RESUMO

BACKGROUND: 5-Fluorouracil (5-FU) is essential in treating gastrointestinal cancers, but some patients show severe toxicity. The toxicity is exposure-related, which is linked to the enzyme dihydropyrimidine dehydrogenase (DPD) decoded by the DPYD gene. This study aimed to evaluate the possible toxicity related to 5-FU plasma levels, DPYD genotyping, and DPD phenotyping. METHODS: Forty-seven gastrointestinal cancer patients receiving 5-FU were included in this study. 5-FU plasma levels and DPD phenotyping were analyzed by UPLC-MS/MS. DPYD genotyping was also assessed. The Common Terminology Criteria for Adverse Events (CTCAE) was used to classify the toxicity. RESULTS: For hematological toxicity, 27.65% showed neutropenia, 78.72% anemia, and 29.78% thrombocytopenia. The area under the curve (AUC) of 5-FU calculated from the plasma was evaluated for three treatment cycles, and we observed that at the initial cycle, 48.93% were underexposed and 10.63% were overexposed, with a total of 59.56% of patients outside the therapeutic range. In the DPYD genotyping, 97.87% of patients had a wild-type genotype, and 2.12% had c.1236G>A mutation (E412E, rs56038477). A total of 82.97% of patients showed a phenotype compatible with normal DPD activity. CONCLUSION: These findings suggest that the evaluation of DPYD genotyping and DPD phenotyping in the Brazilian population still requires further study. Moreover, the analysis of the plasma AUC of 5-FU could contribute to clinical routine, being a very useful tool, especially for identifying patients outside the therapeutic range and thus guiding more individualized doses, or even in the intervention of possible toxicities related to overexposure.

RESUMO

Lumbar disc degeneration (LDD) and low back pain (LBP) are two conditions that are closely related. Several studies have shown Cutibacterium acnes colonization of degenerated discs, but whether and how these finding correlates with LBP is unknown. A prospective study was planned to identify molecules present in lumbar intervertebral discs (LLIVD) colonized by C. acnes in patients with LDD and LBP and correlate them with their clinical, radiological, and demographic profiles. The clinical manifestations, risk factors, and demographic characteristics of participants undergoing surgical microdiscectomy will be tracked. Samples will be isolated and pathogens found in LLIVD will be characterized phenotypically and genotypically. Whole genome sequencing (WGS) of isolated species will be used to phylotype and detect genes associated with virulence, resistance, and oxidative stress. Multiomic analyses of LLIVD colonized and non-colonized will be carried out to explain not only the pathogen's role in LDD, but also its involvement in the pathophysiology of LBP. This study was approved by the Institutional Review Board (CAAE 50077521.0.0000.5258). All patients who agree to participate in the study will sign an informed consent form. Regardless of the study's findings, the results will be published in a peer-reviewed medical journal. Trials registration number NCT05090553; pre-results.

Assuntos

Assuntos

RESUMO

RoundUp® (RUp) is a comercial formulation containing glyphosate (N-(phosphono-methyl) glycine), and is the world's leading wide-spectrum herbicide used in agriculture. Supporters of the broad use of glyphosate-based herbicides (GBH) claim they are innocuous to humans, since the active compound acts on the inhibition of enzymes which are absent in human cells. However, the neurotoxic effects of GBH have already been shown in many animal models. Further, these formulations were shown to disrupt the microbiome of different species. Here, we investigated the effects of a lifelong exposure to low doses of the GBH-RUp on the gut environment, including morphological and microbiome changes. We also aimed to determine whether exposure to GBH-RUp could harm the developing brain and lead to behavioral changes in adult mice. To this end, animals were exposed to GBH-RUp in drinking water from pregnancy to adulthood. GBH-RUp-exposed mice had no changes in cognitive function, but developed impaired social behavior and increased repetitive behavior. GBH-Rup-exposed mice also showed an activation of phagocytic cells (Iba-1-positive) in the cortical brain tissue. GBH-RUp exposure caused increased mucus production and the infiltration of plama cells (CD138-positive), with a reduction in phagocytic cells. Long-term exposure to GBH-RUp also induced changes in intestinal integrity, as demonstrated by the altered expression of tight junction effector proteins (ZO-1 and ZO-2) and a change in the distribution of syndecan-1 proteoglycan. The herbicide also led to changes in the gut microbiome composition, which is also crucial for the establishment of the intestinal barrier. Altogether, our findings suggest that long-term GBH-RUp exposure leads to morphological and functional changes in the gut, which correlate with behavioral changes that are similar to those observed in patients with neurodevelopmental disorders.

Assuntos

RESUMO

Nitrogen, which is the primary nutrient peach trees need, may affect their fruit quality. Thus, this study aimed at evaluating the effect of nitrogen fertilization on two genotypes of peach trees, regarding their fruit quality, in three consecutive crops. The experiment was carried out in the experimental area that belongs to the Embrapa Clima Temperado, located in Pelotas, Rio Grande do Sul (RS), Brazil, from 2016, 2016, 2017 and 2018. Four doses of nitrogen (0, 60, 120 and 180 Kg ha-1) and two peach tree genotypes ('Cascata 1513' and 'Cascata 1067') were used. For the fruit, we evaluated epidermis color, pulp firmness, epidermis firmness, soluble solids concentration, titratable acidity, concentration of total phenolic compounds, anthocyanins and antioxidant activity. Fruit underwent physical, chemical and bioactive compound analyses. Results showed that the highest dose of nitrogen (180 Kg ha-1) applied to the soil retards fruit ripening, while no application of nitrogen fertilization brings fruit maturation forward. Nitrogen fertilization via soil does not favor anthocyanins in fruit. Doses of 60 and 120 Kg ha-1 of nitrogen are recommended because they lead to improvement in peach color, epidermis firmness and acidity. Peach tree genotypes influence soluble solids, juice pH, phenolic compounds and antioxidant activity of their fruit.

Assuntos

RESUMO

Staphylococcus spp. and Cutibacterium acnes are members of the skin microbiome but can also act as pathogens. Particularly, Staphylococcus species are known to cause medical devices-associated infections, and biofilm production is one of their main virulence factors. Biofilms allow bacteria to adhere and persist on surfaces, protecting them from antimicrobials and host defenses. Since both bacteria are found in the human skin, potentially competing for niches, we aimed to investigate if C. acnes produces molecules that affect Staphylococcus spp. biofilm formation and dispersal. Thus, we evaluated the impact of C. acnes cell-free conditioned media (CFCM) on S. aureus, S. epidermidis, S. hominis, and S. lugdunensis biofilm formation. S. lugdunensis and S. hominis biofilm formation was significantly reduced with C. acnes CFCM without impact on their planktonic growth. C. acnes CFCM also significantly disrupted S. hominis established biofilms. The active molecules against S. lugdunensis and S. hominis biofilms appeared to be distinct since initial characterization points to different sizes and sensitivity to sodium metaperiodate, although the activity is highly resistant to heat in both cases. Mass spectrometry analysis of the fractions active against S. hominis revealed several potential candidates. Investigating how species present in the same environment interact, affecting the dynamics of biofilm formation, may reveal clinically useful compounds as well as molecular aspects of interspecies interactions.

Assuntos

RESUMO

Humans live in symbiosis with a diverse community of microorganisms, which has evolved to carry out many specific tasks that benefit the host, including protection against invading pathogens. Within the chemical diversity of the gastrointestinal tract, small molecules likely constitute chemical cues for the communication between the microbiota and pathogens. Therefore, we sought to investigate if molecules produced by the human gut microbiota show biological activity against the human pathogen Vibrio cholerae. To probe the effects of the gut metabolome on V. cholerae, we investigated its response to small-molecule extracts from human feces, from a complex bacterial community cultivated in vitro, and from culture supernatants of Enterocloster citroniae, Bacteroides thetaiotaomicron, and Bacteroides vulgatus. Using RNA sequencing, we determined the impact of the human gut metabolome on V. cholerae global gene expression. Among the genes downregulated in the presence of the fecal extract, the most overrepresented functional category was cell motility, which accounted for 39% of repressed genes. Repression of V. cholerae motility by the fecal extract was confirmed phenotypically, and E. citroniae extracts reproduced this phenotype. A complex in vitro microbial community led to increased motility, as did extracts from B. vulgatus, a species present in this community. Accordingly, mucin penetration was also repressed by fecal and E. citroniae extracts, suggesting that the phenotypes observed may have implications for host colonization. Together with previous studies, this work shows that small molecules from the gut metabolome may have a widespread, significant impact on microbe-microbe interactions established in the gut environment.

Assuntos

RESUMO

Blackberry is a species which has high potential to grow in an organic production system. However, there is scarce information on the behavior of cultivars and selections of this species conducted in an ecologically based system, a fact that makes it difficult to recommend cultivars for this production system. This study aimed to evaluate and characterize the phenology and productive aspects of six blackberry genotypes grown in an organic system, in Pelotas, Rio Grande do Sul (RS) state, Brazil. Evaluation of the following variables was carried out in the three first production cycles (2015-2016, 2016-2017 and 2017-2018): phenology, number of fruits.pl-¹, mean fruit yield.pl-¹, yield (kg.ha-¹), mean fruit mass (g) and soluble solid content (° Brix). Regarding phenology, genotype Black 112 was later than the others whereas Black 178 was the most precocious one. In the last year under evaluation, genotypes yielded around 10 ton.ha-¹, except Black 128 selection, which yielded approximately 6,767 ton.ha-¹. Genotypes Black 178, Black 112 and Black 145 and both cultivars BRS Xingu and Tupy exhibited potential to grow in an organic production system.

Assuntos

RESUMO

Objetivou-se avaliar o desempenho agronômico de cultivares de morangueiro, a partir de mudas ‘plug plant’ produzidas com diferentes soluções nutritivas, em sistema de cultivo sem solo. Os experimentos foram realizados em casa de vegetação com a utilização de mudas das cultivares Aromas e Camarosa, as quais foram produzidas com quatro soluções nutritivas. Foram avaliados dois ciclos de cultivo. O primeiro, de abril de 2017 à março de 2018, foram avaliados o desempenho agronômico de duas cultivares (Camarosa e Aromas) e quatro soluções nutritivas (SN1, SN2, SN3 e SN4), em esquema fatorial 2 x 4. No segundo ciclo, de abril a dezembro de 2018, foram avaliadas duas cultivares (Camarosa e Aromas) e duas soluções nutritivas (SN3 e SN4), em esquema fatorial 2 x 2. Em ambos os ciclos, avaliaram-se variáveis fenológicas, produtivas e matéria seca de folhas, coroas e estolões. A utilização das diferentes soluções nutritivas na fase de produção dos propágulos não influenciou a maioria das variáveis analisadas, uma vez que o ciclo do morangueiro é longo e o efeito das mesmas acaba se diluindo no decorrer do mesmo. No entanto, o efeito do fator cultivar foi significativo, sendo que, no geral, ‘Camarosa’ foi mais precoce que ‘Aromas’ em relação às variáveis fenológicas referentes à floração, frutificação e estolonamento. As cultivares apresentaram produção de frutas similares entre si nos doisciclos de cultivo. ‘Camarosa’ apresenta maior produção de matéria seca de folhas e estolões em comparação com a cultivar Aromas.

The objective of this study was to evaluate the agronomic performance of strawberry cultivars established from plug plant plantlets produced with different nutrient solutions in a soilless system. The experiments were carried out in a greenhouse using seedlings of the Aromas and Camarosa cultivars, produced with four different nutrient solutions. Two cycles were evaluated. In the first, from April 2017 to March 2018, the agronomic performance of two cultivars (Camarosa and Aromas) and four nutrient solutions (NS1, NS2, NS3, and NS4) was assessed in a 2 x 4 factorial scheme. In the second cycle, from April to December 2018, two cultivars (Camarosa and Aromas) and two nutrients solutions (NS3 and NS4) were evaluated in a 2 x 2 factorial scheme. In both cycles, phenological, productive variables and the dry matter of leaves, crowns, and stolons were evaluated. The use of different nutrient solutions in the tip production stage did not influence most of the analyzed variables since the strawberry cycle is long, so their effects end up being diluted over time. However, the effect of the cultivar factor was significant, and, in general, the Camarosa cultivar was more precocious than the Aromas regarding the phenological variables related to flowering, fruiting, and tipping. The cultivars presented fruit production similar to each other in the two crop cycles, with Camarosa presenting greater production of dry matter of leaves and stolons than the Aromascultivar.

Assuntos

RESUMO

Objetivou-se avaliar o desempenho agronômico de cultivares de morangueiro, a partir de mudas ‘plug plant produzidas com diferentes soluções nutritivas, em sistema de cultivo sem solo. Os experimentos foram realizados em casa de vegetação com a utilização de mudas das cultivares Aromas e Camarosa, as quais foram produzidas com quatro soluções nutritivas. Foram avaliados dois ciclos de cultivo. O primeiro, de abril de 2017 à março de 2018, foram avaliados o desempenho agronômico de duas cultivares (Camarosa e Aromas) e quatro soluções nutritivas (SN1, SN2, SN3 e SN4), em esquema fatorial 2 x 4. No segundo ciclo, de abril a dezembro de 2018, foram avaliadas duas cultivares (Camarosa e Aromas) e duas soluções nutritivas (SN3 e SN4), em esquema fatorial 2 x 2. Em ambos os ciclos, avaliaram-se variáveis fenológicas, produtivas e matéria seca de folhas, coroas e estolões. A utilização das diferentes soluções nutritivas na fase de produção dos propágulos não influenciou a maioria das variáveis analisadas, uma vez que o ciclo do morangueiro é longo e o efeito das mesmas acaba se diluindo no decorrer do mesmo. No entanto, o efeito do fator cultivar foi significativo, sendo que, no geral, ‘Camarosa foi mais precoce que ‘Aromas em relação às variáveis fenológicas referentes à floração, frutificação e estolonamento. As cultivares apresentaram produção de frutas similares entre si nos doisciclos de cultivo. ‘Camarosa apresenta maior produção de matéria seca de folhas e estolões em comparação com a cultivar Aromas.(AU)

The objective of this study was to evaluate the agronomic performance of strawberry cultivars established from plug plant plantlets produced with different nutrient solutions in a soilless system. The experiments were carried out in a greenhouse using seedlings of the Aromas and Camarosa cultivars, produced with four different nutrient solutions. Two cycles were evaluated. In the first, from April 2017 to March 2018, the agronomic performance of two cultivars (Camarosa and Aromas) and four nutrient solutions (NS1, NS2, NS3, and NS4) was assessed in a 2 x 4 factorial scheme. In the second cycle, from April to December 2018, two cultivars (Camarosa and Aromas) and two nutrients solutions (NS3 and NS4) were evaluated in a 2 x 2 factorial scheme. In both cycles, phenological, productive variables and the dry matter of leaves, crowns, and stolons were evaluated. The use of different nutrient solutions in the tip production stage did not influence most of the analyzed variables since the strawberry cycle is long, so their effects end up being diluted over time. However, the effect of the cultivar factor was significant, and, in general, the Camarosa cultivar was more precocious than the Aromas regarding the phenological variables related to flowering, fruiting, and tipping. The cultivars presented fruit production similar to each other in the two crop cycles, with Camarosa presenting greater production of dry matter of leaves and stolons than the Aromascultivar.(AU)

Assuntos

RESUMO

Pseudomonas aeruginosa is one of the most common pathogens related to healthcare-associated infections. The Brazilian isolate, named CCBH4851, is a multidrug-resistant clone belonging to the sequence type 277. The antimicrobial resistance mechanisms of the CCBH4851 strain are associated with the presence of the bla[Formula: see text] gene, encoding a metallo-beta-lactamase, in combination with other exogenously acquired genes. Whole-genome sequencing studies focusing on emerging pathogens are essential to identify key features of their physiology that may lead to the identification of new targets for therapy. Using both Illumina and PacBio sequencing data, we obtained a single contig representing the CCBH4851 genome with annotated features that were consistent with data reported for the species. However, comparative analysis with other Pseudomonas aeruginosa strains revealed genomic differences regarding virulence factors and regulatory proteins. In addition, we performed phenotypic assays that revealed CCBH4851 is impaired in bacterial motilities and biofilm formation. On the other hand, CCBH4851 genome contained acquired genomic islands that carry transcriptional factors, virulence and antimicrobial resistance-related genes. Presence of single nucleotide polymorphisms in the core genome, mainly those located in resistance-associated genes, suggests that these mutations may also influence the multidrug-resistant behavior of CCBH4851. Overall, characterization of Pseudomonas aeruginosa CCBH4851 complete genome revealed the presence of features that strongly relates to the virulence and antibiotic resistance profile of this important infectious agent.

Assuntos

RESUMO

Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp. and Salmonella spp. are part of a group of pathogens that pose a major threat to human health due to the emergence of multidrug-resistant strains. Moreover, these bacteria have several virulence factors that allow them to successfully colonize their hosts, such as toxins and the ability to produce biofilms, resulting in an urgent need to develop new strategies to fight these pathogens. In this review, we compile the most up-to-date information on the epidemiology, virulence and resistance of these clinically important microorganisms. Additionally, we address new therapeutic alternatives, with a focus on molecules with antivirulence activity, which are considered promising to combat multidrug-resistant bacteria.

Assuntos

Assuntos

RESUMO

Nitrogen, which is considered the most important nutrient for peach trees, may interfere in both quantitative production characteristics and quality of fruits. This study aimed at evaluating the effect of the combination of doses of N fertilization and different periods of cold storage on physico-chemical and phytochemical characteristics of peaches in post-harvest. The experiment had a randomized complete block design in a 4x3 factorial scheme, i. e., four doses of fertilization (0, 60, 120 and 180 Kg N ha-1) and three periods of storage (on the harvest day, on both the 15th and the 30th storage days at 1±1ºC, each followed by a day of simulated commercialization at 20±1ºC). The following aspects were evaluated in fruits yielded by peach trees of the genotype Cascata 1067: fruit color, soluble solid content, titratable acidity, pulp firmness, mass loss, total phenolic compounds and antioxidant activity. Different periods of cold storage and doses of N fertilization were found to affect epidermis luminosity, pulp firmness and titratable acidity of fruits. Peaches may be stored at low temperatures for 15+1 days. After that, loss of fruit firmness increases. N fertilization affects neither the soluble solid content nor the epidermis color of peaches, but both parameters are influenced by storage. Values of phenolic compounds and antioxidant activity decrease when there is N increment in the soil and when longer storage is carried out. Results suggest that peach composition may be affected by cultural practices, such as N fertilization, in harvest and after storage.

O nitrogênio é o nutriente considerado de maior importância para o pessegueiro, podendo interferir nas características quantitativas da produção, bem como na qualidade dos frutos. O objetivo do trabalho foi avaliar o efeito da combinação de doses de adubação nitrogenada e de diferentes períodos de armazenamento refrigerado nas características físico-químicas e fitoquímicas de pêssegos na pós-colheita. O delineamento experimental foi o de blocos casualizados em esquema fatorial 4x2, quatro doses de adubação (0, 60, 120 e 180 Kg N ha-1) e três períodos de armazenamento (dia da colheita, aos 15 e 30 dias armazenamento refrigerado a 1±1ºC, seguido de um dia de simulação de comercialização a 20±1ºC). Avaliou-se, nos frutos de pessegueiro do genótipo Cascata 1067, a coloração dos frutos, o teor de sólidos solúveis, acidez titulável, firmeza da polpa, perda de massa, compostos fenólicos totais e a atividade antioxidante. Verificou-se que diferentes períodos de armazenamento refrigerado e doses de adubação nitrogenada afetam a luminosidade da epiderme, a firmeza de polpa e a acidez titulável dos frutos. Os pêssegos podem ser armazenados em baixa temperatura até 15+1 dias, após esse período, a perda de firmeza nos frutos é elevada. A adubação nitrogenada não altera o teor de sólidos solúveis e a coloração da epiderme dos pêssegos, mas esses parâmetros são influenciados durante o armazenamento. Os compostos fenólicos e atividade antioxidante decrescem com o incremento de nitrogênio no solo, bem como durante o avanço dos dias de armazenamento. Os resultados sugerem que a composição dos pêssegos pode ser afetada com práticas culturais como a adubação de nitrogênio na colheita e após o armazenamento.

Assuntos

RESUMO

The microbiota influences host health through several mechanisms, including protecting it from pathogen colonization. Staphylococcus epidermidis is one of the most frequently found species in the skin microbiota, and its presence can limit the development of pathogens such as Staphylococcus aureusS. aureus causes diverse types of infections ranging from skin abscesses to bloodstream infections. Given the increasing prevalence of S. aureus drug-resistant strains, it is imperative to search for new strategies for treatment and prevention. Thus, we investigated the activity of molecules produced by a commensal S. epidermidis isolate against S. aureus biofilms. We showed that molecules present in S. epidermidis cell-free conditioned media (CFCM) caused a significant reduction in biofilm formation in most S. aureus clinical isolates, including all 4 agr types and agr-defective strains, without any impact on growth. S. epidermidis molecules also disrupted established S. aureus biofilms and reduced the antibiotic concentration required to eliminate them. Preliminary characterization of the active compound showed that its activity is resistant to heat, protease inhibitors, trypsin, proteinase K, and sodium periodate treatments, suggesting that it is not proteinaceous. RNA sequencing revealed that S. epidermidis-secreted molecules modulate the expression of hundreds of S. aureus genes, some of which are associated with biofilm production. Biofilm formation is one of the main virulence factors of S. aureus and has been associated with chronic infections and antimicrobial resistance. Therefore, molecules that can counteract this virulence factor may be promising alternatives as novel therapeutic agents to control S. aureus infections.IMPORTANCES. aureus is a leading agent of infections worldwide, and its main virulence characteristic is the ability to produce biofilms on surfaces such as medical devices. Biofilms are known to confer increased resistance to antimicrobials and to the host immune responses, requiring aggressive antibiotic treatment and removal of the infected surface. Here, we investigated a new source of antibiofilm compounds, the skin microbiome. Specifically, we found that a commensal strain of S. epidermidis produces molecules with antibiofilm activity, leading to a significant decrease of S. aureus biofilm formation and to a reduction of previously established biofilms. The molecules potentiated the activity of antibiotics and affected the expression of hundreds of S. aureus genes, including those associated with biofilm formation. Our research highlights the search for compounds that can aid us in the fight against S. aureus infections.

Assuntos

RESUMO

For peach trees produced in southern Brazil, information about the influence of potassium fertilization on fruit quality remains scarce. This study set out to determine the physicochemical properties and bioactive compounds of peaches treated with different doses of potassium applied to the soil for three consecutive crop years. The experiment examined the Sensação cultivar in a commercial orchard in the municipality of Morro Redondo, Rio Grande do Sul, Brazil, during the 2016, 2017, and 2018 crop years. Peach trees of the Sensação cultivar were fertilized with potassium (K); doses of 0, 40, 80, 120, and 160 kg ha-1 of K2O in the form of potassium chloride were applied to the soil surface. After harvest, an assessment was made of the soluble solids (SS) content, titratable acid (TA) content, SS/TA ratio, pH levels, flesh color, skin and flesh firmness, total carotenoid content, total phenolic content, and antioxidant activity. The peaches skin firmness, SS/TA ratio, and concentration of carotenoids responded to potassium fertilization, but only in some production cycles. Their color, flesh firmness, soluble solids, juice pH levels, total phenols, and antioxidant activity did not change with the application of potassium in the soil.(AU)

Para pessegueiros produzidos na região sul do Brasil ainda são escassas as informações sobre a influência da adubação potássica sobre a qualidade dos frutos. Deste modo, o presente trabalho teve como objetivo avaliar os atributos físico-químicos e compostos bioativos dos frutos de pessegueiros submetidos a diferentes doses de potássio aplicadas no solo por três safras consecutivas. O experimento foi realizado estudando a cultivar Sensação em um pomar comercial no município de Morro Redondo, RS Brasil, durante as safras de 2016, 2017 e 2018. Os pessegueiros da cultivar Sensação foram adubados com potássio (K) nas doses de 0, 40, 80, 120 e 160 kg ha-1 de K2O na forma de cloreto de potássio, aplicadas na superfície do solo. Após a colheita foram determinados os teores de sólidos solúveis (SS), acidez titulável (AT), relação SS/AT, pH, coloração da polpa, firmeza da epiderme e da polpa, teor de carotenoides totais, compostos fenólicos totais e atividade antioxidante. A firmeza da epiderme, a relação SS/AT e a concentração de carotenoides dos pêssegos responderam à adubação potássica, mas apenas em alguns ciclos de produção. Os parâmetros de coloração, firmeza da polpa, sólidos solúveis, pH do suco, fenóis totais e atividade antioxidante dos pêssegos não alteraram em decorrência da aplicação de potássio ao solo.(AU)

Assuntos

RESUMO

Técnicas que melhorem a eficiência do processo e reduzam o custo de operação são importantes ferramentas na redução dos custos. Dois dispositivos mecânicos foram utilizados para testar a eficiência no raleio de frutos e flores em pessegueiros e a influencia nas características produtivas e qualitativas dos frutos. O estudo foi realizado na cultivar Maciel em pomar comercial no município de Pelotas, Rio Grande do Sul, Brasil. Os tratamentos foram: raleio mecânico de flores com o equipamento Carpa Electro® e derriçadeira, raleio mecânico de frutos com o equipamento derriçadeira e raleio manual de frutos. O raleio mecânico associado ao repasse manual em pessegueiros pode ser uma alternativa viável ao raleio manual, pois reduz o tempo de execução desta prática. Os dois equipamentos podem ser utilizados para o raleio mecânico, pois não alteraram a produção por planta, o número de frutos por planta, a massa dos frutos, diâmetro dos frutos, as características físico-químicas e os compostos bioativos dos frutos.

Techniques that improve process efficiency are important to reduce the operational cost of orchards. Two mechanical devices were tested to verify the efficiency of peach tree thinning and the influence on fruit production and quality characteristics. The experiment was conducted using the Maciel cultivar in a commercial orchard in Pelotas, Rio Grande do Sul, Brazil. The treatments consisted of mechanical flower blossom thinning using the Carpa ElectroTM and trimming equipment; mechanical fruit thinning using the trimming equipment; and manual fruit thinning. The mechanical thinning associated with manual thinning of peach trees may be a viable alternative to manual thinning since it reduces the execution time. Both equipment can be used for mechanical thinning since they didn't change the production per plant, number of fruits per plant, fruit mass, fruit diameter, physicochemical characteristics, and bioactive compounds of the fruits.

Assuntos

RESUMO

For peach trees produced in southern Brazil, information about the influence of potassium fertilization on fruit quality remains scarce. This study set out to determine the physicochemical properties and bioactive compounds of peaches treated with different doses of potassium applied to the soil for three consecutive crop years. The experiment examined the Sensação cultivar in a commercial orchard in the municipality of Morro Redondo, Rio Grande do Sul, Brazil, during the 2016, 2017, and 2018 crop years. Peach trees of the Sensação cultivar were fertilized with potassium (K); doses of 0, 40, 80, 120, and 160 kg ha-1 of K2O in the form of potassium chloride were applied to the soil surface. After harvest, an assessment was made of the soluble solids (SS) content, titratable acid (TA) content, SS/TA ratio, pH levels, flesh color, skin and flesh firmness, total carotenoid content, total phenolic content, and antioxidant activity. The peaches skin firmness, SS/TA ratio, and concentration of carotenoids responded to potassium fertilization, but only in some production cycles. Their color, flesh firmness, soluble solids, juice pH levels, total phenols, and antioxidant activity did not change with the application of potassium in the soil.

Para pessegueiros produzidos na região sul do Brasil ainda são escassas as informações sobre a influência da adubação potássica sobre a qualidade dos frutos. Deste modo, o presente trabalho teve como objetivo avaliar os atributos físico-químicos e compostos bioativos dos frutos de pessegueiros submetidos a diferentes doses de potássio aplicadas no solo por três safras consecutivas. O experimento foi realizado estudando a cultivar Sensação em um pomar comercial no município de Morro Redondo, RS Brasil, durante as safras de 2016, 2017 e 2018. Os pessegueiros da cultivar Sensação foram adubados com potássio (K) nas doses de 0, 40, 80, 120 e 160 kg ha-1 de K2O na forma de cloreto de potássio, aplicadas na superfície do solo. Após a colheita foram determinados os teores de sólidos solúveis (SS), acidez titulável (AT), relação SS/AT, pH, coloração da polpa, firmeza da epiderme e da polpa, teor de carotenoides totais, compostos fenólicos totais e atividade antioxidante. A firmeza da epiderme, a relação SS/AT e a concentração de carotenoides dos pêssegos responderam à adubação potássica, mas apenas em alguns ciclos de produção. Os parâmetros de coloração, firmeza da polpa, sólidos solúveis, pH do suco, fenóis totais e atividade antioxidante dos pêssegos não alteraram em decorrência da aplicação de potássio ao solo.

Assuntos

RESUMO

Técnicas que melhorem a eficiência do processo e reduzam o custo de operação são importantes ferramentas na redução dos custos. Dois dispositivos mecânicos foram utilizados para testar a eficiência no raleio de frutos e flores em pessegueiros e a influencia nas características produtivas e qualitativas dos frutos. O estudo foi realizado na cultivar Maciel em pomar comercial no município de Pelotas, Rio Grande do Sul, Brasil. Os tratamentos foram: raleio mecânico de flores com o equipamento Carpa Electro® e derriçadeira, raleio mecânico de frutos com o equipamento derriçadeira e raleio manual de frutos. O raleio mecânico associado ao repasse manual em pessegueiros pode ser uma alternativa viável ao raleio manual, pois reduz o tempo de execução desta prática. Os dois equipamentos podem ser utilizados para o raleio mecânico, pois não alteraram a produção por planta, o número de frutos por planta, a massa dos frutos, diâmetro dos frutos, as características físico-químicas e os compostos bioativos dos frutos.(AU)

Techniques that improve process efficiency are important to reduce the operational cost of orchards. Two mechanical devices were tested to verify the efficiency of peach tree thinning and the influence on fruit production and quality characteristics. The experiment was conducted using the Maciel cultivar in a commercial orchard in Pelotas, Rio Grande do Sul, Brazil. The treatments consisted of mechanical flower blossom thinning using the Carpa ElectroTM and trimming equipment; mechanical fruit thinning using the trimming equipment; and manual fruit thinning. The mechanical thinning associated with manual thinning of peach trees may be a viable alternative to manual thinning since it reduces the execution time. Both equipment can be used for mechanical thinning since they didn't change the production per plant, number of fruits per plant, fruit mass, fruit diameter, physicochemical characteristics, and bioactive compounds of the fruits.(AU)

Assuntos

RESUMO

Raspberry (Rubus idaeus L.) is an economically important crop and its cultivation has been expanded across temperate and subtropical regions of Brazil. Growing raspberries under plastic cover has becoming more common worldwide. This study investigated the effect of plastic cover on productive and morphological performance of primocane-fruiting raspberry cultivars, in southern Brazil. The experiment was arranged in a 3 × 2 × 2 factorial design, with three raspberry cultivars, ‘Heritage’; ‘Fallgold’ and ‘Alemãzinha’; two cultivation systems, presence and absence of plastic cover; and two production cycles, fall and spring. We measured days from transplanting to flowering and harvesting. Plants were evaluated for dry mass of pruning, plant height, stem diameter, plant leaf area, fruit production, number of fruits, fruit weight, fruit longitudinal and transversal diameter, and harvesting period. Plastic cover reduced incident radiation on the canopy by 17 %. Cultivar ‘Heritage’ is early ripening in the fall cycle. The management under plastic cover prolonged the harvesting period of raspberries in the fall productive cycle for the cultivar ‘Heritage’ and, in spring, for cultivars ‘Alemãzinha’ and ‘Fallgold’. In the spring cycle, plants increased their leaf area, fruit production and number of fruits. The cultivar ‘Alemãzinha’ performed better in the spring cycle when managed under plastic cover and was more productive, with a longer productive cycle and larger fruits.

Assuntos