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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

Parâmetros biométricos e índices fisiológicos de plantas de pinhão manso (Jatropha curcas l.) sob aplicação de herbicidas

Santos, Wembles Ribeiro 04 September 2015 (has links)
Uma alternativa para a mudança da matriz energética, é a utilização de fonte de energia renovável, com isso a produção de biodiesel através de plantas oleaginosas vem ganhando destaque cada vez mais no mundo. Entre as culturas que apresentam destaque para a produção de biocombustível, destaca-se a cultura do pinhão manso. As plantas de pinhão-manso são susceptíveis em seus estádios iniciais a competição por plantas daninhas, sendo assim se faz necessário controle mecânico ou químico durante a fase inicial de estabelecimento da cultura. O presente estudo teve como objetivo a avaliação de índices fisiológicos de plantas de pinhão manso (Jatropha curcas L.) submetidas a diferentes mecanismo de ação de herbicidas. O delineamento adotado foi o de blocos ao acaso, em esquema fatorial (9 x 5) + 1, sendo 9 herbicidas, 5 épocas de avaliação e 1 testemunha. As mudas foram transplantadas para os sacos plásticos com dois meses de idade, os quais receberam adubação com a formulação 5-25-15 de N-P-K (40 g/unidade experimental). Foram estudados os tratamentos Oxifluorfem (240 g.i.a.), Flumioxazina (25 g.i.a.), S-Metolacloro (1920 g.i.a.), Carfentrazona (32 g.i.a.), Tembotriona (100 g.i.a.), Bentazona (1200 g.i.a.), Metribuzin (480 g.i.a.), Flumioxazin + Oxifluorfem (25 + 240 g.i.a.) e Carfentrazone+ S-Metolacloro (32 + 1920 g.i.a.), mais 1 testemunha, tudo replicado cinco vezes. Os tratamentos foram aplicados dia 20 junho 2014, sete dias após o transplante, utilizando-se pulverizador costal de precisão, pressurizado à CO2 e calibrado para aplicar volume de calda de 150 L ha-1. Foram avaliados os sintomas visuais de intoxicação das plantas aos 7, 14, 21, 28 e 35 dias após a aplicação dos tratamentos. Aos 15, 30, 45, 60 e 75 dias após a aplicação, foram avaliadas as seguintes variáveis: altura de planta (AP), diâmetro de caule (DC), número de folhas (NF) e comprimento de raiz (CR), biomassa seca de folhas (MSF), de caule (MSC), de raízes (MSR) e biomassa seca total (MST), área foliar, área foliar específica, razão de área foliar, razão de peso de folha, TCA, TCR e TAL. Os tratamentos com os herbicidas oxifluorfem, flumioxazina e flumioxazina+oxyfluorfem, foram os que mais causarem efeitos prejudiciais nas plantas e influenciando no acumulo de biomassa seca total. Os tratamentos com herbicidas flumioxazina, s-metalacloro, foram os que mais reduziram as taxa de crescimento absoluto, relativo nos períodos avaliados. / An alternative to changing the energy matrix is the use of renewable energy source, thereby producing biodiesel using oilseed plants has been gaining attention increasingly in the world. Among the crops that have an emphasis on the production of biofuel, there is the Jatropha culture. The jatropha plants are likely in its early stages the competition by weeds, so necessary mechanical or chemical control during the early stages of crop establishment. This study aims to evaluate the physiological indices of Jatropha plant (Jatropha curcas L.) submitted to different herbicide mode of action. The adopted design was a randomized block in a factorial design (9 x 5) + 1, with 9 herbicides, 5 evaluation periods and one witness. The seedlings were transplanted to plastic bags with two months of age, who received fertilization with NPK 5-25-15 formulation (40 g / plot). The treatments were studied Oxifluorfem (240 g.i.a.), Flumioxazina (25 g.i.a.), S-Metolacloro (1920 g.i.a.), Carfentrazona (32 g.i.a.), Tembotriona (100 g.i.a.), Bentazona (1200 g.i.a.), Metribuzin (480 g.i.a.), Flumioxazin + Oxifluorfem (25 + 240 g.i.a.) e Carfentrazone+ S-Metolacloro (32 + 1920 g.i.a.), 1 more witness with 5 repetitions. Treatments were applied on 20 June 2014, seven days after transplantation, using a backpack sprayer of accuracy, the pressurized CO2 and calibrated to apply spray volume of 150 L ha-1. They evaluated the visual symptoms of poisoning plants at 7, 14, 21, 28 and 35 days after treatment application. At 15, 30, 45, 60 and 75 days after application, the following variables: plant height (PH, cm), stem diameter (DC, in mm), number of leaves (NF) and root length (CR in cm), dry matter of the leaves (MSF), stem (MSC), root (MSR), total dry matter (MST), leaf area, specific leaf area, leaf area ratio, leaf weight ratio, TCA, RGR and NAR. Treatments with the oxifluorfem herbicides flumioxazin and flumioxazin + oxyfluorfem, were the main cause harmful effects on plants and influencing the total dry matter accumulation. The treatments with herbicides flumioxazin, s-metalacloro, were most likely reduced the absolute growth rate on the assessed periods.
2

Qualifica??o da severidade da requeima em tomateiro por escalas diagram?ticas e suas correla??es com a fluoresc?ncia da clorofolifa A e ac?mulo de biomassa e nutrientes / Quantification of tomato late blight by diagrammatic grading keys and their correlations with chlorophyll A and biomass and nutrients accumulation

COSTA, Evandro Silva Pereira 21 September 2009 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-02-09T19:14:10Z No. of bitstreams: 1 2009 - Evandro Silva Pereira Costa.pdf: 2009437 bytes, checksum: cf64a3e8f7e3e004841a52c65f4c6626 (MD5) / Made available in DSpace on 2017-02-09T19:14:10Z (GMT). No. of bitstreams: 1 2009 - Evandro Silva Pereira Costa.pdf: 2009437 bytes, checksum: cf64a3e8f7e3e004841a52c65f4c6626 (MD5) Previous issue date: 2009-09-21 / CNPq / Defining methods of quantification of tomato late blight, caused by Phytophthora infestans, is important to many researches about strategies of management of the disease. The aim of this present study was to assess and to validate the diagrammatic grading keys - Simplified, James-modified and Broad - and to determinate the possible correlations between the measures of severity and plants? physiological and nutritional state and biomass accumulation. Two simultaneous experiments were carried out: one in greenhouse and the other in field conditions. Two cultivars were studied in greenhouses, Super Sweet and ?Perinha ?gua Branca?, a resistant and a susceptible to late blight genotypes, respectively. The plants were inoculated or not with a sporangia suspension, and submitted to ten evaluations: 1, 2, 3, 4, 6, 7, 9, 10, 17 and 24 days after inoculation. The avaliations were performed in the fifth oldest leaf, and eighth and eleventh leaves, by visual estimation of severity, using three diagrammatic grading keys, Simplified, Broad and James-modified, but also measuring photosynthetic potential (Fv/Fm), by chlorophyll ?a? fluorescence emission. In field conditions, four cultivars were evaluated ? ?Perinha ?gua Branca?, Super Sweet, Santa Clara and Carmen F1. Periodically, late blight severity was quantified using the same three grading keys in leaves of different plant parts, at 51, 62, 74, 94 and 102 days after transplant (DAT). At the day following each severity disease evaluation, one plant was harvested per plot to measure the accumulation of biomass and macronutrients of different plant organs. Fruit yield was determined by summing fruits harvested between 68 and 114 DAT. In greenhouse conditions, the estimative of late blight severity with the three diagrammatic grading keys proved to be adequate to the disease?s quantification, enabling the discrimination between inoculation effects and differences between the cultivars in four and in nine days after inoculation, respectively, which were confirmed by measures of the photosynthetic potential of the leaves. In field conditions, the diagrammatic grading keys Simplified and Broad were more adequate to tomato late blight quantification. Quantifications in the youngest leaves, in the medium and superior third part of the plant, were the most representative of the disease progress and also discriminated the cultivars regarding disease resistance. Negative correlations were observed between severity, estimated with the three grading keys considering the whole plant and its medium third part, and leaf dry mass and leaf concentrations of K and P. The cultivar ?Perinha ?gua Branca? showed the lowest stem and leaf dry mass at the beginning of plant evaluations, and also late fruit yield, but had the higher stem and leaf mass and at the end of the experiment. The cultivar Perinha ?gua Branca and the hybrid Carmen F1 had higher commercial fruit yield. Based in the results, it is recommended the use of Simplified diagrammatic grading key and evaluations in the medium or superior tomato third to quantify the late blight disease. / A defini??o de m?todos de quantifica??o da requeima no tomateiro, causada por Phytophthora infestans, ? importante para v?rias pesquisas sobre estrat?gias de manejo da doen?a. Esse trabalho teve como objetivo aferir e validar as escalas diagram?ticas, Simplificada, James-modificada e Detalhada e determinar as poss?veis correla??es entre as medidas de severidade e o estado fisiol?gico e nutricional da planta e o ac?mulo de biomassa. Realizaram-se dois experimentos simult?neos, um sob condi??es de ambiente protegido e o outro sob condi??es de campo. Em casa de vegeta??o, utilizaram-se duas cultivares de tomate cereja, ?Perinha ?gua Branca? e Super Sweet, suscet?vel e resistente ? requeima, respectivamente. As plantas foram inoculadas ou n?o com suspens?o de espor?ngios de P. infestans e em seguida, avaliadas aos 1, 2, 3, 4, 6, 7, 9, 10, 17 e 24 dias ap?s a inocula??o. As avalia??es foram feitas na quinta, oitava e d?cima primeira folha, contadas do ?pice para a base, usando as tr?s escalas acima citadas e medi??es do potencial fotossint?tico (Fv/Fm) pela emiss?o da clorofila ?a?. No campo, utilizaram-se quatro cultivares, ?Perinha ?gua Branca?, Super Sweet, Santa Clara e Carmen F1. Periodicamente, quantificou-se a severidade da requeima utilizando-se as mesmas escalas acima citadas em folhas de diferentes partes da planta, aos 51, 62, 74, 94 e 102 dias ap?s o transplante (DAT). No dia seguinte a cada avalia??o de severidade, foi coletada uma planta por parcela para mensurar o ac?mulo de biomassa e de macronutrientes nos diferentes ?rg?os da planta. A produ??o de frutos foi determinada pelo somat?rio das colheitas realizadas entre 68 e 114 DAT. Em condi??es de casa de vegeta??o, a estimativa da severidade da requeima com as tr?s escalas se mostrou adequada para quantifica??o da doen?a tendo permitido discriminar efeito de inocula??o e diferen?as entre as cultivares aos quatro e nove dias ap?s a inocula??o, respectivamente, que foram confirmadas pelas medidas do potencial fotossint?tico das folhas. Em condi??es de campo, as escalas Simplificada e Detalhada, foram mais adequadas para a quantifica??o da requeima do tomateiro. Quantifica??es feitas nas folhas mais jovens, no ter?o m?dio e superior da planta, foram as que melhor representaram o progresso da doen?a e discriminaram as cultivares quanto a resist?ncia ? doen?a. Observaram-se correla??es negativas entre a severidade, estimada com as tr?s escalas, considerando a planta inteira e o ter?o m?dio, e a massa seca de folhas e os teores foliares de K e P nas quatro cultivares. A cultivar ?Perinha ?gua Branca? apresentou menor massa seca de caule e de folha no in?cio das avalia??es e produ??o de frutos mais tardia, por?m ao final do ciclo destacou-se pela maior massa seca de caule e de folha. A cultivar ?Perinha ?gua Branca? e o h?brido Carmen F1 apresentaram maior produ??o de frutos comerciais. Com base nos resultados pode-se recomendar o uso da escala simplificada e avalia??es no te?o m?dio ou superior do tomateiro para quantifica??o da requeima.

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