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Metabolismo do carbono em progênies de Cupuaçuzeiro submetida à deficiência hídrica.

Wed, 21 Jan 2026 00:00:00 GMT

Título: Metabolismo do carbono em progênies de Cupuaçuzeiro submetida à deficiência hídrica. Autor(es): MERCÊS, Júlia Karoline Rodrigues das; PALHETA, Juscelino Gonçalves; ALVES, Rafael Moysés; CUNHA, Roberto Lisboa; OLIVEIRA NETO, Cândido Ferreira de; CONCEIÇÃO, Susana Silva Abstract: In the Amazon, rainfall distribution is irregular, and distinct dry periods are common; water stress is known to reduce agricultural production. The objective of this study was to analyze the effect of water deficiency on leaf water potential, starch concentrations, total soluble carbohydrates, and sucrose in T. grandiflorum progenies exposed to 16 days of water restriction. The experiment was conducted in the greenhouse at Embrapa Amazônia Oriental. The seedlings were grown in plastic bags filled with 8 kg of pre-fertilized substrate. The experimental design was completely randomized, using a 2x7 factorial scheme. Each treatment was represented by five replicates, totaling 70 experimental units. An analysis of variance was performed on the results, and when a significant difference occurred, the means were compared using Tukey’s test (p<0.05) with the “SAS” software. Progeny 1074 showed the highest sensitivity to water restriction, with a significant reduction of 2,438% in leaf water potential. However, progenies 32 and 42 showed a significant reduction in starch concentration of 57% and 82% in the leaves, respectively; for the roots, progenies 57, 215, and 1074 showed reductions of 82%, 76%, and 69%, respectively. Therefore, a 16-day water deficit in Theobroma grandiflorum progenies led to a decrease in leaf water potential and starch content. At the same time, there was an increase in the concentration of total soluble carbohydrates and sucrose in all progenies subjected to water restriction.

Avaliação da implementação da política estadual de rastreabilidade na cadeia produtiva do açaí no estado do Pará

Wed, 21 Jan 2026 00:00:00 GMT

Título: Avaliação da implementação da política estadual de rastreabilidade na cadeia produtiva do açaí no estado do Pará Autor(es): PIMENTEL, Lucionila Pantoja; NEVES, Ana Karen de Mendonça; MONTEIRO, Elideth Pacheco; LOPES, Maria Lúcia Bahia; FILGUEIRAS, Gisalda Carvalho; COSTA, Deborah Luciany Pires; LOUREIRO, João Paulo Borges de; SANTOS, Marcos Antônio Souza dos Abstract: This article evaluates the implementation of the state policy for traceability in the açaí production chain in the state of Pará, operated by the Agricultural Defense Agency of the state of Pará, from 2021 to 2023, through Ordinance No. 2.789/2020, which institutes the Plant Transit Guide (GTV). The 5C Protocol by Najan (1995) was used, which establishes five interdependent evaluation dimensions: content, context, capacity, competence, and clients and coalitions. The work was developed based on documentary research, involving legislation, institutional reports, and data from Adepará's control systems. The capacity and commitment dimensions highlighted limitations related to the scarcity of human resources and planning, evidencing the need for greater institutional support to ensure the effectiveness of the policy. The dimensions of content, context, customers and coalitions highlighted the importance of promoting social inclusion, greater transparency, access to technologies and technical training, which are essential factors for increasing the adherence of actors in the production chain to the traceability policy. Despite these limitations, the initial results of the implementation of the Plant Transit Guide (GTV) for açaí were positive, with progress in the registration of production units, expansion of coverage of the target audience and an increase in the issuance of GTVs. The results presented provide support for Adepará and other actors involved in this production chain, proving to be a useful tool in evaluating the implementation of public policies.

Flora arbustivo-arbórea de trecho de mata mesófila semidecídua, na estação ecológica de Ibicatu, Piracicaba (SP).

Wed, 25 Jun 2025 00:00:00 GMT

Título: Flora arbustivo-arbórea de trecho de mata mesófila semidecídua, na estação ecológica de Ibicatu, Piracicaba (SP). Autor(es): COSTA, Luiz Gonzaga Silva; MANTOVANI, Waldir Abstract: Shrub and tree flora of a stretch of semi-deciduous mesophytic forest in the Ibicatu Ecological Station, Piracicaba (SP). A survey was carried out of the shrub and tree flora of a stretch of semi-deciduous mesophytic forest at the Ibicatu Ecological Station, in the municipality of Piracicaba (SP). A total of 3766 individuals were sampled, distributed among 39 families, 80 genera and [03 species. The most abundant species were: Actinostemon concepciones. Angostura pentandra, Metrodorea nigra. Actinostemon concolor and Esenbeckialeiocarpa. The families with the greatest richness were: Leguminosae (with 15 species), Euphorbiaceae (8), Myrtaceae (7), Rutaceae (7) and Rubiaceae (7). The floristic relationships of this area with 23 other surveys carried out in the state of São Paulo were analyzed using the Jaccard index.

Relação hipsométrica em um fragmento de floresta Peri urbana na fazenda experimental de Igarapé Açu, Pará

Mon, 01 Jul 2024 00:00:00 GMT

Título: Relação hipsométrica em um fragmento de floresta Peri urbana na fazenda experimental de Igarapé Açu, Pará Autor(es): OLIVEIRA, Diancarlos Sergio Pereira de; CALDEIRA, Rafael Teles; COSTA, Lena Monteiro; EMMERT, Fabiano; NASCIMENTO, Rodrigo Geroni Mendes Abstract: The hypsometric relationship (RH) is of fundamental use in forest inventories because it reduces data collection time and costs. Although it is widely studied in forest plantations, the hypsometric relationship still lacks studies in native forests of the Amazon, mainly on how to build it. Therefore, the present work aimed to test and select models to adjust the hypsometric relationship in a secondary forest in the Amazon. Data were obtained from a fragment of native peri-urban forest located in the municipality of Igarapé Açu, northeast of Pará, with an area of 44 hectares, included in the Forest Management Project of the Laboratory of Forest Measurement of UFRA-Belém. Ten models were tested, including Simple Linear, Assmann, Trorey, Incomplete Parabola, Polynomial, Exponential-Curtis, Henricksen, Potencia-Stofells, and Hyperbolic models. Statistical parameters such as the adjusted coefficient of determination (RÂ²aj.), the standard error of the estimate (Syx%). The best statistics were for the Exponential-Curtis, Power Stofell and the hyperbolic equation, they obtained the best adjustments, a fact observed by the standard error value of the estimate, which was in the range of 18.37% to 18.79%, being very high compared to the values that can be found in the literature. Descrição: artigo fruto do mestrado de OLIVEIRA, Diancarlos Sérgio Pereira de. Mestrado em Ciências Florestais - Universidade Federal Rural da Amazônia, Belém, 2023.