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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.
21

Morfogênese e componentes do rendimento de sementes de azevém anual cv BRS Integração em função da época de desfolha / Morphogenesis and components of seed yield of annual ryegrass “BRS Integração” according to the period of defoliation

Abib, Flávio Reina 17 December 2015 (has links)
Submitted by Maria Beatriz Vieira (mbeatriz.vieira@gmail.com) on 2017-04-26T15:11:36Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) tese_flavio_reina_abib.pdf: 2239588 bytes, checksum: 7ce416cc287034a56085359f2706a5ed (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-05-02T18:21:15Z (GMT) No. of bitstreams: 2 tese_flavio_reina_abib.pdf: 2239588 bytes, checksum: 7ce416cc287034a56085359f2706a5ed (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2017-05-02T18:22:27Z (GMT) No. of bitstreams: 2 tese_flavio_reina_abib.pdf: 2239588 bytes, checksum: 7ce416cc287034a56085359f2706a5ed (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-05-02T18:22:45Z (GMT). No. of bitstreams: 2 tese_flavio_reina_abib.pdf: 2239588 bytes, checksum: 7ce416cc287034a56085359f2706a5ed (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-12-17 / Sem bolsa / A integração lavoura-pecuária com a utilização de azevém anual é uma prática bastante comum no sul do Brasil. No entanto, a maioria das cultivares oficiais presentes no mercado precisam ser dessecadas antes do final do ciclo para permitir uma adequada época de semeadura para culturas de estação quente. Alguns materiais não certificados apresentam ciclos mais precoces, porém também apresentam resistência a dessecantes e rendimentos de forragem insatisfatórios. Neste sentido a Embrapa lançou a cultivar BRS Integração com a proposta de um ciclo mais precoce, todavia, sem resistência a herbicidas, bem como com elevado rendimento forrageiro. Contudo, se desconhece o efeito do manejo de desfolha nesta cultivar para a colheita de forragem e seus impactos na produção e qualidade de sementes e no comprimento do ciclo produtivo. Deste modo o objetivo do presente estudo foi avaliar o efeito da desfolha na produção de forragem e de sementes do azevém anual BRS Integração. O experimento foi realizado na Estação Experimental Terras Baixas da Embrapa Clima Temperado com delineamento de blocos ao acaso com quatro repetições. Foram testados cinco níveis de desfolha (sem, uma, duas, três e quatro desfolhas) para a verificação da produção de forragem (fração de folhas, colmos e material morto); das características morfogênicas e estruturais; dos componentes de rendimento, do rendimento e da qualidade fisiológica das sementes. Verificou-se que o número de desfolhas afetou as características morfogênicas e estruturais da cultivar BRS Integração e, por conseguinte, o rendimento e a qualidade fisiológica de sementes. A execução de três desfolhas permitiu a colheita de aproximadamente 5t de MS.ha-1 e afetou positivamente o rendimento e a qualidade fisiológica das sementes, as quais foram colhidas ainda nos primeiros dias de novembro, o que possibilita o uso da área para a adequada semeadura de cultivos de estação quente. A realização de quatro desfolhas afetou negativamente as características morfogênicas, a estrutura pré-colheita, os componentes de rendimento de sementes, bem como o rendimento real de sementes. No entanto, a ação de quatro desfolhas (colheita total de aproximadamente 7t de MS.ha-1), não afetou negativamente a qualidade fisiológica da semente e ainda possibilitou um rendimento de sementes 15 vezes superior a densidade de semeadura recomendada. / The crop-livestock integration with the use of annual ryegrass is a common practice in southern Brazil. However, most official cultivars on the market need to be desiccated before the end of the cycle to allow adequate time for sowing warm season crops. Some not certified materials present earlier cycles, but also show resistance to desiccants and poor forage yields. In this sense, Embrapa launched “BRS Integração” with the proposal of an earlier cycle, however, without herbicide resistance as well as high forage yield. However, it is unknown the effect of defoliation management in this cultivar for forage crop and its impact on production and quality of seeds and the length of the production cycle. Thus the purpose of this study was to evaluate the effect of defoliation in the production of fodder and seeds of annual ryegrass “BRS Integração”. The experiment was conducted at the Estação Experimental Terras Baixas in Embrapa Clima Temperado with randomized block design with four replications. Five levels of defoliation were tested (no, one, two, three and four defoliation) for verification of forage production (leaves fraction, stems and dead material); morphogenic and structural characteristics; the yield components, yield and seed quality. It was found that the number of defoliation affect the morphogenic and structural characteristics of the “BRS Integração”, and therefore, the yield and physiological quality of seeds. The execution of three defoliation allowed the harvest of approximately 5 tons of dry matter per hectare and positively affected the yield and seed quality, which were still harvested in early November, what allow the use of the area for proper seeding of warm season crops. The performance of four defoliation adversely affected the morphogenic characteristics, pre-harvest structure, seed yield components and the real yield seeds. However, the action of four defoliation (total harvest about 7 tons of dry matter per hectare) didn’t affect negatively the physiological quality of the seed and still allowed a yield of seeds 15 times the recommended seeding rate.
22

Yield, protein and oil content of selected groundnut cultivars grown at two locations in the Eastern Cape, South Africa.

Mbonwa, Thozamile Nzuzo. 23 September 2014 (has links)
The Eastern Cape Province of South Africa has climatic conditions which differ from region to region. The groundnut (Arachis hypogaea L.) cultivars, as it is the case with other crops, do not always perform equally well in the varying conditions. Abiotic stresses such as drought, extreme temperatures, and high soil acidity restrict plant growth. Lack of studies on adaptability of commercial groundnut cultivars in the Eastern Cape necessitated this study. Abiotic and biotic factors are not the only limiting factors: calcium availability in the soil is also a limiting factor in groundnut production. The aim of the study was to identify best suited cultivars for climatic conditions of Mthatha and Lusikisiki regions of the Eastern Cape. Two similar field experiments were conducted in the two locations with different climatic conditions. The results showed significant differences (P<0.05) in genotypes with respect to seed yield in both locations. Kwarts produced higher seed yield of 1155 kg ha-1 in Mthatha, while the same genotype produced low seed yield of 630 kg ha-1 in Lusikisiki location. In Lusikisiki the highest seed yield was recorded in Anel (936 kg ha-1) which produced low yield of 692 kg ha-1 in Mthatha. The genotypes that performed well in Mthatha in 2010/11 season included Kwarts, Nyanda, ICGV-SM 95714 and Mwenje. These genotypes were further used to investigate their response to calcium supplementation at flowering stage under conditions of Mthatha in the 2011/12 season. The results were significantly different for calcium absorption (P<0.05). Nyanda, Kwarts and Mwenje responded positively to calcium application at flowering stage producing relatively high yield of 153, 150 and 110 kg ha-1, respectively. Oil content was significantly increased by calcium application at flowering in Nyanda with 27.28% compared to 20.7% without Ca.
23

Evaluation of the effect of calcium source application on groundnut (Arachis hypogaea L.) yield and quality in Okhahlamba Local Municipality, KwaZulu-Natal, South Africa.

Sikhakhana, Gerald Sikhumbuzo 07 1900 (has links)
Two field experiments were conducted on sandy loam soils in OKhahlamba Local Municipality (OLM) (Bergville area), KwaZulu-Natal province in South Africa, during the rainy seasons of 2014/15 and 2015/16 to study the effect of calcium source (gypsum) fertilizer application on yield and quality of groundnut (Arachis hypogaea L.). The household economy of OLM is mostly dependent on agriculture and the majority of farmers in this area are small-scale farmers subsisting mainly on maize (constituting the staple diet) and groundnut production. Crop diversification, therefore, becomes an important aspect for farmers, and this is traditionally done using crops that are produced in almost similar agronomic circumstances to that of maize under dryland conditions. A large proportion of the OLM population depend on groundnut as a vital supplement to their daily food requirements, particularly as a cheap source of protein for resource-poor farmers. Therefore, any scientific approach to increase the yield of groundnut should be considered important in the livelihood of this community. Moreover, groundnut is an excellent rotational crop, since it responds well to fertilizer applied to previous crop and maize, as well as to crop, since it responds well to fertilizer applied to previous crop and maize, as well as to nitrogen left over by peanut. Thus, farmers save money because they use less fertilizer. The consideration for this study was based upon the above. The experiment was laid in a randomised complete block design with factorial arrangement, which was replicated three times in 48 plots. The factors studied were four levels of gypsum (CaSO4.2H2O) i.e. 0 kg/ha, 500 kg/ha, 750 kg/ha, and 1000 kg/ha and four levels of lime (MgCO3.CaCO3) i.e. 0 kg/ha, 250 kg/ha, 500 kg/ha, 750 kg/ha. Soil pH, cation exchange capacity (CEC), electrical conductivity (EC), pod yield, seed yield, 100 seeds weight, shelling percentage, dry shoot weight, seed moisture content percentage at harvest, and leaf calcium concentration data were collected prior to, and post harvesting. The application of 500 kg gypsum/ha alone acted as a liming factor for legumes, decreasing acid stress on nodulating bacteria, and improved soil chemical properties (increased soil pH), vegetative growth, yield, and quality of groundnut. The smallholder famers can afford this application rate, since gypsum acts both as a liming factor and as a calcium source to improve crop yield. The application of 1000 kg gypsum/ha improved seed yield, shelling percentage as well as kernel weight, which is yield, and quality of groundnut under dryland conditions. Since smallholder farmers practise dryland production, it is advisable to adopt the application of gypsum at the rate of 1000 kg/ha to improve yield and quality of groundnuts. It was also found to be more economical than using both gypsum and lime. The application of 500 kg gypsum per hectare in combination with 250 kg lime per hectare produced the highest shelling percentage. This combination of two calcium sources (gypsum and lime) is not recommended for small-scale farmers because it is not economical. The application of 500 kg gypsum per hectare in combination with 750 kg lime per hectare increased pod yield. However, this combination is also not recommended because it is not cost-effective. The application of 1000 kg gypsum per hectare in combination with 500 kg lime per hectare increased seed yield and produced sound mature kernel (SMK), whereas the application of 1000 kg gypsum alone per hectare also increased seed yield. This combination is also considered unacceptable due to the high increase in input costs. The application of 750 kg lime per hectare was more effective as an acid ameliorant and led to the improvement of the chemical composition of the soil (increased soil pH), resulting in a higher shoot weight of groundnut. This application also provided the catalyst for stimulating phosphorus production and enhancing the growth of an extensive root system for absorbing water and nutrients. The use of lime in acid soils is highly beneficial because it improves the chemical composition of the soil, ensures the availability of nutrients to plants, serves as an efficient calcium source, and ultimately leads to an improvement in yield. Results show that the application of gypsum at 1000 kg/ha and lime at 500 kg/ha respectively, significantly improved peanut yield and soil pH. The combination of gypsum and lime (500 kg/ha gypsum and 250 kg/ha lime) significantly improved shelling percentage (yield). Based on data on yield, yield components, and soil chemical properties, it is concluded that gypsum is the best calcium source fertilizer for groundnut production in OLM and lime should only be applied on acid soils to attain optimum groundnut yield in the region / Agriculture, Animal Health and Human Ecology / M. Sc. (Agriculture)
24

Produtividade de semente de soja em diferentes sistemas de cultivos na região de Ponte Serrada SC / Productivity of soybeans in different crop systems in the region of Ponte Serrada, Santa Catarina State

Maier, Maira 13 July 2016 (has links)
Submitted by Claudia Rocha (claudia.rocha@udesc.br) on 2018-02-27T14:11:05Z No. of bitstreams: 1 PGPV16MA205.pdf: 427999 bytes, checksum: c7848775f5c9f8d27f42c42baca419e2 (MD5) / Made available in DSpace on 2018-02-27T14:11:05Z (GMT). No. of bitstreams: 1 PGPV16MA205.pdf: 427999 bytes, checksum: c7848775f5c9f8d27f42c42baca419e2 (MD5) Previous issue date: 2016-07-13 / FAPESC / Soybeans play an important role on the Brazilian agricultural activity as can be observed in increases on the production area, production, productivity and profitability. The main goals of this work were to evaluate the productivity of soybeans in order to identify the possible causes of physiological origin, morphological, plant health associated with soil physicochemical characteristics. The study was carried out during 2014/2015 and 2015/2016 vintages, in the region of Ponte Serrada, Santa Catarina state (Southern Brazil), in four crop systems described as: (1) no-till system, soybeans + oats + soybeans + oats, hereinafter designed as (soybeans + oats), (2): fallow land + maize + Soybeans + fallow land + soybeans, hereinafter designed as (soybeans + maize), (3): soybeans +wheat +soybeans + wheat, designed as (soybeans + wheat), and (4):soybeans + pasture + soybeans + pasture, designed as (soybeans + pasture). Were sampled two plantations per crop system. In each, two random points were sampled, a point with the presence of healthy plants and another with the presence of atypical plants. At each point we evaluated soil penetration resistance and their geographical coordinates recorded. Soil samples were collected at three depths (5, 10, and 20cm) in other to evaluate physicochemical characteristics. Five repetitions were performed. In each repetition, 20 plants were sampled for quantification of root diseases. The pathogens were identified by observing the visible symptoms below the cotyledonal node of those plants. The aerial part of the collected plants was used to estimate the productivity. Data were submitted to Pearson's correlation analysis in other evaluate the association between disease, yield, and physicochemical characteristics. The results showed: i) higher incidence of root rot, values above 50%, regardless of soybean crop system; and a prevalence of charcoal by Macrophomina phaseolina fungus in all croppin gr ost ycsateumsesd. II) Higher incidence of root rot did not influence the sanitary quality of soybean seeds. III) Higher seed yield was observed for soybeans +maize crop system with 2105 and 2300 kg ha-1, in the first and second crop harvest or vintage, respectively. IV) Soil physical analyses for the first vintage showed soil resistance to compression in all systems except the system 1. Results from the second vintage showed that trend only for systems 3 and 4. VI) Chemical properties varied according to cropping system and soil depth. Higher productivity of soybean seeds is highly correlated to the low incidence of root rot, unpacked soil, increases in soil pH to 6.5 and increased levels of phosphorus to 30 mg dm3 / A soja é a cultura de maior destaque na atividade agrícola no Brasil, considerando os incrementos registrados na área cultivada, na produção, na produtividade e na rentabilidade. O objetivo deste trabalho foi avaliar a produtividade de semente de soja, em lavouras de produção de semente, visando identificar as possíveis causas de origem fisiológica, morfológica, sanitária da planta ou associadas com as características físico-químicas do solo. O estudo de caso foi exploratório. As avaliações foram realizadas nas safras 2014/2015 e safras 2015/2016, na região de Ponte Serrada Santa Catarina, em lavouras conduzidas em sistema de plantio direto, assim descritos soja+aveia+soja+aveia (soja+aveia), soja+pousio+milho+pousio+soja (soja+milho), soja+trigo+soja+trigo (soja+trigo) e soja+pasto+soja+pasto (soja+pasto). Foram amostradas duas lavouras por sistema especificado. Em cada lavoura foram escolhidos dois pontos, um com presença de plantas sadias (sem reboleira) e outro com presença de plantas atípicas (com reboleira). Em cada ponto foram avaliados a resistência do solo a penetração e obtidas as respectivas coordenadas geográficas. Ambos os pontos foram divididos em cinco partes (repetições) onde foi amostrado o solo nas profundidades 5, 10, e 20 cm respectivamente, para avaliar suas características físicas e químicas. Em cada repetição de campo, foram coletadas separadamente 20 plantas para a quantificação de doenças radiculares. Os patógenos foram identificados pela sintomatologia visível na parte abaixo do nó cotiledonar destas plantas. A parte área das plantas colhidas em 5m lineares foi utilizada para estimativa de produtividade. Os dados obtidos foram submetidos à análise de correlação de Pearson para associar a relação entre doença, rendimento, fatores físicos e químicos do solo. Os resultados indicam: i)alta incidência de podridões radiculares, valores maiores que 50%, independente do sistema de cultivo de soja; mas com prevalência de macrofominia em todos os sistemas de cultivo ser soja+aveia, soja+milho, soja+trigo ou soja+pato. ii)Na patologia de sementes, a alta incidência de podridões radiculares não influenciou na qualidade sanitária das sementes de soja. iii)Para rendimento de sementes, o melhor sistema foi soja+milho, com 2105 e 2300 kg.ha-1, na primeira safra e segunda safra, respectivamente. iv) Análise física: na primeira safra a resistência a compactação ocorreu no sistema soja+milho, soja+pasto, soja+trigo, sem e com reboleira. Na segunda safra a resistência a compactação foi observada nos sistemas soja+pasto e soja+trigo, sem e com reboleira VI) Análise química: dependente do sistema avaliado e da profundidade em que o solo foi analisado. Alta produtividade de sementes está altamente correlacionada à baixa incidência de podridões radiculares, solo descompactado, elevação do pH do solo para 6,5 e aumento da teor de fósforo para 30 mg dm3
25

Estratégias para seleção de linhagens experimentais de soja para tolerância à ferrugem e associações com outras doenças / Strategies for selection of soybean lines to rust tolerance and associations with other diseases

Jair Rogerio Unfried 24 July 2007 (has links)
A ferrugem da soja (Phakopsora pachyrhizi Sydow e Sydow) foi constatada pela primeira vez no Brasil na safra 2000/01, e representa até o momento, um importante desafio para os programas de melhoramento genético de soja. As cultivares e linhagens inicialmente identificadas como resistentes, tiveram sua resistência quebrada já na safra 2002/03, pela ocorrência de prováveis novas raças do patógeno. Por consequência, a longevidade da resistência genética vertical foi colocada em risco, e o desenvolvimento de trabalhos através da utilização da tolerância é a alternativa. Como suporte para a manutenção da longevidade do controle genético da ferrugem, este trabalho objetivou testar estratégias de seleção de genótipos de soja para tolerância à ferrugem, na ausência de genes principais de resistência. Os experimentos foram conduzidos durante os anos agrícolas 2004/05 e 2005/06 em diferentes locais administrados pelo Departamento de Genética, ESALQ/USP, município de Piracicaba, SP. Foi utilizado o delineamento experimental de blocos casualizados com repetições estratificadas em conjuntos experimentais e testemunhas comuns aos conjuntos experimentais. Em 2004/05, no local Anhembi, 60 linhagens experimentais mais quatro testemunhas suscetíveis à ferrugem (BR-16, FT-2000, Conquista e IAC-100), foram avaliadas em três experimentos com e sem fungicidas (Controle, Derosal e Impact). Em 2005/06, as 26 melhores linhagens para tolerância à ferrugem, selecionadas em 2004/05, foram novamente avaliadas através dos três experimentos (Controle, Derosal e Impact) juntamente com as testemunhas (BR-16, IAC-100 e BRS-232), nos locais Anhembi, ESALQ e Areão. Contrastes das médias de produtividade de grãos entre os experimentos de fungicidas, e uma adaptação do modelo de regressão de Eberhart e Russel, foram utilizados para medir a ação da ferrugem e das doenças de final de ciclo (DFC) sobre as linhagens, com o intuito de realizar seleção de linhagens tolerantes. A ferrugem reduziu a produtividade de grãos mas não alterou significativamente o ciclo e o peso de mil sementes, bem como não alterou as outras características agronômicas estudadas. As duas estratégias de seleção propostas e utilizadas neste trabalho, foram eficientes para separar os efeitos das doenças (ferrugem e DFC), e identificar e selecionar genótipos tolerantes na ausência de genes principais de resistência, viabilizando a seleção de linhagens tolerantes. Houve associação entre tolerância à ferrugem, DFC e resistência ao nematóide de cisto da soja. / Soybean rust (Phakopsora pachyrhizi Sydow and Sydow) was first recorded in Brazil during the 2000/01 season and, even today, represents an important challenge to soybean breeding. The cultivars and lines initially identified as resistant had their resistance breakdown on the 2002/03 season, probably by the occurrence of new races of the pathogen. Consequently, the longevity of the vertical genetic resistance was put in risk and the development of works through the use of tolerance is the alternative. As support for the maintenance of the longevity of the genetic control of rust, this work aimed to evaluate strategies for selection of genotypes to rust tolerance in the absence of major resistance genes. The experiments were conducted during the agricultural years of 2004/05 and 2005/06 in different locations administered by the Department of Genetics ESALQ/USP, Piracicaba, SP. It was used the randomized complete-block design with replications stratified in experimental sets with common checks. In 2004/05 at Anhembi, 60 experimental lines and four rust-susceptible checks (BR-16, FT-2000, Conquista and IAC- 100), were evaluated in three experiments with and without fungicides (Control, Derosal and Impact). In 2005/06, the 26 best lines for rust tolerance, selected in 2004/05, were evaluated again through the three experiments (Control, Derosal and Impact) together with the checks (BR-16, IAC-100 and BRS-232), in the locations Anhembi, ESALQ and Areão. Contrasts of seed yield means among the fungicide experiments, and an adaptation of the regression model of Eberhart and Russel, were used to measure the action of rust and late season leaf diseases (LSLD) on the lines, with the intention of selecting tolerant lines. Rust reduced the seed yield but did not significantly alter the cycle or the weight of one thousand seeds, just as there was no significant change in other agronomical traits studied. Both selection methodologies were efficient to separate the effects of the diseases (rust and LSLD) and identify and select tolerant genotypes at the absence of major resistance genes, enabling the selection of tolerant lines. There was an association between rust, LSLD tolerance and soybean cyst nematode resistance.
26

Estratégias de seleção de genótipos de soja para resistência à podridão vermelha das raízes / Selection strategies of soybean genotypes resistant to sudden death syndrome

Walter Fernando Bernardi 01 September 2008 (has links)
Nas últimas décadas, a podridão vermelha das raízes da soja (PVR), causada pelo Fusarium solani f.sp. glycines (FSG), tornou-se uma doença séria nas regiões brasileiras onde já foi constatada, sendo a utilização de cultivares resistentes um componente fundamental de um sistema integrado de controle. Este trabalho teve por objetivo pesquisar estratégias de seleção de genótipos resistentes a PVR. Várias metodologias foram implementadas: avanço de progênies até a geração F7:2 e seleção em campo infestado, de progênies selecionadas em F2. Avaliou-se o cruzamento IAC 4 x Conquista em casa de vegetação (geração F3:2) e em campo infestado (gerações F3:2, F4:2 e F5:2), através de estudo de estabilidade e adaptabilidade das progênies. As metodologias de infecção em vasos de barro e bandejas de isopor em casa de vegetação foram comparadas para melhorar a eficiência de seleção; também foi feita análise de repetibilidade dos sintomas foliares da PVR, para otimização do número de avaliações necessárias para classificar o genótipo de soja quanto à reação ao FSG. Cultivares brasileiras de soja foram avaliadas em campo infestado. Em campo, as plantas foram avaliadas no estádio R5-6, com notas variando de 1 (ausência de sintomas) a 5 (100% da raiz principal com sintomas). Em casa de vegetação, as plantas foram avaliadas aos 35 dias pós-semeadura para sintomas radiculares e da parte aérea. Houve eficiência da seleção para resistência a PVR tanto em F2 (sintomas foliares em casa de vegetação) quanto em F7:2 (sintomas radiculares em campo naturalmente infestado). A seleção praticada nas gerações intermediárias também foi eficiente para aumentar a produtividade de grãos das progênies. Para o cruzamento IAC 4 x Conquista nas gerações F3:2, F4:2 e F5:2 em campo naturalmente infestado e na F3:2 em casa de vegetação, a metodologia de Annicchiarico possibilitou a seleção de genótipos com maior estabilidade e adaptabilidade para os diferentes ambientes; com o estudo genético destas gerações, demonstrou que há efeitos gênicos aditivos e dominantes no controle genético da PVR. Além disso, constatou-se que os genes responsáveis pela resistência estão dispersos nos genitores, provavelmente agrupados em blocos gênicos. A presença de dominância indica que a seleção deve ser postergada para gerações com maior homozigose (linhagem pura); esta idéia foi reforçada pela baixa herdabilidade ao nível de plantas. O uso de bandejas de isopor foi significativamente mais eficiente do que vasos de barro para inoculação de FSG em casa de vegetação. Pela análise de repetibilidade, detectou-se que quatro avaliações foram suficientes para discriminar se o genótipo era realmente suscetível ao FSG. A correlação da geração F3:2 (IAC 4 x Conquista) entre campo infestado e casa de vegetação foi praticamente nula; no entanto, 54% das progênies selecionadas em campo também foram selecionadas em casa de vegetação. A seleção de genótipos superiores para resistência ao FSG não é tarefa fácil, mas pode ser aprimorada pelo uso conjugado de metodologias suplementares que aumentem a eficiência de seleção. / During the last decades, soybean sudden death syndrome (SDS), caused by Fusarium solani f.sp. glycines (FSG), has become a serious disease in the regions where it was encountered. The use of resistant soybean cultivars has been an important component of an integrated management system. The aim of this work was to research selection strategies of SDS-resistant genotypes. A number of methodologies were used: self pollination up to generation F7:2 and progeny selection in infested field of selected F2. The crossing IAC 4 x Conquista was studied in greenhouse (generation F3:2) and in a naturally infested field (generations F3:2, F4:2 and F5:2), where the progeny stability and adaptability study was carried out. The methodologies of infection in clay pots and polystyrene trays in greenhouse were compared to improve selection efficiency. An analysis of the repeatability of foliar SDS symptoms was also performed in order to optimize the number of evaluations needed to classify a soybean genotypes reaction to FSG. Brazilian soybean cultivars were evaluated in a naturally infested field, where plants were evaluated at stage R5-6 with scores varying from 1 (absence of symptoms) to 5 (main root 100% symptoms). In the greenhouse, the plants were evaluated 35 days after sowing for root symptoms, while the leaf symptoms was only evaluated after the appearance of symptoms. The selection done in F2 (leaf symptoms in greenhouse) as well as F7:2 (root symptoms in infested field) for FSG were efficient. The selections performed in intermediary generations were efficient in increasing the grain yield of the progeny. Studies of the F3:2, F4:2 and F5:2 generations of the IAC 4 x Conquista cross in an infested field and F3:2 in greenhouse, enabled through Annicchiaricos methodology, the selection of genotypes with greater stability and adaptability to different environments. The genetic study of these generations demonstrated there are additive and dominant genetic effects on the genetic control of SDS. Moreover, it was noted that the genes responsible for resistance are dispersed on the genitors, probably grouped into genic blocks. The presence of dominance indicates that the selection should be passed onto generations with greater homozygosity. There is also a clear indication that breeders should work with progeny lines in order to assist selection due to the low inheritability at the individual plant level. For the experiments with different FSG inoculation methodologies (clay pots and polystyrene trays) in greenhouse the use of trays was significantly more efficient; by studying the repeatability analysis, it was found that four evaluations is enough to discriminate if the genotype is really susceptible to FSG. The correlation of the F3:2 generation (IAC 4 x Conquista) between infested field and greenhouse was practically null; however, 54% of the progeny selected in the field were selected in greenhouse. As observed, the selection of superior genotypes for FSG resistance is not an easy task, but may be improved by means of new methodologies and the conjugated use of methodologies which improve selection efficiency.
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Desempenho individual e em comunidades de plantas de soja formadas por diferentes proporções de sementes de alto e baixo vigor na linha de cultivo / Individual and in communities performance of soybean plants formed by different proportions of high and low vigor seeds

Pino, Mateus 11 October 2013 (has links)
Made available in DSpace on 2014-08-20T13:44:36Z (GMT). No. of bitstreams: 1 dissertacao_mateus_pino.pdf: 892670 bytes, checksum: 8404af1ff9b9a50b4e9030c69eec22bf (MD5) Previous issue date: 2013-10-11 / The objective of this study was to evaluate the influence of low and high vigor of soybean seeds on agronomic characteristics , yield components and seed yield, in individually plants and on the communities of plants generated by different proportions of plants originated from high and low vigor seeds on the crop row. The experiment was conducted in the county of Selbach - RS, in a no-till seeding system over ryegrass straw, in 2012/2013 crop year. Was used the cultivar of soybean FPS Urano RR, of short-cycle. The experiment design was completely randomized, with five replications. Were selected seven different proportion of high and low vigor seed, along the sowing row. Were evaluated agronomic characteristics, yield components and seed yield on plants and on the communities formed. Based on the results obtained it was found that: plants from high vigor seeds show higher than plants arising from low vigor, in V5 and R8 phenological stages; Based on the results obtained it was found that: plants from high vigor seeds show greater height than plants arising from low vigor, in V5 and R8 phenological stages; even when communities are formed only by plants arising from low vigor seeds, these can not reach yield levels found in plants arising from high vigor seeds; number and weight of seeds per plant, are the yield components that more contributed to increase yield; the plant community formed only of plants grown from seeds of high vigor, shows seed yield per area 29% more, comparatively, to one formed only of plants from low vigor seeds. / O objetivo do presente trabalho foi avaliar a influência do alto e baixo vigor de sementes de soja sobre características agronômicas, componentes de rendimento e rendimento de sementes, nas plantas individualmente e nas comunidades de plantas geradas por diferentes proporções de plantas originadas de sementes de alto e baixo vigor dentro da linha de cultivo. O experimento foi conduzido no município de Selbach - RS, com sistema de semeadura direta sobre palhada de azevém, no ano agrícola de 2012/2013. Utilizou-se a cultivar de soja FPS Urano RR, de ciclo precoce. O delineamento experimental foi totalmente casualizado, com cinco repetições. Foram selecionadas sete diferentes proporções de sementes com alto e baixo vigor, ao longo da linha de semeadura. Avaliaram-se características agronômicas, componentes de rendimento e o rendimento das plantas e das comunidades formadas. Com base nos resultados obtidos verificou-se que: plantas originadas de sementes de alto vigor apresentam maior altura nos estádios fenológicos V5 e R8; mesmo que a comunidade seja oriunda apenas de sementes com baixo vigor, essas não conseguem alcançar níveis de produtividade encontrados em plantas originadas de sementes de alto vigor; o número e peso de sementes por planta, são os componentes que mais contribuíram no aumento de rendimento; a comunidade de plantas formada apenas por plantas oriundas de sementes de alto vigor, apresenta rendimento de sementes por área 29% a mais, comparativamente, a uma formada apenas por plantas originadas de sementes de baixo vigor.
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Análise de cruzamentos dialélicos para o desenvolvimento de soja tipo hortaliça com tolerância à ferrugem / Diallel analysis for the development of vegetable soybean with tolerance to Asian rust

Souza, Renan Silva e 06 February 2018 (has links)
Entre os maiores desafios existentes para a cultura da soja, os estresses bióticos e abióticos se destacam e a incidência de patógenos como a ferrugem asiática, causam grandes perdas aos produtores. No Brasil, a ferrugem é a principal causa de prejuízos nas lavouras e estratégias para o seu controle mais eficiente são necessárias. O melhoramento genético para a tolerância constitui uma importante ferramenta para manter a ferrugem em níveis abaixo de dano econômico por um período mais duradouro. Outro aspecto importante da cultura da soja é relacionado com a sua utilização, destacando-se a produção de farelo com alto teor de proteína e de óleo comestível e combustível. Apesar de apresentar uma rica composição nutricional, o seu uso direto na alimentação humana ainda não é comum no Brasil. Uma das formas de incluir a soja na dieta é na forma de hortaliça, também conhecida como Edamame, em que as vagens são colhidas ainda verdes ou imaturas (estádio R6) e os grãos consumidos após breve cozimento. Contudo, poucos esforços têm sido dedicados para desenvolver novos genótipos com boa performance agronômica e adequados ao consumo humano. O presente trabalho teve o objetivo de avaliar genótipos de soja para a produção de soja hortaliça que apresentem tolerância à ferrugem. Para isto foram realizados cruzamentos entre seis genitores com boas características agronômicas em um esquema dialélico 6x6, gerando 15 cruzamentos. Estes genótipos foram avaliados nas gerações F2 e F3 para a produtividade e o tamanho das sementes, sendo que na geração F3, foram adicionados outros dez caracteres. Nas duas gerações, foi estimada a sua tolerância à ferrugem, utilizando manejos diferentes da doença com fungicidas. Foram realizadas análises de variância individuais e conjuntas, agrupamento de médias, análises dialélicas, tendo sido estimados os coeficientes de herdabilidade e correlações entre os caracteres. As análises mostraram a existência de variabilidade entre os genótipos avaliados e indicaram que os cruzamentos apresentaram desempenho superior aos genitores para caracteres importantes. O uso dos diferentes manejos da ferrugem com fungicidas mostrou-se eficiente uma vez que foi possível identificar genótipos tolerantes. Além disso, foram detectadas interações genótipos x ambientes significativas, fato que representou um desafio para a seleção dos melhores genótipos. Os genitores BRS 267, USP 13-66.136 e USP 13-19.007 destacaram-se por apresentar estimativas altas de capacidade de combinação e os cruzamentos USP 13-66.136 x USP 13-19.007, USP 13-66.136 x USP 13-19.034, BRS 267 x USP 13-19.007 e Tengamine x USP 13-19.007 apresentaram os melhores desempenhos. As estimativas de capacidade específica de combinação (Sii) dos genitores indicaram a existência de divergência entre eles e os caracteres apresentaram altas herdabilidades. A magnitude e a significância das correlações indicaram a possibilidade de seleção de genótipos precoces com sementes grandes e, também, evidenciaram que a seleção de genótipos com período mais longo entre R6 e R7 (SGR6) beneficia a produtividade. Portanto, foi possível identificar genitores e cruzamentos promissores para o desenvolvimento de novas linhagens apropriadas para a produção de soja hortaliça com tolerância à ferrugem. / Among the major challenges for soybean cultivation, biotic and abiotic stresses stand out and the incidence of pathogens such as Asian rust can cause extensive losses to farmers. In Brazil, rust is the main cause of crop damage and strategies for a more efficient control are necessary. Breeding for tolerance is an important tool to keep rust below economic damage for a longer period. Another important aspect of the soybean crop is related to its use, which is directed to the production of high-protein meal, edible oil and fuel. Although this legume has a rich nutritional composition, its direct use in the diet is still not common in Brazil. One of the ways to use soybean as food is in the form of vegetable, also known as Edamame, in which the pods are harvested green or immature (R6 stage) and the grains consumed after brief cooking. However, few efforts have been devoted to developing new soybean genotypes with good agronomic performance and characteristics suitable for human consumption. The present research had the objective of evaluating soybean genotypes for the production of vegetable soybean with rust tolerance. For this, crosses between six parents with good agronomic characteristics were performed in a 6x6 diallel scheme, generating 15 crosses. These genotypes were evaluated in the F2 and F3 generations for seed yield and size, and in the F3 generation, ten other traits were added. In both generations, tolerance to rust was estimated in experiments designed for different managements of the disease with fungicides. Individual and joint analyzes of variance, grouping of means, diallel analyzes, and estimation of heritability and correlation coefficients were performed. The analyzes showed the existence of variability among the evaluated genotypes and indicated that the crosses presented superior performance to the parents for important traits. The use of different rust managements with fungicides was efficient, since it was possible to identify tolerant genotypes. In addition, significant genotypes x environments interactions were detected, a fact that represented a challenge for the selection of the best genotypes. The parents BRS 267, USP 13-66136 and USP 13-19007 stood out for presenting high estimates of general combining ability and the crosses USP 13-66136 x USP 13-19007, USP 13-66136 x USP 13-19034, BRS 267 x USP 13-19007 and Tengamine x USP 13-19.007 presented the best performances. Estimates of specific combining ability (Sii) of the parents indicated divergence between them and the traits showed high estimates of heritability. The magnitude and significance of the correlations indicated the possibility of selecting early genotypes with large seeds and showed that the selection of genotypes with a longer period between R6 and R7 (SGR6) benefits seed yield. Therefore, it was possible to identify promising parents and crosses for the development of new lines suitable for the production of vegetable soybean with rust tolerance.
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Performance de cruzamentos entre genitores tolerantes à ferrugem asiática da soja / Performance of crosses among parents with tolerance to soybean rust

Marques, Marcelo Cunha 29 April 2014 (has links)
A ferrugem asiática da soja (FAS) foi constatada pela primeira vez no Brasil em 2000/2001, tendo desde então ocasionado elevados prejuízos aos sojicultores. O emprego de cultivares geneticamente resistentes/tolerantes é um componente fundamental de um programa integrado para controle desta doença. A pesquisa tem encontrado muita dificuldade, pois o fungo Phakopsora pachyrhizi apresenta grande variabilidade patogênica e as poucas fontes de resistência/tolerância disponíveis não são adaptadas às condições brasileiras. O objetivo geral do presente estudo foi avaliar a performance de linhagens experimentais de soja derivadas de cruzamentos entre genitores tolerantes à ferrugem asiática, com a finalidade de incrementar a tolerância a FAS. Os experimentos foram conduzidos durante os anos agrícolas 2008-09, 2009-10 e 2010-11, nas Estações Experimentais Anhumas e Areão e na sede (ESALQ), áreas estas pertencentes à Escola Superior de Agricultura \"Luiz de Queiroz\" e situadas no município de Piracicaba - SP. Os experimentos com as progênies nas gerações F2:4, F2:5 e F2:6 foram delineados em blocos aumentados de Federer, sendo cada experimento subdividido em conjuntos experimentais com testemunhas comuns. Para estimar o efeito ferrugem e o nível de tolerância de cada genótipo a FAS, em cada local e ano agrícola, foram conduzidos dois experimentos com aplicações de fungicidas diferentes: no primeiro experimento aplicou-se fungicida para controle apenas das doenças de final de ciclo (DFC), enquanto que no segundo experimento, foi aplicado fungicida com princípios ativos para o controle tanto das DFC quanto da FAS. Nos experimentos com controle de DFC e FAS houve tendência de médias maiores para PG e PCS. A metodologia do contraste de reações das plantas a fungicidas distintos foi eficiente em estimar o efeito ferrugem e a reação de cada genótipo a FAS. A pressão do fungo da FAS sobre as progênies variou entre os anos agrícolas, tendo sido maior em 2009-10. O local Anhumas destacou-se entre os demais, possibilitando altas médias de produtividade de grãos (PG) em todos os anos agrícolas avaliados. Este ambiente também mostrou-se apropriado para estimar o efeito ferrugem. Os genitores 1 (USP 04-18.032) e 5 (USP 11-38) foram os que originaram as progênies mais precoces e os genitores 3 (USP 97-08.135) e 10 (USP 191-104-11) as progênies mais tardias. Os genitores 8 (USP 191-102-03) e 10 (USP 191-104-11) foram os que mais contribuíram para elevadas médias de PG e peso de cem sementes (PCS). Já o genitor 4 (BUSP 16-015) destacou-se na média de PG, além de ter apresentado valor alto de capacidade média de combinação para PG, na média dos três anos agrícolas. O cruzamento 7x10 (USP 14-06-20 x USP 191-104-11) destacou-se originando o maior número de progênies com desempenho superior em PG e tolerância a FAS. Por outro lado, os genitores 1 (USP 04-18.032), 3 (USP 97-08.135) e 9 (USP 191-103-12) foram os que menos contribuíram para a geração de progênies com alta PG. Houve variação entre as progênies dentro de cruzamentos para as estimativas dos parâmetros de adaptabilidade e estabilidade fenotípica. Consequentemente, as progênies 231- 2224-12 (6x8 = USP 97-10.046 x USP 191-102-03), 231-6127-06 (1x8 = USP 04- 18.032 x USP 191-102-03) e 231-1120-08 (7x10 = USP 14-06-20 x USP 191-104-11) foram as mais indicadas para a seleção recorrente para tolerância a FAS. / The Asian soybean rust (FAS) was reported for the first time in Brazil in 2000/2001 and has since caused considerable damage to soybean crops. The use of genetically resistant cultivars is a key component of an integrated program to control this disease. In the researches has been found many difficulties because the fungus Phakopsora pachyrhizi shows great variability in pathogenicity and the small number of sources of resistance that are available has no adaptability to Brazilian environmental conditions. The overall objective of this study was to evaluate the performance of experimental soybean lines derived from crosses among soybean rust tolerant parents, in order to increase the horizontal resistance (tolerance). The experiments were conducted during the crop years 2008-09, 2009-10 and 2010-11, in three experimental stations (Anhumas, Areão and ESALQ), areas belonging to the College of Agriculture \"Luiz de Queiroz\" and located within the municipality of Piracicaba, State of São Paulo, Brazil. The experiments with progenies in generations F2:4, F2:5 and F2:6 were designed in augmented block of Federer, with each experiment divided into sets with common checks. In order to estimate the effect of FAS and the level of tolerance of each genotype to FAS, in each location and crop year, there was conducted two experiments with applications of different fungicides: in the first experiment was applied one fungicide for controlling only the soybean late season leaf diseases (DFC), while in the second experiment were applied one fungicides with active principles for controlling DFC as well as FAS. In the experiments with control of DFC and FAS there was tendency of superior means for PG and PCS. The methodology of contrasting the plant reactions to different fungicides was effective for estimating the effect of FAS and the level of tolerance of each genotype to FAS. The pressure of the fungal FAS on progenies ranged among crop years, being highest in 2009-10. The location Anhumas stood out among the rest, enabling high average seed yield (PG) in all evaluated crop years; this environment also proved to be suitable for estimating the rust effect. The parents 1 (USP 04-18032) and 5 (USP 11-38) were those that originated the earliest progenies and parents 3 (USP 97-08135) and 10 (USP 191-104-11) the later progenies. The parents 8 (USP 191-102-03) and 10 (USP 191-104-11) were the main contributors to higher average PG and one hundred seed weight (PSC). However, the parent 4 ( BUSP 16-015 ) exceeded for PG, besides also have presented high value of average combining ability for PG, in average of the three crop years. The cross 7x10 (USP 14-06-20 x USP 191-104-11) stood out by originating the highest number of progenies with superior performance in PG and tolerance to FAS. On the other hand, the parents 1 (USP 04-18 032), 3 (USP 97-08 135), and 9 (USP 191-103-12) have contributed with the smallest number of superior progenies in PG. There was variation among progenies within cross, for the estimates of adaptability and phenotypic stability parameters. Consequently, the progenies 231-2224-12 (6x8 = USP 97-10 046 x USP 191-102-03), 231-6127-06 (1x8 = USP 04-18 032 x USP 191- 102-03), and 231-1120 - 08 (7x10 = USP 14-06-20 x USP 191-104-11) were the most suitable for the utilization as parents in the recurrent selection for tolerance to FAS.
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An agronomic evaluation of subterranean clover cultivars

Scott, W. R. January 1969 (has links)
The permanent pasture based on a grass-clover association and utilised in situ by grazing stock is the basis of New Zealand's chief primary industries. Although white clover is the main legume species used for this purpose its production and persistence in the drier eastern areas of the South Island often leaves much to be desired. In such situations subterranean clover may provide a useful alternative. Subterranean clover has been a very useful species in the past and will probably continue to play an important role in the future, provided the most climatically adapted cultivars are grown. The aim of the field trials was to evaluate the productive performance of several subterranean clover cultivars in Canterbury. Because of the big influence of seed yield on subsequent production and persistence in annuals, this aspect was also investigated. The subterranean clover cultivars Geraldton, Yarloop, Woogenellup, Clare, Mt. Barker and Tallarook were evaluated under cutting in swards at two sites in Canterbury.

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