Experiments were carried out with the objective to evaluate the efficiency of methods for prediction of bitter pit occurrence, on Gala , Royal Gala , Fuji and Braeburn apples after controlled atmosphere storage (CA). Fruits from 11 orchards were picked 20 days before and at commercial harvest date. The experimental design was completely randomized. For each method, treatments consist of 4 replicates of 25 fruits. On the other hand, for evaluation of membrane integrity samples had 6 fruits. The predictive methods evaluated were: infiltration of fruits with 0.1M MgCl2 solution containing 0.4M sorbitol and 0.01% Tween-20; immersion of fruits in solution with 2500nL L-1 ethephon at 20°C; the correlation between quality and maturity parameters and; ion leakage of fruit cells at harvest and after 50, 100 and 150 days on CA storage were compared with the real incidence of bitter pit. For estimating the predictive capacity of methods, symptoms induced on fruits sampled 20 days before harvest date and at commercial harvest were compared with real bitter pit present on fruits stored for 5 months on CA plus 12 days at 20°C. The storage conditions were: for Gala and Royal Gala apples 1.5kPa O2 + 3.0kPa CO2 plus +0.5°C; for Fuji apples 1.2kPa O2 + <0.5kPa CO2 plus -0.5°C; and for Braeburn apples 1.2kPa O2 + 3.0kPa CO2 plus +0.5°C. According to results on Gala apples both methods were inefficient, overestimating the real incidence of bitter pit on fruits sampled 20 days before harvest, and underestimating the real incidence when collected at commercial harvest. On Fuji and Braeburn apples both predictive methods were efficient in predict incidence of bitter pit on fruits sampled 20 days before harvest, however, for fruits sampled at commercial harvest both methods were inefficient. No quality parameters or maturity index showed, in general, correlations that justify its utilization as indicate bitter pit occurrence during storage. In relation to membrane permeability, there was in both cultivars, an increase during storage, related to picking time of fruits. For most orchards, no association was observed between the higher incidence of bitter pit with the higher ion leakage at harvest and during storage, with exception for Gala and Braeburn apples picked 20 days before harvest. The relationship between membrane permeability at harvest and after 5 months of CA storage and the real incidence of bitter pit is not valid as a predictive method / Experimentos foram conduzidos com objetivo de avaliar a eficiência de métodos de predição do potencial de ocorrência de bitter pit , em maçãs Gala , Royal Gala , Braeburn e Fuji após o armazenamento em atmosfera controlada (AC). Os frutos provenientes de 11 pomares foram coletados 20 dias antes e na colheita comercial. O delineamento experimental foi o inteiramente casualizado. Para os métodos, os tratamentos foram compostos por 4 repetições, sendo cada unidade experimental composta por 25 frutos. Já para a avaliação da integridade das membranas, a unidade experimental foi de 6 frutos. Os métodos de predição avaliados foram: a infiltração de magnésio 0,1M MgCl2 mais 0,01% de Tween-20 e 0,4M de sorbitol; imersão de frutos em solução com 2500nL L-1 de ethephon + 20°C; a correlação entre parâmetros de qualidade e maturação e; a comparação entre o vazamento de íons das células dos frutos no momento da colheita e após 50, 100 e 150 dias em AC com a real incidência de bitter pit . Para estimar a capacidade predictiva dos métodos, os sintomas do distúrbio induzidos nos frutos coletados 20 dias antes e na colheita comercial foram comparados com a ocorrência real em frutos armazenados por 5 meses em AC mais 12 dias de exposição a 20°C. As condições de AC foram: para maçãs Gala e Royal Gala 1,5kPa O2 + 3,0kPa CO2 e temperatura de +0,5°C; para maçãs Fuji 1,2kPa O2 + <0,5kPa CO2 e temperatura de -0,5°C e para a Braeburn 1,2kPa O2 + 3,0kPa CO2 e temperatura de +0,5°C. De acordo com os resultados, na cultivar Gala ambos os métodos não foram eficientes, superestimando a incidência real de bitter pit para os frutos colhidos 20 dias antes da colheita e, subestimando a incidência real na colheita comercial. Nas cultivares Fuji e Braeburn ambos os métodos foram eficientes na previsão da incidência de bitter pit em frutos amostrados 20 dias antes da colheita, entretanto, para os frutos colhidos na colheita comercial ambos os métodos foram ineficientes. Nenhum parâmetro de qualidade ou índice de maturação apresentou, no geral, correlação consistente que justifique sua utilização como indicativo da ocorrência de bitter pit após o armazenamento. Com relação à permeabilidade de membranas, verificou-se, para ambas as cultivares, gradual acréscimo durante o armazenamento, estando este relacionado à época de colheita dos frutos. Para a maioria dos pomares, não foi observada associação entre a incidência de bitter pit e o vazamento de íons na colheita e durante o armazenamento, com exceção dos frutos das cultivares Gala e Braeburn amostrada 20 dias antes da colheita comercial. A relação entre a permeabilidade de membranas na colheita e após 5 meses de armazenamento em AC com a incidência real de bitter pit não é válida como método de previsão da ocorrência de bitter pit

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objectives of this work was to estimate the potential of flesh browning development in Gala , Royal Gala , Fuji e Braeburn apples after controlled atmosphere storage (CA). This study was realized through correlation of predictive methods and fruit quality and ripening parameters with the flesh browning occurrence after CA storage. Experiments were carried out with fruits from different orchards and years. In 2004, a first experiment was carried out with Fuji apples from three orchards. In 2005, Gala , Royal Gala , Fuji and Braeburn apples were evaluated from 11 orchards using two picking dates. Theses experiments were carried out at the Núcleo de Pesquisa em Pós-colheita of Federal University of Santa Maria, Santa Maria, Brazil with fruits from Vacaria, RS, Brazil. In 2006 to 2007 experiments were carried out in Germany using Braeburn apples from seven orchards. These methods the disorder occurrence after six months CA storage was correlated with the predictive methods, and with quality and ripening parameters. The predictive methods evaluated were: Mg infiltration, maturity acceleration with ethephon, and stress induction with high CO2. It was also evaluated the capacity of chlorophyll-fluorescence to detect possible stress occurrence on fruits exposed to high CO2 concentrations. Results show that in Fuji fruit juice percentage were able to predict flesh browning, but only in high CO2 (2.0 kPa) CA condition, while TSS level has been able to predict the occurrence of this disorder in fruits stored in low CO2 (<0.5 kPa). The chlorophyll fluorescence was capable of detect stress in fruits caused by exposure to high CO2 at harvest, and with this method it could be predicted the occurrence of physiological disorders in early harvested and with delay CA storage. By nutritional analysis of fruits, the level of K show high correlation with the occurrence of flesh browning after the CA storage of Braeburn apple. Some predictive methods and quality parameters evaluated at harvest were able to predict flesh browning occurrence in apple stored, in certain storage conditions, but in other storage conditions there wasn t significant correlation between flesh browning and this predictive methods and quality parameters. These predictive methods and quality parameters do not show high correlation with flesh browning in all situations. / O objetivo deste trabalho foi correlacionar à degenerescência da polpa das maçãs Gala , Royal Gala , Fuji e Braeburn após o armazenamento em atmosfera controlada (AC). O estudo foi realizado através da correlação com métodos preditivos e com atributos de qualidade e maturação dos frutos com a incidência real de degenerescência da polpa após o armazenamento em AC. Foram realizados experimentos com frutos de diferentes pomares, sendo executado em 2004 o primeiro experimento com a cultivar Fuji. Em 2005, os experimentos foram realizados com as cvs. Gala, Royal Gala, Fuji e Braeburn, avaliando frutos de 11 pomares em duas épocas de colheita. Os experimentos destes dois primeiros anos foram realizados no Núcleo de Pesquisa em Pós-colheitas da UFSM com frutos provenientes de pomares de Vacaria, RS. No período de 2006 e 2007 foram desenvolvidos experimentos em Ravensburg, na Alemanha, com a cv. Braeburn de sete pomares. Para isso, foram correlacionados a ocorrência de degenerescência da polpa após o armazenamento de seis meses em AC, com os testes preditivos e com atributos físico-químicos dos frutos analisados em duas épocas de colheita. Os testes preditivos avaliados foram: infiltração de Mg, aceleração da maturação com Ethephon e indução de estresse pelo alto CO2. Avaliou-se no experimento de 2006/2007 a possibilidade de detectar o estresse no fruto causado por diferentes concentrações de CO2 através da fluorescência de clorofila. Conforme os resultados, no ano de 2004 com a cv. Fuji, a percentagem de suco dos frutos foi capaz de prever a degenerescência da polpa, porém somente na condição de armazenamento de 2,0kPa CO2, enquanto que os SST previu a ocorrência dessa desordem somente em frutos armazenados com baixo CO2 (<0,5kPa). A fluorescência de clorofila foi capaz de detectar após colheita o estresse causado por pressões parciais de CO2 nos frutos armazenados. Com essa metodologia foi possível prever a ocorrência de degenerescência, somente quando se realizou a colheita precocemente e com atraso na instalação da AC. A análise nutricional dos frutos, destacando o nível de K, foi o atributo que melhor previu a ocorrência de degenerescência da polpa durante o armazenamento em AC na cv. Braeburn. Alguns métodos preditivos e atributos avaliados na colheita foram capazes de prever a incidência de degenerescência da polpa nos frutos armazenados numa determinada condição de AC, porém em outra condição de armazenamento não se confirmou essa correlação. Isso significa que estes testes e atributos de qualidade não apresentam alta correlação com a ocorrência da degenerescência em maçãs armazenadas em qualquer situação.

Masters of Science / It is well documented that cigarette smoking and nicotine exposure create widespread physiological disorders in humans and animals. The primary tobacco constituent that is responsible for the toxicological consequences associated with the effects of tobacco smoke is nicotine (Van Lancker 1977). After maternal nicotine exposure, the fetal gonads and lungs are the principle sites of nicotine damage (Szuts et al. 1978, Mosier & Jansons 1972). Whilst the fetal lung has received widespread attention in this regard (Maritz 1988), the testis has never been studied. Therefore, I have chosen to explore the effects of maternal nicotine exposure on the testis of male offspring by evaluating various aspects of the male reproductive tract. It is believed that, in adult male smokers (Rosenberg 1987, Handelsman et al. 1984) and sexually mature animals (Mattison 1982) that are exposed to nicotine, male fertility may be compromised. However, these studies provide conflicting data on single parameters. It was therefore my objective to identify the effect of nicotine exposure on the male reproductive tract and to establish possible sites through which these effects may be mediated in adult male rats. The influence of nicotine was then investigated in male offspring after maternal nicotine treatment (MNT), and in sexually mature adult males after direct adult nicotine treatment (ANT). In the former experiment (MNT), 7 day pregnant rats were exposed to Img nicotine/kg body weight/day. Therefore, these offspring were indirectly exposed to nicotine during fetal development and early neonatal development. After weaning the animals were divided into two groups. One group did not receive further treatment (withdrawn group), whilst the other group was continually treated till adulthood (nicotine group), after which both groups were sampled together with the control. In the latter experiment (ANT), the animals were treated daily for 3 weeks and were sampled as above (MNT animals). The fundamental parameter investigated in both experiments to assess reproductive status was sperm quality (motility and morphology). Thereafter, it was necessary to establish a possible site where the effects of nicotine would occur. Testicular growth, epididymal structure, and plasma testosterone content were measured as probable localities of nicotine's effect. The results signify that maternal nicotine exposure poses a greater threat to the male reproductive system than adult nicotine exposure. In the MNT experiment, progressive sperm motility of the nicotine and withdrawn groups were 1.7% and 3.4% respectively. The proportion of abnormal sperm was 72% in each of the above groups. The lower quality sperm that is evident after nicotine exposure implies that the fertilizing ability of the animals may be impaired during adulthood. The data on testicular growth indicates that nicotine exposure during early development results in slower testicular development until maturity. The epididymal lining of these animals also increased after nicotine exposure, indicating increased cellular activity. However, these results from testicular and epididymal studies are inconclusive and need further work. In the ANT experiment, progressive sperm motility of the nicotine group was 1.2%, whilst the proportion of abnormal sperm was 58%. No other parameter was affected after nicotine exposure to adult animals. From the above data it is evident that nicotine exposed animals were subject to greater nicotine damage after maternal nicotine exposure during early development. Moreover, within the maternal nicotine treated experiment, the withdrawal of nicotine after weaning did not appear to reverse the injurious effects of nicotine that were established during early development. These effects were evident since the nicotine and withdrawn groups showed similar levels of damage in all instances. The most profound effects after adult nicotine exposure and maternal nicotine exposure were on sperm quality. The probable site of sperm impairment appears to be via retarded testicular growth and possibly, structural status of the epididymis after maternal nicotine exposure. The results from adult nicotine exposure however, suggest that sperm cells may be directly affected by nicotine exposure. An epidemiological survey was included to validate the basic conclusions established in animal research when compared to clinical data from human patients. No statistically significant changes were observed in this study between the patient's spermiogram results versus his smoking habits, and, that of his mother. From the level of significance it was concluded that cigarette smoking does not appear to be a cause of impaired fertility in already infertile patients. However, the data does suggest that cigarette smoking may well be a precipitating agent in male infertility. Experimentally, nicotine exposure impairs the male reproductive system to some extent. The effects of which are irreversible after indirect exposure (MNT) during development and may begin with poor testicular development. The effects of adult nicotine exposure implies that nicotine exposure in mature animals (ANT) acts directly on sperm cells to incapacitate them. It is well advised that cigarette smoking should be curbed in pregnant women and in adult males to alleviate contributing effects to male infertility.

Thesis (M.Sc. (Horticulture)) -- University of Limpopo, 2017 / Tomato is popularly consumed as fresh vegetable or processed product due to its nutritional and health benefits. However, due to its high perishability, tomato cannot be stored for longer duration. Therefore, the aim of this study was the determination of appropriate dipping times into different calcium chloride concentrations to preserve the postharvest quality, storage and the shelf-life of tomato fruit. 'Classic round' tomato fruit were harvested at their pink maturity stage. The experiment was carried out as a completely randomized design (CRD), factorial arranged as 4 × 3 × 8. Treatment factors were: 4 × CaCl2 (0, 0.0045, 0.01 and 0.03%), 3 × dipping times (0, 30 and 60 minutes) and 8 × shelf-life (0 - 7 days). Fruit were stored at 15⁰ C for 30 days, thereafter, held under room temperature for 0 - 7 days of shelf-life while collecting data. During shelf-life period, fruit were evaluated for weight loss, firmness, colour, TSS, TA, pH, physiological and pathological disorders. The interaction between the treatments and dipping times showed a significant effect on weight loss, firmness, colour parameters [L*, b*, chroma and hue angle (⁰)], total soluble solids (TSS), titratable acidity (TA), pH, decay and black mould occurrence. However, significant interactive effects were not shown on a* colour component and chilling injury. In conclusion, calcium chloride (CaCl2) improved the quality and shelf-life of 'Classic round' tomato fruit. Calcium chloride concentration 0.01% was effective at 30 minutes dipping time, meanwhile, 0.03% CaCl2 was effective at 60 minutes dipping time. Therefore, 0.01 and 0.03% can be recommended for commercial preservation use for tomato fruit quality and shelf-life. / Agricultural Research Council-Tropical and Subtropical Crops (ARC-TSC) and National Research Foundation (NRF)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The aim of the present work was to evaluate alternative methods to conventional (CA) and dynamic controlled atmosphere (DCA), in order to maintain the quality of 'Royal Gala' apples, particularly the physical disorders occurrence. So, we evaluated the effect of initial low oxygen stress in maintaining the quality of 'Royal Gala' apples stored in ultralow oxygen conditions (less than 0.8 kPa) and also the effect of low oxygen conditioning through the gradual decreasing of oxygen in the storage chambers, and comparison of these techniques by applying 1-MCP. Two experiments were established, one in 2010 and another in 2011. At the first, the treatments were as follows: [1] CA with 1.2 kPa O2 + 2.0 kPa CO2; [2] 1.0 kPa O2 + 2.0 kPa CO2; [3] 0.8 kPa O2 + 1.0 kPa CO2; [4] 0.6 kPa O2 + 1.0 kPa CO2 e [5] 0.5 kPa O2 + 1.0 kPa CO2. For each CA treatment fruits were divided into two lots, one of them received 1-MCP application and another don´t. Then the fruits of each were again divided into two lots, and a portion was subjected to an initial low oxygen stress (0.3 kPa for seven days) and the other was enclosed in CA chambers. For the second experiment were used the following treatments: [1] CA with 1.0 kPa O2 immediately installed; [2] 1.0 kPa O2 and conditioning for seven days; [3] 0.8 kPa O2 and conditioning for seven days; [4] 0.7 kPa O2 and conditioning for seven days; [5] 0.7 kPa O2 and conditioning for 14 days; [6] 0.7 kPa O2 and conditioning for 28 days; [7] 0.5 kPa O2 and conditioning for seven days; [8] 0.5 kPa O2 and conditioning for 14 days; [9] 0.5 kPa O2 and conditioning for 28 days; [10] 0.7 kPa O2 with conditioning and low oxygen stress; [11] 1.0 kPa O2 immediately installed, plus 1-MCP and [12] DCA with chlorophyll fluorescence. For all treatments the partial pressure of CO2 was 1.2 kPa. The initial low oxygen stress increases the occurrence of physiological disorders, and shouldn t recommended for use immediately after harvest, however, after one low O2 adaptation period of the fruit, this procedure helps to maintaining quality during storage in ultralow oxygen conditions. The gradual reduction of O2 for approximately one month, allows storage in ultralow oxygen conditions and maintaining fruit quality better than the DCA. 1-MCP application offers low efficiency when the O2 concentration in the storage chambers are extremely low, or when the fruits presented an advanced maturity stage. / O objetivo do presente trabalho foi avaliar métodos alternativos à atmosfera controlada convencional (AC) e dinâmica (ACD), na manutenção da qualidade de maçãs Royal Gala , em especial a ocorrência de distúrbios fisiológicos. Para tanto, avaliou-se o efeito do estresse inicial com baixo O2 na manutenção da qualidade de maçãs armazenadas em condições ultrabaixas de oxigênio (menor que 0,8 kPa) e também o efeito do condicionamento ao baixo O2, por meio da redução gradativa do oxigênio nas câmaras de armazenamento, além de comparação destas técnicas com a aplicação de 1-MCP. Foram instalados dois experimento, um no ano de 2010 e outro em 2011. No primeiro, os tratamentos foram os seguintes: [1] AC com 1,2 kPa O2 + 2,0 kPa CO2; [2] 1,0 kPa O2 + 2,0 kPa CO2; [3] 0,8 kPa O2 + 1,0 kPa CO2; [4] 0,6 kPa O2 + 1,0 kPa CO2 e [5] 0,5 kPa O2 + 1,0 kPa CO2. Para cada condição de AC os frutos foram divididos em duas subamostras, sendo que uma recebeu aplicação de 1-MCP e outra não. Em seguida, os frutos foram novamente divididos em dois lotes, sendo que uma parte foi submetida a um estresse inicial por baixo O2 (sete dias em 0,3 kPa) e a outra foi acondicionada nas minicâmaras de AC. Para o segundo experimento utilizou-se os seguintes tratamentos: [1] AC com 1,0 kPa O2 e instalação imediata; [2] 1,0 kPa O2 e condicionamento de sete dias; [3] 0,8 kPa O2 e condicionamento de sete dias; [4] 0,7 kPa O2 e condicionamento de sete dias; [5] 0,7 kPa O2 e condicionamento de 14 dias; [6] 0,7 kPa O2 e condicionamento de 28 dias; [7] 0,5 kPa O2 e condicionamento de sete dias; [8] 0,5 kPa O2 e condicionamento de 14 dias; [9] 0,5 kPa O2 e condicionamento de 28 dias; [10] 0,7 kPa O2 com condicionamento e estresse por baixo O2; [11] 1,0 kPa O2 com instalação imediata, mais 1-MCP e [12] ACD com fluorescência de clorofilas. Para todos os tratamentos a pressão parcial de CO2 foi de 1,2 kPa. O estresse inicial por baixo O2 aumenta a ocorrência de distúrbios fisiológicos, não sendo recomendada a sua utilização logo após a colheita, no entanto, após um período de adaptação dos frutos ao baixo O2, mantém a qualidade durante o armazenamento em condições ultrabaixas de oxigênio. A redução gradativa de O2 durante aproximadamente um mês, permite o armazenamento em condições ultrabaixas de O2, com resultados superiores a ACD na manutenção na qualidade dos frutos. A aplicação de 1-MCP apresenta pouca eficiência quando as concentrações de O2 nas câmaras de armazenamento são extremamente baixas, ou quando os frutos apresentam um estádio de maturação avançado.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of this work was to evaluate the respiration and respiratory quotient of fruits of several species with respect to cultivars, ripening stage, temperature and atmosphere conditions during storage, to obtain information about the possibility of fermentation and physiological disorders occurrence in fruits stored in modified atmosphere. Also, we aimed at developing a methodology to evaluate the permeability to O2 and CO2 of polymeric films under experimental storage conditions in order to provide results that could be used to choose film for storaging fruits in modified atmosphere. Respiration of fruits of some cultivars of apple, kiwifruit, persimmon and peach, in two ripening stages at harvest, different temperatures (0, 10 and 20ºC) and storage conditions (cold storage and modified atmosphere) were evaluated. The effect of storage conditions on the internal breakdown, alcoholic taste and the relation of these parameters with respiration in Jubileu peach and Bruno kiwi was evaluated. For the study of permeability of polymeric films, the effect of relative humidity, temperature (0, 5, 10, 15, and 20ºC) and concentration gradient of gases (10, 15, and 20% of O2 and 5, 10, and 15 of CO2) on the permeability of different polymeric films (cellophane permeable and inpermeable to water vapour, polyvinyl chloride, nylon, polypropylene bioriented, low and high density polyethylene) was evaluated. The effect of thickness, density, presence of additives, temperature and concentration gradient of gases on the permeability of polyethylene films was also determined. Internal breakdown incidence and presence of alcoholic taste in Jubileu peach and Bruno kiwi were lower at the lowest levels of CO2 (5 and 8kPa), independently of O2 level, respectively. The incidence of these physiological disorders, in both species, showed positive correlation with respiratory quotient and negative with respiration of fruits. Gala apple, stored at 0ºC, and Fuji apple, at 0 and 10ºC, did not show a characteristic of climacteric respiratory rise. Fruit ripening stage at harvest influenced the respiration rate at two apple cultivars and at Giombo persimmon at 0ºC and at Fuyu and Rama Forte persimmons stored at 10ºC. The respiration rate was influenced by cultivars in all species of evaluated fruits. The increase of temperature had a strong effect on the increment in respiration rate. Q10 value ranged according to species and with range of temperature. The modification of atmosphere, on average, reduced the respiration rate in 14.3%, at 0°C. The permeation chamber projected and constructed permitted to evaluate polymeric films in relation to gases permeability and its determination must be done under conditions like those used in commercial storage. Results of gases permeability, obtained by the methodology described could be used for choosing a suitable film to the store fruits in modified atmosphere. / O objetivo deste trabalho foi de avaliar a respiração e o quociente respiratório de frutos de diversas espécies em função da cultivar, ponto de maturação, temperatura e condições de atmosfera, durante o armazenamento, para obter dados sobre a possibilidade de ocorrer fermentação e distúrbios fisiológicos em frutos armazenados em atmosfera modificada. Também, objetivou-se desenvolver uma metodologia para avaliar a permeabilidade de filmes poliméricos ao O2 e CO2 sob condições experimentais de armazenamento que produzam resultados que possam ser utilizados na escolha de um filme para o armazenamento de frutas em atmosfera modificada. Para tanto, avaliou-se a respiração de frutos de algumas cultivares de maçã, quivi, caqui e pêssego, em dois estádios de maturação, diferentes temperaturas de armazenamento (0, 10 e 20ºC) e condições de armazenamento (armazenamento refrigerado e atmosfera modificada). Também avaliou-se o efeito de condições de armazenamento sobre a incidência de degenerescência da polpa, de sabor e de aroma alcoólico em pêssegos Jubileu e quivi Bruno e a relação destes parâmetros com a respiração. Para o estudo da permeabilidade dos filmes poliméricos, foi avaliado o efeito da umidade relativa, da temperatura (0, 5, 10, 15 e 20ºC) e do gradiente da concentração de gases (10, 15 e 20% de O2 e 5, 10 e 15% de CO2) sobre a permeabilidade de diferentes filmes poliméricos (celofane permeável e impermeável ao vapor d água, policloreto de vinila, náilon, polipropileno biorientado, polietileno de baixa e de alta densidade). Também avaliou-se o efeito da espessura, da densidade, da presença de aditivos, da temperatura e do gradiente de concentração de gases sobre a permeabilidade de filmes de polietileno. Segundo os resultados, a incidência de degenerescência da polpa e a presença de sabor alcoólico em pêssego Jubileu e quivi Bruno foi menor nos níveis de CO2 mais baixos (5 e 8kPa de CO2), independentemente do nível de O2, respectivamente. A ocorrência destes distúrbios fisiológicos, em ambas espécies, apresentou correlação positiva com o quociente respiratório e negativa com a respiração dos frutos. As cultivares de maçã, Gala a 0ºC e Fuji a 0 e 10ºC, não apresentaram pico respiratório característico de frutos climatéricos. O estádio de maturação influenciou a taxa respiratória nas duas cultivares de maçã e no caqui Giombo a 0ºC, e nos caquis Fuyu e Rama Forte armazenados a 10ºC. O aumento da temperatura exerceu forte efeito sobre o incremento na taxa respiratória. O valor Q10 variou de acordo com a espécie e com a faixa de variação da temperatura. A modificação da atmosfera, em média, reduziu a taxa respiratória em 14,3%, em frutos armazenados a 0°C. A câmara de permeação projetada e construída permitiu avaliar filmes poliméricos quanto à permeabilidade aos gases e a sua determinação deve ser realizada em condições semelhantes as utilizadas no armazenamento comercial. Os resultados de permeabilidade aos gases, obtidos pela metodologia descrita, podem ser utilizados para a escolha de um filme adequado ao armazenamento de determinado fruto em atmosfera modificada.

Thesis (MSc. Agriculture (Horticulture)) -- University of Limpopo, 2016 / The Agricultural Research Council-Institute for Tropical and Subtropical Crops (ARC-ITSC) is continuously developing new avocado selections, in order for the South African Avocado Industry (SAAI) to remain competitive in various international avocado markets. However, information on the response of some of these selections, including ‘Fuerte 2 and 4’, ‘BL1058’ and ‘H287’ to low temperature storage and ripening physiology, has not been investigated. Thus, the objective of this study was to evaluate the effect of harvest season and ripening duration on the physico-chemical properties of newly developed ‘Fuerte-type’ avocado fruit selections during ripening. ‘Fuerte-type’ avocado fruit were indexed for maturity using moisture content, thereafter harvested and stored at 5.5°C for 28 days during the 2014 and 2015 harvest seasons. The experiment comprised five treatments: control (commercial ‘Fuerte’), ‘Fuerte 2 and 4’, ‘BL1058’ and ‘H287’ arranged as a factorial in a completely randomised design (RCD) with 3 replicates. The treatment factors were: (i) 2 x harvest seasons, (ii) 5 x selections and (iii) 6 x ripening days. After withdrawal from low storage temperature, fruit were ripened at ambient temperature. During ripening, the following physico-chemical properties were evaluated; external chilling injury, electrolyte leakage, mass loss, firmness, respiration rate and peel colour. Results showed that selections and harvest seasons had no significant effect (P=0.668) on the moisture content of the evaluated ‘Fuerte-type’ avocado fruit. After withdrawal from low storage temperature, there was a significant interaction (P˂0.05) between selections and harvest seasons on external chilling injury and electrolyte leakage. Results further showed that external chilling injury correlated with electrolyte leakage during both harvest seasons. Treatment factors had no significant effect (P=0.997) on mass loss. Similarly, treatment factors had no significant effect (P=0.139) on firmness. However, selection ‘H287’ had hard skin with an average firmness of 83.44 densimeter units during ripening in both harvest seasons. Treatment factors were highly significant (P˂0.05) on respiration rate. Respiration rate followed a climacteric pattern and the magnitude of climacteric peak and day of occurrence varied amongst selections during both harvest seasons. Ripening percentage differed significantly (P˂0.05) amongst harvest seasons, selections and ripening days. Treatment factors had no significant effect on lightness (P=0.711), chroma (P=0.378) and hue angle (P=0.536) skin colour parameters,however, variations were recorded as a result of the cold damage black spots. The results indicated that the ‘Fuerte-type’ avocado selections had poor storage qualities. Further studies are required to evaluate physico-chemical properties during low storage temperature and the effect of season, production conditions and maturity level on development of chilling injury. In addition, studies on application of treatments to reduce chilling injury symptoms and analysis of bioactive compounds should be considered for conclusive recommendations. Thereafter, the selections can be planted in different production regions to assess and select the best producing and quality combinations for a given region as part of phase III of the project / Agricultural Sector Education Training Authority (AgriSeta) and National Research Foundation (NRF)

Thesis (M.Sc. (Horticulture)) -- University of Limpopo, 2020 / The South African Agricultural Sector has a mandate to reduce water use so that water can be available for other economic sectors. Thus, various water saving techniques must be continuously investigated in agricultural production to find efficient water use technique that saves water without compromising fresh fruit quality. Therefore, combined effect of irrigation method, 1-methylcyclopropene (1-MCP) and cold storage temperature on postharvest quality of ‘Hass’ avocado fruit was evaluated. Postharvest attributes of fruit colour, flesh firmness, ripening percentage, respiration, weight loss, body rot, stem end-rot, vascular browning, chilling injury and electrolyte leakage were assessed for 2 x irrigation methods [Full irrigation (FI) and Partial root-zone drying (PRD)], 2 x 1-methylcyclopropene (300 ng/L 1-MCP and untreated) and 2 x storage temperature (2.0 and 5.5°C) treatments. An interaction between the three treatments did not significantly (P > 0.05) influence fruit colour, flesh firmness, ripening percentage, fruit weight loss, body rot, stem end-rot, vascular browning, chilling injury and electrolyte leakage. Their combined effect was only significant (P = 0.019) on ‘Hass’ fruit respiration rate. The combination of full and PRD irrigation, 1-MCP and low storage temperature (2.0°C) did not negatively affect fruit quality. However, fruit stored at 2.0°C without 1-MCP treatment were affected by chilling injury when compared with fruit stored at 5.5°C. In conclusion, due to the inconclusiveness of results obtained, further studies, on the effect of these treatments especially under 5.5°C storage temperature should be carried out prior recommending the combination treatment for export markets. / Agricultural Research Council-Tropical and Subtropical Crops (ARC-TSC) and Agricultural Sector Education Training Authority (AgriSeta)

Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Being the harvest time of apples concentrated in a short period, fruit storage is needed for market regulation. New storage technologies are being developed, such as dynamic controlled atmosphere with respiratory quotient (DCA-RQ), that needs to be evaluated under different temperatures and with the application of growth regulators such as aminoethoxyvinylglycine (AVG), naphthalene acetic acid (NAA) and 1-methylcyclopropene (1-MCP). This thesis is composed of four papers, which resulted from studies with the following objectives: to evaluate volatile compounds concentration in ‘Galaxy’ and ‘Royal Gala’ apples stored under DCA-RQ, DCA with chlorophyll fluorescence (DCA-CF), controlled atmosphere (CA) with and without 0,625 μL L-1 of 1-MCP application; to evaluate if DCA-RQ and DCA-CF allow employing higher temperatures during apple storage; to evaluate the effect of the application of AVG (0.83 kg ha-1) in combination with NAA (40g ha-1), as well as the effects of 1-MCP in the production of volatile compounds and physical-chemical quality of apples stored under DCA monitored with chlorophyll fluorescence and respiratory quotient; identify if the stress by low O2 partial pressure during RQ measurement has an effect on apple quality conservation. ‘Galaxy’ and ‘Royal Gala’ apples were stored for 9 months plus 7 days at 20 °C. It is worth noting that ‘Galaxy’ apples stored under DCA-RQ1.5 maintained better quality when compared to CA, ultralow oxygen (ULO – 0.4kPa) and DCA-CF, also increasing the production of esters responsible for the aroma. Besides, 1-MCP reduced volatile compounds concentration, even in apples stored under DCA-RQ1.5. Likewise, DCA-CF had a similar effect to ULO with 0.4 kPa of O2. The DCA-RQ1.3 and DCA-CF allowed storing ‘Galaxy’ apples under temperatures higher (2.0 and 2.5 °C) than recommended (1.5 °C). In addition, 1-MCP application did not have additional effects when fruit were stored under DCA and higher temperatures. Higher temperatures (2.0 and 2.5 °C) could be used without reducing the production of important volatile compounds. In DCA-RQ, the stress by low O2 employed during RQ measurement has presented a beneficial effects, with fruit maintaining higher flesh firmness, lower mealiness and decay incidence compared to fruit without RQ calculation. ‘Royal Gala’ apples stored under DCA-RQ1.3 and DCA-CF, submitted to the application of AVG and NAA during prehavest did show an increase in the concentration of volatile compounds. However, the combination of AVG plus NAA and the storage under DCA-RQ1.3 or DCA-CF presents an excellent alternative for storing apples, because maintains higher flesh firmness, reduce physiological disorders and maintain higher percentage of healthy fruit. / Devido à colheita de maçãs ser concentrada em curto período, faz-se necessário o armazenamento de uma grande parte dos frutos para regulação do mercado. Existem tecnologias de armazenamento em desenvolvimento, como a atmosfera controlada dinâmica com quociente respiratório (ACD-QR), a qual precisa ser avaliada em diferentes temperaturas e em frutos com aplicação de fitorreguladores como o 1-metilciclopropeno (1-MCP), a aminoetoxivinilglicina (AVG) e o ácido naftaleno acético (ANA). Esta tese é composta por quatro artigos científicos que resultaram de trabalhos com os seguintes objetivos: Avaliar a produção de compostos voláteis em maçãs ‘Galaxy’ e ‘Royal Gala’ armazenadas em ACD-QR, atmosfera controlada dinâmica com fluorescência de clorofilas (ACD-FC), atmosfera controlada (AC) convencional e com aplicação de 1-MCP; avaliar se a ACD-QR e a ACD-FC permitem utilizar temperaturas mais elevadas para o armazenamento das maçãs; avaliar o efeito da aplicação da AVG (0,83 kg ha-1) em combinação com o ANA (40g ha-1), bem como o efeito do 1-MCP na produção de compostos voláteis e qualidade físico-química dos frutos armazenados em ACD monitorada com fluorescência de clorofilas e com quociente respiratório; identificar se o estresse por baixa pressão parcial de O2 durante o período de cálculo do quociente respiratório possui efeito na conservação da qualidade de maçãs. Foram utilizadas maçãs ‘Galaxy’ e ‘Royal Gala’, armazenadas por nove meses mais sete dias de exposição à temperatura de 20 °C. Pode-se destacar que a maçã ‘Galaxy’ quando armazenada em ACD com QR 1,5 (ACD-QR1,5) manteve melhor qualidade, do que o armazenamento em AC convencional com pressões parciais de O2 ultrabaixas (ULO – 0,4 kPa CO2) e em ACD-FC, além de aumentar a produção de ésteres responsáveis pela formação do aroma. Além disso, a aplicação de 0,625 μL L-1 de 1-MCP reduziu a concentração de compostos voláteis, mesmo em frutos armazenados em ACD-QR1,5. A ACD-FC teve efeito similar ao armazenamento em ULO com 0,4 kPa de O2. A ACD-QR1,3 e a ACD-FC permitiram armazenar a maçã ‘Galaxy’ em temperatura mais elevada (2,0 e 2,5 °C) do que a normalmente recomendada (1,5 °C). Além disso, a aplicação de 1-MCP não teve efeito adicional em maçãs armazenadas com temperatura mais elevada quando em ACD. A alta temperatura (2,0 e 2,5 °C) pôde ser usada em ACD-QR1,3 sem perda na produção de compostos voláteis importantes. No armazenamento em ACD-QR, o estresse causado pelas baixas pressões parciais de O2 a que os frutos são submetidos durante o período de cálculo do QR (13 h), que pode atingir 0,0 kPa, possuiu efeito benéfico, pois manteve firmeza da polpa mais elevada, menor incidência de polpa farinácea e podridões, comparado aos frutos que não sofreram esse estresse por baixo O2. O armazenamento de maçãs ‘Royal Gala’ em ACD-QR1,3 e ACD-FC tratadas em pré-colheita com AVG e ANA não aumentaram a concentração de compostos voláteis. Entretanto, a aplicação associada de AVG e ANA e o armazenamento em ACD-QR1,3 ou ACD-FC foram excelentes alternativas para a conservação dos frutos, pois mantiveram a firmeza da polpa, reduziram os distúrbios fisiológicos, proporcionando maior volume de frutos sadios.

Made available in DSpace on 2016-12-06T17:42:08Z (GMT). No. of bitstreams: 1 PGPV15DA025.pdf: 2109681 bytes, checksum: 1bb93c3d645d7f8696a1db721aad0c99 (MD5) Previous issue date: 2015-09-30 / The aim of this study were to evaluate effect of apple trees spraying with gibberellins (GAs) and prohexadione calcium(ProCa), na inhibitor of gibberellin synthesis, on the vegetative growth and xylem functionality, total mineral contente, expression. Of tonoplast calcium pumps and exchangers and H pumps, maturation and post-harvest fruit quality. Two experiments were developed. The first was developed in a comercial orchard in Elk Grove, California, USA, Clarksburg town, in 2013. The second was accomplished in na orchard at São Joaquim, Santa Catarina, Brazil, in two crop seasons (2011-2012 ansd 2012-2013). In the study accomplished at the USA, Braeburn apple trees were sprayedweekly after full bloom AFB (six weekly applications, starting 15 days after full bloom 0 DAFB) and before-harvest (BH, weekly applications, starting 5 weeks before harvest) with ProCa and GA&#8324;&#8330;&#8327; (both at 300 mg L¯¹). In Brazil, Fuji and Gala apple trees were sprayed with ProCa AFB (at concentrations of 165, 330 and 495 g ha¯¹), which were sprayed at 30, 60 and 90 DAFB. In both the experiments, control plants were sprayed with water and the plant and fruit were evaluated for vegetative growth, xylem functionality,total mineral contente and bitter pit incidence and other physiological disorders. Additionally, the USA experimente were evaluated for soluble calcium; expression. Of tonoplast calcium pumps and exchangers and H pumps; and fruit quality at harvest and after storage. In both experiments, the vegetative growth decreased with ProCa AFB plant spraying. In Brazil, the Gala apple from trees sprayed with GA&#8323; has higher cracking, N/Ca mineral relation in the pulp and lower xylem function at the beginner of fruit development, as compared with ProCa (405 mg L¯¹). in USA, the Ca concentration is higher in Breaburn apples sprayed with ProCa as compared GA&#8324;&#8330;&#8327;, when both treatments were applied AFB. The red color, starch index value and ethylene production were lower and the firmness higher at harvest moment in the Breaburn apple from trees sprayed with ProCa at BH, as compared with control fruits. In Brazil, the bitter pit and scald incidence is lower in Fuji apple sprayed with increasing of ProCa concentrations. In USA, the Breaburn trees sprayed with GA&#8324;&#8330;&#8327; AFBhave higher Ca-ATPase and H&#8314;-PPase expression. And bitter pit, cracking and rot incidence in the fruits, as compared with control treatment / Este trabalho teve como objetivo avaliar o efeito da pulverização de macieiras com giberelinas (GAs) e proexadiona-cálcio (ProCa), um inibidor da síntese de giberelinas, sobre o crescimento vegetativo das plantas e a funcionalidade do xilema, composição mineral, expressão dos transportadores de Ca e bombas eletrogênicas, maturação e qualidade pós-colheita dos frutos. Foram elaborados dois experimentos. O primeiro foi desenvolvido em um pomar comercial no município de Elk Grove, Califórnia, EUA, localidade de Clarksburg, em 2013. O segundo foi em um pomar localizado no município de São Joaquim, Santa Catarina, Brasil, nas safras de 2011-2012 e 2012-2013. No trabalho realizado nos EUA, macieiras Braeburn foram pulverizadas, em pós-floração (PF; uma pulverização a cada semana, totalizando seis aplicações, iniciando 15 DAPF) e em pré-colheita (PC; uma pulverização a cada semana, totalizando quatro aplicações, iniciando 5 semanas antes da colheita), com ProCa e GA4+7 (ambos com doses de 300 mg L-1). No trabalho realizado no Brasil, macieiras Fuji e Gala foram pulverizadas PF com ProCa (doses: 165, 330 e 495 mg L-1) e GA3 (dose: 330 mg L-1), sendo estas doses divididas em três aplicações (30, 60 e 90 DAPF). Em ambos os experimentos, as plantas do tratamento-controle foram pulverizadas com água e as avaliações realizadas foram: crescimento vegetativo das plantas; funcionalidade do xilema; conteúdo mineral total de Ca e a suas relações com Mg, N e K; e ocorrência de bitter pit e demais distúrbios fisiológicos. Adicionalmente, no experimento desenvolvido nos EUA foram avaliados: o teor de cálcio solúvel; a expressão dos genes que codificam para transportadores de Ca e bombas eletrogênicas no tonoplasto; e a maturação e a qualidade dos frutos no momento da colheita e após o período de armazenamento. O crescimento vegetativo de macieiras é menor com a utilização do ProCa em pós-floração, independente da condição experimental. No Brasil, maçãs Gala de plantas pulverizadas com GA3 (330 mg L-1) tendem apresentar maior manifestação de rachaduras, maior relação N/Ca no tecido polpa e menor funcionalidade do xilema no início do desenvolvimento dos frutos, em relação ao ProCa na dose de 495 mg L-1. Nos EUA, o conteúdo de Ca total é maior em maçãs Braeburn pulverizadas com ProCa em comparação ao GA4+7, quando ambos os tratamentos foram aplicados em pós-floração. Além disso, a porcentagem de cor vermelha, os valores do índice iodo-amido e a taxa de produção de etileno são menores e a firmeza de polpa superior no momento da colheita em maçãs Braeburn de plantas pulverizadas com ProCa em pré-colheita, em relação ao tratamento-controle. No Brasil, a incidência de bitter pit e de escaldadura em maçãs Fuji é menor com o aumento das doses de ProCa. Nos EUA, frutos de macieiras Breaburn pulverizadas com GA4+7 em pós-floração tendem apresentar maior expressão da Ca-ATPase e H+-PPase e maiores valores de incidência de bitter pit , rachaduras e podridões nos frutos, em relação ao tratamento-controle