390 research outputs found
Spad index for diagnosis of nitrogen status in 'Esmeralda' peach.
O objetivo do presente trabalho foi avaliar a viabilidade técnica do índice SPAD no diagnóstico do estado de N em pessegueiros cv. Esmeralda. O experimento, com cinco níveis de N aplicado no solo (0; 40; 80; 120 e 160 kg ha-1 de N na forma de ureia), foi conduzido a campo, em delineamento experimental de blocos ao acaso, com quatro repetições. Durante os anos de 2014, 2015, 2016 e 2017, realizaram-se leituras com clorofilômetro, modelo Minolta SPAD-502, na parte mediana da folha, em 40 folhas por parcela. A determinação do teor foliar de N foi realizada em Analisador ElementarCHN-S. O índice SPAD e o teor de N nas folhas aumentaram de forma linear, de acordo com o aumento das doses de N aplicadas no solo. Houve efeito das doses de N aplicadas no solo sobre o índice SPAD, e os teores foliares de N apresentaram correlação linear positiva com as leituras SPAD (0.652; 0.756; 0.762 e 0.767, p<0.05). O índice SPAD pode ser utilizado no diagnóstico nutricional de N em pessegueiro, quando as leituras são realizadas entre a 13a e a 15a semana após a plena floração. Na faixa compreendida entre 39 e 49, o índice SPAD indica que o N foliar está compreendido na classe ?normal? (33 ? 45 g kg-1) de interpretação agronômica, para os Estados do Rio Grande do Sul e de Santa Catarina, Brasil
Nitrogen fertilization associated with cold storage and its impacts on the maintenance of peach quality.
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
Integração interinstitucional como estratégia PARA A diversificação produtiva da agricultura familiar.
Dark chocolate modulates platelet function with a mechanism mediated by flavan-3-ol metabolites
Cocoa is a rich source bioactive compounds, i.e., flavan-3-ols, and its consumption has been associated with several beneficial effects, such as the positive modulation of the hemostasis targeted by the platelet function. However, these phenolic compounds have a very low bioavailability and extensively undergo phase I and II metabolism, with the appearing into the bloodstream of (epi) catechin conjugates and phenyl-g-valerolactones and their conjugates, at different times. The aims of this study were to explore the effect of dark chocolate on platelet function and to investigate the relationship between this interplay and flavan-3-ol derived metabolites. Eighteen healthy male volunteers ingested 50 g of 90% cocoa chocolate within 5 minutes. Blood samples were collected immediately before chocolate ingestion (T0) and 4 hours afterwards (T1). Platelet function analyzer (PFA)-100 closure time was assessed using collagen/adenosine-50-diphosphate (COL/ADP) and collagen/epinephrine (COL/EPI) cartridges. Plasma flavan-3-ol metabolites were identified and quantified by means of liquid chromatography coupled to a triple quadrupole mass spectrometer (UHPLC-ESI-MS/MS). Results evidenced a significant increase of COL/ADP-induced PFA-100 closure time, but not COL/EPI, 4 hours after ingestion of dark chocolate. Total plasma structurally-related (epi)catechin metabolite (SREM) concentration significantly increased at T1, together with 4 out of the 6 detected metabolites. Total phenyl-g-valerolactone concentrations remained unchanged. Spearman correlations evidenced a strong correlation between COL/ADP closure time and SREMs, mainly led by (epi)catechin-sulfate isomers. These data confirm that the potential beneficial effect of dark chocolate on primary hemostasis may be mediated by flavan-3-ol circulating metabolites
Raleio mecânico de flores e frutos de diferentes genótipos de pessegueiros.
O raleio em pessegueiro tem como objetivo retirar o número excessivo de frutos da planta e eliminar aqueles danificados e/ou doentes, mas sem prejudicar a produtividade do pomar. Na produção de pêssegos, o raleio é realizado de forma manual para retirada dos frutos em excesso, necessitando ser executado em um curto período de tempo e com mão de obra especializada, o que eleva os custos de produção. Nesse sentido, o raleio mecânico pode ser uma alternativa ao raleio manual de frutos. Assim, o objetivo deste trabalho foi avaliar a eficiência do raleio mecânico de flores e frutos de pessegueiros com dois tipos de equipamentos. Foram realizados testes com os equipamentos derriçadeira e Carpa Electro®, mantendo-se o raleio manual como testemunha. No primeiro experimento, foi testado, nos anos de 2016 e 2017, o raleio mecânico de flores em seleções avançadas de pessegueiros. O segundo experimento foi realizado no ano de 2017, em pomar comercial da cultivar Maciel, testando-se os raleios mecânicos de flores e de frutos. Nos dois ensaios avaliou-se: porcentagem de derrubada de flores ou frutos, número de frutos por planta, massa média dos frutos, produção por planta e tempo de execução do raleio. Conforme os resultados, o raleio mecânico com os dois equipamentos pode ser alternativa ao raleio manual de frutos no cultivo de pessegueiros. Os equipamentos testados podem ser utilizados para o raleio mecânico de pessegueiro, pois auxiliam na derrubada de flores e frutos e reduzem o tempo de realização dessa operação.bitstream/item/224624/1/Boletim-339.pd
Nitrogen fertilization and genotypes of peaches in high-density.
Entre os fatores que afetam a produtividade dos pessegueiros, está a nutrição adequada das plantas, sendo o nitrogênio (N) um dos nutrientes primordiais para a cultura. Deste modo, o objetivo do presente trabalho foi avaliar o efeito da adubação nitrogenada de manutenção nos teores foliares de macronutrientes, no crescimento das plantas e na produção de diferentes genótipos de pessegueiros cultivados em alta densidade de plantio, buscando-se recomendar a concentração mais adequada. O experimento foi conduzido entre 2016 e 2018, com seleções avançadas de pessegueiros "Cascata 1513" e "Cascata 1067", e com concentrações de adubação nitrogenada (0; 60; 120 e 180 kg ha-1 de N). Avaliaram-se: massa de poda, diâmetro de tronco, número de frutos por planta, massa dos frutos, produção por planta e teor de macronutrientes nas folhas. O incremento das concentrações de N aumenta o teor do N nas folhas. Para as condições deste experimento, a máxima produção por planta foi obtida para a maior dose de 180 kg ha de N
Effect of salicylic acid in post-harvest quality of "BRS Kampai" peaches submitted to different cold storage periods.
Fast ripening of fruits is one of the main hindrances to peach preservation. Even though the use of cold storage has extended commercialization periods, fruit quality is affected during storage. This study aimed at evaluating the influence of application of salicylic acid (SA) during cold storage, followed by commercialization simulation, regarding physical and chemical characteristics of ?BRS Kampai? peaches, which were harvested in the 2017 crop. The experiment was conducted in a completely randomized factorial design (4×3: SA concentrations × storage days), with four replications of ten fruits each. SA was applied at the following concentrations: 0, 2, 4 and 6 mM. Afterwards, fruits were submitted to cold storage at 1±0.5ºC and 80-85% relative humidity. Analyses were carried out on harvest day, on the 10th cold storage day, followed by a day at room temperature (20ºC) and on the 20th cold storage day, followed by a day at room temperature. Fruits were evaluated in terms of their mass loss, epidermis color, chromatic hue, pulp firmness, soluble solids (SS), pH and titratable acidity (TA). Both application of SA and cold storage contributed to decrease mass loss and TA, besides increasing the SS/TA relation. Fruits which were stored for 20 days and kept at room temperature for a day exhibited the highest values of SS and the lowest values of both brightness and pulp firmness. SA was efficient to maintain the quality of ?BRS Kampai? peaches submitted to cold storage for 10 and 20 days and an extra day of commercialization simulation
Measurement of the Spin-Dependence of the pbar-p Interaction at the AD-Ring
We propose to use an internal polarized hydrogen storage cell gas target in
the AD ring to determine for the first time the two total spin-dependent pbar-p
cross sections sigma_1 and sigma_2 at antiproton beam energies in the range
from 50 to 450 MeV. The data obtained are of interest by themselves for the
general theory of pbar-p interactions since they will provide a first
experimental constraint of the spin-spin dependence of the nucleon-antinucleon
potential in the energy range of interest. In addition, measurements of the
polarization buildup of stored antiprotons are required to define the optimum
parameters of a future, dedicated Antiproton Polarizer Ring (APR), intended to
feed a double-polarized asymmetric pbar-p collider with polarized antiprotons.
Such a machine has recently been proposed by the PAX collaboration for the new
Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt, Germany.
The availability of an intense stored beam of polarized antiprotons will
provide access to a wealth of single- and double-spin observables, thereby
opening a new window on QCD spin physics.Comment: 51 pages, 23 figures, proposal submitted to the SPS committee of CER
Deficiência de nutrientes com efeitos no desenvolvimento de morangueiros.
A adubação do morangueiro é uma das principais práticas responsáveis pelo aumento da produção. Entretanto, ainda são insuficientes as informações sobre o efeito da omissão dos nutrientes minerais sobre o desenvolvimento do morangueiro. Neste contexto, o objetivo deste trabalho foi avaliar o crescimento dos morangueiros, visualizar os sintomas de deficiência nutricionais e os teores de nutrientes nas folhas decorrentes da omissão de macro e micro nutrientes. O delineamento experimental utilizado foi o inteiramente casualizado, com dez tratamentos e três repetições. Os tratamentos constituíram-se de solução completa e omissão individual de cada um dos seguintes nutrientes: nitrogênio (N), fósforo (P), potássio (K), cálcio (Ca), magnésio (Mg), cobre (Cu), manganês (Mn), zinco (Zn) e ferro (Fe). Avaliou-se: a massa fresca e seca da raiz, da parte aérea e da coroa, número de folhas e coroas, teores de macro e micronutrientes nas folhas e sintomas visuais de deficiência nutricional. A massa fresca e seca da parte aérea, o número de coroa e o número de folhas são mais prejudicados pela ausência de macronutrientes. O desenvolvimento do sistema radicular do morangueiro é menor na omissão dos macronutrientes. Menores teores de N, P, K, Ca, Mg e Fe nas folhas de morangueiro ocorrem quando são realizadas omissão desses elemento
Intermittent temperatures in the conservation of "BRS Kampai" peaches.
This study aimed at evaluating the quality of peaches borne by the cultivar BRS Kampai when cooled at intermittent temperatures throughout storage. They were stored at 1°C and relative humidity between 80% and 90% in a cold storage chamber. The following treatments were applied: T1 - fruit stored at 1±0.5°C; T2 - fruit stored at 1±0.5°C and increase in temperature every five days to 25°C; and T3 - fruit stored at 1±0.5°C and increase in temperature every seven days to 25°C. Fruit were submitted to increase in temperature when they were withdrawn from the cold storage chamber and kept in a heated room. Evaluations were conducted when fruit were harvested, after 10 cold storage days and 2 days of commercialization simulation at 25ºC (10+2) and after 20 cold storage days and 2 days of commercialization simulation at 25ºC (20+2). Peaches were evaluated in terms of mass loss, pulp firmness, soluble solids, titratable acidity, pH and epidermis color. T1 exhibited higher mass loss, higher soluble solid content and higher pulp firmness after 20 cold storage days, by comparison with the other treatments. T2 led to lower mass loss after 20 cold storage days than the ones of the other treatments. However, T2 also showed higher loss of pulp firmness in the same period. The use of intermittent temperatures throughout storage of ?BRS Kampai? peaches may be an alternative to extend their post-harvest period
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