoculated with Azospirillum brasilense and associated with nitrogen fertilization. The treatments were: randomized blocks in a 2x3 factorial scheme, represented by maize with and without mesotrione application (192 g ha-1) and treatments: 1-inoculation of the seeds with A. brasilense; 2-Application in coverage of 140 kg ha-1 of N; And 3- A. brasilense + 140 kg ha-1 of N in cover applied at 26 days after sowing (DAS). The application of mesotrione was performed at 21 DAS, with evaluations performed up to 28 days after application (DAA). At 7 DAA a reduction of the net assimilation rate of CO2 in 35% in the plants with mesotrione was observed, as well as increase of the peroxidases activity and greater degradation of carotenoids in the mesotrione plants. At 14 DAA the mesotrione reduced the rate of CO2 net assimilation and transpiration, while at 28 DAA, lower plant height, leaf area and shoot dry mass were verified in herbicide plants. The inoculation with A. brasilense + N increased peroxidase activity at 7 DAA and helped maintain the transpiratory rate at 14 DAA. It is concluded that inoculation with A. brasilense + N can minimize the harmful effects caused by mesotrione in the initial development of corn. [ABSTRACT FROM AUTHOR]