RESUMO Plantas cultivadas sob salinidade estão sujeitas a muitos distúrbios morfológicos e fisiológicos. Neste sentido, práticas que possam viabilizar o uso de águas salinas são essenciais. Os efeitos deletérios da salinidade podem ser mitigados ao utilizar microrganismos benéficos, especialmente bactérias diazotróficas. Nesse contexto, objetivou-se avaliar o efeito da inoculação e co-inoculação bacteriana utilizando Bradyrhizobium spp. e Azospirillum brasilense no crescimento, nodulação e produção de feijão-caupi sob estresse salino. O experimento foi conduzido em blocos casualizados, em arranjo fatorial 4 × 5, sendo quatro fontes de nitrogênio (F1 - sem nitrogênio e sem inoculante; F2 - adubação com nitrogênio mineral e sem inoculante; F3 - inoculação de Bradyrhizobium ssp. e F4 - coinoculação de Bradyrhizobium ssp. e Azospirillum brasilense) e cinco valores de condutividade elétrica da água de irrigação - CEa (0,4; 1,9; 3,4; 4,9 e 6,4 dS m-1), com cinco repetições. A coinoculação com Azospirillum brasilense e Bradyrhizobium favoreceu o crescimento, a produção e a nodulação de plantas de feijão caupi quando irrigadas até CEa de 0,4 dS m-1. O aumento da condutividade elétrica da água de irrigação afetou negativamente o crescimento, a produção e a nodulação de plantas de feijão Caupi da variedade Corujinha independentemente da fonte de nitrogênio utilizada.

ABSTRACT Plants grown under salinity are subject to many morphological and physiological disorders. In this context, practices that can enable the use of saline water are essential. The deleterious effects of salinity can be mitigated by using beneficial microorganisms, especially diazotrophic bacteria. In this context, this study aimed to evaluate the effect of bacterial inoculation and co-inoculation using Bradyrhizobium spp. and Azospirillum brasilense on the growth, nodulation and production of cowpea under salt stress. The experiment was conducted using a randomized block design, in a 4 × 5 factorial arrangement, corresponding to four nitrogen sources (N1 - without nitrogen and without inoculant; N2 - fertilization with mineral nitrogen and without inoculant; N3 - inoculation of Bradyrhizobium spp.; and N4 - co-inoculation of Bradyrhizobium spp. and Azospirillum brasilense) and five values of electrical conductivity of irrigation water - ECw (0.4, 1.9, 3.4, 4.9 and 6.4 dS m-1), with five replicates. Co-inoculation with Azospirillum brasilense and Bradyrhizobium spp. favors the growth, production and nodulation of cowpea plants up to ECw of 0.4 dS m-1. Increase in the electrical conductivity of irrigation water negatively affects the growth, production and nodulation of cowpea plants in Corujinha variety, regardless of the nitrogen source used.

ABSTRACT The Caatinga biome in Brazil comprises the largest and most continuous expanse of the seasonally dry tropical forest (SDTF) worldwide; nevertheless, it is among the most threatened and least studied, despite its ecological and biogeographical importance. The spatial distribution of volumetric wood stocks in the Caatinga and the relationship with environmental factors remain unknown. Therefore, this study intends to quantify and analyze the spatial distribution of wood volume as a function of environmental variables in Caatinga vegetation in Bahia State, Brazil. Volumetric estimates were obtained at the plot and fragment level. The multiple linear regression techniques were adopted, using environmental variables in the area as predictors. Spatial modeling was performed using the geostatistical kriging approach with the model residuals. The model developed presented a reasonable fit for the volume m3 ha with r2 of 0.54 and Root Mean Square Error (RMSE) of 10.9 m3 ha–1. The kriging of ordinary residuals suggested low error estimates in unsampled locations and balance in the under and overestimates of the model. The regression kriging approach provided greater detailing of the global wood volume stock map, yielding volume estimates that ranged from 0.01 to 109 m3 ha–1. Elevation, mean annual temperature, and precipitation of the driest month are strong environmental predictors for volume estimation. This information is necessary to development action plans for sustainable management and use of the Caatinga SDTF in Bahia State, Brazil.

Resumen La selva amazónica presenta diferentes estratos forestales, debido a su estructura heterogénea. En el que estos estratos pueden variar en altos, medios y bajos. El conocimiento de los diferentes patrones de estructuras verticales que se encuentran en el bosque es extremadamente importante para comprender la dinámica de la vegetación, lo que influye en las estrategias de conservación del bosque. Con el fin de optimizar el proceso de clasificación de los diferentes tipos de estratos, el objetivo del presente trabajo fue utilizar redes neuronales artificiales (RNA) para clasificar estos estratos. Se utilizaron dos algoritmos de resilient propagation (Rprop+ y Rprop-), en cuatro configuraciones diferentes de variables de entrada. El entrenamiento y la prueba de los ocho modelos de RNAs se realizaron utilizando el software R. Los modelos se evaluaron mediante una matriz de confusión. En qué modelos con entradas: HT, DAP y QF; HT, DAP y solo HT del algoritmo Rprop + obtuvieron 100% de aciertos en la clasificación de estrato, presentando una alta tasa de aprendizaje, confiabilidad y generalización de datos.

Abstract The Amazon forest presents different forest strata, due to its heterogeneous structure. In which these strata can vary in upper, middle and lower. Knowledge about the different patterns of vertical structures found in the forest is extremely important for understanding the vegetation dynamics, influencing forest conservation strategies. In order to optimize the process of classifying the different types of strata, the objective of the present work was to use artificial neural networks (ANNs) to classify these strata. Two resilient propagation algorithms (Rprop + and Rprop-) were used, in four different configurations of input variables. The training and testing of the eight RNA models were performed using the R software. The models were evaluated using a confusion matrix. In which models with inputs: HT, DAP and QF; HT, DAP and only HT from the Rprop + algorithm obtained 100% correct answers in the classification of strata. Demonstrating a high rate of learning, reliability and generalization of data.

ABSTRACT The distribution modeling in diameter classes is an important indicator of the potential use of a forest community, as well as the projection of future forest production. The objective of this study was to evaluate the diametric structure and to select probabilistic density functions for three woody species in forested arboreal Caatinga vegetation in Bahia, Brazil. The study was carried out in the Contendas do Sincorá National Forest in the state of Bahia, Brazil. A total of 16 plots of 20 x 20 m were installed and all individuals with diameter at breast height equal to or greater than 5.0 cm were measured. The three species with the highest population density (Commiphora leptophloeos, Manihot catinga and Patagonula bahiensis) were selected for analysis and modeling of the diametric structure. Four probabilistic density models were adjusted. The Akaike information criterion was used to select the best model. The results found indicated that the three species presented a decreasing type curve. The Log-Normal function best described the diametric distribution and it can be indicated to describe the diametric distribution and assist in making decisions about the management and conservation of these species. It is concluded that the Normal function was less adequate to represent the distribution of the studied species.

RESUMO Objetivou-se avaliar as trocas gasosas de mudas de maracujá Redondo Amarelo sob a ação mitigadora da adubação nitrogenada sobre a salinidade da agua de irrigação. O experimento foi conduzido em casa de vegetação da Universidade Federal de Campina Grande, Campus Pombal, PB. O delineamento experimental foi em blocos casualizados, parcelas subdivididas, compreendendo cinco condutividades elétricas da água de irrigação (parcela) (CEa) (0.3; 1.0; 1.7; 2.4 e 3.1 dS m-1) e cinco doses de nitrogênio (subparcela) (60; 80; 100; 120 e 140% de 300 mg de N dm-3), em cinco blocos. As plantas foram cultivadas em citropotes com volume de 3.780 mL, preenchidos com solo, esterco bovino curtido e maravalha na proporção de 2:1:0,5 (base massa), respectivamente. A aplicação dos níveis de salinidade ocorreu no período de 40 a 85 dias após a semeadura. Mensurou-se, aos 55 e 70 dias após a semeadura a concentração interna de CO2, transpiração, condutância estomática e fotossíntese. Verificou-se efeito atenuante das doses de nitrogênio para as águas de irrigação de 1.7 e 2.4 dS m-1 sobre a fotossíntese aos 55 dias. A salinidade da água de irrigação reduz a maioria das variáveis avaliadas, sobretudo no maior nível estudado (3.1 dS m-1).

ABSTRACT The objective of this study was to evaluate the gas exchange of ‘Redondo Amarelo’ passion fruit seedlings under the mitigating action of nitrogen fertilization on the salinity of irrigation water. The experiment was carried out in a greenhouse of the Universidade Federal de Campina Grande (CCTA-UFCG), Campus of Pombal, PB, Brazil, The experimental design was in randomized blocks, split plots, comprising five irrigation water electrical conductivities (plot) (ECw) (0.3; 1.0; 1.7; 2.4 and 3.1 dS m-1) and five doses of nitrogen (subplot) (60; 80; 100; 120 and 140% of 300 mg of N dm-3), in five blocks. Plants were grown in pots (Citropote JKS®) with volume of 3.780 mL, filled with soil, bovine manure, wood shavings in a proportion of 2:1:0.5 (mass basis), respectively. Water with salinity levels was applied in the period from 40 to 85 days after sowing. The internal CO2 concentration, transpiration, stomatal conductance and photosynthesis were measured at 55 and 70 days after sowing. There was an attenuating effect of nitrogen doses at irrigation water electrical conductivities of 1.7 and 2.4 dS m-1 on photosynthesis at 55 DAS. Irrigation water salinity reduces most of the variables evaluated, especially at the highest level studied (3.1 dS m-1).

ABSTRACT Dynamics studies associated with prognosis can support planning actions for the conservation and sustainable use of forest resources. Therefore, the objective of this study was to evaluate the dynamics and predict the diameter structure using the Markov chain model for an area of caatinga forest submitted to different management practices. The study was carried out in the Contendas do Sincorá National Forest in the state of Bahia. Four treatments were installed, corresponding to three management systems and one control. Data was obtained measuring all individuals with a diameter greater than or equal to 5 cm. The measurements were performed at two moments in 2015 and 2018. The results indicated that the selective cut-by-diameter treatment had the lowest mortality rate and the highest recruitment rate. Predictions of the diameter structure using the Markov chain do not generally present statistical differences (α0.01) between the observed and expected frequencies for the year 2018. It was concluded that the basal area showed a tendency for recovery and growth in the treatments which involved suppression compared to the control, with no statistically significant differences among treatments until the moment after intervention.

Resumo O objetivo deste trabalho foi avaliar os efeitos de brassinosteroide sobre os parâmetros de fluorescência da clorofila a, o índice SPAD e a suculência foliar em plantas jovens de tomate (Lycopersicon esculentum) sob estresse salino. O delineamento experimental utilizado foi o em blocos ao acaso, em arranjo fatorial 5×2 - cinco níveis de salinidade da água (0,5, 1,5, 3,0, 4,5 e 6,0 dS m-1) × duas doses de 24-epibrassinolídeo (0 e 10-6 mol L-1 de EBL). Aos 23 dias, o tratamento sem EBL mostrou que o aumento da salinidade da água reduziu a eficiência fotoquímica máxima, primária e efetiva do PSII, assim como a taxa de transporte de elétrons, o índice SPAD, a suculência foliar, a massa de matéria seca total e o índice de tolerância ao estresse, mas aumentou a fluorescência inicial e o excesso relativo de energia no PSII. Com o aumento da salinidade, nos tratamentos com EBL, houve aumento da eficiência efetiva do PSII, da taxa de transporte de elétrons, do índice SPAD, da suculência foliar, da matéria seca total e do índice de tolerância ao estresse. O epibrassinolídeo promove efeitos benéficos sobre a integridade do PSII, o índice de clorofila e a suculência foliar em plantas jovens de tomate submetidas a níveis de até salinidade 6,0 dS m-1.

Abstract The objective of this work was to evaluate the effects of brassinosteroid on chlorophyll a fluorescence parameters, the SPAD index, and leaf succulence in young tomato (Lycopersicon esculentum) plants under salt stress. The experimental design was a randomized complete block, in a 5×2 factorial arrangement - five levels of water salinity (0.5, 1.5, 3.0, 4.5, and 6.0 dS m-1) × two rates of 24-epibrassinolide (0 and 10-6 mol L-1 EBL). At 23 days, the treatment without EBL showed that the increase of water salinity reduced the maximum, primary, and effective photochemical efficiency of PSII, as well as the electron transport rate, the SPAD index, leaf succulence, total dry mass, and the stress tolerance index, but increased initial fluorescence and relative excess energy in PSII. With the increase of water salinity, in the EBL treatments, there was an increase in the effective photochemical efficiency of PSII, the electron transport rate, the SPAD index, leaf succulence, total dry mass, and the stress tolerance index. EBL promotes beneficial effects on PSII integrity, the chlorophyll index, and leaf succulence in young tomato plants subjected to salinity levels of up to 6.0 dS m-1 .

ABSTRACT Warm mixtures are an essential alternative for paving as they minimize costs and environmental impacts, and their performance is similar to hot mixtures. This research evaluated the effect of adding linseed oil obtained from Linum usitatissimum in the contents of 1, 2, 3, 4, 5, and 6% by weight on the physical and rheological properties of the asphalt binder. The asphalt binder was evaluated through tests of penetration, softening point, rotational viscosity, performance grade (PG); these tests were performed before and after the short-term aging procedure; multiple stress creep and recovery (MSCR), and linear amplitude sweep (LAS). It has been verified that the mixing temperature could be reduced by up to 15 °C for the 6% linseed oil content, but it was lost in terms of performance, level of supported traffic, and fatigue life. In the so-called ideal content found, 4% linseed oil, there is a reduction in the mixing temperature of around 10 °C, as well as a maximum temperature of PG, 58 °C, it reduces by only one step compared to the pure binder, 64 °C, in addition to presenting the second-longest fatigue life of the grades studied, being classified as ideal for standard traffic by the MSCR test. Linseed oil proved to be an excellent green alternative for the production of warm mixtures.

Abstract The objective of this work is to investigate the conversion of spent coffee grounds (SCG) into biochar (BSC) and the ecotoxicological effects of the product obtained. The SCG and BSC were characterized by characterized by different techniques (TGA/DTG, FTIR, XRD, SEM, EDS, and EDXRF). Proton Nuclear Magnetic Resonance (1H NMR) was used to characterize the aqueous extract of BSC. The inhibitory effect on lettuce (Lactuca sativa) germination was investigated. Besides, antimicrobial activity evaluation trials were conducted with Azospirillum brasilense and Trichoderma spp. The results showed that in the BSC production process, the extractives and lignocellulosic components in the SCG were partly decomposed. Tests conducted with microorganisms did not reveal any toxic effect of BSC. However, high phytotoxicity against lettuce was recorded for rate 100 t/ha of BSC. This effect was associated with the presence of carboxylic acids identified by 1H NMR in the BSC extract aqueous.

ABSTRACT. Salinity is one of the environmental stresses that most cause losses in agricultural systems, including tomato production. Brassinosteroids, such as epibrassinolide (EBL), have multiple actions in essential processes in plants. Thus, the objective of this study was to evaluate the contributions of EBL to the growth, physiology, and production of tomato plants under salinity. The experiment was conducted in a factorial scheme, with five levels of water salinity (0.5 [the control], 1.5, 3.0, 4.5, and 6.0 dS m-1) and two concentrations of EBL (0 and 10-6 M). Salt stress reduced tomato growth, relative water content, membrane integrity, gas exchange, and fruit production. However, the exogenous application of EBL attenuated the adverse effects, partially improving these characteristics at all salinity levels. EBL reduced electrolyte leakage and increased membrane integrity and relative water content in control and stressed plants. Additionally, it increased the content of photosynthetic pigments, stomatal conductance, transpiration, and photosynthesis, which led to higher leaf dry mass production, fruit transverse diameter, and production per plant. Therefore, our results confirmed that foliar application of EBL improved the characteristics of stressed and non-stressed tomato plants.

RESUMO O girassol ornamental tem grande importância no setor de floricultura devido a cor e exuberância de suas flores. Porém, sua produção e qualidade das flores diminuem sob estresse salino, o qual pode ser atenuado com a aplicação de paclobutrazol. O objetivo foi avaliar os efeitos de diferentes métodos de aplicação de paclobutrazol em girassol ornamental ‘Sol Noturno’ irrigado com águas salobras. O delineamento experimental consistiu em blocos casualizados em esquema fatorial 5 × 3, correspondendo a cinco condutividades elétricas da água de irrigação - CEa (0,4; 1,9; 3,4; 4,9 e 6,4 dS m-1) e três métodos de aplicação de paclobutrazol (aplicação foliar, via solo e uma testemunha - sem paclobutrazol), com quatro repetições. O aumento da salinidade da água de irrigação reduziu as trocas gasosas, eficiência efetiva do fotossistema II, índice SPAD, altura de plantas e diâmetros do capítulo. A aplicação de paclobutrazol na folha e via solo aumentou a condutância estomática e a transpiração por 21,09 e 17,80%, respectivamente, em relação às plantas sem aplicação, enquanto a fotossíntese e eficiência instantânea de carboxilação aumentaram 28,33 e 31,18% via solo, e 14,40 e 16,12% via foliar, respectivamente. A aplicação de paclobutrazol, principalmente via solo, favoreceu as plantas de girassol ‘Sol Noturno’ sob estresse salino, aumentando o índice de clorofila SPAD e o diâmetro externo do capítulo, e mantendo o número de pétalas.

ABSTRACT The ornamental sunflower has great importance in the floriculture sector due to the color and vitality of its flowers. However, the production and quality of flowers decrease under salt stress, which can be mitigated with paclobutrazol application. The objective of the present study was to evaluate the effects of different application methods of paclobutrazol in ornamental sunflower ‘Sol Noturno’ irrigated with brackish waters. The experimental design was randomized blocks arranged in a 5 × 3 factorial scheme, corresponding to five electrical conductivities of irrigation water - ECw (0.4; 1.9; 3.4; 4.9, and 6.4 dS m-1) and three paclobutrazol application methods (foliar application, via soil and a control treatment - without paclobutrazol), with four replicates. The increase in salinity of irrigation water reduced gas exchange, photosystem II photochemical efficiency, SPAD index, plant height, and chapter diameter. The paclobutrazol application via soil or foliar increased stomatal conductance and transpiration by 21.09 and 17.80%, respectively, in comparison to plants without application, whereas photosynthesis and instantaneous carboxylation efficiency increased by 28.33 and 31.18% via soil and 14.40 and 16.12% via foliar, respectively. The paclobutrazol application, mainly via soil, favored ‘Sol Noturno’ sunflower plants under salt stress, increasing chlorophyll SPAD index and external chapter diameter, and keeping the number of the petals.

Resumen Los herbicidas inhibidores de la ALS en combinación con inhibidores de la ACCase pueden ser utilizados como alternativa al glifosato en el control de malezas en soya RR2/STS. En el presente estudio se evalúa la eficacia de herbicidas inhibidores de la ALS, en asociación con haloxyfop, en el control de malezas para aplicación en post-emergencia (V4) de soya RR/STS. El experimento se realiza en la campaña 2017/18 en Piracicaba, Sao Paulo (SP), Brasil. Se utiliza el cultivar BMX Garra RR2/STS y los tratamientos fueron compuestos por la aplicación de herbicidas inhibidores de la ALS en asociación con haloxyfop. El diseño experimental fue de bloques al azar, con cuatro repeticiones. Se evaluaron control y masa seca de malezas, nivel de daño en las plantas de soya y productividad. Los datos fueron sometidos al análisis de varianza y las medias de los tratamientos fueron comparados por el test de Tukey. Se observaron síntomas visuales de daño en las plantas de soja, principalmente para aplicación de nicosulfuron y nicosulfuron + cloransulam. La productividad fue mayor en todos los tratamientos con herbicidas en comparación con el control sin deshierbe manual. Las asociaciones entre herbicidas inhibidores de la ALS y haloxyfop aplicadas en post emergencia (V4) del cultivar de soya BMX Garra RR2/STS fueron eficaces en el control de malezas.

Abstract It is believed that ALS inhibitor herbicides in combination with ACCase inhibitors can be used as an alternative to glyphosate in weed control in RR2/STS soybeans. In the present study, the efficacy of ALS inhibitor herbicides, in combination with haloxyfop, is evaluated in the control of weeds for post- emergence application (V4) of RR/STS soybeans. The experiment is carried out in the 2017/18 season in Piracicaba, Sao Paulo (SP), Brazil. The cultivar BMX Garra RR2/STS is used, and the treatments were composed by the application of ALS inhibitor herbicides in association with haloxyfop. The experimental design was a randomized block with four replications. Were evaluated control and dry mass of weeds, symptoms of injury in soybean plants and yield. The data were submitted to analysis of variance and the means of the treatments were compared by the Tukey test. Visual symptoms of injury were observed in soybean plants, mainly for the application of nicosulfuron and nicosulfuron + cloransulam. Soybean yield was higher in all herbicide treatments compared to the control without weeding. Associations between ALS inhibitor herbicides and haloxyfop applied post-emergence (V4) of soybean cultivar BMX Garra RR2/ STS were effective in weed control.

RESUMO A produção agrícola tem se tornado um desafio nas regiões áridas e semiáridas devido à escassez de água para irrigação, sendo comum o uso de água salobra. Objetivou-se avaliar as respostas fisiológicas e produtivas de cultivares de tomate cereja sob diferentes salinidades da solução nutritiva em sistema hidropônico. O experimento foi conduzido em parcela subdividida e esquema fatorial 5 × 3, com quatro repetições. Os fatores corresponderam a valores da condutividade elétrica da solução nutritiva (CEsn 2,5, 4,0, 5,5, 7,0 e 8,5 dS m-1) e cultivares (Samambaia, Tomate Vermelho e Caroline). O aumento da salinidade da solução nutritiva afetou negativamente as trocas gasosas, o extravasamento de eletrólitos e os pigmentos fotossintetizantes das cultivares de tomate cereja, principalmente com o prolongamento do estresse. O sistema fotossintético foi eficiente até 4,0 dS m-1, mas, a partir desta condutividade elétrica na solução nutritiva houve fotoinibição ou fotodanos nas plantas de tomate cereja, com 30 dias após o transplantio. As cultivares de tomateiro cereja Samambaia e Caroline foram as mais adaptadas às soluções salobras, enquanto a cultivar Tomate Vermelho mais susceptível.

ABSTRACT Agricultural production has become a challenge in arid and semi-arid regions due to the scarcity of water for irrigation, so brackish water is commonly used. The present study aimed to evaluate the physiological and production responses of cherry tomato cultivars under salinity levels of the nutrient solution in a hydroponic system. The experiment was conducted in a split plot and 5 × 3 factorial scheme with four repetitions. The factors corresponded to different values of electrical conductivity of the nutrient solution (ECns 2.5, 4.0, 5.5, 7.0 and 8.5 dS m-1) and cultivars (Samambaia, Tomate Vermelho and Caroline). The increase in nutrient solution salinity negatively affected the gas exchange, electrolyte leakage and photosynthetic pigments of the cherry tomato cultivars, mainly with the prolongation of stress. The photosynthetic system was efficient up to 4.0 dS m-1, but, above this electrical conductivity in the nutrient solution, there was photoinhibition or photodamage in the cherry tomato plants at 30 days after transplanting. The cherry tomato cultivars Samambaia and Caroline were the most adapted to brackish solutions, while Tomate Vermelho was the most susceptible.

RESUMO: O objetivo deste estudo foi determinar a diversidade, composição e estrutura florestal de um trecho de floresta ombrófila densa do estado do Amapá. A área está localizada a leste do Estado do Amapá, Amazônia Oriental. Nas seguintes coordenadas: 2º 0’0,00’’ N. 14º 0’0.00’’O. O processo de amostragem utilizado foi o sistemático em que foram alocadas nove parcelas de 1 ha (100 m x 100 m), distanciadas em 0.5 km entre si, dentro de um transecto de 13 km de comprimento por 0.03 km de largura. A estrutura horizontal da floresta foi avaliada por meio de parâmetros fitossociológicos. 1790 árvores foram amostradas neste estudo. Elas estão distribuídas em 131 espécies, 69 gêneros e 48 famílias. As espécies que apresentaram mais indivíduos foram Pouteria guianensis Aubl. (136), Eschweilera coriacea (DC.) S.A.Mori (78), Inga paraensis Ducke (45), Licania paraensis Prance (38). A área é altamente diversa e dissimilar com grande variabilidade e complexidade na formação vegetal.

ABSTRACT: The aim of this study was to determine the diversity. composition. forest structure of a stretch of dense ombrophilous forest in the state of Amapá. The area is located in the east of the state of Amapá. in the Eastern Amazon. at the following coordinates: 2º 0’0.00 ’’ N. 14º 0’0.00’’O. The sampling process used was systematic. where nine plots of 1 ha (100 m x 100 m) were allocated. 0.5 km apart. within a 13 km long and 0.03 km wide transect. The horizontal structure of the forest was evaluated using phytosociological parameters. One thousand seven hundred and ninety trees were sampled in this study. they were distributed in 131 species. 69 genera and 48 families. The species that presented more individuals were Pouteria guianensis Aubl. (136). Eschweilera coriacea (DC.) S.A.Mori (78). Inga paraensis Ducke (45). Licania paraensis Prance (38). The area is highly diverse and dissimilar with great variability and complexity in vegetable formation.

RESUMO Objetivou-se estudar a ação atenuante de doses de nitrogênio sobre o dano à membrana celular das folhas, a produção de fitomassa seca e a área foliar na formação de mudas de maracujazeiro amarelo irrigadas com água salina. Para tanto, foi usado o delineamento experimental em blocos casualizados, com os tratamentos dispostos em parcelas subdivididas, estudou-se cinco níveis de salinidade da água de irrigação (parcela) (CEa) (0,3;1,0; 1,7; 2,4 e 3,1 dS m-1) e cinco doses de adubação nitrogenada (subparcela) (60; 80; 100; 120 e 140%) de 300 mg de N dm-3), que foram repetidos em cinco blocos. As plantas foram cultivadas em citropotes com volume de 3.780 mL, que foram preenchidos com uma mistura de solo, esterco bovino curtido e resíduo de serraria (maravalha) na proporção de 2:1:0,5, respectivamente. A aplicação das águas com diferentes salinidades ocorreu no período de 40 a 85 dias após a semeadura, época em que as plantas estavam em condições de transplante. Aos 85 dias após a semeadura, estudaram-se o percentual de dano celular, por meio do extravasamento de eletrólitos, variáveis de fitomassa seca, a área foliar e área foliar especifica. O incremento na salinidade da água de irrigação reduz o acúmulo de fitomassa das mudas de maracujazeiro amarelo; O aumento na dose de nitrogênio não mitigou o efeito da salinidade, que reduziu a integridade da membrana celular, proporcionando maior sensibilidade à planta.

ABSTRACT The aimed of this study was to evaluate the attenuating action of nitrogen doses on leaf cell membrane damage, dry biomass production and leaf area in the formation of yellow passion fruit seedlings irrigated with saline water. Treatments were arranged in a randomized block design, in split plots, corresponding to five levels of irrigation water salinity (plot) (ECw) (0.3; 1.0; 1.7; 2.4 and 3.1 dS m-1) and five doses of nitrogen fertilization (subplot) (60; 80; 100; 120 and 140% of 300 mg of N dm-3), which were repeated in five blocks. Plants were grown in pots (Citropote®) with a volume of 3,780 mL, which were filled with a mixture of soil, aged bovine manure and sawmill residue (shaving) in a ratio of 2:1:0.5, respectively. Waters with different levels of salinity were applied from 40 to 85 days after sowing, when the plants were in transplanting conditions. At 85 days after sowing, the percentage of cell damage based on electrolyte leakage, variables of dry biomass, leaf area and specific leaf area were evaluated. Increment in irrigation water salinity reduces the biomass accumulation of yellow passion fruit seedlings; The increase in nitrogen dose did not mitigate the effect of salinity, which reduced cell membrane integrity, making the plant more sensitive.