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Postharvest conservation methods such as heat shock can increase the nutritional profile of fruits, inducing greater accumulation of antioxidants that participate in the physiological maintenance of fruits. The objective of this work was to evaluate the antioxidant properties of “Sweet Grape” tomatoes treated with heat shock in pre-storage. “Sweet Grape” tomatoes were heat shocked in hot water (45°C) for 10 min. and stored at room temperature for 9 days. β-carotene, ascorbic acid, total phenolic compounds, and antioxidant activity (DPPH, ABTS, and FRAP) were evaluated every 3 days. The pulp and skin of the treated tomatoes had higher β-carotene content than the control during storage, according to the findings. The content of total phenolic compounds in the pulp reduced, regardless of the treatment. There was a reduction of ascorbic acid, but with significantly higher values ​​in the fruits treated on the third and sixth days of storage. The DPPH antioxidant activity of the pulp decreased, regardless of the treatment. In the skin there was a significant effect of the treatment until the sixth day. There was no variation in the ABTS antioxidant activity of the pulp of the treated tomatoes. There was no significant effect of heat shock on the FRAP antioxidant activity of the pulp until the sixth day. Heat shock promoted an increase in β-carotene in tomato skin, which was related to increases in its DPPH antioxidant activity. The heat shock treatment promoted greater retention of ascorbic acid in the fruit, but it was not able to avoid its reduction during storage. The tomatoes’ antioxidant biochemical response to heat shock is most expressed in their skin.

Silver nanoparticles (AgNPs) can be produced through an easy and safe process called green synthesis and have been considered an efficient antimicrobial agent. The antimicrobial effect of silver nanoparticles green synthesized with E. tirucalli (aveloz) can be a promising technique for preserving stored strawberries. The objective of this work was to perform a green synthesis of AgNPs with aveloz extract (Av) and evaluate its effect on the physiology and preservation of stored strawberries. Silver nitrate was reduced with Av to produce Av-AgNPs. The Av-AgNPs were characterized by Scanning Electron Microscope, Energy Dispersive X-ray Spectrometry, and laser diffraction. The in vitro antifungal activity of Av-AgNPs was evaluated against Botrytis cinerea and Rhizopus stolonifer. Strawberries were treated with Av-AgNPs and stored (5 °C) for 12 days. Respiratory rate, decay, fresh mass loss, firmness, total phenolics and antioxidant activity of the strawberries were evaluated. According to the results, Av-AgNPs synthesis was performed, and it presented sizes between 40 and 90 nm. Av-AgNPs inhibited B. cinerea but was less effective for R. stolonifer. Total phenolic compounds, antioxidant activity, fresh mass loss and firmness of strawberries were not influenced by Av-AgNPs. Treated strawberries had a lower respiratory rate than the control and showed no symptoms of microbiological deterioration until 9 days of storage, while in the control the deterioration symptoms started after 3 days. This study showed that the green synthesis of AgNPs with Av produced nanoparticles smaller than 100 nm, and that they were effective against strawberries decay during storage, indicating to be a promising protection technique against decay.

The objective of this work was to evaluate the physicochemical characteristics, the bioactive compounds and the antioxidant potential of honey produced by Africanized bees (Apis mellifera L.) from municipalities in western Paraná state. Sixty-six samples of honey were analyzed from October 2018 to August 2019. The physicochemical parameters evaluated were: color, moisture, hydroxymethylfurfural, pH and free acidity, with mean values ​​of 0.36±0.24nm, 18 .80±1.01%, 10.34±3.24mg.kg-1, 4.01±0.18 and 17.36±4.11 meq.kg-1, respectively. The bioactive compounds (phenolic compounds and flavonoids) and the antioxidant activity were also analyzed, and the mean values ​​of 16.34±7.41mg.GAE 100 g-1 were observed for Total Phenols, 21.35±9.63mg.QE 100 g-1 for flavonoids and 0.09±0.03µmol.TE g-1 for antioxidant activity (DPPH). The honey samples were influenced by their phytogeographic origin and have antioxidant potential. O objetivo do trabalho foi avaliar as características físico-químicas, os compostos bioativos e o potencial antioxidante do mel produzido por abelhas africanizadas (Apis mellifera L.) de municípios do Oeste paranaense. Foram analisadas 66 amostras de mel, no período de outubro de 2018 a agosto de 2019. Os parâmetros físico-químicos avaliados foram: cor, umidade, hidroximetilfurfural, pH e acidez livre, com valores médios de 0,36±0,24nm, 18,80±1,01%, 10,34±3,24mg.kg-1, 4,01±0,18 e 17,36±4,11 meq.kg-1, respectivamente. Também foram analisados os compostos bioativos (compostos fenólicos e flavonoides) e atividade antioxidante, sendo observados valores médios de 16,34±7,41mg.EAG 100 g-1 para Fenois Totais, 21,35±9,63mg.EQ 100 g-1 para flavonoides e 0,09±0,03µmol.ET g-1 para atividade antioxidante (DPPH). As amostras de mel sofreram influência quanto a sua origem fitogeográfica e possuem potencial antioxidante.

Silver nanoparticles (AgNPs) can be produced through an easy and safe process called green synthesis and have been considered an efficient antimicrobial agent. The antimicrobial effect of silver nanoparticles green synthesized with E. tirucalli (aveloz) can be a promising technique for preserving stored strawberries. The objective of this work was to perform a green synthesis of AgNPs with aveloz extract (Av) and evaluate its effect on the physiology and preservation of stored strawberries. Silver nitrate was reduced with Av to produce Av-AgNPs. The Av-AgNPs were characterized by Scanning Electron Microscope, Energy Dispersive X-ray Spectrometry, and laser diffraction. The in vitro antifungal activity of Av-AgNPs was evaluated against Botrytis cinerea and Rhizopus stolonifer. Strawberries were treated with Av-AgNPs and stored (5 °C) for 12 days. Respiratory rate, decay, fresh mass loss, firmness, total phenolics and antioxidant activity of the strawberries were evaluated. According to the results, Av-AgNPs synthesis was performed, and it presented sizes between 40 and 90 nm. Av-AgNPs inhibited B. cinerea but was less effective for R. stolonifer. Total phenolic compounds, antioxidant activity, fresh mass loss and firmness of strawberries were not influenced by Av-AgNPs. Treated strawberries had a lower respiratory rate than the control and showed no symptoms of microbiological deterioration until 9 days of storage, while in the control the deterioration symptoms started after 3 days. This study showed that the green synthesis of AgNPs with Av produced nanoparticles smaller than 100 nm, and that they were effective against strawberries decay during storage, indicating to be a promising protection technique against decay.

A avaliacao da qualidade da agua e considerada uma ferramenta de extrema importância para a conservacao dos recursos hidricos. Nesse contexto o objetivo do trabalho foi avaliar a qualidade das aguas de diferentes cursos d’agua no municipio de Capitao Poco - PA. Foram coletadas amostras de agua de quatro cursos de agua: Alencap, Riacho Doce, 23 de Dezembro e Virgilio, nos quais foram avaliados o indice de coliformes fecais, oxigenio dissolvido na agua e pH. O indice de coliformes fecais nos cursos de agua Alencap e 23 de Dezembro foram superiores a 1600 NMP/100 ml, indicando um alto nivel de poluicao, o que pode acarretar serios riscos a saude da populacao. Com relacao ao nivel de oxigenio dissolvido, Riacho Doce foi o que apresentou um maior numero 11,3 mg/L, sendo considerado o mais apropriado para utilizacao humana. O local mais improprio para a variavel oxigenio dissolvido, foi o curso d’agua Alencap, que apresentou apenas 1 mg/L. Quanto ao pH, foi possivel constatar que todos os igarapes apresentaram-se acidos, variando de 4,0 a 5,5. Existe a necessidade de uma conscientizacao ambiental da populacao residente no municipio principalmente da comunidade no entorno dos cursos d’ agua, para minimizar os impactos negativos da poluicao desses recursos hidricos.

The objective of this study is to identify and quantify the floristic composition of the weed community in the rice crop waterlogged in the municipality of Arari-MA. The botanical material was obtained in three areas by randomly a hollow rectangle of 0.50 m × 0.30 m by forty five times in each plot. The aerial parts of weeds were harvested, identified, counted and oven dried with forced air ventilation at 333.15 K to 343.15 K. These data were used to determine the phytosociological parameters and the Shannon-Wiener diversity index was also calculated. A total of 6607 plants were collected, being 4115 (62.28%) in the vegetative phase and 2492 (37.72%) in the reproductive phase. The monocotyledonous group obtained the largest number of plants, 2882 in the vegetative phase and 1535 in the reproductive phase. The Cyperaceae family recorded nine species and four genera and the Poaceae, seven and four species in the vegetative and reproductive phases, respectively. The species of higher IVI in the vegetative phase was E. sellowiana in the area A1 with 82.86%, and in the reproductive F. dichotoma with IVI of 90.49% in the area A3. The individuals density and species richness were higher in the vegetative phase of the culture and the monocotyledonous group predominated with the Cyperaceae and Poaceae families, and the weed diversity among the areas was low.

O feijao-caupi (Vigna unguiculata L. Walp.), compoem a dieta alimentar da populacao de baixa renda, em funcao do seu alto valor nutritivo. Objetivou-se com esse trabalho avaliar a evolucao e identificar as fontes de crescimento da produtividade de feijao-caupi para os principais produtores da regiao Nordeste Paraense no periodo de 2000-2014. Os dados utilizados foram provenientes de series temporais compostas pelas seguintes variaveis: area colhida, producao e produtividade da cultura do feijao-caupi, dos municipios Capanema, Braganca, Capitao Poco, Tracauteua, Augusto Correia, Garrafao do Norte, Ourem, Irituia no periodo de 2000 a 2014, disponibilizados pelo Instituto Brasileiro de Geografia e Estatistica. Sendo utilizado para quantificar as fontes de crescimento da producao, o metodo shift-share. A partir da analise dos dados foi possivel observar que as variaveis area colhida, producao e produtividade vem sofrendo reducao ao longo dos ultimos oito anos. A taxa geometrica de crescimento (TGC) obteve resultados de crescimento negativo para grande parte dos municipios produtores de feijao-caupi. Com relacao a produtividade se destaca com um leve crescimento em rendimentos o municipio de Irituia (1,68% ao ano) e o municipio de Augusto Correa com um crescimento em torno de (0,10 % ao ano). Nesse sentido e de grande importância politicas publicas de incentivos aos pequenos produtores rurais bem como assistencia tecnica que viabilizem o desenvolvimento produtivo da cultura na regiao.

Knowledge on the ideal conditions for the formation of high quality seedlings is fundamental to guarantee establishment success of crops in a safe and efficient manner. Here, we evaluate the effect of different substrates and irrigation frequencies on the initial growth of parica (Schizolobium parahyba var. amazonicum) seedlings. The experiment was conducted in a greenhouse at the Federal Rural University of Amazônia, Capitão Poço, PA. Several variables were analyzed including seedling height, stem diameter, number of leaflets, shoot dry matter, root dry matter, total dry matter, height and stem diameter ratio, shoot dry matter ratio and root dry matter. We found significant differences in seedling development between the applied treatments, including a significant interaction between substrate type and irrigation regime on seedling height, stem diameter, the number of leaflets and plant growth indices, with the best response for proportions 75% soil + 25% bovine manure and 50% soil + 50% bovine manure. Therefore, the substrates containing organic compounds resulted in a higher quality of the seedlings, while the sand consistently presented the lowest increases in seedling production under the three experimental irrigation frequencies, and thus is not recommended as a substrate for the development of Schizolobium parahyba var. amazonicum.

RESUMO: As aplicações de técnicas de agricultura de precisão no manejo da fertilidade do solo tem otimizado o uso de adubos possibilitando maior sustentabilidade dos sistemas agrícolas. Objetivou-se neste trabalho avaliar a variabilidade temporal de alguns atributos químicos do solo sob cultivo de grãos no município de Paragominas - PA, por meio do uso de técnicas de agricultura de precisão. O estudo foi desenvolvido em 17 propriedades agrícolas, nos anos de 2009 e 2010, mensurando resultados de 1.945 amostras de solos. Os solos cultivados com grãos apresentaram baixa acidez, saturação por base abaixo de 50%. A fertilidade do solo avaliada pelos resultados obtidos é de média a alta. Palavras-chave: adubação, fertilidade, manejo., The applications of precision agriculture techniques in the management of soil fertility has optimized the use of fertilizers enabling more sustainable agricultural systems. The objective of this study was to evaluate the temporal variability of some soil chemical properties under grain cultivation in the municipality of Paragominas - PA, through the use of precision agriculture techniques. The study was conducted on 17 farms in the years 2009 and 2010, measuring results of 1945 soil samples. The soils cultivated with grains had low acidity, base saturation below 50%. Soil fertility is evaluated by the results obtained from medium to high. Key-words: fertilization, fertility, management.

The state of Roraima has an area of ??225 116 km2, representing 2.64% of the national territory and 5.81% in the northern region. detailed knowledge of the spatial variability of soil fertility attributes can improve the localized applications of lime and fertilizers. The objective of this study was to evaluate the variability of some attributes (ph, ca +2 and p) chemical soil under cultivation of soybean and rice in the state of Roraima, with the help of precision agriculture. Soil sampling was conducted in 3265 ha, with sampling grid of 5 ha, totaling 653 sampling points (composite samples). Each composite sample was georeferenced and formed from 10 single samples collected in a circle around each sampling grid, thus resulting in a total of 6530 samples collected simple. For soils assessed with precision agriculture of the two municipalities, the attributes showed satisfactory levels of variation (available p) disabled (ca available), and very low (pH). Keywords: georeferencing, grains, soil fertility., O Estado de Roraima possui uma superfície de 225.116 km2, representando 2,64% do território nacional e 5,81% da Região Norte. O conhecimento detalhado da variabilidade espacial dos atributos da fertilidade do solo pode aperfeiçoar as aplicações localizadas de corretivos e fertilizantes. Objetivou-se neste trabalho, avaliar a variabilidade de alguns atributos (pH, Ca+2 e P) químicos de solos sob cultivo de soja e arroz no estado de Roraima, com auxílio da Agricultura de Precisão. A amostragem do solo foi realizada em 3265 ha, com grade amostral de 5 ha, perfazendo o total de 653 pontos amostrais (amostras compostas). Cada amostra composta foi georreferenciada e formada a partir de 10 amostras simples coletadas em um círculo ao redor de cada grade de amostragem, resultando assim num total de 6530 amostras simples coletadas. Para os solos avaliados com agricultura de precisão dos dois municípios, os atributos mostraram variação de níveis satisfatórios (P disponível) a deficientes (Ca disponível), e muito baixo (pH). PALAVRAS-CHAVE: fertilidade do solo, georreferenciamento, grãos.

RESUMO: A adocao de tecnicas racionais de manejo conservacionista do solo e da agua e de fundamental importância para a sustentabilidade. Os atributos fisicos do solo possuem importância edafica, uma vez que implicam diretamente na producao agricola. O objetivo desse trabalho foi avaliar o comportamento de alguns atributos fisicos do solo: a lâmina d`agua e a densidade do solo, em dois periodos do ano, em um Latossolo Amarelo no municipio de Capitao Poco, PA. As coletas foram realizadas aleatoriamente nas profundidades (0-20, 20-40, 40-60 e 60-80) em dois periodos consecutivos do ano, seco e chuvoso, respectivamente. O delineamento experimental utilizado foi o inteiramente casualizado (4 profundidades x 2 periodos de coleta). Os parâmetros fisicos analisados neste trabalho apresentaram distincoes entre os periodos analisados e quanto a profundidade amostrada. PALAVRAS-CHAVE: densidade, umidade, perfil do solo.