RESUMO A interferência de plantas daninhas representa um dos fatores de maior impacto na redução da produtividade na cultura da cenoura. O objetivo deste estudo foi determinar os períodos de interferência de plantas daninhas na cenoura em dois sistemas de irrigação localizada. O delineamento experimental utilizado foi o de blocos casualizados, com três repetições, no esquema de parcelas subdivididas. As parcelas foram constituídas dos dois sistemas de irrigação (gotejamento e microaspersão), e as subparcelas corresponderam à duração da convivência com as plantas daninhas, constituídos de períodos de controle (no limpo) ou convivência (no mato) das plantas daninhas com a cultura (0, 10, 20, 30, 40, 50 e 120 dias após a emergência (DAE)). O início e o fim do período crítico de prevenção a interferência (PCPI), com base em uma perda de produtividade de 2,5, 5 e 10 % de cenoura comercializável, foi determinado pelo ajuste do modelo Sigmoide aos dados de produção relativa. A presença da comunidade de plantas daninhas durante todo o ciclo da cultura pode acarretar perdas de até 98% na produtividade. O PCPI variou em 16 dias entre os sistemas de irrigação utilizados. O cultivo da cenoura com e sem competição, sob o sistema de irrigação por microaspersão apresentou maior produtividade em comparação ao cultivo no sistema de gotejamento. No sistema de irrigação por gotejamento o PCPI foi de 23 DAE e no sistema de irrigação por microaspersão foi de 7 DAE, considerando perdas de produtividade de 5 %. | ABSTRACT Weed interference is one of the factors that reduces carrot yield considerably. The aim of this study was to determine the periods of weed interference in carrots cultivated under two localized irrigation systems. The experiment used a completely randomized block design, with three replications, using the split plot scheme. The plots consisted of two irrigation systems (drip and micro sprinkler) and the subplots corresponded to the duration of coexistence of the crop with weeds, comprising periods of control (weed -free) or coexistence (with weeds) (0, 10, 20, 30, 40, 50, and 120 days after emergence (DAE) of the crop). Considering a yield loss of 2.5%, 5%, and 10% in marketable carrots, the beginning and end of the critical period of weed control (CPWC) was determined by adjusting a sigmoid model to the relative production data. The presence of the weed community throughout the crop cycle resulted in yield losses of up to 98%. The CPWP varied for the irrigation systems used. Carrot cultivation with and without competition, under the micro sprinkler irrigation system showed a higher yield than with the drip system. Considering a yield loss of 5%, the CPWC was 23 DAE and 7 DAE in the drip irrigation and micro sprinkler irrigation systems, respectively.

RESUMO A utilização de fertilizantes orgânicos pode contribuir para melhoria das propriedades químicas, físicas e biológicas do solo, com seu uso apresentando baixo impacto ambiental. O objetivo deste trabalho foi avaliar a produtividade e a qualidade do maracujá amarelo em sistema orgânico, combinado com irrigação e níveis de insumos. Utilizou-se delineamento experimental em blocos casualizados, disposto em esquema fatorial (3x2) com quatro repetições. Os fatores avaliados foram: três níveis de insumos (fertilizantes e defensivos alternativos), com presença e ausência de irrigação. A adubação constou da aplicação no plantio em: 5, 10 e 15 litros de composto por planta e 500, 1.000 e 1.500 g de calcário por planta, para os níveis de insumos 1, 2 e 3, respectivamente. A adubação de cobertura foi parcelada em duas vezes: 118, 235 e 353 g por planta de termofosfato e 59,1, 118,20 e 176,40 g por planta de sulfato de potássio, para os níveis 1, 2 e 3 de aplicação de insumos, respectivamente. Os defensivos alternativos foram pulverizados a cada 30, 15 e 7 dias para os níveis 1, 2 e 3, respectivamente. O número de frutos por planta e a produtividade aumentaram utilizando o nível 3 de insumo aliado à irrigação. O nível 2 e 3 de insumos, na ausência de irrigação aumentaram o teor de sólidos solúveis. A acidez titulável, ratio e frutos classificados como extra não diferiram significativamente entre os tratamentos estudados. Utilizando insumos nos níveis 1 e 2 e na ausência de irrigação, aumentou a porcentagem de frutos classificados como orgânicos. | ABSTRACT The use of organic fertilizers can improve the chemical, physical, and biological properties of the soil, with their use implying low environmental impact. This study aimed to evaluate the yield and quality of yellow passion fruit grown in an organic system associated with irrigation and input levels. A randomized complete block design in a 3x2 factorial arrangement with four replications was adopted. The factors evaluated were: three input levels (fertilizers and alternative pesticides) and the presence or absence of irrigation. Fertilization consisted of the application of 5, 10, and 15 liters of organic compost per plant and 500, 1,000, and 1,500 g of lime per plant, corresponding to input levels 1, 2, and 3, respectively. Topdressing fertilization was split into two applications, corresponding to 118, 235, and 353 g per plant of thermophosphate and 59.1, 118.20, and 176.40 g per plant of potassium sulfate for levels 1, 2, and 3 of input application, respectively. The alternative pesticides were sprayed every 30, 15, and 7 days for levels 1, 2, and 3, respectively. The number of fruits per plant and the yield increased using the input level 3 associated with irrigation. In the absence of irrigation, input levels 2 and 3 increased the content of soluble solids. The titratable acidity, TSS/TTA ratio, and the fruits classified as extra did not differ significantly between treatments. Input levels 1 and 2 associated with the absence of irrigation increased the percentage of fruits classified as commercial.

RESUMO Em florestas tropicais sazonalmente secas, como a Caatinga brasileira, fatores como tipo de solo e luminosidade são conhecidos por causar alterações nos tecidos foliares que possibilitam a sobrevivência de espécies nesses locais. O presente estudo teve como objetivo descrever a morfoanatomia foliar de Senna cana e observar a plasticidade em tecidos foliares que recebem radiação de luz direta e indireta. O estudo foi realizado no Parque Nacional do Catimbau em Buíque, PE, Brasil. Amostras de folhas maduras foram coletadas sob plena luz do sol e plena sombra em três áreas com solos de cores diferentes. Lâminas histológicas foram preparadas para visualização das faces epidérmicas, estrutura foliar interna e testes histoquímicos. A plasticidade foi notada no tipo de tricoma que recobriu as faces epidérmicas, e no número de camadas dos parênquimas paliçádico e esponjoso, mesmo sob efeito indireto da radiação. Compostos fenólicos e lipídios também apresentaram plasticidade. Esses resultados demonstram que Senna cana é uma espécie com alta plasticidade para o fator de luminosidade. Além disso, percebeu-se que a luz indireta também promove alterações anatômicas e deve ser considerada em análises futuras. | ABSTRACT In seasonally dry tropical forests such as the Brazilian Caatinga, factors such as soil type and luminosity are known to cause changes in foliar tissues that enable the survival of species in such places. The present study aimed to describe the leaf morphoanatomy of Senna cana and to observe the plasticity in leaf tissues receiving both direct and indirect light radiation. The study was carried out in the Catimbau National Park in Buíque, PE, Brazil. Mature leaf samples were collected from under full sunlight and full shade in three areas with soils of different colors. Histological slides were prepared for visualization of epidermal faces, internal leaf structure, and histochemical tests. Plasticity was noted in the type of trichome that covered the epidermal faces, and in the number of layers of the palisade and spongy parenchymas, even under the indirect effect of radiation. Phenolic compounds and lipids also showed plasticity. These results demonstrate that Senna cana is a species with high plasticity for the luminosity factor. Further, it was noticed that indirect light also promotes anatomical changes and should be considered in future analyses.

RESUMO A mangabeira (Hancornia speciosa Gomes) é uma espécie frutífera nativa do Brasil, pertencente à família Apocynaceae. Seu cultivo é predominantemente extrativista e suas propriedades antioxidantes têm sido recentemente relatadas. O objetivo do presente trabalho foi avaliar os compostos bioativos e atividade antioxidante em frutos de acessos oriundos do Banco Ativo de Germoplasma da Embrapa Tabuleiros Costeiros (BI, CA, LG, PR, PT e TC). Os extratos foram analisados em cromatografía líquida de alta eficiência (HPLC) e identificou-se o ácido clorogênico (93,71 - 131,66 mg.100g-1); ácido ferúlico (0,85 - 2,27 mg.100g-1) e rutina (238,59 - 442,94 mg.100g-1). Os acessos CA e PR apresentaram os maiores valores de fenóis totais (1179,39 e 1167,05 mg EAG.100g-1, respectivamente). Os acessos CA e TC apresentaram a maior concentração do composto majoritário rutina (436,78 e 442,94 mg.100g-1, respectivamente). Os valores da atividade antioxidante variaram entre 125,95 e 158,67 g.g-1 DPPH. A análise de componentes principais agrupou os acessos em quatro grupos, em consequência da variabilidade genética previamente verificada em estudos anteriores. Os resultados serão úteis para direcionar ações de seleção e futuro programa de melhoramento genético da espécie. | ABSTRACT Mangaba (Hancornia speciosa Gomes) is a fruit species native to Brazil, belonging to the Apocynaceae family. Its cultivation is predominantly extractivist and its antioxidant properties have been recently reported. The objective of this study was to evaluate the bioactive compounds and antioxidant activity in fruits of accession from the Active Germplasm Bank of Embrapa Coastal Tablelands (BI, CA, LG, PR, PT and TC). The extracts were analyzed by high-performance liquid chromatography (HPLC), which identified chlorogenic acid (93.71 - 131.66 mg.100g-1), ferulic acid (0.85 - 2.27 mg.100g-1) and rutin (238.59 -442.94 mg.100g-1). The accessions CA and PR showed the highest values of total phenols (1179.39 and 1167.05 mg GAE.100g-1, respectively). The accessions CA and TC had the highest concentration of the major compound rutin (436.78 and 442.94 mg.100g-1, respectively). Antioxidant activity values ranged from 125.95 to 158.67 g.g-1 DPPH. Principal component analysis grouped the accessions into four groups, due to the genetic variability verified in previous studies. The results will be useful to guide actions of selection and future breeding program of the species.

ABSTRACT Gypsum is widely used in agriculture to supply nutrients to the soil-plant system. However, the excessive use of gypsum may lead to a reduction of cationic soil nutrients such as potassium in the most superficial soil layer. Thus, the objective of this study was to evaluate the feasibility of using gypsum and potassium for cauliflower crop nutritional status and commercial production. The experiment was conducted in 5×5 factorial scheme, corresponding to five K doses (0, 100, 180, 240, 360 kg ha−1 of K2O) and five gypsum doses (0, 500, 1000, 2000, 4000 kg ha−1) in dystrophic Red Latosol. Leaf N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn contents, commercial head mass, diameter and height and peduncle diameter were evaluated. The application of 360 kg ha−1 of K2O resulted in 29.69% more K in cauliflower leaf and 18.94% more commercial head mass compared to the non-application of K. The application of 4000 kg ha−1 of gypsum resulted in reductions of leaf S and Mn and increase in leaf Cu. Based on the results observed, 4000 kg ha−1 of gypsum and 360 kg ha−1 K2O could be required for high cauliflower production.

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 This study aimed to assess the physical, chemical, and sensory attributes of mango varieties grown under the organic farming. Fruits from ten varieties of mango grown under the organic system in the Chapada Diamantina region, BA, Brazil, were assessed. The following physical and chemical characteristics were assessed: fruit mass, pulp yield, pulp color (L*, C*, and h*), soluble solids (SS), titratable acidity (TA), total carotenoids, and ascorbic acid. The sensory acceptance test was performed with 50 consumers using the nine-point structured hedonic scale and the attributes acidity, sweetness, and firmness of the pulp were assessed using the just-about-right scale. Differences among the varieties of mango grown under the organic production system were observed for physical, chemical and sensory attributes. The varieties showed a percentage of pulp equal or above 60%, which makes them more suitable for processing. According to the PCA analysis, the characteristics soluble solids, total carotenoids, fruit mass, titratable acidity, h* and L* were considered the most important to differentiate the mango varieties evaluated. Ubá and Beta varieties had the highest levels of SS, while Favo de Mel was characterized by the highest values of TA and L*. The varieties Favo de Mel, Palmer, Surpresa, Juazeiro 2, Imperial and Joa had fruits with higher mass and h* values and the varieties Amrapali and Roxa Embrapa 141 had the highest levels of total carotenoids. Imperial, Palmer, Beta and Joa varieties were the most accepted for all sensory attributes.

ABSTRACT Little is known about the management of high-yield clonal Coffea canephora in the Amazonian Region, mainly for nutritional aspects and cultivation system efficiency. This study aimed to evaluate the influence of different nitrogen and potassium fertilization rates on coffee grain yield and fertilizer use efficiency of C. canephora trees. An experiment was performed at an experimental field of the Embrapa Rondônia in Porto Velho (RO), Brazil. It was carried out in a split-plot scheme with six doses of 20-00-20 NPK formulation (0; 250; 500; 1,000; 2,000; and 3,000 kg ha-1) and three years of evaluation (2014, 2015, and 2016). An interaction between fertilizer dose and crop year was observed. Fertilizer doses showed an exponential behavior, with maximum yields of 51, 114, and 79 bags ha-1 at 3,000 kg ha-1 in the crop years of 2014, 2015, and 2016, respectively. Such a behavior impacted average and accumulated yields in the three harvest seasons. As for crop year effect within each fertilizer dose, the highest yield was reached in the second harvest after pruning for renewal of orthotropic stems. Moreover, fertilizer use efficiency by plants decreased exponentially, with the highest value at the lowest dose. Increasing doses of 20-00-20 formulation promoted an exponential increase in grain yield but decreased its use efficiency by C. canephora plants. This management also stimulated a strong biannual production.

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.