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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

Effects of competition and water availability on tillering and growth in wheat

Leverton, Ray January 1989 (has links)
No description available.
2

Desempenho agronômico de cultivares de mamona no Rio Grande do Sul

Aires, Rogério Ferreira 28 March 2008 (has links)
Made available in DSpace on 2014-08-20T14:33:05Z (GMT). No. of bitstreams: 1 Dissertacao_ Rogerio_ F_ Aires.pdf: 523607 bytes, checksum: a908349e99f4ee12d83b2ba89b389cde (MD5) Previous issue date: 2008-03-28 / The demand for technical information about castor crop in Rio Grande do Sul, has intensified in the past two years due to the government stimulation for the production of biofuels, through several applications of castor oil in the chemical and pharmaceutical industry and productivities achieved by castor crop in trials and experimental crops. Undoubtedly, this crop is an alternative to family farming diversification and to the development of the southern of the state, helping to create jobs and income. Research about the techmiques on castor planting are still incipient, lacking local technical information about the specie, difficulting its expansion. Thus, simultaneous actions are needed from several knowledge areas to generate technical information aiming to build a viable and sustainable castor production system. The objective of this work was generate technical information that will contribute to the construction of a production system that allows the commercial castor exploitation in the southern region of Brazil, through the evaluation of genotypes, times and densities of sowing. The test for evaluating cultivars have been conducted in three locations using seven varieties and six hybrids. The experiments of sowing time were planted in three places and three times, using four cultivars, two varieties and two hybrids. The density trial was composed of four cultivars, two varieties and two hybrids, where have been tested three sowing densities for varieties and hybrids. Ricinus communis. sowing times. sowing densities / A demanda por informações técnicas sobre a cultura da mamona no RS, se intensificou nos últimos dois anos, devido ao estímulo do governo para a produção de biocombustíveis, pelas diversas aplicações do óleo de mamona na indústria química e farmacêutica e pelos índices de produtividade alcançados pela cultura da mamona em ensaios e lavouras experimentais. Sem dúvida a cultura é uma alternativa para a diversificação da agricultura familiar e importante alternativa para impulsionar o desenvolvimento da Metade Sul do Estado, contribuindo na geração de empregos e renda. As pesquisas sobre prática de cultivo da mamona ainda são incipientes, havendo falta de informações técnicas regionalizadas sobre esta cultura, o que dificulta a expansão do cultivo. Desta forma, são necessárias ações conjuntas das diversas áreas de conhecimento para gerar informações técnicas para um sistema de produção de mamona viável à exploração econômica e sustentável. O objetivo deste trabalho foi gerar informações técnicas que venham a contribuir com a construção de um sistema de produção que permita a exploração comercial sustentável da mamona na região Sul do Brasil, através da avaliação de genótipos, épocas e densidades de semeadura. O ensaio de avaliação de cultivares foram conduzido em três locais utilizando sete variedades e seis híbridos. Os experimentos de época de semeadura foram semeados em três locais e três épocas, utilizando quatro cultivares, duas variedades e dois híbridos. O ensaio de densidade foi composto de quatro cultivares, duas variedades e dois híbridos, onde foram testadas três densidades para variedades e três para híbridos.
3

Rokovi i gustine setve u funkciji prinosa ozime pšenice u dugotrajnom poljskom ogledu / Sowing dates and densities in a function of winter wheat yield in the long-term field trial

Aćin Vladimir 08 December 2016 (has links)
<p>Vreme (rok) setve jedan je od najvažnijih faktora u proizvodnji strnih žita i praktično određuje intenzitet delovanja svih ostalih činilaca proizvodnje p&scaron;enice. Među brojnim faktorima koji određuju visinu prinosa, najče&scaron;ći uzrok malih prinosa ozime p&scaron;enice vezan je za vreme setve izvan optimalnog roka, upotreba neadekvatnih količina semena i izbor sorti nedovoljno prilagođenih datim agroekolo&scaron;kim uslovima. Osim toga, vreme setve predstavlja ekonomski najjeftiniju agrotehničku meru i najisplativiji način za povećanje prinosa zrna ozime p&scaron;enice, međutim eventualno ka&scaron;njenje u setvi ne može se na adekvatan način nadoknaditi ni jednom drugom agrotehničkom merom. Ekstremne vremenske prilike već predstavljaju izazov za proizvođače, a mnogobrojni klimatski scenariji predviđaju dalje povećanje njihove učestalosti u budućnosti. Upravo će u ovakvim promenljivim vremenskim uslovima optimalno vreme steve uz adekvatnu gustinu useva i izbor odgovarajućih genotipova biti od velike važnosti u cilju ublažavanja negativnog delovanja vremenskih činioca na visinu i stabilnost prinosa, kao i na tehnolo&scaron;ki kvalitet zrna ozime p&scaron;enice.<br />Prevashodni cilj istraživanja u disertaciji bio je proučavanje uticaja različitog vremena, gustina setve i njihove interakcije na prinos, komponente prinosa i kvalitet zrna različitih sorti p&scaron;enice. Istraživanje interakcije vremena, gustina setve i sorti ozime p&scaron;enice izvedeno je na oglednim poljima Instituta za ratarstvo i povrtarstvo na Rimskim &scaron;ančevima, u periodu od proizvodne 1981/82. do 2012/13. godine, na ogledu pod nazivom &bdquo;Rokovi setve&ldquo;. Ogled se postavlja svake godine, na zemlji&scaron;tu tipa karbonatni černozem, a izvodi se kao trofaktorijalni (Split-split-plot dizajn), u četiri ponavljanja, sa rasporedom varijanti po slučajnom blok sistemu.<br />Tokom 32-godi&scaron;njeg ispitivanog perioda, prinos zrna je znatno varirao u zavisnosti od vremenskih uslova i kretao se u proseku za sve tretmane od 4,35 t ha-1 u 2003., do 8,70 t ha-1 u 2013. godini. Na osnovu jednačine trenda prinosa, uočeno je da je godi&scaron;nje povećanje prinosa, u proseku za sve tretmane iznosilo 10,7 kg ha-1. Iz 32 analizirane godine izdvojeno je 5 godina sa najvećim prinosima, 12 godina sa malim prinosima p&scaron;enice, dok se preostalih 15 godina moglo označiti kao srednje rodne godine. U pogledu temperaturnih uslova i uslova vlažnosti u rodnim, srednje rodnim i nerodnim godinama postojale su značajne razlike između ovih grupa. U rodnim godinama, variranje prinosa u zavisnosti od rokova setve bilo je najmanje. Najveći prinos zrna, tokom posmatranog perioda, u proseku za sve ispitivane sorte i gustine setve ostvaren je setvom u II roku (11-20. X), i bio je značajno veći u odnosu na sve ostale rokove izuzev I roka. Između I i III roka, nije ostvarena statistički značajna razlika u visini prinosa, ali su prinosi u oba ova roka bili značajno veći u odnosu na novembarske i decembarski rok setve. Drugi rok odlikovao se najmanjim variranjem prinosa tokom istraživanog perioda. Novembarska setva smanjivala je prinos u proseku za 11%, a decembarska za 27%, u odnosu na prinose iz optimalnih agrotehničkih rokova. Prosečno dnevno smanjenje prinosa zrna iznosilo je 38 kg dan-1. Najmanje smanjenje prinosa prilikom ka&scaron;njenja u setvi bilo je u rodnim, zatim u srednjerodnim, a najveće u nerodnim godinama. U optimalnim rokovima setve (I i II rok) gustina od 500 kl. zrna m-2 bila je optimalna, dok je u kasnim rokovima (novembarskim i decembarskom), povećanje količine semena (do najvi&scaron;e 700 kl. zrna m-2),<br />imalo opravdanja. Odlaganje setve od I do V roka, uticalo je na povećanje sadržaja proteina, vlažnog glutena, moći upijanja vode, sedimentacionu vrednost, zapreminu i vrednosnog broja sredine hleba, kod obe sorte. Na osnovu prosečnih vrednosti za sve rokove setve, sorta Zvezdana ostvarila je bolje parametre kvaliteta u odnosu na NS 40S.</p> / <p>Sowing date is one of the most important field crop management measures in the production of small grains and it practically determines the intensity of all other factors in wheat production. Among many factors which determine yield, sowing outside the optimum period, use of inappropriate seed rates and selection of cultivars insufficiently adapted to a given agro-ecological conditions, are recognized as the most common causes of low yields of winter wheat. Moreover, sowing date is economically cheapest field crop management measure and a cost-effective way to increase grain yield. However, eventual delay in sowing cannot be adequately compensated by any other field crop management measure. Extreme weather events are already a significant challenge for grain producers and are predicted to increase under numerous future climate scenarios. In these altered weather conditions, optimal sowing date with an adequate sowing density and choice of appropriate genotypes will be of great importance in order to mitigate the negative effects of climate factors on yield stability, as well as on the bread making quality of winter wheat.<br />The aim of this research was to investigate the effects of different sowing dates, sowing densities and their interactions on yield, yield components and grain quality of different wheat cultivars. The study of interaction of sowing dates, sowing densities and cultivars of winter wheat was carried out on experimental fields of the Institute of Field and Vegetable Crops, in the 1981/82. &ndash; 2012/13. period. The experiment was set each year, on the calcareous chernozem soil, as a three factor trial (split-split-plot design), in four replications, with variants in the randomized block design.<br />During the 32-year studied period, grain yield has varied considerably depending on weather conditions and ranged from 4.35 t ha-1 in 2003., to 8.70 t ha-1 in 2013., on average for all treatments. It was observed that the annual increase in yields during the investigated period was 10.7 kg ha-1. From the 32 years analyzed there were 5 years with high yields, 12 years with low grain yields, while the remaining 15 years could be identified as a medium yielding years. There were significant differences in temperature regimes and moisture conditions between these three types of years. Yield variation caused by the different sowing date was much lower in high yielding in comparison to low yielding years. For the entire examined period, on average of all tested cultivars and planting densities, the highest grain yields were obtained in the II sowing date (11-20. X), and were significantly higher in comparison to all other sowing dates, except the earliest (I sowing date). There were no statistically significant differences in yields between I and III sowing date, but they were significantly higher in comparison to sowing in November and December. Second sowing date had the lowest yield variation during the studied period. Sowing in November reduced yield by 11% and December sowing by 27% on average, compared to optimal (October) sowing dates. During the investigated period, average daily reduction of grain yield was 38 kg day-1. The smallest decline in yields caused by the delay in sowing was in high yielding years, followed by medium yielding, and the largest yield decline was found in low yielding years. In the optimal sowing dates (I and II), a density of 500 viable kernels m-2 proved to be optimal, while in the later sowing dates (November and December), increasing the sowing density up to 700 viable kernels m-<br />2, was justified. Delay in sowing from I to V sowing date caused an increase in the bread-making quality parameters such as protein content, wet gluten content, water absorption capacity, Zeleny sedimentation value, bread loaf volume and value number of bread, for both cultivars examined. On average for all sowing dates and densities, cultivar Zvezdana achieved higher values for almost all bread-making quality parameters tested in comparison to NS 40S.</p>
4

Potencial do composto flintisa anão de milho para melhoramento em condições de espaçamento reduzido e na safrinha /

Candido, Liliam Silvia. January 2005 (has links)
Orientador: João Antonio da Costa Andrade / Banca: Pedro Cesar dos Santos / Banca: José Branco de Miranda Filho / Resumo: Técnicas como a redução do espaçamento entre linhas, permitindo um melhor arranjo das plantas no campo, juntamente com o aumento da densidade de semeadura, podem ser empregadas para aumentar a interceptação da radiação solar, visando o aumento do rendimento para algumas cultivares de milho. O objetivo deste trabalho foi quantificar a variação genética do composto Flintisa Anão de milho, a fim de verificar se o mesmo apresenta potencial para melhoramento em condições de safrinha, espaçamento reduzido e duas densidades de semeadura. Foram avaliadas, na safrinha/2004, 150 progênies de meios irmãos, no espaçamento de 0,45 m entre linhas e nas densidades de 57.800 e 80.000 plantas ha-1, para os caracteres florescimento feminino, altura de plantas, altura de espigas, tombamento, prolificidade, grãos ardidos e rendimento de grãos. Variância genética aditiva, herdabilidade, correlação entre os caracteres, resposta correlacionada de um caráter mediante seleção em outro e ganho esperado com seleção, foram estimados para cada densidade e conjuntamente. Foram estimados ganhos de 16,0 e 19,2% para rendimento, 11,1 e 10,5% para prolificidade e 12,3 e 12,9% para altura de espigas, respectivamente para as densidades de 57.800 e 80.000 plantas ha-1. As estimativas de herdabilidade para altura de plantas, altura de espigas e rendimento, nas densidades 57.800 e 80.000 plantas ha-1 foram respectivamente 65,19 e 61,27%, 64,30 e 66,86% e 53,53 e 63,32%. As estimativas parecidas, e a ausência de interação progênies x densidades, indicam que não há necessidade de programas de seleção distintos. A densidade de 57.800 plantas ha-1 pode ser preferida apenas pelo fato das progênies...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Techniques as spacing row reduction, allowing a better plant arrangement in the field, together with the increase of the sowing density, can be used to increase the interception of the solar radiation, seeking the increase of the grain yield for some maize cultivars. The objective of this work was to quantify the genetic variation of the Dwarf Flintisa composite of maize, to verify its potential for improvement in off season crop, in reduced spacing between rows and two sowing densities. In the off season crop (March to July/2004) 150 half sib progenies were evaluated, in 0.45 m spacing rows and densities of 57800 and 80000 plants ha-1, for the traits female flowering, plant height, ear height, lodging, prolificacy, burning grains and grain yield. Additive genetic variance, heritability, correlation between traits, correlated response of a trait by selection in other and expected gain from selection, were estimated for each density and jointly. Gains of 16.0 and 19.2% for grain yield, 11.1 and 10.5% for prolificacy and 12.3 and 12.9% for ear height, respectively for the populations of 57800 and 80000 plants ha-1 were estimated. The heritability estimates for plant height, ear height and grain yield, in densities 57800 and 80000 plants ha-1 were 65.19 and 61.27%, 64.30 and 66.86% and 53.53 and 63.32%, respectively. The similar estimates and the absence of progenies x densities interaction, indicate that there different selection programs are not justified. The density of 57800 plants ha-1 can just be preferred because the progenies present larger grain yield, smaller lodging and higher prolificacy, on average. Therefore the Dwarf Flintisa composite has sufficient genetic variability for improvement for low and for high sowing density, in off season crop conditions...(Complete abstract click electronic access below) / Mestre
5

Potencial do composto flintisa anão de milho para melhoramento em condições de espaçamento reduzido e na safrinha

Candido, Liliam Silvia [UNESP] 22 July 2005 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:29:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-07-22Bitstream added on 2014-06-13T19:18:10Z : No. of bitstreams: 1 candido_ls_me_ilha.pdf: 332984 bytes, checksum: 467381227e709e8b87b6b03749be5529 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Técnicas como a redução do espaçamento entre linhas, permitindo um melhor arranjo das plantas no campo, juntamente com o aumento da densidade de semeadura, podem ser empregadas para aumentar a interceptação da radiação solar, visando o aumento do rendimento para algumas cultivares de milho. O objetivo deste trabalho foi quantificar a variação genética do composto Flintisa Anão de milho, a fim de verificar se o mesmo apresenta potencial para melhoramento em condições de safrinha, espaçamento reduzido e duas densidades de semeadura. Foram avaliadas, na safrinha/2004, 150 progênies de meios irmãos, no espaçamento de 0,45 m entre linhas e nas densidades de 57.800 e 80.000 plantas ha-1, para os caracteres florescimento feminino, altura de plantas, altura de espigas, tombamento, prolificidade, grãos ardidos e rendimento de grãos. Variância genética aditiva, herdabilidade, correlação entre os caracteres, resposta correlacionada de um caráter mediante seleção em outro e ganho esperado com seleção, foram estimados para cada densidade e conjuntamente. Foram estimados ganhos de 16,0 e 19,2% para rendimento, 11,1 e 10,5% para prolificidade e 12,3 e 12,9% para altura de espigas, respectivamente para as densidades de 57.800 e 80.000 plantas ha-1. As estimativas de herdabilidade para altura de plantas, altura de espigas e rendimento, nas densidades 57.800 e 80.000 plantas ha-1 foram respectivamente 65,19 e 61,27%, 64,30 e 66,86% e 53,53 e 63,32%. As estimativas parecidas, e a ausência de interação progênies x densidades, indicam que não há necessidade de programas de seleção distintos. A densidade de 57.800 plantas ha-1 pode ser preferida apenas pelo fato das progênies... / Techniques as spacing row reduction, allowing a better plant arrangement in the field, together with the increase of the sowing density, can be used to increase the interception of the solar radiation, seeking the increase of the grain yield for some maize cultivars. The objective of this work was to quantify the genetic variation of the Dwarf Flintisa composite of maize, to verify its potential for improvement in off season crop, in reduced spacing between rows and two sowing densities. In the off season crop (March to July/2004) 150 half sib progenies were evaluated, in 0.45 m spacing rows and densities of 57800 and 80000 plants ha-1, for the traits female flowering, plant height, ear height, lodging, prolificacy, burning grains and grain yield. Additive genetic variance, heritability, correlation between traits, correlated response of a trait by selection in other and expected gain from selection, were estimated for each density and jointly. Gains of 16.0 and 19.2% for grain yield, 11.1 and 10.5% for prolificacy and 12.3 and 12.9% for ear height, respectively for the populations of 57800 and 80000 plants ha-1 were estimated. The heritability estimates for plant height, ear height and grain yield, in densities 57800 and 80000 plants ha-1 were 65.19 and 61.27%, 64.30 and 66.86% and 53.53 and 63.32%, respectively. The similar estimates and the absence of progenies x densities interaction, indicate that there different selection programs are not justified. The density of 57800 plants ha-1 can just be preferred because the progenies present larger grain yield, smaller lodging and higher prolificacy, on average. Therefore the Dwarf Flintisa composite has sufficient genetic variability for improvement for low and for high sowing density, in off season crop conditions...(Complete abstract click electronic access below)

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