Optar al Titulo Profesional de Ingeniero Agrónomo Mención: Fruticultura

Memoria para optar al Título Profesional de: Ingeniero Agrónomo. Mención Fruticultura / El objetivo de este trabajo fue desarrollar un método fácil y económico para incrementar la conservación de postcosecha en fruta de palto var. Hass. Para ello se implementó el sistema de atmósfera modificada (AM) pasiva mediante el uso de un envase plástico semipermeable a los gases para así obtener la combinación de CO2 y O2 adecuada que permita prolongar la vida de postcosecha de paltas. La frutas fue almacenada a 5°C durante de 21 y 42 días. En estos frutos se evaluó el color y firmeza (apta para consumo) a salida de frío y a medida que fuera madurando a 20°C, simulando condiciones comerciales de maduración. Se utilizaron frutas con 2 estados de madurez (fechas de cosecha, agosto y diciembre). Los parámetros evaluados fueron contenido de humedad, contenido de aceite, resistencia de la pulpa a la presión, período de maduración y cambio de color de cubrimiento (días), color (luminosidad, tono y saturación) de epicarpio y mesocarpio (piel y pulpa), pérdida de peso, pudriciones, desórdenes fisiológicos, aceptabilidad y apariencia. La AM pasiva al utilizar películas plásticas con una permeabilidad superior a 9.000 mL•m-2 •día-1 demostró ser un buen método de conservación de los frutos, logrando mantener niveles de CO2 entre 4 y 5% y entre 2 y 4% de O2, logrando así disminuir la incidencia de desórdenes fisiológicos como pardeamiento y aparición de fibras en la pulpa, retardar el viraje de color, mantener la firmeza de la fruta y disminuir la pérdida de peso durante el almacenamiento en frío. Además esta técnica mantuvo el color interno (epicarpio y mesocarpio), la aceptabilidad y apariencia de los frutos maduros. La técnica de AM fue fácil de implementar en una línea de embalaje. Se logró mantener estable la concentración de gases y una humedad relativa de 95% durante todo el tiempo de almacenamiento en frio a 5ºC. Además al ser un sistema que es caja a caja, posibilita manejar la oferta al permitir graduar el volumen de fruta puesta a la venta. / The objective of this project was to develop a low cost and easy method to increase the time in storage of Hass variety avocados. In order to achieve a passive modified atmosphere (MA) environment was created using a semi-permeable to gas plastic container which provided the required combination of CO2 y O2 in order to lengthen the lifespan of the avocadoes. The fruit was stored at 5°C during 21 and 42 days. The color and firmness (eating quality) of the fruit was assessed on removing it from cold storage and whilst it matured up to 20°C, thus simulating standard commercial maturing processes. Fruits in two different mature states were used (harvest dates, august and december). The parameters that were evaluated were humidity level, oil content, firmness, maturity period, as well as color change of the skin (in days), color in general (luminosity, tone and saturation) of both the skin and fruit, weight loss, level of decay, physiological disorders and general appearance and aptness. The passive MA achieved by using plastic with a permeability over 9.000 mL•m-2 •día-1 was proven to be an efficient method of fruit conservation, managing to maintain CO2 levels between 4 and 5% and 2 to 4% of O2, thus achieving a reduction in physiological disorders including internal flesh browning and the appearance of fibers in the fruit, a delay in skin color changes, maintaining the firmness of the fruit and reducing weight loss during cold storage. Additionally this technique allowed for the preservation of fruit color and the general acceptability and appearance of the mature fruit. The MA technique was easy to implement in a packing line and cheaper than using CA containers. In addition the level of gas concentration was maintained stable as well as a level of 95% relative humidity during cold storage at 5°C. In addition as this system is box by box, it allows for supply regulation as it is possible to control the amount of fruit that is ready for market.

Tesis presentada como parte de los requisitos para optar al Grado de Magíster en Ciencias Agropecuarias Mención Producción Frutícola / El palto es una especie que presenta bajos rendimientos comparado con otros frutales. Para lograr incrementar el nivel productivo, de manera estable en el tiempo, es de suma importancia conocer cómo la carga frutal afecta a algunas variables fisiológicas en el palto. El año 2013 se realizó un estudio, en dos sectores plantados con paltos “Hass” en la zona de Llay-Llay, región de Valparaíso, con el objetivo de determinar el efecto de la carga frutal sobre algunas variables fisiológicas en las plantas. En uno de los sectores se seleccionaron aleatoriamente 27 paltos con distintos niveles de carga frutal, sobre los cuales se evaluó el crecimiento de frutos, concentración foliar de minerales, concentración de clorofila, conductancia estomática, fotosíntesis y floración. En un segundo sector contiguo, se seleccionaron 64 árboles de muy baja o nula floración, y posteriormente una muy baja o nula carga frutal, para generar 8 tratamientos de 8 plantas cada uno. 7 de los tratamientos fueron pulverizados con 300 mg·L-1 GA3 en una sola oportunidad, entre diciembre y junio, donde el mes correspondió al tratamiento, además de dejar un tratamiento como testigo absoluto. En estos tratamientos, posteriormente, se evaluó el estado de la yema terminal y el retorno floral. La mayor carga frutal afectó negativamente el calibre de la fruta, el retorno floral y el contenido de zinc foliar, y positivamente la conductancia estomática, la fotosíntesis, el contenido de calcio, magnesio y manganeso foliar. Aplicaciones de GA3 afectaron negativamente el retorno floral, sobre todo cuando este regulador de crecimiento se aplicó en enero o febrero.

Premature and excessive leaf abscission during flowering time in the late avocado (Persea americana Mill.) cultivar ‘Ryan’ is a considerable problem for avocado growers. They are especially concerned that premature and excessive leaf abscission will have a negative effect on yield. No previous investigations have been performed where premature and excessive leaf abscission in avocado has been studied in detail. This study therefore aimed to investigate the pattern of premature and excessive leaf abscission in ‘Ryan’, and compare it with two other important commercial cultivars, ‘Fuerte’ and ‘Hass’, which do not display this phenomenon. Time course studies of leaf abscission in the orchard were performed during 2006 and 2007 to determine the pattern of leaf abscission on ‘Ryan’, Fuerte’ and ‘Hass’. This also included anatomical studies to determine the time of leaf abscission zone formation. Possible stress factors, which accelerate leaf abscission were also investigated, namely unfavourable climatic conditions (temperature, solar radiation, rainfall, relative humidity and evapotranspiration), nutrient imbalances, excessive flowering and leaf area. The possible impact leaf abscission may have on yield was then assessed by determining levels of reserve carbohydrates in the bark of the tree. In addition, practical solutions, i.e. the application of fertilizers, plant growth regulators (PGRs) and kaolin, were investigated in order to reduce or eliminate premature and excessive leaf abscission. This study was carried out over the period 2005 until 2007, with experiments being modified on an annual basis as information was gathered on the phenomenon. Experiments began in 2005 with a study on the pattern of leaf abscission in ‘Ryan’, which revealed an increase in leaf abscission just prior to flowering. However, this increase was not significant. During 2006, the leaf abscission pattern for ‘Ryan’ was compared with the leaf abscission patterns of ‘Fuerte’ and ‘Hass’. Leaf abscission for ‘Ryan’ was significantly higher than for ‘Fuerte’ and ‘Hass’ during 2006. During 2006 ‘Ryan’ displayed two periods of high leaf abscission, namely the spring flush between bud dormancy and bud swell, and a drastic increase in spring and summer flush leaf abscission between inflorescence development and full bloom. These periods of increased leaf abscission were absent during the 2007 season. In addition, ‘Fuerte’ and ‘Hass’ did not display these peaks of high leaf abscission, with leaf abscission occurring in these cultivars at higher rates from full bloom onwards. Premature and excessive leaf abscission is therefore not an annual event in ‘Ryan’ and is in all likelihood influenced by external factors. Anatomical studies did not reveal any results in terms of initiation of leaf abscission, with only the protective layer of the abscission zone being visible after leaf yellowing occurred. During 2006, two peaks of extremely low temperatures (<4°C) occurred just prior to the acceleration of leaf abscission. During the second period of low temperatures, the solar radiation:temperature-ratio was also considerably higher. These periods of low temperatures were absent during 2007, indicating that cold and light stress could be contributing to premature and excessive leaf abscission in ‘Ryan’ in 2006. In addition, ‘Ryan’ flowered excessively during 2006, which could have been triggered by low temperature stress just prior to flower initiation. A significant correlation was found between excessive flowering and excessive leaf abscission in ‘Ryan’ during 2006. The occurrence of reduced flowering in ‘Fuerte’ and ‘Hass’ may possibly be due to these two cultivars being more tolerant to stress, and it is possible that ‘Ryan’ is genetically more prone to excessive flowering than ‘Fuerte’ and ‘Hass’. Excessive flowering could accelerate leaf abscission by causing an unusually high demand for water, nutrients and carbohydrates, resulting in the acceleration of leaf abscission. No significant relationship between nutrient levels and excessive leaf abscission was found for either 2006 or 2007. In addition, no significant correlation could be found between leaf abscission on a branch and the total leaf area of that branch during the 2007 season. During 2007, leaf abscission was low and it is possible that a significant correlation could be found in a season with excessive leaf abscission. During 2005, chemical applications to reduce leaf abscission did not yield any significant improvement in leaf retention. In fact, the 50 g/tree Solubor® and 50 g/tree Solubor® in combination with 2 kg/tree dolomitic lime had a significant negative effect on fruit set, possibly because too high concentrations were applied too close to fruit set. Chemical applications during 2006 were therefore made at bud dormancy and bud swell, as it was found that leaf abscission occurred before flowering time. However, no effect was observed on leaf retention or fruit set. During 2007, emphasis was placed on treatments that might reduce stress, as it became evident that stress could be responsible for premature and excessive leaf abscission in ‘Ryan’. Most treatments showed a slight positive effect on leaf retention, but no significant results were obtained possibly because that particular season was a season of low leaf abscission. Further research on application of stress-reducing treatments is therefore recommended. Best farm management practices including optimal fertilization and irrigation is therefore vital to prevent stress, accelerating leaf abscission. Copyright / Dissertation (MSc)--University of Pretoria, 2009. / Plant Science / unrestricted

O abacateiro (Persea americana Mill.) possui desenvolvimento organizado em fluxos de crescimento e florescimento em panículas, provenientes principalmente de gemas terminais, podendo ocorrer em menor intensidade a partir de gemas axilares. Dessa forma, o presente estudo teve como objetivo avaliar a capacidade de florescimento e a presença de substâncias ergásticas nas células de gemas axilares, bem como determinar a contribuição dos fluxos de crescimento de primavera e verão para a composição floral dos abacateiros \'Geada\', \'Fortuna\', Quintal\', \'Margarida\' e \'Hass\', localizados no sudoeste do Estado de São Paulo, Brasil. Adotou-se o delineamento experimental inteiramente casualizado e por meio da contagem do número de brotações e inflorescências, o acompanhamento do desenvolvimento vegetativo e reprodutivo foi feito em 40 ramos do fluxo de primavera e 40 ramos do fluxo de verão, distribuídos em cinco plantas por cultivar, no período de março a agosto/2016. A capacidade de florescimento de gemas axilares foi avaliada em estruturas coletadas mensalmente entre março e julho de 2016 nos ramos dos fluxos de primavera e verão, sendo as alterações anatômicas do meristema e a presença de substâncias ergásticas (amido, proteínas totais, compostos fenólicos e polissacarídeos) monitoradas a partir de testes histológicos e histoquímicos. Para as análises histológicas, as amostras vegetais foram desidratadas em série gradual de álcoois, emblocados em historesina e coradas em coloração dupla com reagente ácido periódico de Schiff e Naftol Blue Black. O florescimento de todas as cultivares ocorreu no mês de agosto/2016 e a formação de inflorescências foi predominante em ramos provenientes do fluxo de verão para todas as cultivares. Os resultados evidenciam a capacidade de florescimento de gemas axilares dos abacateiros, as quais são anatomicamente idênticas às gemas terminais e apresentaram início do comprometimento com o florescimento, caracterizada pelo aparecimento dos eixos secundários da inflorescência, dois meses antes (entre maio e julho) da época de floração (agosto/setembro). / Avocado trees (Persea americana Mill.) has an organized development in fluxes of growth and flowering in panicles, mainly coming from terminal buds, and may occur in less intensity from axillary buds. Thus, the present study had as objective the evaluation of the flowering potential and presence of ergastic substances in axillary buds, as well as to determine the contribution of the spring and summer fluxes growth to the floral composition of the avocado trees \'Geada\', \'Fortuna\' , Quintal \',\' Margarida \'and\' Hass\', located in the southwest of São Paulo State, Brazil. The experimental design was completely randomized and the vegetative and reproductive development was monitored in 40 branches of the spring flux and 40 branches of the summer flux by counting the number of shoots and inflorescences, distributed in five plants per cultivar, in the period from March to August / 2016. The flowering capacity of axillary buds was evaluated in monthly collected structures between March and July of 2016 in the branches of spring and summer fluxes, being the anatomical alterations of the meristem and the presence of ergastic substances (starch, total proteins, phenolic compounds and polysaccharides) monitored from histological and histochemical analyses. For the histological analyzes, the plant samples were dehydrated in a gradual series of alcohols, placed in historesin and stained in double staining with periodic acid reagents of Schiff and Naftol Blue Black. The flowering of all cultivars occurred in August / 2016 and inflorescence formation was more significant in branches from the summer flow for all cultivars. The results showed the flowering ability of axillary buds of the avocado trees, which are anatomically identical to the terminal buds and showed the beginning of the flowering, characterized by the appearance of the secondary axes of the inflorescence two months before (between May and July) of flowering (August / September).

O abacateiro (Persea americana Mill.) possui desenvolvimento organizado em fluxos de crescimento e florescimento em panículas, provenientes principalmente de gemas terminais, podendo ocorrer em menor intensidade a partir de gemas axilares. Dessa forma, o presente estudo teve como objetivo avaliar a capacidade de florescimento e a presença de substâncias ergásticas nas células de gemas axilares, bem como determinar a contribuição dos fluxos de crescimento de primavera e verão para a composição floral dos abacateiros \'Geada\', \'Fortuna\', Quintal\', \'Margarida\' e \'Hass\', localizados no sudoeste do Estado de São Paulo, Brasil. Adotou-se o delineamento experimental inteiramente casualizado e por meio da contagem do número de brotações e inflorescências, o acompanhamento do desenvolvimento vegetativo e reprodutivo foi feito em 40 ramos do fluxo de primavera e 40 ramos do fluxo de verão, distribuídos em cinco plantas por cultivar, no período de março a agosto/2016. A capacidade de florescimento de gemas axilares foi avaliada em estruturas coletadas mensalmente entre março e julho de 2016 nos ramos dos fluxos de primavera e verão, sendo as alterações anatômicas do meristema e a presença de substâncias ergásticas (amido, proteínas totais, compostos fenólicos e polissacarídeos) monitoradas a partir de testes histológicos e histoquímicos. Para as análises histológicas, as amostras vegetais foram desidratadas em série gradual de álcoois, emblocados em historesina e coradas em coloração dupla com reagente ácido periódico de Schiff e Naftol Blue Black. O florescimento de todas as cultivares ocorreu no mês de agosto/2016 e a formação de inflorescências foi predominante em ramos provenientes do fluxo de verão para todas as cultivares. Os resultados evidenciam a capacidade de florescimento de gemas axilares dos abacateiros, as quais são anatomicamente idênticas às gemas terminais e apresentaram início do comprometimento com o florescimento, caracterizada pelo aparecimento dos eixos secundários da inflorescência, dois meses antes (entre maio e julho) da época de floração (agosto/setembro). / Avocado trees (Persea americana Mill.) has an organized development in fluxes of growth and flowering in panicles, mainly coming from terminal buds, and may occur in less intensity from axillary buds. Thus, the present study had as objective the evaluation of the flowering potential and presence of ergastic substances in axillary buds, as well as to determine the contribution of the spring and summer fluxes growth to the floral composition of the avocado trees \'Geada\', \'Fortuna\' , Quintal \',\' Margarida \'and\' Hass\', located in the southwest of São Paulo State, Brazil. The experimental design was completely randomized and the vegetative and reproductive development was monitored in 40 branches of the spring flux and 40 branches of the summer flux by counting the number of shoots and inflorescences, distributed in five plants per cultivar, in the period from March to August / 2016. The flowering capacity of axillary buds was evaluated in monthly collected structures between March and July of 2016 in the branches of spring and summer fluxes, being the anatomical alterations of the meristem and the presence of ergastic substances (starch, total proteins, phenolic compounds and polysaccharides) monitored from histological and histochemical analyses. For the histological analyzes, the plant samples were dehydrated in a gradual series of alcohols, placed in historesin and stained in double staining with periodic acid reagents of Schiff and Naftol Blue Black. The flowering of all cultivars occurred in August / 2016 and inflorescence formation was more significant in branches from the summer flow for all cultivars. The results showed the flowering ability of axillary buds of the avocado trees, which are anatomically identical to the terminal buds and showed the beginning of the flowering, characterized by the appearance of the secondary axes of the inflorescence two months before (between May and July) of flowering (August / September).

Made available in DSpace on 2014-07-29T15:30:38Z (GMT). No. of bitstreams: 1 GeorgeHarrison.pdf: 311872 bytes, checksum: 1d09dab2e74a25c19bd15b1748b7bc46 (MD5) Previous issue date: 2011-02-25 / In the search for new alternatives for control of Aedes aegypti, in view of its resistance to chemical insecticides in use, research on plant substances has been increasing, due to be degradable and less toxic to vertebrates. The aim of this study was to evaluate the insecticidal effect of crude ethanol extract (cee) of bark of Persea americana Mill, on larvae and pupae of Ae. aegypti in the laboratory and field. After obtaining this cee was dissolved in dimethyl sulfoxide (DMSO), thus obtaining the test solution. For each test, and repetition, in both laboratory and field were used 100 larvae of the 1st, 2nd, 3rd and 4th instars and 100 pupae too. The same amount of larvae and pupae was used for the groups positive and negative controls, performed respectively with temephos at 1 ppm and 1.6% of the DMSO. Both the laboratory bioassays and field were conducted with key artificial urban tire, glass and plastic. The results showed the insecticidal activity of the cee P. americana larvae and pupae of Ae. aegypti, both in laboratory and field. There was 100% mortality of the larvae of the 1st and 2nd instars in the laboratory at a dose of 5 ppm and field at a dose of 10 ppm. In the laboratory the LC50 and LC90 were respectively 7.2 and 19.3 ppm for 3rd instar, 6.6 and 15.4 ppm for 4th instar and 93.6 and 158.7 ppm for pupae. Following the same order, in the field, the LC50 and LC90 were 27.8 and 51.3 ppm plows the 3rd instar, 23.8 and 46.9 ppm for the 4th instar and 145.3 and 261.9 ppm for the pupae. The most important factor of this study was the effect pupicida of P. americana, because it is very rare to find this effect on other products, both natural and synthetic.Tests acute oral toxicity in rats were conducted to cee this plant that proved to be nontoxic according to norms (Acute Toxic Class Method - OECD 423) for products of plant origin. / Na busca de alternativas ao controle do Aedes aegypti, em vista da resistência aos inseticidas sintéticos, a investigação de compostos vegetais vem se destacando, pela degradação mais rápida e menor toxicidade aos vertebrados. Assim, avaliou-se o efeito inseticida do extrato bruto etanólico (ebe) da casca de Persea americana Mill sobre larvas e pupas de Ae. aegypti. Após a obtenção do ebe este foi solubilizado em dimetilsulfóxido (DMSO), obtendo assim a solução-teste. Para cada bioensaio e repetição, tanto em laboratório quanto em campo foram utilizadas 100 larvas de cada estádio e 100 pupas. A mesma quantidade foi usada para os controles positivos e negativos realizados com o temefós (1ppm) e DMSO a 1,6%. Todos os bioensaios foram realizados com os principais criadouros artificiais urbanos, pneu, vidro e plástico. Os resultados obtidos demonstraram a atividade inseticida do ebe de P. americana em larvas e pupas de Ae. aegypti. Houve mortalidade de 100% das larvas de 1° e 2° estádios em laboratório na dose de 5ppm e em campo na dose de 10ppm. No laboratório as CL50 e CL90 foram, respectivamente, de 7,2 e 19,3 ppm para o 3° estádio, de 6,6 e 15,4 ppm para 4° estádio e de 93,6 e 158,7ppm para pupas. Seguindo a mesma ordem, no campo, as CL50 e CL90 foram de 27,8 e 51,3ppm ara o 3°estádio, de 23,8 e 46,9 ppm para o 4° estádio e de 145,3 e 261,9 ppm para as pupas. O fator mais importante deste trabalho foi o efeito pupicida de P. americana, pois é muito raro encontrar esse efeito em outros produtos, tanto naturais quanto sintéticos. Esses resultados são sugestivos de aprimorarem estudos químicos para identificação de compostos ativos. Testes de toxicidade oral aguda com ratos foram realizados com o ebe dessa planta que mostraram-se atóxico de acordo com as normas do (Acute Toxic Class Method - OECD 423) para produtos de origem vegetal.

As frutas são fontes importantes de substâncias nutricionais e apresentam em sua constituição compostos com características funcionais, podendo ser apontadas como boas fontes de antioxidantes naturais. O abacate é uma fruta tropical com características nutricionais e organolépticas atrativas, destacando-se a quantidade de lipídeos com alto teor de ácidos graxos insaturados que trazem benefícios à saúde. Além disso, os resíduos de origem agroindustrial como cascas e sementes obtidos durante o processamento contêm compostos bioativos. Entretanto, ainda não existem estudos sobre a capacidade de desativação de espécies reativas de oxigênio, atividade anti-inflamatória e avaliação da composição fenólica em tempo real por HPLC-DAD-UV do fruto e dos resíduos do processamento de abacate, conforme a literatura científica. Por ser uma fonte de ácidos graxos poli-insaturados, há possibilidade de uma grande variedade de antioxidantes presentes no fruto, dentre os quais compostos fenólicos, para proteção e integridade do óleo contra oxidação. Assim, o objetivo deste trabalho foi caracterizar, isolar e identificar substâncias com atividade antioxidante da polpa, casca e semente de abacates das cultivares Hass e Fuerte; avaliar a capacidade de desativação de espécies reativas de oxigênio e a atividade anti-inflamatória. O conteúdo de compostos fenólicos totais foi avaliado pelo método de Folin-Ciocalteu, o potencial antioxidante foi avaliado pelos métodos do sequestro do radical livre DPPH e ABTS, redução do ferro, auto-oxidação do sistema ?-caroteno/ácido linoléico, estabilidade oxidativa em Rancimat e capacidade de desativação de espécies reativas de oxigênio pelos métodos ORAC, ânion superóxido e ácido hipocloroso. No geral, cascas e sementes de ambas as cultivares apresentaram maior atividade antioxidante em relação à polpa dos frutos. Os compostos de maior atividade antioxidante dos resíduos do abacate foram quantificados pelas técnicas HPLC-DAD-UV e LC-MS/MS e confirmados por RMN. Nas cascas de ambas as cultivares foram encontrados o ácido trans-5-O-cafeoil-D-quínico, procianidina B2 e epicatequina, enquanto que nas sementes foram o ácido trans-5-O-cafeoil-D-quínico, procianidina B1, catequina e epicatequina. Os resíduos das duas cultivares apresentaram elevada capacidade de sequestro do radical superóxido e ácido hipocloroso. Os compostos fenólicos mais frequentemente encontrados nas amostras pela técnica de GC/MS foram o ácido trans-5-O-cafeoil-D-quínico e epicatequina. A casca da cultivar Fuerte suprimiu significativamente a produção de TNF-? e NO, envolvidos no processo inflamatório, e pode estar relacionado ao alto teor de compostos fenólicos e atividade antioxidante encontrados nesta espécie. Portanto, resíduos da cadeia de processamento de abacate podem ser considerados fontes de compostos bioativos de grande potencial funcional / Fruits are important sources of nutritional substances and are rich in compounds with functional features that can be identified as good sources of natural antioxidants. The avocado is a tropical fruit with attractive nutritional and organoleptic characteristics, especially the amount of lipids with high content of unsaturated fatty acids that provide health benefits. Furthermore, agroindustrial residues such as peels and seeds obtained during processing contain bioactive compounds. However there are no studies about evaluate the capacity for scavenging reactive oxygen species, the anti-inflammatory activity and the phenolic composition of fruits and residues from avocado according to the scientific literature. A source of polyunsaturated fatty acids, the fruit must contain a variety of antioxidants, phenolic compounds among which, for protection and integrity against oil oxidation. The goal of the present study was to characterize, isolate and identify substances with antioxidant activity of the pulp, peel and seed of Hass and Fuerte avocados cultivars; evaluate the capacity for scavenging reactive oxygen species, the anti-inflammatory activity. The total phenolics content was measured by the Folin-Ciocalteu method. The methods for evaluating the antioxidant activity used were the DPPH free radical and ABTS, ?-carotene bleaching, reduction of Fe3+, oxidative stability in Rancimat, evaluate the capacity for scavenging reactive oxygen species by ORAC, superoxide anion and hypochlorous acid. Peels and seeds of both cultivars showed higher antioxidant activity than the pulp of the fruit. Compounds present in peels and seeds from both cultivars were quantified through LC-DAD-UV and LC-MS/MS and confirmed through RMN. The compounds exhibiting the greatest antioxidant activity were trans-5-O-caffeoyl-D- quinic acid, procyanidin B2 and epicatechin in the peels and trans-5-O-caffeoyl-D-quinic acid, procyanidin B1, catechin and epicatechin in the seeds. Residues from both cultivars exhibited high superoxide radical and hypochlorous acid-scavenging capacity. Phenolic compounds found most frequently in the samples by GC/MS technique were trans-5-O-caffeoyl-D-quinic acid and epicatechin. Peel from the cultivar Fuerte significantly suppressed the production of TNF-? and NO, which are involved in inflammatory processes, and this suppression may be related to the high phenolic content and antioxidant activity observed. Residues of avocado processing can therefore be considered sources of bioactive compounds with high functional potential

A cultivar Hass detém cerca de 90% do comércio de abacate para exportação. Em contrapartida, são descritas diversas cultivares de abacateiro protegidas por patentes em vários países, sendo menos da metade delas estabelecidas comercialmente. Ampliar o período de oferta de abacates do tipo \'Hass\' no mercado é de interesse para os exportadores brasileiros, pois impulsiona melhores negociações frente à demanda do fruto no mercado externo, sobretudo com países do Hemisfério Norte, em épocas em que o mercado se encontra num período crítico de alta demanda e baixa oferta. Este estudo objetivou avaliar variáveis que caracterizaram o desenvolvimento, a produção e os atributos de qualidade dos frutos das cultivares de abacateiros \'Hass\', \'Carmen\' e \'Gem\' nas condições edafoclimáticas da região Centro-Oeste do estado de São Paulo durante os anos de 2016 e 2017, visando ampliar o período de oferta dos frutos do tipo \'Hass\' no mercado internacional. No primeiro capítulo dessa dissertação, são apresentados os resultados relativos à comparação entre a cultivares Hass e Carmen, quanto às variáveis de crescimento de ramos de verão e de final de inverno/primavera, número de panículas por ramo, intensidade e tipo de florescimento, tamanho da planta (altura, diâmetro paralelo e perpendicular à linha de plantio e volume de copa), produção (Kg por planta, número de frutos por planta, eficiência produtiva e índice de alternância produtiva) e qualidade dos frutos (massa, diâmetro, comprimento, relação C:D, calibre e variáveis pós-colheita). Os resultados apontaram que \'Carmen\' apresentou maior crescimento dos ramos de verão, enquanto o mesmo foi observado para \'Hass\' nos ramos de final de inverno/primavera. No ano de 2016, \'Carmen\' produziu um número maior de panículas por ramo, em contrapartida, em 2017, a intensidade de florescimento foi maior para \'Hass\'. Nos dois anos, \'Carmen\' produziu mais inflorescências indeterminadas e menos determinadas em relação a \'Hass\'. Quanto à maturação dos frutos, \'Carmen\' mostrou-se mais precoce em cerca de quinze dias, embora ambas as cultivares tenham florescido na mesma época. \'Carmen\' apresentou superioridade em todas as variáveis produtivas analisadas, no entanto, mostrou-se mais alternante. Em ambos os anos, os frutos de \'Hass\' foram maiores em todas as variáveis que caracterizam o seu tamanho. As variáveis de pós-colheita apresentaram a mesma tendência em frutos de ambas as cultivares. No segundo capítulo, objetivou-se caracterizar o hábito vegetativo e reprodutivo da cultivar Gem na mesma região de cultivo. As avaliações foram executadas conforme as descritas no primeiro capítulo. \'Gem\' apresentou crescimento dos ramos de final de inverno/primavera mais acentuado, maior porcentagem de flores indeterminadas nos dois anos, maturação tardia, atingindo o percentual mínimo de matéria seca no final do mês de junho que evolui até o mês de outubro. As árvores possuem hábito de crescimento vertical, sendo indicada para pomares adensados. Os frutos produzidos são de tamanho grande. \'Carmen\' e \'Gem\' são promissoras para a região de cultivo, podendo ser indicadas como novas opções na produção de abacates do tipo \'Hass\'. / The Hass variety holds about 90% of the world avocado production. In contrast, within a wide range of several other avocado cultivars available in different countries, less than half of them had established commercially. Expanding the period of supply of \'Hass\' and \'Hass\'-type avocados is of interest to Brazilian exporters, because it facilitates fruit commercialization in the external markets of the Northern Hemisphere, in critical periods of high demand and low supply. The objective of this research was to evaluate plant growth, production and fruit quality attributes of \'Hass\', \'Carmen\' and \'Gem\' avocado cultivars in the edaphoclimatic conditions of the central-western region of the São Paulo State during the years of 2016 and 2017, aiming to extend the period of supply of \'Hass\' type fruits in the international market. In the first chapter of this dissertation, the results of the comparison between Hass and Carmen avocado cultivars are presented, regarding growth variables of summer and late winter/spring shoots, the number of panicles per shoot, the intensity and flowering type, tree size (height, diameter parallel and perpendicular to the planting line and canopy volume), yield (kg per plant, number of fruits per plant, yield efficiency and alternate bearing index) and fruit quality (mass, diameter, length and post-harvest quality variables). The results showed that \'Carmen\' avocado trees have higher growth of summer shoots, while \'Hass\' trees show larger growth of the shoots flushing by the end of winter/spring. In 2016, the \'Carmen\' trees yielded a larger number of panicles per shoot, while in 2017, the flowering intensity of \'Hass\' trees was higher. In both years, the \'Carmen\' trees produced a larger percentage of indeterminate inflorescences in comparison with \'Hass\' trees. In terms of fruit maturity, the \'Carmen\' fruit ripened about fifteen days earlier than \'Hass\' fruit in, although both cultivars flowered at the same time. The \'Carmen\' cultivar was superior than \'Hass\' in all the production variables analyzed in this study, despite of having a stronger tendency to alternate bearing. In both years, Hass\' yielded larger fruit size. Fruit post-harvest variables showed a similar tendency in both cultivars. In the second chapter, the objective was to characterize the vegetative and reproductive habit of the Gem cultivar in the same region of cultivation. The \'Gem\' trees have a vertical growth habit, being indicated for densified orchards, and showed stronger vigor of the winter/spring vegetative flush, with higher percentage of indeterminate flowers large fruit size and late maturation in both evaluated years. Both the \'Carmen\' and \'Gem\' avocado cultivars are promising for the growing region and may be indicated as new options for production of \'Hass\'-type avocados.

Apesar das excelentes condições edafoclimáticas para a produção de abacates no Brasil, a cultura encontra limitações relacionadas à baixa produtividade e suscetibilidade à podridão da raiz causada por Phytophthora cinnamomi, a principal doença da cultura nas distintas regiões produtoras. A aplicação de coberturas naturais ao solo é uma das estratégias que visa o controle desta doença, e entre seus benefícios estão a maior disponibilidade de água e nutrientes, menor competição das plantas daninhas, melhoria da estrutura, porosidade e fertilidade do solo e melhor aspecto sanitário das plantas, por favorecer a formação de um ambiente supressivo ao desenvolvimento do patógeno, pelo aumento do sistema radicular e da população de microorganismos antagônicos. Todos estes benefícios das coberturas naturais, junto ao aporte de nutrientes após sua incorporação, favorecem indiretamente a produção e o crescimento dos frutos. O objetivo deste trabalho foi avaliar distintos manejos da vegetação intercalar em abacateiros \'Hass\' visando à obtenção de coberturas naturais que, aplicadas ao solo, permitam minimizar a incidência da podridão radicular, promovendo melhorias no estado sanitário das plantas e na produção. Entre 2011 e 2013 foram avaliados cinco tratamentos: T1: ausência de vegetação intercalar, sem aplicação de cobertura morta sob a copa das plantas; T2: ausência de vegetação intercalar e duas aplicações externas de cobertura morta sob a copa; T3: duas deposições de cobertura morta sob a copa, obtida pelo corte da vegetação intercalar com roçadeira enleiradora lateral (REL); T4: três deposições de cobertura morta sob a copa, obtida pelo corte da vegetação intercalar com REL, e T5: manutenção da vegetação intercalar com três cortes anuais utilizando roçadeira convencional, sem deposição de cobertura morta sob a copa. O delineamento estatístico foi em blocos aleatorizados, com 6 repetições e 3 plantas úteis por parcela, nas quais foram avaliados: os teores de macronutrientes e micronutrientes em folhas e no solo; desenvolvimento vegetativo e radicular, produção de frutos, aspecto visual das plantas, massa seca da vegetação intercalar, espessura da cobertura morta e características químicas e microbiológicas do solo. A aplicação de coberturas vegetais resultou em um maior crescimento das plantas e maior tamanho dos frutos, sem efeito significativo sobre a produção. A deposição de cobertura morta obtida com REL favoreceu o desenvolvimento das raízes na camada superficial do solo. No entanto, os tratamentos não influenciaram significativamente o aspecto visual sanitário das plantas, nem os teores de macronutrientes e micronutrientes nas folhas e no solo. O manejo da vegetação intercalar com roçadeira convencional resultou em maior volume de massa seca, já o manejo desta com dois ou três cortes anuais utilizando REL depositou uma quantidade similar de cobertura morta sob a copa, que foi inferior à depositada pela aplicação externa de cobertura (T2). Todos os tratamentos com deposição de cobertura vegetal suprimiram o desenvolvimento de plantas daninhas sob a copa. No tratamento sem aplicação de cobertura morta e sem vegetação intercalar, houve aumento na população de P. cinnamomi no solo. Comparativamente, no período de dois anos, não foram observadas diferenças na população de actinomicetos no solo dos distintos tratamentos. / Despite the excellent soil and climatic conditions for avocado production in Brazil, the culture has limitations related to low productivity and susceptibility to avocado root rot caused by Phytophthora cinnamomi, the main crop disease in all producing areas. Mulching is one of the strategies utilized for controlling this disease, with several benefits such as an improved soil water and nutrients availability for roots, reduced weed competition, improved soil structure, porosity and fertility and enhanced plant health condition, due to the creation of a suppressive environment for the development of the pathogen, by increasing root density and the population of antagonistic microorganisms. All these benefits of natural mulches, together with the supply of nutrients and assimilates after their incorporation to the soil, indirectly enhance fruit yield and size. The aim of this work was to evaluate different managements of inter-row vegetation in an adult \'Hass\' avocado orchard in order to obtain mulches which, after being applied to the soil, will allow reducing root rot incidence, thus promoting improvement of plant sanitary condition, with positive effects on fruit yield. From 2011 through 2013, five treatments were evaluated: T1: absence of inter-row vegetation, without mulch application under the canopy; T2: absence of inter-row vegetation and two applications of external mulch under the canopy: T3: two mulch depositions under the canopy obtained after cutting off the inter-row vegetation with a lateral alignment mower (LAM); T4: three mulch depositions under the canopy obtained after cutting off the inter-row vegetation with a LAM, and T5: maintenance of natural inter-row vegetation with three annual cuttings using a conventional mower, without mulch deposition under the canopy. The experiment was conducted in randomized blocks, with 6 repetitions and 3 plants per plot, on which the following variables were measured: levels of macro and micronutrients in leaves and soil; root and plant size development; fruit yield and size; plant sanitary condition visually assessed with a 10-note scale; biomass of inter-row vegetation; mulch thickness and chemical and microbiological soil characteristics. Mulching resulted in larger plant growth and fruit size, with no significant effects on fruit yield. Application of mulch obtained with a LAM enhanced root growth in the surface soil layer. Nonetheless, the treatments did not significantly affect nor the plant sanitary aspect, neither the leaf or soil levels of macro and micronutrients. Management of inter-row vegetation with a conventional mower resulted in larger biomass development, while managing inter-row vegetation with two or three cuttings with LAM per year resulted in similar amounts of mulch laid down under the canopy, yet less than with the application of external mulch (T2). All the treatments with mulch deposition suppressed weed growth under the canopy. In the treatment with no mulch and no inter-row cropping, a larger population of P. cinnamomi was recorded. There were no differences in the Actinomycetes soil population among treatments.