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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Influence of various storage conditions on rind breakdown and quality parameters in tangelo (Citrus reticulata Blanco x Citrus paradisi Macf.)

Van der Westhuizen, Anna Maria 09 November 2005 (has links)
Minneola tangelos were obtained from different production areas in two seasons (1996: Western Cape and Swaziland, 1997: Western and Eastern Cape), and stored at two different temperature regimes simulating the shipping and storage treatments of fruits for overseas markets to determine if storage regimes have an influence on quality parameters. Samples were taken every two weeks and quality parameters such as fruit shape index, mean rind thickness, % juice, %TSS, and % acid were determined. An experiment to determine weight loss during storage time was done at the same time. Main significant differences across all the parameters were observed between fruits from the different production areas, while fruit shape, % juice, and occurrence of rind breakdown did not differ significantly. In 1996, the weight loss developed in storage only showed a significant difference after 8 weeks in storage. In 1997, there was no clear pattern, but the interaction between producers and storage temperatures differed significantly. Focusing on the producer from the Western Cape, there was a significant difference between storage temperatures, confirming that citrus fruits stored at a higher temperature (11°C) will loose moisture faster than those stored at a lower temperature (4.5°C). Even with the higher moisture loss, there were no differences between the fruit stored at the different temperatures, apart from the difference between the producers indicating that changes in quality of 'Minneola' fruit are mainly determined by the producers and apparently to a lesser extent by storage temperatures of 4.5°C and 11°C. With the high rate of over-maturity developing in storage, it is possible that the fruit might have been stored too long. Therefore, the marketing period for soft citrus types is apparently too long and problems with physiological ageing can be abundant at this storage length. / Dissertation (MSc (Agric) Horticultural Science)--University of Pretoria, 2005. / Plant Production and Soil Science / unrestricted
2

Caracterização e avaliação de frutos de tangores e tangelos / Characterization and evaluation of tangors and tangelos fruits

Delgado, João Pedro 03 March 1999 (has links)
Com o objetivo de caracterizar novas variedades de citros existentes no banco ativo de Germoplasma (BAG-Citro) do Centro de Citricultura Sylvio Moreira - Cordeirópolis SP, foi verificado características dos frutos de três tangores e três tangelosa saber: tangor da India, tangor Santa Maria Madalena e tangor Ortanique e os tangelos Minneola, tangelo Samfison e o tangelo Seminoole. Os tangores foram comparados com o tangor Murcott que para o trabalho desenvolvido, é a variedade padrão, jáos tangelos foram comparados com o tangelo Orlando, como variedade padrão. De acordo com o experimento, os tangores e os tangelos não apresentaram características favoráveis para serem usados como copa no período de dois anos de estudo / Three types of tangors and three of tangelos, with potential commercial value, were analysed in regard to their fruit characteristics, under the climatic conditions of the Centro of Citriculture Sylvio Moreira (CCSM) – Instituto Agronômico, Campinas, (IAC) located in Cordeirópolis country, São Paulo State, Brazil. The analysed types (materiaIs) from nucellar origin, were: Índia, Santa Maria Madalena and Ortanique tangors and Minneola, Sampson and Seminole tangelos, selected among those existing in the active germoplasm bank of the CCSM. The plants were grafted on 'Cleopatra' mandarine and were 10 years old at the beginning of the evaIuation. The study was carried out during two years in a row, starting from July through September 1996 and from June through September 1997, being the analyses carried out approximately, bi-monthly. Studied, were the following characteristics of the fruits: height, diameter, height/diameter, weight, rind colour, morphology, soluble solids (brix), acidity, soluble solids relation: acidity (ratio), juice yield, technological index, seed number and pulp colour. This work made the, description of the fruit's characteristics from each type, possible. From the results obtained, the following conclusions could be drawn: The varieties that presented the highest medium values in fruit's size were the Sampson, Seminole and the Minneola tangelos. The highest medium values for fruti's weight were obtained with the Minneola and Sampson tangelo. Most of the varieties presented high juice's yie1d, above 50%, being the highest values of Minneola, Sampson, Seminole tangelos and for the Ortanique tango r. AlI the varieties presented high rate of seeds per fruit. The tangores and tangeIos studied, in a general way, were not suitable to be used as canopies in the period in which they studied
3

Requerimentos reprodutivos de duas culturas agrícolas no agreste pernambucano

SANTOS, Ramon da Silva 25 February 2016 (has links)
Submitted by Mario BC (mario@bc.ufrpe.br) on 2018-06-08T14:27:06Z No. of bitstreams: 1 Ramon da Silva Santos.pdf: 1075873 bytes, checksum: 4e9e4e32c0a2aac8278de237b68b094f (MD5) / Made available in DSpace on 2018-06-08T14:27:06Z (GMT). No. of bitstreams: 1 Ramon da Silva Santos.pdf: 1075873 bytes, checksum: 4e9e4e32c0a2aac8278de237b68b094f (MD5) Previous issue date: 2016-02-25 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Phenology and reproductive biology assist in understanding the requirements of plants grown for the formation of fruits and seeds as well as in the management of pollinators when needed. This study aims to investigate the phenology and the reproductive biology Macadamia integrifolia (Proteaceae) and the tangelos Nova and Lee in the Experimental Station of the Agronomic Institute of Pernambuco (IPA), the municipality of Brejão (PE). The vegetative and reproductive phenophases of M. integrifolia (n = 7), tangelo Nova (n = 6) tangelo Lee (n = 6) were followed every two weeks from July / 2014 to June / 2015. The intensity of flowering and fruiting were estimated, the pattern of flowering was described and the correlation between rainfall and the occurrence of phenophases was tested. The investigation of the floral biology included analysis of anthesis period, stigmatic receptivity, as well as pollen and nectar availability. The reproductive system was determined by means of controlled pollination in the field. The floral visitors and their frequency of visits were determined by means of focal observations. The results are distributed in two chapters: The first one regarding M. integrifolia and the second one regarding the tangelos. In the first chapter the phenological events were not influenced by rainfall. Lepidopterans, himenopterans and dipterans were the most frequently observed visitors, which visited in low frequency. The species is self-compatible, had low fruit set, low reproductive efficiency and pollen limitation. In the second chapter, the varieties showed similar phenological patterns. Flowering occurred three times, with a peak in December (dry period), and there was no significant correlation between precipitation and analyzed phenological phases. The varieties have terminal inflorescences, hermaphroditic, actinomorphic flowers that were visited by Hymenoptera, Diptera and Lipidoptera species; bees were the most frequent. Both plants are self-compatible and the fruits resulted from and the fruits resulted from cross-pollination has similar to those resulted from the natural pollination. Pollen limitation and a low reproductive efficiency were observed, a result that may be related to the frequent pesticide spraying. These compounds may cause floral abcision and reduce pollinators‟ populations (and, consequently, fruit set), especially in plants that need pollinators to. / A fenologia e a biologia reprodutiva auxiliam na compreensão dos requerimentos de plantas cultivadas para a formação de frutos e sementes, bem como no estabelecimento de manejo de polinizadores, quando necessário. Este trabalho tem como objetivo investigar a fenologia e a biologia reprodutiva de Macadamia integrifolia (Proteaceae) e dos tangelos Nova e Lee na Unidade Experimental do Instituto Agronômico de Pernambuco (IPA), município de Brejão (PE). As fenofases vegetativas e reprodutivas de M. integrifolia (n= 7), do tangelo Nova (n=6) e tangelo Lee (n= 6) foram acompanhadas quinzenalmente no período de julho/2014 a junho/2015. As intensidades de floração e de frutificação foram estimadas, o padrão de floração foi descrito e a correlação entre precipitação pluviométrica e ocorrência das fenofases foi testada. A investigação da biologia floral incluiu análises de período de antese, receptividade estigmática, disponibilidade de pólen e presença de néctar. O sistema reprodutivo foi determinado por meio de polinizações controladas em campo. Os visitantes florais e sua frequência de visitas foram determinados por meio de observações focais. Os resultados obtidos estão dispostos em dois capítulos: o primeiro trata de Macadamia integrifolia e o segundo dos tangelos Nova e Lee (citros). Macadamia integrifolia não sofre influência da precipitação em seus eventos fenológicos; os visitantes florais mais comumente observados Lepidoptera, Hymenoptera e Diptera, os quais visitavam com baixa frequência. Foram registrados baixa formação de frutos nos testes reprodutivos, baixa eficiência reprodutiva e limitação polínica. No segundo capítulo, as varidedades apresentaram padrão fenológico semelhante: a floração ocorreu três vezes, com pico em dezembro (período seco) e não houve correlaçõ significativa entre precipitação e os eventos fenológicos observados. As variedades possuem inflorescências terminais, flores hermafroditas, actnomorfas, que foram visitadas por espécies de Hymenoptera, Diptera e Lepidoptera, sendo as abelhas as mais frequentes. Ambas variedades são auto-incompatíveis e frutos resultantes de polinização cruzada apresentaram características semelhantes em relação àqueles formados por polinização natural. Similarmente ao observado para macadâmia, as variedades apresentaram baixa eficiência reprodutiva e limitação polínica. Esses resultados podem ser resultado da aplicação semanal de pesticidas, que podem causar abscisão floral e reduzir as populações de polinizadores (e, consequentemente, a formação de frutos).

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