29 research outputs found

    Efeitos da pulverização pré-colheita com thidiazuron sobre a qualidade e a maturação de frutos em macieiras

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    ABSTRACTApple trees, cultivars Gala and Fuji, were sprayed at full bloom with thidiazuron (TDZ) at the doses of 0, 5, 10, or 20 g (a.i.) ha-1 and fruit were assessed for quality and maturity. In both cultivars, the increase of TDZ dose had detrimental effects on fruit quality, causing a reduction of fruit red surface and an increase of percentage of fruit that was asymmetrical and with calyx-end rot. TDZ caused an increment of calyx-end aperture that might have increased calyx-end rot. TDZ increased density and the length : diameter (L : D) ratio of the fruit. The number of viable seeds was not affected by TDZ. TDZ resulted in a substantial delay of fruit maturity in ‘Gala’ but not in ‘Fuji’. TDZ also reduced soluble solids content (SSC) in ‘Gala’ and reduced titratable acidity in both cultivars. ______________________________________________________________________________ RESUMOMacieiras, cultivares Gala e Fuji, foram pulverizadas em plena floração com thidiazuron (TDZ), nas doses de 0; 5; 10 e 20 g (i.a.) ha-1, e os frutos avaliados em termos de qualidade e maturação. Em ambas as cultivares, o TDZ apresentou efeitos negativos na qualidade dos frutos, com redução na percentagem de cor vermelha na casca e aumento na percentagem de frutos assimétricos e com podridão carpelar. O TDZ causou aumento na abertura carpelar, o que pode ter ocasionado aumento de incidência de podridão carpelar. O TDZ aumentou a densidade e a relação comprimento : diâmetro (C : D) dos frutos. O número de sementes viáveis não foi afetado pelo TDZ. O TDZ retardou substancialmente a maturação dos frutos na cultivar Gala, mas não na cultivar Fuji. O TDZ reduziu os teores de sólidos solúveis totais na cultivar Gala e reduziu a acidez titulável em ambas as cultivares

    Influence of different parts of cuttings and substrates on vegetative propagation of Pereskia aculeata miller

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    Pereskia aculeta Miller, commonly know as ora-pro-nóbis in some regions of Brazil, is a plant stands out due to its high protein content, presenting great potential for use. There is na increasing interest in the use of ora-pro-nóbis as raw material by the food industry like as concentrate form (deydrated and ground) or for direct consumption as leafy vegeTables by the population. So, is important to know the best way to propagate this specie. This study was carried out to evaluate the influence of cutting position from stem and the substrate type under growth and development of ora-pro-nóbis during seedlings production. For incresing the seedlings production to supply the demand and the lack scientific studies on this theme, this study is important to development research to vegetative propagation and substrate to produce ora-pro-nóbis seedlings. For vegetative propagation three types of cutting were used: apical, median and from the basal part of the stem. The cuttings were planted in four types of substrate: S1 = soil; S2 = soil + clean sand (1:1); S3 = soil + clean sand + cattle manure (2:1:1) and S4 = Bioplant® commercial substrate. Sixty days after the experiment was set up, the cuttings were examined considering: the Soil Plant Analysis Development (SPAD) index, the number of leaves, the number of shoots, root length, and dry and fresh mass from the root and from the aerial part. The physiological maturation of the stem and the tested substrate type showed differences on the quality of the cutting. The cutting originated from the basal and medium part harvested from the branch of the year and the substrate soil + sand + manure allowed the best growth and development of the ora-pro-nóbis seedlings

    A PULVERIZAÇÃO PRÉ-COLHEITA COM TIDIAZURON REDUZ O TEOR DE CÁLCIO E AUMENTA A ABERTURA CARPELAR E A INCIDÊNCIA DE PODRIDÃO CARPELAR EM FRUTOS DE MAÇÃ

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    Thidiazuron (TDZ; N-phenyl-N’-1,2,3- thiadiazol-5-ylureia) is a substituted phenylurea that shows strong cytokinin-like activity in plant tissues. The product is sprayed at full bloom on apple trees to increase fruit set and improve fruit growth. Besides affecting tree physiology and fruit size, TDZ might influence other aspects related to fruit quality. Treated plants normally bear malformed fruits with a more protruded distal end. This work was carried out to investigate the effects of TDZ on fruit carpel aperture, fruit shape, seed number, fruit calcium content, and moldy core (caused by several pathogens) of apples. Apple trees, cultivars Gala and Fuji, were sprayed at full bloom with TDZ at doses of 0, 5, 10, or 20 g (a.i) ha-1. TDZ caused fruit malformation and an increment of carpel aperture, reduced the concentration of calcium in the fruit skin, and increased the incidence of moldy core in ‘Gala’ (from 0 to 4%) and in ‘Fuji’ (from 29 to 42%). The increase of moldy core by TDZ in apples may be related to decreases on fruit calcium content and increases on carpel aperture.O tidiazuron (TDZ; N-phenil-N’-1,2,3-thiadiazol- 5-ilureia) é uma feniluréia substituida que apresenta forte ação citocinínica em tecidos de plantas. O produto é pulverizado em macieiras na plena floração para aumentar a frutificação efetiva e promover crescimento de frutos. Além de afetar a fisiologia das plantas e crescimento de frutos, o TDZ interfere em outros aspectos relacionados com a qualidade dos frutos. As plantas tratadas normalmente apresentam frutos deformados, com a parte distal protrusa. Este trabalho foi conduzido com o objetivo de avaliar os efeitos do TDZ na abertura carpelar, no formato dos frutos, no número de sementes, nos teores de cálcio e na incidência de podridão carpelar (causada por diversos patógenos) em maçãs. Macieiras, cultivares Gala e Fuji, foram pulverizadas na plena floração com TDZ nas doses de 0, 5, 10 e 20 g (i.a.) ha-1. O TDZ ocasionou deformação e aumento na abertura carpelar, reduziu a concentração de cálcio na película e aumentou a incidência de podridão carpelar em ‘Gala’ (de 0 para 4%) e ‘Fuji’ (de 29 para 42%). O aumento na incidência de podridão carpelar em macieiras pulverizadas com TDZ pode estar relacionado à redução nos teores de cálcio e o aumento na abertura carpelar nos frutos

    HYDROTHERMIC TREATMENT IN THE SOFT ROT CONTROL IN POTATOES AND THEIR CHANGES IN THE POST-HARVEST CHARACTERISTICS

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    Several strategies have been the object of studies to control soft rot in potatoes, but in many cases they are based on methods that, even though they present promising results, demand a high investment, besides the difficulty of being applied in large volumes, which makes the use of hydrothermal treatment an interesting alternative. The aim of this study was to evaluate the influence of different immersion temperatures used in the hydrothermal treatment on the post-harvest quality of the treated tubers. The experiment was conducted following a completely randomized design with five immersion temperatures: control, 40, 50, 60 and 70 C °, and five storage periods: 0, 5, 10, 15 and 20 days. Post-harvest quality determination was performed by evaluating pulp firmness, pH, titratable acidity (% citric acid) and soluble solids content (° Brix) Throughout the storage period the tubers with symptoms of soft rot were counted and discarded. The immersion temperature caused changes in the parameters of pulp firmness, titratable acidity and soluble solids content. Tubers submitted to immersion temperature of 70 ° C were all eliminated on the 5th day of evaluation. The immersion of potatoes at 40 ° C was the most efficient in reducing the appearance of soft rot, while maintaining the physical-chemical characteristics of the treated tubers during the storage period of 20 days.Several strategies have been the object of studies to control soft rot in potatoes, but in many cases they are based on methods that, even though they present promising results, demand a high investment, besides the difficulty of being applied in large volumes, which makes the use of hydrothermal treatment an interesting alternative. The aim of this study was to evaluate the influence of different immersion temperatures used in the hydrothermal treatment on the post-harvest quality of the treated tubers. The experiment was conducted following a completely randomized design with five immersion temperatures: control, 40, 50, 60 and 70 C °, and five storage periods: 0, 5, 10, 15 and 20 days. Post-harvest quality determination was performed by evaluating pulp firmness, pH, titratable acidity (% citric acid) and soluble solids content (° Brix) Throughout the storage period the tubers with symptoms of soft rot were counted and discarded. The immersion temperature caused changes in the parameters of pulp firmness, titratable acidity and soluble solids content. Tubers submitted to immersion temperature of 70 ° C were all eliminated on the 5th day of evaluation. The immersion of potatoes at 40 ° C was the most efficient in reducing the appearance of soft rot, while maintaining the physical-chemical characteristics of the treated tubers during the storage period of 20 days

    Ripening and quality of 'Laetitia' plums following harvest and cold storage as affected by inhibition of ethylene action

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    A inibição da ação do etileno pelo 1-metilciclopropeno (1-MCP) prolonga a vida de prateleira e de armazenagem de vários frutos climatérios. Entretanto, 1-MCP parece ter efeitos limitados em frutas de caroço dependendo da espécie e cultivar. Os efeitos do 1-MCP na maturação e qualidade de ameixas 'Laetitia' foram determinados durante a maturação a 23oC após a colheita e após a armazenagem refrigerada. Ameixas (Prunus salicina, cv. Laetitia) foram colhidas em estádio pré-climatério, resfriadas a 2oC em 36 horas da colheita e então tratadas com 1-MCP nas doses de 0; 0,05; 0,10; 0,50 ou 1,00 μL L-1 a 1°C por 24 horas. Após o tratamento os frutos foram mantidos a 23oC por 16 dias ou armazenados a 1oC por 50 dias. Os frutos foram removidos da câmara de armazenagem refrigerada a cada 10 dias e então deixados a amadurecer a 23°C, por cinco dias. O retardamento do climatério respiratório e da produção de etileno pelo tratamento 1-MCP durante a maturação após a colheita e após a armazenagem refrigerada foi associado à redução da taxa de amolecimento da polpa dos frutos. O tratamento 1-MCP também retardou a perda da acidez titulável e as mudanças de coloração da polpa e da epiderme, mas teve pequeno ou nenhum efeito sobre o teor de açúcares solúveis. Os efeitos do 1-MCP dependeram da sua concentração e do período de armazenagem dos frutos e, normalmente, a dose de saturação das respostas dos frutos ao 1-MCP ocorreu entre 0,5 e 1,0 μL L-1. Durante a maturação, ameixas tratadas com 1-MCP desenvolveram qualidade semelhante a dos frutos controle. Os resultados indicam que o tratamento 1-MCP pode estender a vida de prateleira (23oC) e de armazenagem (1oC) de ameixas 'Laetitia' por aproximadamente seis e 20 dias, respectivamente.The inhibition of ethylene action by 1-methylcyclopropene (1-MCP) extends shelf and storage life of many climacteric fruits. However, 1-MCP appears to have limited effects on stone fruit depending on specie and cultivar. The effects of 1-MCP on ripening and quality of 'Laetitia' plums were determined during ripening at 23oC following harvest and cold storage. Japanese plums (Prunus salicina, cv. Laetitia) were harvested at mature pre-climacteric stage, cooled to 2oC within 36 hours of harvest and then treated with 0, 0.05, 0.10, 0.50 or 1.00 mL L-1 of 1-MCP at 1°C for 24 hours. Following treatment, fruits were either held at 23oC for 16 days or stored at 1oC for 50 days. Fruits were removed from cold storage at 10-day intervals and allowed to ripe at 23°C for five days. A delay of climacteric respiration and ethylene production by 1-MCP treatment during ripening following harvest and cold storage was associated to a slow rate of fruit softening. 1-MCP treatment also delayed the loss of titratable acidity and changes of flesh and skin color, whereas it had little or no effect on soluble solids content. 1-MCP effects were concentration- and storage duration-dependent and, generally, a saturation fruit response to 1-MCP occurred between 0.5 and 1.0 mL L-1. During ripening, 1-MCP treated fruits attained quality similar to that of controls. Results indicated that 1-MCP treatment may extend shelf life (23oC) and storage life (1oC) of 'Laetitia' plums by approximately six and 20 days, respectively

    Influência de diferentes intervalos de processamento de milho doce sobre características quantitativas e qualitativas

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    Sweet corn differs from common corn due to its lower concentrations of starch in relation to the sucrose in its endosperm, a characteristic that gives cultivars in this segment a unique sweet taste for this vegetable species. Because of this product’s high perishability, the interval between harvest and processing is recommended to be as short as possible so as to preserve both its quantitative and qualitative characteristics. The objective of this study was to observe the effects on the quantity and quality of sweet corn when it is harvested and subjected to late processing, i.e., periods that are not recommended. A randomized block design with five replications was adopted for the experiment. The following intervals were chosen for processing the ears of corn: 0, 4, 8, 12, 16, 20 and 24 hours after harvest. Characteristics such as the fresh weight of the ear with and without the husk, of only the cob, and of only the kernels from processing as well as the industrial yield were noted. The sample’s moisture, soluble solids content, titratable acidity, and sucrose and reducing sugar content were also evaluated. No quantitative gains or losses were verified during the postharvest storage and pre-processing periods for the ears of sweet corn. Depending on the interval before processing there was a 15.6% reduction in the concentration of soluble solids.O milho doce se diferencia do milho comum devido a menores concentrações de amido em relação à sacarose em seu endosperma, característica essa que confere a cultivares deste segmento um sabor adocicado único para essa espécie vegetal. Devido à alta perecibilidade deste produto, recomenda-se que o intervalo entre a colheita e seu processamento seja o menor possível, a fim de preservar tanto características quantitativas como as de ordem qualitativa. Portanto, objetivou-se com esse trabalho estudar os efeitos ocorridos em ordem quantitativa e qualitativa em milho doce quando este é colhido e submetido ao processamento tardio, ou seja, em períodos não recomendados. O experimento foi conduzido em delineamento experimental de blocos ao acaso, com cinco repetições. Adotou-se como períodos de processamento das espigas 0, 4, 8, 12, 16, 20 e 24 horas após a colheita. Características como peso fresco da espiga com palha, sem palha, somente do sabugo e somente dos grãos oriundos do processamento foram anotados bem como seu rendimento industrial. Também foram avaliados a umidade da amostra, teor de sólidos solúveis, acidez titulável, teor de sacarose e de açúcares redutores. Durante os períodos de armazenamento pós-colheita e pré-processamento das espigas de milho doce não foi verificado ganhos ou perdas em caráter quantitativo. Verificou-se uma redução de 15,6% na concentração de sólidos solúveis, em função do período de processamento

    VISUAL QUALITY AND PHYSICAL-CHEMICAL CHARACTERISTICS IN POTATO TUBERS TREATED WITH HYDROGEN PEROXIDE

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    Unconventional techniques such as the use of visible ultraviolet light (UV-C) and physical treatments have been used to combat post-harvest diseases. Attention has been focused on the use of hydrogen peroxide, but little is known about its effects on the control of bacteria causing soft rot. The objective of this study was to evaluate the incidence of soft rot and physical-chemical and visual characteristics in potato tubers (Solanum tuberosum L.) treated with hydrogen peroxide. The experiment was conducted following a completely randomized design in subdivide plots scheme with four treatments: 0, 50, 100 and 150ppm of hydrogen peroxide whit an inoculated plot and a non inoculated. The visual aspects were evaluated by for to the incidence of soft rot appearance of shoots. pH, titratable acidity (% citric acid), soluble solids content, pulp firmness and total sugar content were used to determine post-harvest quality. Hydrogen peroxide was not effective in controlling soft rot in potato tubers, but increased the metabolic activity of tubers leading to an increase in soluble solids content and reduced in titratable acidity

    Efeito do tratamento com aminoetoxivinilglicina (AVG) na queda pré-colheita e na maturação dos frutos em macieiras

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    ABSTRACTApple trees cultivars Gala and Fuji were sprayed four weeks before commercial harvest with aminoethoxyvinilglycine (AVG), at doses of 0, 125, or 250 mg L-1, and assessed for preharvest fruit drop, fruit growth, and maturation on tree. In 'Gala', 64 days after AVG spraying, fruit drop for control treatment was 85%, and AVG (at 125 and 250 mg L-1) reduced it to 10%. In 'Fuji', 64 days after AVG spraying, fruit drop for control was 6%, while treatments with AVG (at 125 and 250 mg L-1) increased fruit drop to 10%. AVG was a powerful retardant of fruit maturation for 'Gala' but not for 'Fuji'. In 'Gala', the most affected attribute was the skin background color, followed, in decreasing order, by soluble solids content, the starch index, skin red color, the flesh firmness, and titratable acidity. In 'Gala', only flesh firmness retention was improved by increasing AVG dose from 125 mg L-1 to 250 mg L-1. The AVG at 250 mg L-1 inhibited "Gala" late fruit growth but not 'Fuji'. __________________________________________________________________________________ RESUMOMacieiras, das cultivares Gala e Fuji, foram pulverizadas quatro semanas antes do início da colheita comercial dos frutos com aminoetoxivinilglicina (AVG), nas concentrações de 0; 125 ou 250 mg L-1, e avaliadas quanto à queda de frutos na pré-colheita, o crescimento e maturação dos frutos. Na cultivar Gala, 64 dias após a pulverização com AVG, a queda pré-colheita no tratamento-controle era de 85%, mas os tratamentos com AVG (125 e 250 mg L-1) reduziram esta queda para 10%. Na cultivar Fuji, 64 dias após a pulverização com AVG, a queda de frutos no tratamento-controle era de 6%, e os tratamentos com AVG (125 e 250 mg L-1) aumentaram esta queda para 10%. Tratamentos com AVG retardaram substancialmente a maturação dos frutos da cultivar Gala, mas não da 'Fuji'. Na cultivar Gala, o atributo mais afetado foi a cor de fundo da casca, seguido, em ordem decrescente, pelo conteúdo de sólidos solúveis totais, índice de iodo-amido, cor vermelha da casca, firmeza de polpa e acidez titulável. Na cultivar Gala, apenas a retenção de firmeza de polpa foi significativamente aumentada com o aumento na concentração de AVG de 125 mg L-1 para 250 mg L-1. A concentração de 250 mg L-1 inibiu o crescimento final de frutos na cultivar Gala, mas não na 'Fuji'
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