Interdisciplinaridade Decolonial no Espaço Não Formal: Saberes dos Ferreiros Africanos Usados Durante a História da Humanidade

O presente texto é resultado de uma reflexão levantada após uma aula de campo, que englobou diversas áreas do saber, com o fito de destacar os saberes científicos feitos por outros povos, que não o branco europeu/colonizador. Em outras palavras, uma decolonização do ensino das ciências, à qual é marcada pela valorização das contribuições, saberes, técnicas empregadas por povos tradicionais e africanos. A aula interdisciplinar (História e Química) em questão tratou-se de uma aula de campo ao Museu Náutico da Bahia, entre estudantes da 2ª série do Colégio Estadual Assis Chateaubriand, no município de Salvador, Bahia, Brasil. Nela, os estudantes puderam ter acesso não só a um monumento histórico, como também ao “tocar” no passado e notar que em especial os africanos escravizados, traziam consigo também, conhecimentos e tecnologias. Dentre os saberes resgatados nas Ciências, destacamos para este trabalho o conhecimento da metalurgia do ferro na África Ocidental, que influenciou sobremaneira as relações sociais e econômicas dessa população na diáspora e em sua terra natal – dos ofícios (ferreiros, mineiros) aos rituais e usos desse metal nas mais diversas áreas. O processo de fundição trouxe às civilizações avanços técnicos e práticos, instrumentalizando o homem em suas atividades cotidianas – das domésticas às laborais –, como também no que se refere ao uso bélico, haja vista a confecção de armas brancas e de fogo – canhões – e o comércio que se articulou entre os tempos e os continentes. As aulas e atividades foram realizadas sob o prisma afrocentrado.: This text is the result of a reflection raised after a field class, which encompassed several areas of knowledge. In order to highlight the scientific knowledge made by other peoples, other than the European white / colonizer; in other words, a decolonization of science education marked by disregard for contributions, knowledge, techniques employed by traditional peoples, and Africans. The interdisciplinary class (History and Chemistry) in question was a field class at the Nautical Museum of Bahia, among 2nd year students at Colégio Estadual Assis Chateaubriand, in the city of Salvador, Bahia, Brazil. In it, the students were able to have access not only to a historical monument, but also to “touch” the past and notice that especially the enslaved Africans also brought with them knowledge and technologies. Among the knowledge recovered in Sciences, we highlight for this work the knowledge of iron metallurgy in West Africa, which greatly influenced the social and economic relations of this population in the diaspora and in their homeland - from crafts (blacksmiths, miners) to rituals and uses of this metal in the most diverse areas. The foundry process brought technical and practical advances to civilizations, instrumentalizing man in his daily activities - from domestic to work -, as well as with regard to war use, given the manufacture of white weapons and firearms - cannons - and the trade that was articulated between the times and the continents

Photosynthetic capacity, leaf respiration and growth in two papaya (Carica papaya) genotypes with different leaf chlorophyll concentrations

StudiesGolden genotype of papaya (Carica papaya), named for its yellowish leaves, produces fruits very much appreciated by consumers worldwide. However, its growth and yield are considerably lower than those of other genotypes, such as ‘Sunrise Solo’, which has intensely green leaves. We undertook an investigation with the goal of evaluating key physiological traits that can affect biomass accumulation of both Golden and Sunrise Solo genotypes. Papaya seeds from two different genotypes with contrasting leaf colour ‘Sunrise Solo’ and Golden were grown in greenhouse conditions. Plant growth (plant height, leaf number, stem diameter, leaf area, plant dry weight), leaf gas exchanges, leaf carbon balance, RuBisCO oxygenation and carboxylation rates, nitrogen, as well as chlorophyll concentrations and fluorescence variables were assessed. Although no significant differences were observed for photosynthetic rates between genotypes, the accumulation of small differences in photosynthesis, day after day, over a long period, might contribute to some extend to a higher C-budget in Sunrise Solo, higher leaf area and, thus, to higher productivity. Additionally, we consider that physiological processes other than photosynthesis and leaf respiration can be as well involved in lower growth and yield of Golden. One of these aspects could be related to the higher rates of photorespiration observed in Sunrise Solo, which could improve the rate of N assimilation into organic compounds, such as amino acids, thus contributing to the higher biomass production in Sunrise Solo relative to Golden. Further experiments to evaluate the effects of N metabolism on physiology and growth of Golden are required as it has the potential to limit its yieldinfo:eu-repo/semantics/publishedVersio

Nitrogen and plant density in the economic evaluation and fruit quality of pineapple

The appropriate use of nitrogen fertilization and higher population densities increase the pineapple yield and can improve economic returns. This study aimed to evaluate the economic return and postharvest characteristics of irrigated Vitória pineapple under different nitrogen (N) sources and doses, as well as the increase in population density. A randomized blocks design with three replications was installed in a 2 x 5 x 4 factorial scheme, corresponding to two N sources (urea and cattle manure), five N doses (0 g plant-1, 5 g plant-1, 10 g plant-1, 15 g plant-1 and 20 g plant-1) and four densities (51,282 plants ha-1, 76,923 plants ha-1, 90,909 plants ha-1 and 126,984 plants ha-1). The N sources did not affect the pH, total titratable acidity and total soluble solids/total titratable acidity ratio (TSS/TTA). However the TSS content was higher in plants fertilized with cattle manure. The plants density did not affect the quality of postharvest fruit. The increase of N doses supplied by urea and cattle manure influenced only the total titratable acidity of the fruits. The combination of 20 g plant-1 of N-manure and a population of 126,984 plants ha-1 resulted in the maximum partial net income of R$132,096.48, however, the dose of 19.75 g plant-1of N-urea, in the population of 119,686.00 plants ha-1, reached a partial net income of R$ 154,997.15

Macronutrient uptake, accumulation and export by the irrigated 'vitória' pineapple plant

The nutritional state of the pineapple plant has a large effect on plant growth, on fruit production, and fruit quality. The aim of this study was to assess the uptake, accumulation, and export of nutrients by the irrigated 'Vitória' pineapple plant during and at the end of its development. A randomized block statistical design with four replications was used. The treatments were defined by different times of plant collection: at 270, 330, 390, 450, 510, 570, 690, 750, and 810 days after planting (DAP). The collected plants were separated into the following components: leaves, stem, roots, fruit, and slips for determination of fresh and dry matter weight at 65 ºC. After drying, the plant components were ground for characterization of the composition and content of nutrients taken up and exported by the pineapple plant. The results were subjected to analysis of variance, and non-linear regression models were fitted for the significant differences identified by the F test (p N > S > Ca > Mg > P, which corresponded to 898, 452, 134, 129, 126, and 107 kg ha-1, respectively, of total accumulation. The export of macronutrients by the pineapple fruit was in the following decreasing order: K > N > S > Ca > P > Mg, which was equivalent to 18, 17, 11, 8, 8, and 5 %, respectively, of the total accumulated by the pineapple. The 'Vitória' pineapple plant exported 78 kg ha-1 of N, 8 kg ha-1 of P, 164 kg ha-1 of K, 14 kg ha-1 of S, 10 kg ha-1 of Ca, and 6 kg ha-1 of Mg by the fruit. The nutrient content exported by the fruits represent important components of nutrient extraction from the soil, which need to be restored, while the nutrients contained in the leaves, stems and roots can be incorporated in the soil within a program of recycling of crop residues

MICRONUTRIENT CONCENTRATION AND CONTENT IN PASSION FRUIT LEAVES UNDER SAMPLING METHODS AND N-K FERTILIZATION RATES

<div><p>ABSTRACT Balanced uptake of micronutrients by the passion fruit plant is essential for increased production and fruit quality. However, similar fertilizer management in varieties with different productive capacities and high levels of nitrogen and potassium can cause nutritional disorders in plants. The objective of this study was to evaluate leaf micronutrient concentrations and contents in passion fruit as affected by two different sampling methods, different N-K fertilization proportions, and different cultivars. The study was conducted in a randomized block design, with three replications, following a 4 × 6 factorial arrangement consisting of four cultivars of yellow passion fruit (BRS Gigante Amarelo, IAC 275, BRS Ouro Vermelho, and BRS Sol do Cerrado) and six application rates ofN-K2O fertilizer (0-0, 50-125, 100-250, 150-375, 200-500, and 250-625 kg ha-1 year-1). Two leaf sampling methods (leaf located at a position adjacent to the fruit, and leaf located at the end of the fruit-bearing branch) were adopted for nutritional assessment. At 240 days after planting passion fruit seedlings in the experimental area, 20 leaves per plot were sampled. Higher accumulated micronutrient contents were obtained in the adjacent leaves, possibly because of greater leaf weight (more fully developed leaf) compared to the standard leaf. The cultivar IAC 275 had lower concentration and content of Cu, Fe, e Mn in the adjacent leaf, indicating variations in the levels of micronutrients among the cultivars and different micronutrient demands by the cultivars studied. N and K fertilization had less effect on leaf micronutrient concentration and content, but the Zn concentration and content decreased in the standard leaf of the BRS Gigante Amarelo cultivar, and Cu decreased in the standard leaf of the BRS Ouro Vermelho cultivar.</p></div

Volatilização de amônia do solo após doses de ureia com inibidores de urease e nitrificação na cultura do abacaxi

RESUMO Os inibidores de urease N-(n-butil) tiofosfóricotriamida (NBPT) e nitrificação dicianodiamida (DCD) minimizam as perdas de nitrogênio (N) pela volatilização da amônia (NH3), por redução da velocidade de hidrólise da ureia e conversão de amônio em nitrato, respectivamente. O objetivo deste estudo foi avaliar as perdas de N do solo por volatilização, após a adição de doses de N, na forma de ureia combinada com inibidores de urease e de nitrificação, no semiárido mineiro. Utilizou-se o delineamento em blocos casualizados, com três repetições, em esquema fatorial 4 x 5 x 7, constituídos por: quatro combinações de ureia com inibidores (ureia comum; ureia + NBPT; ureia + DCD e, ureia + NBPT + DCD), cinco doses de N (0,0; 3,7; 7,4; 11,1 e 14,8 g/planta) e sete tempos de avaliação (3, 6, 9, 12, 15, 18 e 21 dias) após a aplicação, em cobertura, no cultivo de abacaxi irrigado. Foram avaliadas as perdas de amônia e o pH em torno do grânulo de ureia. O inibidor de urease (ureia + NBPT) foi mais eficiente nas menores doses de nitrogênio, além de reduzir e atrasar os períodos de volatilização de N-NH3 e também diminuir o pH do solo, por causa, provavelmente da maior nitrificação e, ou, do aumento da taxa de decomposição da matéria orgânica do solo (MOS), pela maior disponibilidade de N em comparação aos tratamentos com ureia e ureia + DCD. O aumento das doses de nitrogênio reduziu as perdas relativas de N por volatilização, graças à maior saturação dos sítios de ação da enzima urease