Influence of 1-Methylcyclopropene Treatment on Postharvest Quality of Four Scab (Venturia inaequalis)-Resistant Apple Cultivars

Scab (Venturia inaequalis) is a very serious disease for apples causing up to 80% of loss in yield but there are only a few studies on postharvest quality of scab-resistant cultivars. In this study we evaluated the effect of 1-methylcyclopropene (1-MCP) on fruit quality, total phenolic content, and antioxidant capacity after storage of four scab-resistant cultivars and compared to a standard cultivar, “Golden Delicious.” In general, ethylene production and respiration rates significantly differed among cultivars, between control and 1-MCP-treated fruits, and between storage duration regimes. 1-MCP treatment retarded fruit softening and lowered juice pH but storage effect on soluble solids and acidity depended on cultivar and 1-MCP treatment. Total phenolic content was significantly affected by storage duration and 1-MCP treatment. Antioxidant capacity of the four scab-resistant cultivars was either similar to or significantly higher than that of “Golden Delicious” with the 1-MCP-treated fruits having significantly higher antioxidant capacity than the nontreated fruits after storage. Our results clearly show that the quality of four scab-resistant cultivars was comparable to that of “Golden Delicious” and 1-MCP effect differed among cultivars. These differences need to be considered in developing storage regime to minimize quality deterioration during long-term storage

Postharvest treatments to mitigate the internal browning in "Bartlett" pears.

Internal browning is an important disorder in pear fruit which can lead to economic losses. Pears (Pyrus communis L. cv. Bartlett) were harvested at early harvest maturity of 90 N from a commercial orchard in southern Brazil. Methyl jasmonate, ethanol, and 1-methylcyclopropene vapor treatments were carried out for 24 hours in order to mitigate the internal browning disorder. Fruit were stored for up to 150 days at 0 ± 1 °C and 90 ± 5 % RH. Pears exhibited internal browning in 37 % of the control samples after 90 days of cold storage. However, no internal browning symptoms were observed in the 1-MCP treatment. The first symptoms in 1-MCP samples were noticed after 120 days of cold storage (12 %)and reached 100 % in five days at room temperature. 1-MCP-treated pears showed flesh firmness values of 82 N after 90 days of cold storage and 18.7 N when they were removed from the cold storage and kept at 20 °C. The greatest acceptance index was attributed to 1- MCP pears after 90 days at 0 ± 1 °C followed by 5 days at 20 ± 1 °C (89.35). High acceptance indexes were attributed to MeJa (77.95) and control pears (76.40) after 30 days in cold storage followed by 5 days at room temperature. 1-MCP (0.3 µL L-1 , 24 hours at 0 ± 1 °C) treatment delays ripening and mitigates the internal browning in early harvested ?Bartlett? pears, that can be stored for up to 90 days at 0 ± 1 °C

Extended cold storage of winter pears by modified atmosphere packaging.

The aim of this work was to evaluate the effect of passive modified atmosphere packaging (MAP) on the maintenance of fruit quality during the extended storage of ‘Rocha’ and ‘Packham’s Triumph’ pears. Fruit were packed in linear low density polyethylene (100 mm), with 6% BIF 1500 additive placed into perforated plastic boxes and kept at 0 ± 1 °C and 90 ± 5% RH for up to 180 days. MAP reduced weight loss by 14.8% for ‘Rocha’ and 11.5% for ‘Packham’s’ pears after 180 days in cold storage and retained the green color of the skin, which means that the yellowing visual perception was delayed in 60 and 90 days for ‘Rocha’ and ‘Packham’s’ pears, respectively. A strong softening was observed for ‘Packham’s’ pears after being kept for 150 days at 0° C followed by 5 days at room temperature, which did not limit the storage of both pear cultivars under modified atmosphere packaging. MAP created by linear low density polyethylene (100 mm), with 6% BIF 1500 additive extended in 30 days the cold storage for ‘Rocha’ and 60 days for ‘Packham’s’ pears. Index terms: Pyrus communis L., ‘Rocha’, ‘Packham’s Triumph’, polyethylene film, water loss, acceptance. O objetivo deste trabalho foi avaliar a eficiência da atmosfera modificada na manutenção dos atributos de qualidade e na extensão do armazenamento refrigerado de peras "Rocha" e "Packham's Triumph". Os frutos foram acondicionados em filme de polietileno de baixa densidade linear (100 ?m) com aditivo BIF 1.500 6% no interior de caixas plásticas vazadas e mantidos a 0 ± 1 °C e 90 ± 5% UR por até 180 dias. A atmosfera modificada reduziu em 14,8% a perda de massa de peras "Rocha" e em 11,5% a de peras "Packham's", após 180 dias de refrigeração, e mostrou-se útil na preservação da coloração verde dos frutos, retardando em 60 e 90 dias a percepção visual do amarelecimento da casca de peras "Rocha e Packham's", respectivamente. Houve amolecimento excessivo da polpa de peras "Packham"s" controle após 150 dias a 0 °C, seguidos por 5 dias a 20 °C, o que não limitou o armazenamento das peras de ambas as cultivares sob atmosfera modificada. A atmosfera modificada proporcionada pela embalagem de polietileno de baixa densidade linear (100 ?m) com aditivo BIF 1.500 6%, proporcionou a extensão de 30 dias no período de armazenamento refrigerado de peras ?Rocha? e de 60 dias para "Packham's Triumph". Termos para indexação: Pyrus communis L., "Rocha", "Packham"s Triumph", filme de polietileno, perda de massa, aceitabilidad

Valor nutritivo de algumas dietas artificiais para Anastrepha obliqua (Diptera, Tephritidae)

Valor nutritivo de algumas dietas artificias para Anastrepha obliqua (Diptera, Tephritidae). Algumas dietas artificias, em diferentes concentrações, foram testadas e sua eficiência foi calculada a partir do peso das pupas, do tempo para apupar e da porcentagem de empupação. Os melhores resultados foram obtidos com fermento 4,5 g/ 150 ml de dieta; os outros produtos testados foram: germe de trigo, feijão soja, leite em pó e aveia

Desempenho das larvas de Anastrepha obliqua (Diptera, Tephritidae) alimentadas com dietas artificiais

Fruit flies of the genus Anastrepha Schiner, 1868 are well-known for having economical importance since they damage commercially cultivated fruits. Nutritional demands during the immature and adult stages are different, so the larvae do not develop well using the same diet as the adults. Although the insect basic nutritional needs are well-known, there is also the challenge to elaborate rearing diets adequate to species with specific needs. The aim of this study was to determine the effect on the Anastrepha obliqua (Macquart, 1835) larvae performance of different kinds and amounts of carbohydrates in the diet. Larvae were individually reared until pupation in test tubes containing one of the artificial diets to be tested. The basic composition of the diets to be tested included 2.5 g agar, 3.25 g brewer's yeast and several different amounts of flour and sucrose. The suitability of the artificial diet for A. obliqua was tested evaluating the larvae and pupae survival (%) and the larvae, pupae and larvae-adults periods of development. The diet containing flour (2 g) and sucrose (2 g) and the diet containing only sucrose (5.5 g) have shown the best results regarding larval performance. All tested diets presented similar or superior results as compared to diets used in other studies. The importance of flour and its nutritional value for the larvae was discussed.Moscas das frutas do gênero Anastrepha Schiner, 1868 são conhecidas por sua importância econômica devido aos danos que elas causam nos frutos comerciais. As exigências nutricionais dos estágios imaturo e adulto são diferentes e as larvas não se desenvolvem bem utilizando a mesma dieta do adulto. Embora as necessidades nutricionais básicas dos insetos sejam bem conhecidas, existe ainda o problema de elaborar dietas de criação adequadas para espécies com necessidades específicas. O objetivo deste trabalho foi verificar o efeito de diferentes tipos e quantidades de carboidratos na dieta sobre a performance larval de Anastrepha obliqua (Macquart, 1835). Larvas foram criadas individualmente em tubos de ensaio contendo uma das dietas artificiais a serem testadas onde elas foram mantidas até a pupação. A composição básica das dietas testadas incluia 2,5 g de agar, 3,25 g de levedo de cerveja e quantidades variadas de sacarose e farinha de trigo. A adequação do meio artificial para A. obliqua foi testada pela avaliação da sobrevivência larval e pupal (%) e o tempo de desenvolvimento larval, pupal e de larva-adulto. A dieta contendo farinha de trigo (2 g) e sacarose (2 g) e a dieta somente com sacarose (5,5 g) foram as que apresentaram melhor performance larval. Todas as dietas testadas apresentaram resultados similares ou superiores às dietas utilizadas em outros trabalhos. A importância da presença da farinha de trigo e seu valor nutricional para as larvas são discutidos

Baixa temperatura para indução do amadurecimento e extensão da conservação de peras "Abate Fetel".

A cultivar "Abate Fetel", também conhecida como Abbé Fetel, é a mais importante dentre as peras europeias cultivadas a Itália.bitstream/item/169450/1/Lucimara-Agapomi-n283-p12-2017.pd

Effect of Dietary Components on Larval Life History Characteristics in the Medfly (Ceratitis capitata: Diptera, Tephritidae)

Background: The ability to respond to heterogenous nutritional resources is an important factor in the adaptive radiation of insects such as the highly polyphagous Medfly. Here we examined the breadth of the Medfly’s capacity to respond to different developmental conditions, by experimentally altering diet components as a proxy for host quality and novelty. Methodology/Principal Findings: We tested responses of larval life history to diets containing protein and carbohydrate components found in and outside the natural host range of this species. A 40% reduction in the quantity of protein caused a significant increase in egg to adult mortality by 26.5%±6% in comparison to the standard baseline diet. Proteins and carbohydrates had differential effects on larval versus pupal development and survival. Addition of a novel protein source, casein (i.e. milk protein), to the diet increased larval mortality by 19.4%±3% and also lengthened the duration of larval development by 1.93±0.5 days in comparison to the standard diet. Alteration of dietary carbohydrate, by replacing the baseline starch with simple sugars, increased mortality specifically within the pupal stage (by 28.2%±8% and 26.2%±9% for glucose and maltose diets, respectively). Development in the presence of the novel carbohydrate lactose (milk sugar) was successful, though on this diet there was a decrease of 29.8±1.6 µg in mean pupal weight in comparison to pupae reared on the baseline diet. Conclusions: The results confirm that laboratory reared Medfly retain the ability to survive development through a wide range of fluctuations in the nutritional environment. We highlight new facets of the responses of different stages of holometabolous life histories to key dietary components. The results are relevant to colonisation scenarios and key to the biology of this highly invasive species